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SC-ASHVE-015 Sr Louis Public Library American Society of Heating and i Ventilating Engineers Heating ventilating air conditioning guide. VOL 16 19 St 628.8 AMERICAN 21718 77104 - -i i ' -i \V No._ Xfi859iM. This Book Shall Not Be Taken From.The Library. r\7 q'1' -:j" Heating Ventilating Air Conditioning Guide 1938 Tr<^^ssipsrryT TEXT AND ILLUSTRATIONS ARE FULLY PRO TECTED BY COPYRIGHT AND NOTHING THAT APPEARS MAY BE REPRINTED EITHER WHOLLY OR IN PART WITHOUT SPECIAL PERMISSION. \ Printed and Bound by Tbs Hobh-Shapb* Company BALTZKORB >; MARYLAND Heating Ventilating Air Conditioning GUIDE 1938 An Instrument of Service prepared for the Profession--Containing a Technical Data Section OF REFERENCE MATERIAL ON THE DESIGN AND SPECIFICATION OF HEATING, VENTILATING AND AIR CONDITIONING SYSTEMS--BASED ON THE TRANSr actions-1--the Investigations of the Research Laboratory and Co operating Institutions--and the Practice of the Members and Friends of the Society ' together with a . - Manufacturers' Catalog Data Section Containing Essential and-Reliable Information Concerning . Modern Equipment . . ALSO .' The Roll,of Membership of the Society * / ? *, * with : ,c.<- ; -i'J ' .- Complete Indexes : to Technical and Catalog Data Sections VoL 16 . $5-oo Per Copy ' . X685974 Copyright, 1938 ,- . AND Published Annually by . * v . . - - J American Society of Heating and Ventilating Engineers 51 Madison Avenue New York, N. Y. PREFACE TO THE 16th EDITION HE general acceptance of the Heating, Ventilating, Air TConditioning Guide as an authoritative source of scientific infor mation on all engineering phases of the industry, has imposed each year since 1922 more and greater responsibilities on the Guide Publication Committee. Although extensive new material has been added to this edition, the ideals of the founders have been carefully preserved by pre senting only authentic and current investigative results which have been tried and accepted in practice. The sequence and arrangement of the various chapters have been changed to provide for a more logical grouping according to related subject matter, and a visual chapter index has been added. Probably, ' the greatest changes that have been made in the text are those relating to cooling phases of the industry. The chapters on Refrigerants and Air Drying Agents, Cooling Load, Central Systems for Cooling and Dehumidifying and Cooling and Dehumidification Methods have been entirely revised to bring them up-to-date and to correlate them more closely. One entirely new chapter on Air Conditioning in the Treatment of Disease was introduced in this edition which outlines many of the appli cation requirements found in the medical field. Some minor changes were made in the chapters on Heat Transmission Coefficients, Air Leakage, Heat and Fuel Utilization, Heating Boilers and Steam Heating Systems. The chapters have been rewritten which deal with Air Pollution, Automatic Fuel Burning Equipment, Hot Water Heating Systems and Piping, Spray Equipment for Humidification and Dehumidification, Air Cleaning Devices, Railway Air Conditioning, Industrial Air Conditioning, Piping and Duct Insulation, Electrical Heating and Radiant Heating. The Catalog Data Section of the Guide is receiving more recognition as each issue appears for the valuable product data contained therein. As usual, the manufacturers have cooperated in accomplishing the dual purpose of this part of the Guide; to "provide authoritative and condensed catalog information for t;he Guide user,, and 0-develop an effective and productive adVertfsjng^,m'edium for;the manufacturer^ ? In offering tfie-lfith edition of the Heating, Ventilating, Air Con ditioning Guide, the Committee, wishes to" acknowledge not only the editorial assistance unselfishly, given by many whose aid is specifically accredited elsewhere, but also the valuable suggestions offered by the many readers and users of other editions;It is hoped that improvements and additions will be suggested to future Committees by readers of this volume, particularly, as perfection is not of human attainment. Without the publication of previous editions, the issuance of the Heating, Ventilating, Air Conditioning Guide 1938 in this fairly complete state in so short a time would be practically impossible. It is the Committee's hope that the same enthusiastic reception given to earlier volumes will be accorded this edition of 15,500 copies. < 7 , Chairman GUIDE PUBLICATION COMMITTEE CONTENTS HEATING VENTILATING AIR CONDITIONING Guide 1938 Page Title Page............................................................................................................................. . . Preface.-............................................................................... -........................... ................. *> Contents.-:--......................-.......... -...................................................................................... >>'~v Editorial Acknowledgment.......................................................................................... iy Code of Ethics for Engineers..................................................................................... vi Index to Technical Data................................................ vii Technical Data Section............................................................................................--- 1-840 Catalog Data Section............................................................................. Index to Advertisers.........:........ Index to Modern EquipmentRoll of Membership.-................. 841-1162 843 1165 1-80 Section I. Principles ' Chapter 1. Air, Water and Steam.-........................................................... Chapter 2. Refrigerants and Air Drying Agents................ ...... ............... Chapter 3. Physical and Physiological Principles of Air Conditioning- Chapter 4. Air Pollution.............................................. .............................. Section II. Basic Data and Computations Chapter 5. Heat Transmission Coefficients and Tables.--....................... Chapter 6. Air Leakage..... ..................................... ,.... ............................. Chapter 7. Heating Load........................................ .................. i............. Chapter 8. Cooling Load..................................... ....................................-- Section III. Combustion and Utilization of Fuels Chapter 9. Fuels and Combustion.......................................... ................. Chapter 10. Chimneys and Draft Calculations.--...................................... Chapter 11. Automatic Fuel Burning Equipment..................................... Chapter 12. Heat and Fuel Utilization........... ...... .................................... Section IV. Steam and Hot Water Heating Systems Chapter 13. Heating Boilers...... ......................... ....................... ,.............. Chapter 14. Radiators and Gravity Convectors.-..................................... Chapter 15. Steam Heating Systems.............................................. -.......... Chapter 16. Piping for Steam Heating Systems.-.......... .......................... Chapter 17. Hot Water Heating Systems and Piping...................... ....... Chapter 18. Pipe, Fittings and Welding............... (Continued on Page V) EDITORIAL ACKNOWLEDGMENT FOR 16 years the Heating, Ventilating, Air Conditioning Guide has been published by the American Society of Heating and Ventilating Engineers and it retains its leadership as the authoritative reference volume of the profession and its allied industries. Its users are legion and they have adopted The Guide as their standard reference source because they recognize that the data are unbiased, up-to-date and readily usable. TJiis has been made possible because of the willingness of hundreds of technical experts to contribute freely from their knowledge and practical experience for the advancement of the profession. To the following individuals the Guide Publication Committee is profoundly grateful for their assistance in the production of the 1938 edition, and also to those former contributors who have previously prepared a firm foundation for the addition of new material. , H. E. Adams T. N. Adlam J. C. Albright H. L. Alt . O. W. Armspach C. L. Arnold C. M. Ashley Prof. J. L. Beal F. R. Bichowsky J. L. Blackshaw M. G. Bluth C. A. Booth C. J. Braatz C. E. Bronson Prof. A. I. Brown C. A. Bulke'ley W. H. Carlton P. D. Close Sabin Crocker R. C. Cross D. N. Crosthwait, Jr. Philip Drinker G. G. Early, Jr. E. V. Erickson C. E. Ernst John Everetts, Jr. PRof. M. K. Fahnestock W. L. Fleisher W. G. Frank J. E. Godfrey . C. D. Graham W. A. Grant J. R. Hertzler C. G. Hillier F. C. Houghten Prof. C. M. Humphreys H. F. Hutzel L. P. Hynes A. J. Johnson E. F. Jones C. F. Kayan R. T. Kern R: E. Keyes Prof. V. O. Knudsen Prof. S. Konzo Prof. A. P. Kratz Prof. G. L. Larson L. L. Lewis S. R. Lewis H. A. Lockhart ' Arthur McCutchan Prof. L. G. Miller PfioF. P. E. Mohn L. L. Munier H. C. Murphy Prof. D. W. Nelson P. Nicholls R. F. Norris A. J. Offner ' O. W. Ott J. S. Parkinson H. G. Rappolt Prof. T. F. Rockwell J: O. Ross S. I. Rottmayer Prof. F. B. Rowley - . J. S. Sandfort Prof. W. M. Sawdon Prof. L. E. Seeley Lester Seelig C. G. Segeler A. M. Selvey C. D. Shields R. W. Shields A. L. Simison D. C. Simpson ' T. H. Smoot A. E. Stacey, Jr. D. J. Stewart C. A. Thinn R. J. Thompson W. W. Timmis Prof. G. L. Tuve J. H. Van Alsburg F. O. Urban : A. R. Walker J. H. Walker . Prof, G. B. Wilkes M. S. Wunderlich Prof. C. P. Yaglou ! . ; 1 ' , , '" `. ! ; i ! j i i ] . The members of the Society are especially indebted to these engineers who have aided in the preparation of this volume and the Guide Publi cation Committee hereby expresses its appreciation for the loyal coopera tion of the many contributors to this 16th edition. GUIDE PUBLICATION COMMITTEE Albert Buenger, Chairman . , S. H. Downs C. H. B. Hotchkiss E. N. McDonnell, Advisory S. S. Sanford W. H. Severns- John James, Technical Assistant IV CONTENTS (Concluded) Section V. Air Systems Page Chapter 19. Gravity Warm Air Furnace Systems.......................... :............ 377 Chapter 20. Mechanical Warm Air Furnace Systems.... 1............................ 393 Chapter 21. Central Systems for Heating and Humidifying...... ................ 409 Chapter 22. Central Systems for Cooling and Dehumidifying........... ........ 423 Chapter 23. Unit Heaters, Ventilators, Air Conditioning, Cooling Units 435 Chapter 24. Cooling.and Dehumidification Methods................:.................. 469 Chapter 25. Spray Equipment for Humidification and Dehumidification.. 499 Chapter 26. Air Cleaning Devices............... .................................................. 519 Chapter 27. Fans........ ...............-.......................... J.......... :............................ 531 Chapter 28. Air Distribution.............................................. v........................ 547 Chapter 29. Air Duct Design..... ......... ......... ......................... ...... -............... 563 Chapter 30. Sound Control...................................... ...................................... 583 Section VI. General . Chapter 31. Air Conditioning in the Treatment of Disease.... ................... 597 Chapter 32. Railway Air Conditioning.`.................................... *`09 Chapter 33. Industrial Air Conditioning....................................................... 621 Chapter 34. Industrial Exhaust Systems......... ............................................... 633 Chapter 35. Drying Systems........................ ................... -............................ 647 Chapter 36. Natural Ventilation.... .......... ;............................................. ;..... 669 Chapter 37. Automatic Control............................... 683 Chapter 38. Motors and Controls....,................................... 703 Chapter 39. Piping and Duct Insulation....................................................... 719 Chapter 40. Electrical Heating..................................................................... 741 Chapter 41. Radiant Heating....................................................................... 753 Chapter 42. District Heating-......... :............................................................ 765 Chapter 43. Water Supply Piping and Water Heating.............. ................. ' 783 Chapter 44. Test Methods and Instruments--.............................................: 807 Chapter 45. Terminology. 819 CODE of ETHICS for ENGINEERS NGINEERING work has become an increasingly important factor E in -the progress of civilization and in the welfare of the community. The engineering profession is held responsible for the planning, construc tion and operation of such work and is entitled to the position and authority which will enable it to discharge this responsibility and to render effective service to humanity. That the dignity of their chosen profession may be maintained, it is the duty of all engineers to conduct themselves according to the principles of the following Code of Ethics: 1--The engineer will carry on his professional work in a spirit of fairness to employees and contractors, fidelity to clients and employers, loyalty to his country and devotion to high ideals of courtesy and personal honor. 2-- He will refrain from associating himself with or allowing the use of his name by an enterprise of questionable character. 3-- He will advertise only in a dignified manner, being careful to avoid misleading statements. 4-- He will regard as confidential any information obtained by him as to the business affairs and technical methods or processes of a client or employer. 5-- He will inform a client or employer of any business connections, in terests or a (filiations which might influence his judgment or impair the disinterested quality of his services. 6-- He will refrain from using any improper or questionable methods of soliciting professional work and will decline to pay or to accept com missions for securing such work. 7-- He will accept compensation, financial 6r otherwise, for a particular service, from one source only, except with the full knowledge and consent of all interested parties. 8-- He will not use unfair means to win professional advancement or to injure the chances of another engineer to secure and hold employment. 9-- He will cooperate in upbuilding the engineering profession by exchang ing general information and experience with his fellow engineers and students of engineering and also by contributing to work of engineering societies, schools of applied science and the technical press. 10--He will interest himself in the public welfare in behalf of which he will be ready to apply his special knowledge, skill and training for the use and benefit of mankind.vii vi INDEX Heating Ventilating Air Conditioning GUIDE 1938 Technical Data Section Chapters 1-45 and Pages 1-840 A Abbreviations, 831 Absolute humidity, 8, 819 Absolute pressure, 807, 819 Absolute temperature, 819 Absolute zero, 819 Absorption, {see also Regain) agents, 44 -~ as means of dehumidification, 492 by building materials, 155 of solar radiation by glass, 152 of sound, 592 system, 492, 493 Acceleration, 819 - due to gravity, 819 Acclimatization, 56 Acoustics, acoustical, 583 treatment, 591 Activated alumina, 39 . Adiabatic saturation, 11, 495, 502, 819 driers, 649 Adjustable speed motor, 704, 709, 710 Adsorption, 819 agents, 37 as means of dehumidification, 490 systems ' alumina, 491 silica gel, 491 Air . adiabatic saturation of, 11 amount per person, 70 atmospheric, 1 changes of, indoors, 51, 129 cleaning devices, 519, 819 A.S.H.V.E. code for. 519 requirements of, 519 types of, 520 . composition of, 1, 51 density of, 6 distribution of, 72, 397, 547- balancing, system, 560 for comfort, 69 effect of turning blades, 554 factors in room cooling, 552 factors in room heating, 554 grille locations. 547 natural ventilation, 669 railway air conditioning, 560, 610 residence, 397 with unit air conditioners, 455 with unit heaters, 441 - with unit ventilators, 446 dry, 1, 4, 8, 59, 822 drying agents, 35, 37 ' ducts, 563, {see also Ducts, Air) excess, 168 exfiltration, 121, 413 filtration, 121, 180, 229. 413, 820 Air {continued) flow, 72. 77 control, principles of, 675 ' formulae, 563 ' into a hood, 638 loudness chart, 556 natural, measurement of, 678 ' requirements, 676 through openings, 670, 675 friction of, in pipes, 567, 568 impurities in, 79, 676 ' size of, 80 . ionization of, 75 leakage, 121, 127 minimum outdoor, requirements, 72 mixtures with water vapor, 12 moist, 68 motion, 72, 74 movement, measurement of, 811 odors in, 51 optimum conditions, 62 indoors in summer, 68 outlet noises, 554 outside, introduced, fan systems, 414 * through cracks, 126, .129 through doors, 127 unit air conditioners, 455 unit ventilators, 447 , pollution, 79 - abatement of, 84 effect on health, 83 primary, 167 . properties of, 3, 4 ' quality, 70 quantity necessary, for combustion, 167, 176 ,, for ventilation, 70, 609 recirculation of, 77 . fan systems, 411, 417 unit ventilators, 447 ' saturated, 1, 5, 10, 827 secondary, 167 space conductances, 93 ' speeds to convey material, 642 . standard, 828 . summer, conditions, 68 still. 57 - synthetic chart, 829 velocity, (see Velocity, Air) vitiation, 51 volume, 12 * washer, 499, 820, (see also Washer, Air) . operation of, 690 - saturation efficiency, 502 weight of, 6 Air conditioning, 51, 503, 819, {see also Air) . air change per occupant, 71 . chemical factors, 55, 81 comfort chart, 63, 64 in disease treatment, 597 vii 7~7 Heating Ventilating Air Conditioning Guide 1938 Air conditioning (continued) Barn ventilation 679 . fundamentals of, 1 Barometer, hospital, 597 aneroid, .808 with ice. 496 mercurial, 807 industrial, 621 apparatus for, 503 automatic control, 683 exhaust systems, 633 operation of, 485 process conditions, 621 unit coolers, 449 ` ' ' Barometric pressure, 183, 807 Baudelot, chamber, 502 cooler, 496 Bends, expansion, 362 * BET, British equivalent temperature, 356 objective of, 1 Biochemical reactions, control of, 628 physical factors, 51 Bituminous coal, 165, 171 recirculation, 77, 411, 417, 447 symbols, 836 units, 451 Algae formations, 514 Allergic disorders, 604 classification of, 604 treatment of, Blast, 820 Blower, blowers, 531, (seealso Fans) standard test code for, 534 V ' Body, . human, surface area, 71- \ . odors, 71 - apparatus for, 604 Boiler, boilers, 243, 820 ' limitations in, 605 allowances, 252, 802 Alternating current motor, 705 A.S.H.V.E. test codes, 248, 840 Altitude, 183 A.S.M.E. construction code, 258 Alumina system of adsorption, 39, 491 baffles. 395, 820 Aluminum foil, 94 Aluminum oxide, 39 Ammonia, 35. 36, 511 Anemometer, 812, 820 capacity, 243, 442 ` care during summer, 261 ^ cast-iron, 243 ----"" cleaning, 260 codes, 248 * Anesthesia, 597 ' combustion rate, 244 apparatus, 597 connections, 258, 316 effect of, 598 ` controls, 698 . inflammability, 598 conversion. 218, 256 Anthracite, 165, 169, (see also Coal) design of, 246 stokers, 205 1 domestic oil burners, 218 Apartment houses, hot water supply to, 797 steam consumption, 234 - stokers suitable for, 206 Appendicitis, 599 Artheritis, 607 A.S.H.V.E. Codes and Standards, 247, 281, 518, 534. 680, 839 A.S.M.E. boiler construction code. 257 draft loss through, 189 efficiency of, 247, 251 for electric steam heating, 745 erection of, 259 - fittings, 258 gas-fired, 222, 245, 256 -grate area, 255 heat transfer rates, 247 heating surface, 247, 820 horsepower, 251, 820 . . Artificial fever, 602 installation, 256, 259 conditions for, 603 insulation, 261 diseases treated, 603 limitations, 257 - limits for, 603 * low pressure, construction code, 258 production of, 603 maintenance, 259 Asbestos, 725 oil burners, 4, 218 ' Ash, cared for by stokers, 201 fly, 79 Asphyxia, 605 Asthma, 604, 605 Atelectasis, 605 * . operation, 259 output, 250 performance curves, 254 pick up, 252 pipe tax, 253 ratings of, 248, 249 run out sizes, 319 - Atmosphere, standard, 807 scale in, 260 - Atmospheric steam heating system, (see also selection of, 251, 254, 255 . ' Steam Heating Systems) settings, 218, 246 ' Atmospheric water cooling apparatus, 507 design of, 510,511 , efficiency of, 512, 516 Atomization. for humidifying, 504 of oil, 214 . -. . Attic fans, 464 Automatic control, 399, 698, (see also Controls) Automatic fuel burning equipment, 201 Awnings, 156, 406 - for mechanical stokers, 211 special, 245 steel, 243 troubles with, 260 types of, 240 warming-up allowance, 252, 254 water line, 258 Boiling point of water, 27 Booster, coils, 411 fans. 390, 426 . - Axial velocity formula, for hoods, 637 Booths, spray, 640 Bourdon tube, 808 Boyle's law, 7 Brake horsepower, heat equivalent of, 141 Breeching, draft loss through, 193 Babcock's formula for steam flow, 301, 766 Baby care, (see Nurseries) Baffles, 595, 820 tiring air distribution system, 560 Bananas, 628 Brine, 454. 483 British equivalent temperature, 756 British thermal unit, 820 Building, buildings, absorption coefficients, 155 air velocities in, 569 . Alphabetical Index to Technical Data Section Building, buildings (continued) classification for district heating, 777 construction, heat transmission of, 91. 97 district heating, 770 fuel requirements of, 229 hot water supply to, 794, 797 intermittently cooled, 149 intermittently heated, 141 load factors, 240 materials, heat transmission of, 97 noise in, 587 . saving of steam in 771 steam consumption, 234 tall, infiltration in. 128 water supply to, 783 Burner, burners,' automatic equipment, 201 coal, 201 conversion, 224 , gas, 221 oil. 213 By-pass method, 425, 820 C Cabinets, (see Enclosures) Calorie, 820 Calorific values, coal, 166 gas, 176 oil. 174 -^ Capacitor motor, 706 Capillary moisture, 651 Carbon dioxide, 36 concentration in air, 72 as corrosion agent/374 . as an index of, . combustion, 168, 176, 212, 220, 224 draft loss, 192 odors, 52 measurement of 815 as a refrigerant, 38 Carbon monoxide, in air, 84 . in garages, 681 poisoning, 84 produced by gas, 224 - produced by oil burners, 220 produced by stokers, 212 Carnot cycle, 475 ' Cattle, heat and moisture produced by, 678 Ceilings, heat transmission, 111 Central air conditioning systems, 423 classification of, 423 cooling cycle control for, 691 design of, 427 location of apparatus, 428 ratings of, 429 spray type, 424 zoning, 428 Central fan heating systems, 409, 688, 820 computations for 413 design of, 413 electrical, 744 heating cycle control for, 688 y heating requirements of, 412 Characteristics of motors, 708 Charles' law, 7 Chemical reactions, control of, 628 Chimney, chimneys, 179 areas of, 187, 189. 191 characteristics, 182 construction of, 195 effect. 129, 670, 672 for gas heating, 196 gas temperature, 184 performance, 186 sizes, 187, 189. 191, 198 Venturi, 180 Chorea, 603 Cleaners, air, (see Air, Cleaning Devices) Clearance, window sash, 124 Climatic conditions, 138 Coal, (see also Anthracite, Coke, Lignite) air speed for conveying, 642 analysis of, 165 bituminous, 165, 171 burning rate chart, 238 calorific value, 166 classification of, 165 dust, disposal of, 79 dustless, 172 . pulverized, 172 semi-bituminous, 165, 172 - size of, 169 - . * . Coal burning systems, automatic control of, 699 automatic firing equipment, 201 . boilers, 243 combustion rate, 394 . draft required for, 192 fuel requirements, calculation, 230 furnace requirements, 395, 400 hand-fired, 173 stokers, 201 - Codes, A.S.H.V.E. codes and standards, 839 for grinding, polishing, and buffing wheels, 636 for proportioning warm air heating plants, 222 for rating air conditioning equipment, 435, 462 for use of refrigerants, 426 Coefficients of heat transmission, (see Heat Trans-* mission, Coefficients) Coils, booster, 411 - - cooling, 406, 453 evaporator, 406 heating, 404,411 hot water, 404 pipe, 323 preheater, 411 ' radiator, 263 reheater, 411 steam, 411 tempering, 411 . . - . *- - Coke. 166. 210, 411 combustion of, 172 Cold, effects on human body, 55 Collectors, dust, 643 . Column radiator, 821 Combined system, . air conditioning equipment, 423' central fan, 409 Combustion, 165 air required for, 167, 168, 176 constants, 659 of different coals,' 169, 171, 209 in driers, 655 of gas. 176, 224 - of oil. 219 rates for heating boilers, 244 smokeless, 247 with various stokers, 209 Comfort, 57 chart, 64 - conditions of, 147 effective temperature, 60, 61, 62 beating for, 753 level, 267 ' line. 63, 66. 821 for men working, 66 optimum air conditions for, 62 school children, 65 zone, 62, 821, (see also Zone, Comfort) ' - Compensated cooling control, 693 Composition of water, 27 Compound wound motor, 703 Compressed air, 504 Compressors, 470 control of, 701 reversed refrigeration 495, 749 ' types of, 471 IX Heating Ventilating Air Conditioning Guide 1938 Condensation, - on building surfaces. 141 meters, 775 prevention of, 141, 734 rate in radiators, 267 return pumps, 292 in steam heating systems. 275, 301 Condenser, 481 design data, 481, 511 performance of, 481 - turbine, 507 types of, 481 water temperatures, 511 Conditioning and drying, 627, (see also Air Condi tioning) Conductance, 90, 92, 821 of air spaces, 90, 93 of building materials, 97 of insulation, 97, 723 surface, 92 Conduction, 263, 821 drying by, 647 heater, 742 . Conductivity, 90, 92, 821 Conductor, 821 Conduit, 767 Constant relative humidity, 821 Constant speed motor, 704, 708, 709 Constant temperature drier, 650 Construction code for low pressure boilers, 258 Contours, velocity, 637 Control, controls, 683, 821 of air conditioning equipment, 485, 683, 688, 700 combined system, 688 split system, 689 apparatus, 684 ` automatic, 399. 683. 697, 698 ' gas burner, 698 oil burner. 698 stoker, 699 compensated cooling, 693 of cooling units,.695 domestic hot water, 700 of draft, 181. . of electric motors, 711 electric system, 686 of electrical heating, 750 of fans, 541 modulating, 687, 745 moisture content, 625 .. of natural ventilation, 399, 673 .. . of noise, 584 of oil burning equipment, 698 pneumatic system, 686 . rpositive acting, 686 /." pressure, 685 , railway systems, 612, 613 rate of biochemical reactions 628 rate of chemical reaction, 628 * rate of crystallization, 629 . of refrigeration equipment, 701 - ` compressor, 701 ice, 701 vacuum, 701 well water, 702 of regain, 624 of relative humidity, 685 . residential, systems, 699 . room, 687 self-contained, system, 686 of sound, 583 . of steam heating systems, 291 of temperature, 220, 683, 750 types of, 686 unit, 220, 683, 750 of vacuum pumps, 295 ' ` zone, 291, 688 Convection, 821 Convectors, 263, 268, 821 A.&H.V.E. code for, 271 connections for, 322 correction rating factors. 271 design of, 269 drying by, 649 . Convectors (continued) gravity, 263 heat emission by, 270 heating capacity, 270 performance characteristics, 270 selection, 270 Conversion burners, 224 Conversion equations, 833 Coolers, surface, 431 ' types of 483 unit, 435, 449 Cooling, 11, 24 . with central fan heating systems, 406, 423, 485 design, system, 407,427 ' effect, 10 \ effective temperatures for, 68 by electric refrigeration,'470, 74.9 equipment, design of, 507 , - evaporative, 423, 483, 501 . - of fluids, 511 ' of human body, 147 load. 147 with mechanical warm air systems, .407 methods, 406, 423, 469 ponds, 512 railway air conditioning, 411 . relative humidities for, 68 spray, 469 surface, 469 towers, 482, 512 units, thermostatic control, 695 water, 507 -' - Copper pipe, 356 heat loss. 721 Corrosion, of boilers, 261 - of industrial exhaust systems, 645 protective materials, 646 ` inhibitors, 375 of pipe, 374 . ' tester, 375 Costs, ' of attic fans. 460 of district heating service, 778 of railway air conditioning, 617 of unit conditioners, 464 Crack, window, 124 Crystallization, control of, 629 - Cyclone dust collector, 643 D Dalton, law of partial pressures, 1 , Damper, dampers, . apparatus which operates, 683 control, 673 ' in duct systems, 398 motors, 685 types of, 398 ' Decibel. 583. 822 Definitions, 68 Defrosting coils, 450 Degree-day, 822 base temperature for, 234 methods of estimating fuel consumption, 231 records for cities, 232 Degrees, perspiration, 73, 75 - Dehumidification, 11, 419, 469, 822 by absorption, 492 by adsorption, 490 effective temperatures for, 66 . methods of, 423, 453, 490 by refrigeration, 469 relative humidities for, 68 Dehumidifier, dehumidifiers, 1C9' alumina, 491 in central air conditioning systems, 424 in industrial air conditioning, 503 silica gel, 491 types of,' 453, 507 X Alphabetical Index to Technical Data Section Density, 3, 822 . of air, 6 of saturated vapor, 12 specific, 3 of water, 27 Dermatitus, 604 Design conditions in industrial conditioning, 621 Design temperature, dry-bulb, 138, 147 ' wet-bulb, 147, 511 Dew-point, 822 relation to relative humidity, 9 temperature, 2 Diameter, circular equivalents of rectangular ducts, 572 Diarrhea, 600, 601 Dichlorodifluoromethane, 35, 40, 473, 511 Diffuser, 822 Diphtheria, 52 Direct current motor, 703 Direct-indirect heating unit, 822 Direct radiator, 822 Direct return system, 332, 822 ' Dirt pockets. 328 Disc fans, test code for, 524 Disease treatment, air conditions for, 599, 600, 603 allergic disorders, 604 anesthesia, 597 artificial fever, 602 classification of diseases, 602, 605 diseases treated, 52, 599, 600, 603, 604, 605, 607 explosion hazard, 597 fever therapy, 602 _ ' filtering in, 600 " . ' hospital air conditioning, 597, 607 nurseries, 600 operating rooms, 597 oxygen therapy, 605 premature infants, 600 satisfactory air conditions, 599, 600, 603 sterilization of air, 650 ventilation rates, 598, 602 Distribution of air, 547, (see also Air, Distribution) District heating, 765 building connections, 770 conduits, 767 economies in, 770 meters, 774, 775 pipe, (see also Piping)' distribution, 765 . ' returns, 767 sizing, 766 . rates, 778 steam consumption, 777 tunnels, 769 . '' Diverter, back draft, 196 ' Domestic oil burners, 215 Domestic stokers, 204 Domestic supply, hot water, 747, 799 control. 700 load. 253 water, 783 , Doors, - . air leakage through, 127 coefficients of transmission of. 117 natural ventilation through, 672 Down-feed piping systems, (see Steam Heating Systems) Draft, 179 available. 182,186 back, diverter, 196 dimensions, 196 calculations, 179 capacity, 181 control, 181 . equation. 187 gage, 808 head, 822 intensity required, 167, 190 losses, 190 in chimneys, 192 through fuel bed, 190 , Draft (continued) mechanical, 180 natural, 179 requirements, 169 theoretical, 182 Drain connections, 259 . Drawing, symbols for, 836 Drip, 822 Dripping of steam pipes, 327 Drum driers, 648 Dry air, 822 Dry-bulb temperature, (see Temperature, Dry-bulb) Dry return, 823 Driers, 648, 649 adiabatic, 649 agitated, 648 batch. 648 compartment, 648 continuous. 648 cylinder, 648 design, 658 drum, 648 festoon, 648 high temperature, 663 , induction, 648 intermittent, 648 rotary, 648 spray, 648 ' tower, 648 tunnel, 648 vacuum, 648 ' Drying, 627, 647, (see also Regain) adiabatic temperature, 649 air circulation in, 653 combustion, 655 by conduction, 649 constant temperature, 650 by convection, 649 ' ' design, 658 direct contact, 649 equipment for, 653 estimating method, 665 factors influencing, 651 gas combustion constants for, 659 high temperature, 652, 663 ' . humidity in, 652 humidity chart, 654, 655 industrial, 627, 647 low temperature, 652 ' mechanism of, 650 ` methods of, 647 moisture in, 651 omissions in the cycle, 650 by radiation, 647 rules for, 652 _ stages of moisture diffusion, 650 - - constant rate period, 650 falling rate period, 650 sun, 647 temperature in, 652 ' time of, 653 materials, 656 ventilation phase, 661 - . . Duct, ducts air, 398, 563 ' design of, 563 equal friction method. 569, 575 velocity method, 569 for air distribution, 547 ' air velocities in, 401, 642 circular equivalents, 572 construction details, 580, 641 . design of duct systems, 398, 569, 578, 634, 640, 641 heat loss from, 732 humidity measurement in, 814 insulation of, 719, 732 lining factor for sound, 592 noise transmission through, 592 pressure loss in, 564 elbows, 564, 642 . . for recirculated air, 381 resistance, 643 sheet metal for, 580, 642 XI Heating Ventilating Air Conditioning Guide 1938 Duct, ducts (icontinued) . sizes of, 567, 571, 635 temperature loss in. 415 # temperature measurement m, 809 velocity measurement in, 811 Dust, 79, 823 air speeds to convey, 635, 642 catching devices, 86 . collectors. 643 concentration in air, 82, 815 '. counter, 815 - disposal of, 86 . industrial exhaust systems, 633 measurement of, 815 - Dynamic equilibrium. Carrier's equation for, 2 Dynamic head, 823 Dysenteria, 52 Eczema, 604 EDR, equivalent direct radiation, 828 Effective temperature, (see Temperature, Effective) Ether. 81. 579 . Elbow, elbows, design of, 367, 398 equivalents, 340 loss of pressure in, 564 . resistance in, 643 sheet metal used in, 641 welding of, 368 . Electric, electrical, automatic, control system, 686 central fan heating systems, 744 control, motor, 703 . current, as corrosion agent, 374. heat equivalent, 141, 160, 750 heating, 741 . . auxiliary, 749 ' cost of, 750 of hot water,- 747 industrial, 748 heaters, 742 conduction, 742 gravity convection, 743 radiant. 743 heating elements, 252, 742, 743 with unit heaters, 743 lamp bulbs, heat from, 160 motors, 703 resistors, 742 . ` Eliminator plates and baffles, 499 Enthalpy. 22, 823 Entropy, 473, 478, 823 tables. 36, 38. 40, 42. 44 Equations, conversion, 833 Equilibrium, dynamic, 2 hygroscopic, 626 . - Equipment noise, 586 . Equipment room, design of, 591 Equivalent, equivalents, circular, 572 ' direct radiation, 304, 601, 828 - elbow, 340 ' evaporation, 251, 823 heat, 823 ' of air infiltration, 140 . of brake horsepower, 141 electrical, 833 mechanical, 826 length of run, 305 ' square feet, 264 Estimated design load, 823 Estimated maximum load, 823 , Estimating driers, 665 Estimating fuel consumption, 229' . Ethylene, 597 Eupatheoscope, 762, 817 Evaporation, 516 equivalent, 251 from human body, 54, 74 from water pans, 268 Evaporative condensers, 483 Evaporative cooling, 423, 483, 495, 501 Evaporators, 483 Exfiltration, 121, 229, 413 Exhaust systems, 633 classification of, 633 collectors, 643 corrosion, protection against, 645 design procedure for, 634 ducts for, construction of, 641 design of, 640 ;' resistance in, 643, 644 .. . efficiency of, 645 '- . fans for, 645 .* filters for, 644 flexible. 640 hoods for, 637 air flow in, 638 ' axial velocity formula for, 637 chemical laboratory, 640 large open, 639 velocity contours In, 637 industrial, 633 lateral, 637 motors for, 645 spray booth, 640 suction requirements, 635 velocity requirements, 635, 642 Expansion, of joints, 315, 767 of pipe. 315, 359, 767 in steam piping, 767 ' tanks, 349 Explosion hazard, inflammability of gases, 81 in operating rooms, 597 Exposure factors, 140 ' Extended heating surface, 823 Extended surface heating unit, 823 . F Fan, fans, 531 A.S.H.V.E. test code for, 534 attic, 464 booster, equipment, 390, 426 control of, 541 designation of, 543 ' drives, arrangement of, 542 for drying, 540 for dust collecting, 541, 645 dynamic efficiency of, 533 efficiency of, 533 in electrical heaters, 744 furnaces, 393 for gas-fired furnaces, 222 ' induced draft. 180 for industrial exhaust systems, 645 mechanical draft, 180 '. mechanical efficiency of, 533 motive power of, 543, 706 control of, 703 operating characteristics, 180, 533 operating velocities, 539, 540 performance of, 531, 539 quietness of, 442 . ratings of, 538 selection of. 396, 538, 541, 543, 645 static efficiency of, 533 ' system characteristics, 537 systems of heating, 409 tip speeds, 538 total efficiency of, 533 types of. 393, 531, 535. 539 in unit conditioners, 455 in warm air systems,- 390, 396 - Xll Alphabetical Index to Technical Data Section Fatigue, human, 56 Fever therapy, (see Artificial Fever) Filter, filters, 521 automatic, 523 cloth, 644 . ` design of, 521 dry air, 524 hay fever air, 604 installation of. 525 resistance of, 396 for sound, 392 unit type, 521 ' viscous type, 521 ** Fire walls, 640 . Firing rate, 169, 171 Fittings, 355, (see also Connections, Pipe) areas of, 364 boiler, 258 copper, 365 flanged, 366, 723 lift, 287 screwed, 364 welding, 366, 370 Flame, with oil burners, 214, 219 . Flanges, welding neck. 371, 372 Flexible exhaust systems, 640 Flexible materials, 589 Floors, heat transmission through. 111 Flue-gas analysis, 816 . - Fluid, fluids, cooling of, 511 ' formula for flow of, 563 meters, 774 Foodstuffs. regain of moisture of, 626 temperatures and humidities for processing, 622, 656 Force, 824 Forced-air heating system, design, 393 Forge shops, heat given off in, 675 Formulae, conversion, 833 heat transmission, 91 Foundries, heat given off in, 675 Freezing, of cooling water, 517 insulation against, 733 ' ' Friction, of air. In pipes. 566, 567 in chimneys, 185 coefficients, 567 factors, 393 heads in pipes, 336 in heating units, 412 losses in ducts, 565, 567, 571 in water pipes, 791 ' . > Fuel, fuels, 165; (see also Anthracite, Coal, Coke, Gas, Lignite, Oil) bed, draft loss through, 189 _ burning equipment, automatic, 201 burning rate charts, 238 consumption, 229, 236 oil gages, 221 oil, heating value, 174, 660 -' ' oil specifications, 174 requirements, of buildings, 236 degree-day method, 231 theoretical method, 230 ' utilization of, 229 Fumes, 79, 824 . industrial exhaust systems, 633 toxicity of, 83. ' Fundamentals of heating and air conditioning, 1 Furnace, furnaces, 824 capacity, 383 design of. 173, 211, 246, 377, 383, 394,400 door slot openings, 486 gas-fired, 222 , hand-fired, 173 .1 performance curves of. 385 types of. 221. 393, 403 volume, 824 ' for warm air systems, 393 - Furnacestat, 399 * ' G Gage, gages, draft, 808 fuel oil, 221 pressure, 824 steam, 258 - vacuum, 808 Galvanometer, 809 Garage, garages, air flow necessary in, 676 A.S.H.V.E. ventilation code, 679 . heaters, for, 224 ' Gas, gases, . burner control, 698 . burning rate chart, 239 calorific value, 141, 176 . in chimneys, 183 combustion constants. 659 . constant for dry air, 8 flue, analysis, 816 fuel, manufactured, 176 natural, 176 properties of, 176 inflammability, 81 requirements per degree day, 237 scrubbers, 86 / toxicity of, 83 Gas-fired appliances, 221 - automatic control of, 225, 698 boilers, 222, 245, 456 carbon monoxide produced by, 224 chimneys for, 196 classification, 221 . combustion in, 224 conditioning unit, 462 control of, 225, 698 conversion burners,-224 furnace requirements for, 394, 900 heat from, 160 rate of gas consumption, 395 Tarings of, 226 sizing, 225 types of space heaters, 223 ' used with unit heaters, 443 warm air furnaces, 222 ' Gaskets. 366 Glass, heat transmitted through, 117, 152 solar radiation through, 152 Globe thermometer, 762 Glossary of terms. 819 - Goitre, 599 Gonorrhea, 603 ' - Grates, 824 .' areas of. 249. 255, 383. 402, 421. 824 of furnaces, 249, 255, 383, 402, 421 of stokers, 201 Gravity, -. circulation, 345 convectors, 263, 743 ' heat emission of, 263 gravity-indirect heating systems, 272 pressure heads, 344 specific, 3 ' . steam heating systems, 275, (see also Steam Heating Systems) . . - warm air heating systems, design of, 377 Grille, grilles. 824, (see also Registers) anemometer readings through, 812 for concealed heaters, 270 recirculating, 381 . of roof ventilators, 672 velocity through, 401 for warm air systems, 381, 397 ' H Hartford return connection, 258, 278, 318 Hay fever, 604 Hazard of explosion, in operating rooms, 597 xiii Heating Ventilating Air Conditioning Guide 1938 Health, 83, 599; (see also Disease Treatment) Heart trouble, 605 Heat, 824 absorbed by building structure, 141 of adsorption, 43 air infiltration equivalent of, 130 capacity, 155, 825 of leader pipes, 378 - of condensation, 45 ^ conduction, 821 " consumption, 224 content, .. of air and water vapor, 2 of coal, 166 of dry air, 22 of gases, 661 of saturated water vapor, 23 convection, 821 conversion equations, 833 , demand, factors governing, 133, 241 effects on human body, 54 electrical equivalents of, 750, 834 emission, * of convectors, 263, 270 by radiation, 756 of radiators, 263, 270 . equivalent, equivalents, 834 of air infiltration, 130 of brake horsepower, 140 electrical, 350, 834 exchanger, 507, 508 shell and tube, 481 flow meter, 817 gain, ' from fixtures and machinery, 160 for insulated pipe, 735 from outside air, 158 to be removed, 430 . infiltration equivalent of, 130 latent, 31, 826, loss, 73, 76 of the liquid, 28, 825 loss, from bare pipe, 719, 721 computation of, 89, 142, .750, 758 cost of. 720 determination of, 133, 140, 229, 753 from ducts, 730 effect of insulation on, 737 from human body, 73, 753, 755 by infiltration, 130, 229 latent, 73, 76 from piping of gas-fired furnaces, 225 by radiation, 61, 753 sensible, 73, 755 to unheated rooms, 118 ventilation, 675 maximum probable demand, 133, 241 of mixing, 47 . mechanical equivalent of, 826 produced by cattle, 679 produced by human body, 53 pump, 472, 749 radiant, 753 calculation of, 758 measurement of, 761 . - . types of, 756 . radiation, 743, 753 regulation in man, 53, 57 requirements, 229 ` sensible, 147, 827 of air, 12 loss, 73, 756 of water, 31 solar, 151 sources of, 745, 754 other than heating plant, 140, 149 > specific, 31 total, 22. 829 of saturated steam, 28 transfer, 89 coefficients, 90 rate, 247 Heat (continued) _ transmission, 89, 754 through air spaces, 91 through building materials, 91 calculations, 89 coefficients, 89, 96 of ceilings. 111 combined, 118 of copper pipe, 721 of doors, 117 of floors. 111 of glass walls, 117 of insulation, 97, 821 of partition walls, 110 of roofs, 114 .. of skylights, 117 V . of surface conductance, 92 of walls, 104 1 , of windows, 117, 151 ' . ` convection equation, 754. - definition of terms used, 90 effects of solar radiation on, 151 formulae, 91 through glass, 116, 151 measurement of, 817 in surface coolers, 431 by surfaces not exposed to the sun, 149 symbols used in formulae, 90 tables, 89, 97 through ducts, 730 time lag, 155 utilization, 229 Heaters, direct-fired, 443 for domestic hot water, 799 electric, 741 capacity of, 750 conduction, 743 convection, 743 , radiant, 223, 743 space, 223 unit, 437, 743 wall, 222 Heating, (see also'Heat) auxiliary, 749 district, 765 effect of radiators, 266 electrical, 741 elements, electric, 742 fundamentals of, 1 load, 133 medium, 825 radiant, 743, 753 railway air conditioning, 611 by reversed refrigeration, 472, 749 surface, 247, 825 square foot of, 828 symbols, 836 systems, district, 765 electrical, 741 fan, 409 gravity warm air furnace, 377 ^ hot water, 331, 825 * mechanical warm air furnace, 393 . radiant, 743, 753 steam, 275, 745 units, blow-through, 411 central fan, 744 draw-through, 411 value, fuel oil, 660 water, 783 , Henry and Dalton, law of, 375 Hoods, . axial velocity formula, 637 canopy, 639 ' for chemical laboratories, 640 design of, 634 ' . for exhaust systems, 637 . of furnaces, 395 open, 639 suction pressures at, 635 velocity pressures at, 637 XIV Alphabetical Index to Technical Data Section Horsepower, 825 boiler, 251 brake, heat equivalent of, 140 Hospital air conditioning, (see Disease Treat ment) Hot box, 817 Hot plate, 817 Hot water, domestic control of, 700 load. 253 supply, 797 Hot water heaters, 245, 799 . '. Hot water heating systems, 331, 825 electric, 720 forced circulation, 331, 337 gravity circulation, 331 installation of, 351 mechanical circulation, 333 Hot water piping, 331 Hotels, - steam consumption, 234 stokers suitable for, 201 temperatures of, in winter, 134 . water supply, 783 Humidification, 10, 499, 825 apparatus for, 503 atomization for, 504 effective temperatures for, 65 methods of, 452 relative humidities for, 68 for residences, 403 ` ' , systems of, 503 with washer, 501 Humidifier, humidifiers; 466 _ atomizing, 504 with fan systems, 419 high-duty, 504 self-contained, 505 spray, 505 types of, 466, 503 '. Humidistat, 400, 825 Humidity, 8, 825 absolute, 8, 819 control, 685 railway air conditioning, 612 in drying, 652 in hospitals, 597 for industrial processing, 622, 623 - measurement of, 814 optimum, 68 relative, 9, 827, (see also Relative Humidity) in comfort zone, 63 . effect on moisture regain, 625 . relation to dew-point, 9 specific, 8. 825 Hygroscopic materials, 626 moisture content, 625 processing of, 627 regain, 626 Hygrostat, 825 Hypertension, 607 Hyperthyroidism, 607, 699 1 Ice, in air conditioning, 407, 454, 496 . control of, 701 Inch of water, 825 . Induction motor, 707, 710, (see also Motors) Industrial, - air conditioning, 621 apparatus for, 449, 503 calculations, 629 air pollution, 79 control, biochemical reactions, 628 chemical reactions, 628 . crystallization, 629 ' moisture content, 625 of regain, 624 .\ Industrial (continued) cooling systems, 469 design conditions, 621 drying, 540, 627 electrical heating systems, 748 , exhaust systems, 633, (see also Exhaust Systems) general requirements, 624 ' heat sources, 141 temperatures and humidities for processing, 622, 623 unit heaters, 444 Infants, premature. 63, 65, 600 Infiltration, 121 average, 126 fuel utilization, 229 heat equivalent, 130 through shingles, 123 through walls, 122 through windows, 124 Inflammability of gases, 81 Institutions, water supply to, 804 Instruments, 807 Insulation, 825 asbestos type, corrugated, 725, 726 laminated, 727, 728 of boilers, 261 bright metal foil, 94, 95 ` building, 751 ` characteristics of, 97, 723 ' of conduits, 738 - of ducts, 732 economical thickness, 736 with electrical heating, 715 . heat transmission through, 97, 723 for low temperatures, 733 magnesia type, 724 of piping, 719 ' ' to prevent condensation, 141, 734 to prevent freezing, 733 reflective type, 94, 95 . rock wool type, 729 ' of sound, 587 . tables, 97. 724 thickness needed, 736 underground, 737 of vibration, 587 ' Ionization of air, 75 Isobaric, 825 Isothermal, 7, 826 J-K Joints, expansion, 315, 767 Kata thermometer, 811 L Lag in heat transmission, 155 Latent heat, 31, 826 . loss, 72 of water vapor, 12 Lateral exhaust system, 637 Leader pipes, 378 - heat carrying capacity of, 379 size of, 379, 389 ' Leakage of air, 121, (see also Infiltration) Lignite, 166 . Liquid, heat of the, 28, 825 Lithium chloride system of adsorption, 46, 492, 493 Load, building factors, 240 cooling, 147 . design, 251, 823 heating, 133 hot water supply, 825 maximum, 824 radiation, 824 Low temperature insulation, 733 ' XV Heating Ventilating Air Conditioning Guide 1938 M Machinery, as heat source, 140, 159 mountings vibration, 587 sound insulation of, 587 . Magnesia insulation, 724 Manometer, 811, 826 , Manual control, (see Controls) Masonry materials, heat transmission through. 97 Mass. 826 Mb. 331. 826 Mbh, 331, 826 Mean radiant temperature, 754, 758 Mechanical, draft towers, 515 equivalent of heat. 826, 834 fuel burning equipment, 201 refrigeration, 35 ventilation, 77 warm air furnace systems, 391 ' air distribution, 397 design of, 400 w ^sister and grille locations, 397 Medical treatment, (see Diseases) ' Mental trouble, 605 v Mercurial thermometer, 809 Metabolism, 53, 73 Meters, choice of, 774 condensation, 771 fluid. 774 Nicholls heat flow, 817 steam flow, 776 types of, 774 water, disc. 789 ' Methyl chloride, 37, 42, 511 Metric units, 835 Micromanometers, 808 Micron, 79, 826 . Mixture, air and water vapor, 12 Modulating control, 687 Moisture. content, of air, 72, 147, 503, 625 capillary or free, 651 . of hygroscopic materials, 626, 651 loss by human body, 76 from outside air, 158 produced by cattle, 679 - regain, 625 Mol, 826 ' Monitor openings, 672 . , Monofluorotrichloromethane, 37, 44 Motive power, 703 Motors, electric, 703 adjustable speed, 704, 709 adjustable varying speed, 704 alternating current, 705 application of. 708 capacitor type, 706 characteristics of, 708 dassiflcation of, 708 compound wound, 703 constant speed, 704, 708 ' control equipment for, 711 ' automatic, 712 manual, 711 multispeed. 714 pilot, 712 single phase, 716 slip ring, 715 damper. 685 '. direct current, 703 control of, 713 speed characteristics, 704, 708 as heat source, 159 induction, automatic start, 710 - capacitor start, 706 repulsion, 706 . repulsion start, 707 - ' slip-ring wound rotor, 710 squirrel cage, 707 Motors, electric (continued) polyphase, 707 selection of, 645 series wound, 703 shunt wound, 703 single phase, 706 special applications, 711 split phase, 707 synchronous, 711 . varying speed, 705 MRT, mean, radiant temperature, 754, 758 N Natural draft towers, 515- Natural ventilation, 72, 669.' Nervous instability, 607 * Neurosyphilis, 603 - Nicholls heat flow meter, 817 Noise, (see also Sound) air outlet, 554 in buildings, 584, 587 control of, 584 through ducts, 592 through room wall surface, 591 with warm air systems, 396 equipment, 586 kinds of, 586 level, acceptable, 585 of compressors, 471 of fans, 539 ' of unit heaters, 442 measurement of 584 . through building construction 587 Nozzle, 499 air spray, 499 . oil atomizer, 214 water spray, 499 Nurseries. 600 equipment for, 602 requirements for, 601 ventilation rate, 602 O Odors, 69 of human origin. 51 . concentration 70 removed by outside air, 71 Off peak heating, 748 Oil, oils, atomization of, 507 * burner, burners, air for combustion, 214 air supply for, 214, 219 boilers. 216. 218 burning rate chart, 238 classification. 215 ' combustion, 218 for commercial use, 216 control of, 220, 698 . - design considerations, 219 for domestic use, dassiflcation, 214 efficiency of combustion, 220 flame with, 214 furnace requirements, 246, 394 ignition, 214 oil consumption, 229, 238 operation, 214 Orsat test, 220 specifications, 173 types of, 215 calorific value of, 174 classifications, 171 as corrosion inhibitor, 375 cost of. 175 gages, 221 ignition of, 174, 214 ' preheating, 217 specifications, 174 XVl Alphabetical Index to Technical Data Section One-pipe steam heating systems, 275, 826 (see also Steam Healing Systems) Openings, 670 air inlet, 672 monitor, 672 for natural ventilation, . ' location of, 675 resistance offered to flow, 676 size of. 669 types of, 670 Operating rooms, ' anesthesia, 597 explosion hazard, 597 humidification, 598 static electricity, 598 ventilation, 598 Orifice, orifices, friction heads, 612 steam heating systems, (see Steam HeatingSystems) Orsat test apparatus, 212, 220, 224, 816 Outlets, (see also Registers, Grilles) design and location of, 559 ' Oxygen, 375, 559 . Oxygen therapy, diseases treated, 605 oxygen chambers, 606 oxygen tents. 605 ` . Ozone, 77 P Paint, - effect on radiators, 265 ~ spray booths, 640 temperatures and humidities for processing, 623 Panel radiation, 826 ' Panel warming, 827 Partial pressures, Dalton's law of, 1 Perspiration, 51, 54, 73, 75 .. Petterson-Palmquist apparatus, 815 Pipe, piping, 355 bare, heat loss from, 719 bends. 315, 362 capacities, (see Pipe, Sizes) coil radiators, 263 ` conduit, 738, 767 connections, 316, 770, (see also Connections) copper, 356 corrosion of, 374 district steam, 765 . dimensions of. 359 (see also Pipe Sizes) expansion of, 315, 359, 767 fittings, 364, (see also Connections, Fittings) for water supply, 788 . welding fittings, 366 flanges, 370, 723 flexibility of, 359 freezing, prevention of, 733 friction, 791 of air in, 566,567 ' heads in, 336 - . ` gaskets, 366 hangers, 364 heat loss from 225, 719 cost of, 720 ' for hot water heating systems, 331, 351 insulation of, 719- joints, 315, 769 ' leaders, 378 radiating surface, 722 -. - radiators, 263 . refrigerant, 484 . , scale in. 374 sizes, . for boiler runouts. 318, 766 for central fan systems. 323 for convector connections, 322 dimensions,- 356, 359 for district heating, 766 ' for domestic hot water, 795 Pipe, piping, sizes (continued) elbow equivalents, 340 equivalent length of run, 305 friction head, 337, 791 of orifices in unions, 343 for Hartford return connection, 318 for hot water heating systems, 335 for black iron, 337, 338 for copper tube, 337, 339 forced circulation systems, 337 gravity circulation systems, 345 for indirect heating units. 325 mains, 790 - for pipe coil connections, 323 for radiator connections, 320 refrigerant, 484, 486 return, capacity of, 308, 767 ` steam. 302, 306, 307 underground, 767 tables. 306, 655 tees. 364 for underground steam, 767 for water supply, 787 weights, 361 steam, capacity of, 304 for steam heating systems, 275, 301, (see also Steam Heating Systems) supports, 364 sweating, 734 , tax, 253 tees, dimensions of, 367 threads, 363, 365 tunnels, 767 ' types of, 355 underground, insulation of, 737 steam, 767 for unit heaters, 442 valves, 370 water supply, 783 ' weights of, 356 welding, 366 Pitot tube, 811 Plastering materials, heat transmission through, 101 Plenum, chamber, 827 . systems, automatic control of, 688 `' Plumbing fixtures, 377 Pneumatic control system, 286 Pneumonia, 52, 599, 605, 607 Pollen, 605 ' Pollution of air, 83 Polyphase motors, 707 Ponds, cooling, 512 Positive acting control, 686 Post-operative pneumonia, 599 Potassium permanganate, 514 Potentiometer, 827 Power, 827 conversion equations, 833 electric, 750 . supply for controls, 686 .- railway air conditioning, 613 - Precipitators, dust, 527 Premature infants, 600 humidity of, 601 mortality of, 602 requirements of, 601 . Pressure, pressures, . absolute, 819 air. in heating unit, 412 measurement of, 811 atmospheric, 807, 820 ' for atomization, 504 automatic control, 685 . barometric, 183, 807 - basic, 3 . controllers. 685 .* conversion equations. 833 drop, 566, 791 drop through refrigerant pipe, 486 ` dynamic. 823 gage, 808 loss in copper pipe, 339, 486 loss through ducts. 563, 643 Heating Ventilating Air Conditioning Guide 1938 Pressure, pressures (continued) measurement of, 807 partial, Dalton's law of. 1 refrigerating plant, 486 of saturated vapor, 12 ' static, 421, 828 steam, in direct heating, 765 drop, 278, 302, 307 initial, 302 in orifice systems, 290 saturated, 28 in sub-atmospheric systems, 289 total. 829 vapor, 31, 830 velocity, 830 water, 27, 789 Prime surface, 827 Processing, 621 cooling systems, 469, 621 ' industrial, temperatures and humidities for, 622 of textiles, 626 unit heaters, 444 Propeller fans, test code for, 534 Psychrometer, 827 sling, 811 Psychrometric, chart, 25, 60, 61, 62, (back cover) for drier, 654 explanation, 25 . tests, 59 - Pulmonary disturbances, 605 * Pump, pumps, centrifugal, 334 characteristics, 181 - circulating, 333 condensation return, 292 heat. 472, 749 vacuum, 293 Pyrometer, 810, 827 mercurial, 810 . optical, 810 radiation, 810 i thermo-electric, 810 Q-R Quality, of air, 69, 70, 71 impaired by recirculation 83 Quantity, . of air, . measurement of, 811 necessary for ventilation, 70, 71, 72, 168, 609, 675 of cooling water, 511 Radiant heaters, 743 Radiant heating, 753 physical and physiological factors, 753 Radiation, 827 by black body, 759 ' drying with, 647 ' equivalent direct. 304, 828 - heat loss by, 63, 76, 754 by human body, 63, 76, 754 load. 252 of pipe, 722 . by radiators, 263 solar, 151, (see also Solar Heal) . occlusion of, 84 ' through glass, 152 through walls, 152 ultra-violet, 75, 82 Radiator, radiators, 263, 827 A.S.H.V.E. code for, 271 column, 821 concealed, 821 condensation rate in, 267 connections, 320, 348 control of, 687 correction rating factors. 271 effect of superheated steam, 265 ' enclosed, 267 gas-fired, 223 Radiator, radiators (continued) heat emission of, 263, 270 heating capacity of, 270 heating effect of, 266 for hot water systems, 346 output of, 264 paint, effect of, 265 panel, 827 pipe coil, 263 ratings of, 264 recessed, 827 selection, 270 tube. 829 types of, 263 wall, output, 264 warm air, 223 - Railway air conditioning; 609 - air distribution, 560, 610 > cleaning, 611 . *" . cooling equipment, 611 ' calculation of, load, 6191' capacity, 612 costs, 617 heating, 611 humidity control, 612 power requirements, 613 tractive resistance, 615 temperature control, 613 ventilation, 609 Raoults law, 493 Receivers, alternating, 299 _ . Refrigerants, 35, 827 ammonia, 36 * carbon dioxide, 38 codes for use of, 426 dichlorodifluoromethane, 40 lithium chloride, 46, 47 methyl chloride, 42 monofluorotrichloroniethane, 44 water, 45 Refrigerating, capacity, 429,' 475 Refrigerating plant, 24, 469 . centrifugal, 478 ` ` . compressor, 470, 512 ` - operating methods. 485 size of, 429, 475, 485 steam jet system, 477, 512 types of, 471 . Refrigeration, . characteristics, 481 curves, 480, 481 coefficient of performance, '475 camot cycle, 475 compression ratio, 477 . ," control of, equipment, 701 . dehumidification by, 470 efficiency, ' cycle, 475 ejector, 479 .: mechanical, 477 losses, 476 . mechanical, 472 pipe sizing, 484 discharge, 486 liquid, 487 . suction, 488 practical cycle, 475 reverse cycle, 749 limiting factors, 749 systems, absorption, closed, 493 centrifugal, 479 mechanical, 496 steam ejector, 477 ' various types, 469 theoretical mechanical cycle, 473 theoretical work per pound, 474 ton of, 429, 475, 829 ton days of, 829 unit of, 429, 475 Regain, control of, 624 of hygroscopic materials, 626 ' Registers, 827, (see also Grilles) with gas-fired furnaces, 223 with gravity furnace systems, 381 xvill Alphabetical Index to Technical Data Section Registers (continued) with mechanical warm air furnace systems, 397 selection of, 381 sizes, 381, 389 temperature, 401 velocity through, 401 Reheater, 424, 432 . Relative humidity, 9, 826 apparatus sensitive to, 684 in comfort zone, 64, 68 relation of dew-point to. 9 control of, 684 in industrial plants, 622, 624 for processing, 622 in public buildings, 67 in residences, 403 from water pans, 403 Relays, 685 Relief valves, 350 Repulsion motors, 706, 707 Research residence, 388, 406 Residences, air distribution in, 397 automatic fuel burning equipment, 201 conditioning units, 291, 460 control systems, 399, 699 gas heat, 221 humidification of, 403 oil burners for, 213 requirements in, 405 . steam consumption, 234 stokers for, 204 Resistance, of bright metallic surfaces, 94 of building materials, 97 in ducts, 565, 643 - of exhaust systems, 643 of filters, 396 of insulators, 97 thermal, 829 thermometer, 810 Resistor, 742 Respiratory diseases. 607 Restaurants, . tobacco smoke, in, 70 water supply to, 804 Return, dry, 823 mains, 827 pipe, capacity, 308 ' reversed, 827 wet, 830 - Reverse cycle of refrigeration, 495, 749 Reversed return system, 332 Reynolds number, 184 . Ringelmann chart, 816 - Rock wool insulation, 100, 729 Roof, roofs, . coefficients of transmission of, 114 conductivities of, 101 solar radiation on, 152, 153, 154 ventilator, 672, 827 Room absorption correction charts, 557 Room control, 687 S Salts in cooling water, 509 Saturated air, 827 Saturation, fiber point, 651 Scale, in boilers, 260 Centigrade, 809 on equipment, 509 ' Fahrenheit, 809 in pipe, 374 Reaumur, 809 School, schools, air flow necessary in, 70 optimum air conditions, 65 stokers suitable for, 201 temperature of, in winter, 134 ventilation in, 70 ' Scrubbers, 499, 528 Self-contained control system, 686 Sensible heat, 147, 827 of air, 12 loss, 73 of water, 31 - Series wound motor, 703 Service connections, 770 Sheet metal, for ducts, 580, 641 Shingles air leakage through, 123 Shunt wound motor, 703 Skin diseases, 607 Silica gel with oxygen chambers, 606 regain of moisture of, 626 - silicon dioxide, 41 equilibrium conditions, 43 system of adsorption,* 39, 41, 491 Single phase motor, 706 Sizes of pipe, (see Pipe Sizes) Skylights. 117, 671 Sling psychrometer, 814 Slip-ring wound motors, 710 Smoke, 79, 827 abatement of, 84 measurement of, 816 ' recorders, 816 tobacco, 70 Smokeless arch, 828 Solar heat, 151 ' . absorption coefficients, 155 effect of, awnings, 155 latitude, 152 - - intensity chart, 150 occlusion of, 84 radiation, factors, 154 through glass, 152 through walls, 152 time lag, 155 . Solenoid valves, 685 Sound, 583. (see also Noise) absorption coefficients, 589 control, 583 duct lining factor, 593 effect on duct design, 567 insulation of, 589 . intensity, 335 measurement of, 584 in steam heating systems, 303 unit of, 583 Specific density, 3 Specific gravity, 2, 828 of fuel gas, 176 Specific heat, 3, 828 of air, 5 . mean, of water vapor, 3 of water, 31 Specific humidity, 8 Specific volume, 3, 828 of saturated steam, 31 Split phase motor, 707 Split system, 828 air conditioning equipment, 461 automatic control of, 689 central fan, 409 unit ventilators, 445 Spray, booths for painting, 640 cooling, ponds, 513 efficiency of, 512 towers, 514 distribution of, 504 generation of, 504 humidifiers, 505 - type of central station system, 423 water coolers, 482, 512 Square foot of heating surface, 828 Squirrel cage motors, 707 Stack, stacks, 378, 689 . effect, 670 height, 828 ` size of. 380, 389, 675 wall, 380 Stairways, 129 XIX Heating Ventilating Air Conditioning Guide 1938 Standards, air, 828 air conditioning, 51 A.S.H.V.E. codes and standards, 248, 271, 839 for fuel oil, 173 . for pipe, 356 for radiators, 271 for welding, 368 Static pressure, 828 Steam, 828 coils, 452 condensing rates, 266 consumption for buildings, 234 flow, Babcock's formula, 502 heat content of, 23 beating systems, 275, 828 air-vent. 276, 279, 309, 310 atmospheric, 283, 313, 321 classification, 275 condensation return pumps, 292 connections, {see Connections, Fittings) corrosion of, 374 design of, 275, 301 dirt pockets, 328 district heating, 765 - dripping of, 327 electric, 745 equivalent length of run, 305 ' gravity systems, 275 one-pipe, 275, 279, 309, 321 two-pipe, 279, 310, 321 with high-pressure steam, 313 mechanical, 275 orifice, 290, 303, 313, 321 pipe, 301, {see also Pipe) capacity, 304, 306 sizes, 303, 306 pressure drop in, 278 sub-atmospheric, 287, 293, 303, 313, 321 types of, 275 vacuum, 285, 293, 295, 312, 830 vapor, 303, 321, 830 one-pipe, 280, 826 . two-pipe, 281, 282, 311, 829 water hammer in, 303 ' zone control, 291 high pressure, 313 jet apparatus, 477 meters for, 774 pressure, 313 properties of, 28 . requirements of buildings, 234, 777 saturated, properties of, 31 . savings in use of, 770 * superheated, 265, 828 . supply mains, 828 tables, 8. 28 trap, 828 . tunnels, 769 ` underground,' 767 in unit beaters. 440 Sterilization of air, 600 Stokers, ' -apartment house, 206 automatic control of, 399, 699 classes of, 204 combustion process, 209 adjustments, 212 efficiency, 212 commercial, 206, 208 controls, 213 design of, 201 economy, 201 household, 204 mechanical, 201 operating requirements, 205 overfeed flat grate, 201 overfeed inclined grate, 202 heating boilers, setting heights, 211 types of. 201 underfeed, 201, 829 ' underfeed rear cleaning. 203 underfeed side cleaning, 202 Storage, of hot water. 798, SQ2 . - temperatures and humidities for,622 Storm sash, 125 - Streptococcus, 52 Stroke, heat, 599 Sub-atmospheric systems, (see also Steam Heating Systems) Suction, static in exhaust systems, 635 Summer, care of heating boilers, 261 comfort zone, 64. 66 conditioning, apparatus for, 423, 451, 499 - desirable indoor conditions in, 66 . temperatures. 148 wind velocities and directions, 148 Sun, . effect on heating requirements; 291 factor of cooling load, 151 ' Supply outlets, . " selection of, 381 types of, 389 ' /' . Surface, conductance, 828 cooling, 431 equipment, 431 air conditioning, 423 ratings, 429 . extended, gravity-indirect heating systems, 272 heating, 829 square foot of, 828 radiant heating, 759 Sweating of pipe, 734 Swimming pool, 804 Symbols, for drawings, 836 for heat transmission formulae, 90 Synchronous motor, 711 Synthetic air chart, 829 - Systems of control, 686 T Tank, tanks, for domestic water supply, 798, 802 expansion, 349 flush, 790 Tees, dimensions of, 367 Temperature, absolute, 819 of air leaving outlets, 428, 549 apparatus sensitive to, 684, 819 atmospheric, 184 of barns, 697 base, for degree-day, 231, 234, 235 basic, 3 body, 53, 54, 754 changes, effect on human beings, 55 of chimney gases, 184 in cities, 138, 148, 232 . of city water main, maximum, 508 control of, 213, 220, 225, 684, 750 railway air conditioning, 613 of cooling water, 482 ' ' dew-point, 3, 822 difference, between floor and ceiling, 136, 226. 439 desired, determination of, 674 in stacks and leaders, 378, 673 ` dry-bulb, 2, 68, 823 maximum design, 148 specified in winter, 134 for drying, 652 effect on moisture regain, 622 ' effective, 58. 68, 135, 147, 823 chart, 58, 60. 61, 62, 64 for maximum comfort, 64, 756 ' optimum, 62 scale, 59 - of gas flame, 176 ' in industrial processing, 722, 723 inside, 63, 64. 134, 412 . surfaces, 758 low, insulation for, 723 of mean interior surface, 758 XX Alphabetical Index to Technical Data Section Temperature {continued) ' mean radiant, 754, 758 measurement of, 679, 683, 809 in occupied space, 68 outside, 136, 148' radiation-convection, 762 range of cooling equipment, 511 records of cities, 138, 148 at registers, 428, 549 room, 10, 231, 820 sensations, 57 surface, of man, 755 - mean interior, 758 systems for control of, 213, 220, 225, 684, 750 thermo-equivalent conditions, 59 water main, maximum, 508 of well water, 506 wet-bulb, 11, 814, 830 average, 511 design, 147, 511 as index of air distribution, 72 . maximum, 511 Terminology, 819 ' Test codes, 248 Test instruments. 807 Test methods, 807 - Textile, textiles. fibers, regain of moisture, 621- temperatures and humidities for processing, 623 Theaters, temperatures of, 67, 134 Therm, 829 Thermal resistance, 829 . - Thermal resistivity, 829 Thermocouples, 807 _ Thermodynamics, 829 of air conditioning, 1 laws of, 826 - Thermo-equivalent conditions, 59 Thermometer, 809,810,811 ' Thermocouple, 809 'Thermopile, 810 Thermostat, thermostats, 684, 829 differential. 10, 683 with gas-fired furnaces, 225 immersion, 684 insersion, 684 location of, 399 with oil burners, 220 pilot, 690 " with radiant heaters, 750 room, 684 ' surface, 684 ' types of, 673, 684 Time lag, 155 - Tobacco smoke, 70 Ton of refrigeration, 475, 829 Ton-day of refrigeration, 829 Total heat, 829 . Total pressure, 829 Towers, cooling, 482, 512, 514, 515 Traps, return, automatic, 298,299 . - with steam heating systems, 281, 295 types of, 295 Tube, Bourdon, 808 Pitot, 811 shell and tube heat exchanger, 483 Tuberculosis, 83, 608 Tubing, copper or brass, 365 Tunnels, for steam pipe, 769 Turbines, with unit heaters, 444 Two-pipe steam heating systems, {see also Steam Healing Systems) Two position controls, 686 Typhosus, 52 U Ultra-violet light, 75,84 Underfeed distribution system, 829 Underfeed stoker, 229 Underground piping, 767 Underwriters' loop, 276,318 Unit air conditioners, 435,451,829 - air distribution, 455 * classification, 436 controls for, 466 ^ cooling, 453 dehumidification, 453 filtering, 454 - heating, 452 humidifying, 452 * location of, 455 residential, 460 types of, 436, 456 Unit coolers, 435, 449 control of, 695 design of, 450 frost removal from, 450 Unit equipment, 435 advantages, 435 controls, 694 miscellaneous, 464 Unit heaters, 435, 744. 829 air temperatures, 439 control of, 695 . direction of discharge, 441 piping connections, 442 ratings of, 441 Unit ventilators, 435, 444, 445, 446, 447, 829 control of, 696, 830 - Unwin pressure drop formula, 766 Up-feed piping systems, 275. 830, {see also Steam . Heating Systems) V Vacuum gage, 808 Vacuum pumps, 292. Vacuum refrigeration, 477 control of, 701 _ Vacuum system of steam heating, {see also Steam Heating Systems) Valve, valves, 370 apparatus which operates, 683 on boilers, 258, 316 connections for, 770 control, 685 with steam heating systems, 315, 370 with high pressure steam, 313 pressure-reducing, 314, 770 ratings of, 313 for radiators, 277, 581 relief, 350 ' -. roughing-in dimensions, 373 solenoid, 685 sub-atmospheric system, 587 / on traps, 596 types of, 370 for water supply, 788 Velocity, 830 air, ` in ducts of buildings, 401, 569, 579 in exhaust systems, 635, 642 through heating units. 411 measurement of, 811 through openings, 698 through towers, 515 sound effect of, 579 . chimney gas. 187 . .' draft loss, 192 . . contours, 637 in ducts. 401. 635, 642, 811 ' of fans, 539 * head, of fluids, 563 -. meter, 813 steam, through an orifice, 313 in underground pipes. 765 water, in pipes, 336,338,339 wind, choosing, 126 measurement of, 678 on natural draft equipment, 515 in natural ventilation, 669 xxi Heating Ventilating Air Conditioning Guide 1938 Vent, vents, ' on traps, 296 in unit ventilators, 446 Ventilation, 51, 669, 830, (see also Air Dis tribution) ' of bams, 679 in drying, 661 of garages, 680 in hospitals, 598, 602 mechanical, 77 ' with roof ventilators, 672 natural, 77 air changes per hour, 127 control of, 673 . general rules for, 677 heat to be removed by, 675 openings, doors, 671 - formula to determine size of, 669 location of, 675 . skylights, 671 types of, 670 windows, 671 for public buildings, 70, 575 purpose of, 675 quantity of air necessary for, 70 railway air conditioning, 609 . by registers. 673 for schools, 70 by stacks, 670, 673 symbols. 836 Ventilator, ventilators, ' resistance of, 672 roof, 672, 827 unit, 235, (see also Unit Ventilators) Venturi chimney, 180 Vibration of machine mountings. 587 Vitiation of air, 51 Volume,. of air and saturated vapor, 12 ' conversion equations, 834 furnace, 824 specific, 3 of saturated steam, 28 - of water, 27 W-Z Wall, walls, ' absorption of heat, 155 air leakage through, 122 of chimneys, 195 condensation on, 141 fire, 640 heat transmission coefficients for, 89, 90, 97, 104, 106, 108 . radiators, output, 264 solar radiation on, 152, 153 time lag through, 155 Warm air heating systems, 830 gas-fired furnaces for, 222 gravity, 377 . mechanical, 393 Washers, air, 396, 499,. 524, 525. 820 Water, . boiling point of, 27 > circulating, temperature of, 512, 724 from city mains, 482, 508 cooling, equipment, 507 - quantity, 509 temperature. 506, 508 . composition of, 27 demand, 785, 804 density of, 27 . domestic supply, 783, 797 evaporation of, 516 factor of usage, 785, 804 flow from fixtures, 784, 785 freezing, 733 friction losses through pipes, 791 hammer, 303 heaters, 411, 799 heating, 783 Water (continued) hot, domestic supply, 783, 797 boilers, 799 demand for, 803 electric heating of, 747 pipe sizes for, 798 storage of, 798, 802 heating systems, 331, (see also Hot Water Heat ing Systems) inches of water, 825 - line, in boilers, 258, 259, 275 in water supply systems, 790 make-up, 516 meters, disc, 789 pans, for humidification, 403 ' pipe, 787 . ` pressures, 27 . ' . probable usage, 785, 804 properties of, 27 * as a refrigerant, 37, 45 replacement of, 516 supply piping, 783 ` down-feed systems, 786 mains, 790 up-feed systems, 788 temperature, maximum main, 508 from wells, 506 . thermal properties of, 27 vapor, 5, 10, 12 given off in combustion of gas, 175 heat content, 12, 23 mean specific heat of, 3 weight of saturated, 12 Weatherstripping, 126 Weight, of air, 6 conversion equations, 834 of steam, 28 of vapor, 12 . of water, 27 Welding, 355,366 . ' neck flanges, 371, 372 Well water refrigeration control of, 702 Well water temperature, 506 Wet-bulb temperature, (see Temperature, Wet-bulb) Wet return, 830 Wind, in cities, 138, 148 effect on heating requirements, 137 forces in natural ventilation, 121, 669, 675 prevailing, direction of, 127, 148 records of velocity and direction, 138, 148 velocity on natural draft equipment, 515 average, 127, 137, 148, 669 equivalent, in tall buildings, 128 used in calculations, 127 Window, windows, 671, 673 air leakage through, 124, 126 clearance of sash, 125 coefficients of transmission of, 117 - comparison of various shades for, 156 crack, 124 measurement of, 124 solar radiation through, 152 . storm sash, 125 ` Winter, comfort zone, 63, 64 ; conditioning, apparatus for, 393, 409 cooling in, 147 humidification in, 63, 68, 403 inside temperature, 134 . relative humidity in, 68 temperatures, 138 wind velocities and directions, 138 Zero, absolute, 819 Zone, zoning, for air conditioning systems, 428 ' automatic control, CSS comfort, 63, 64, 66, 821 . control of steam heating systems, 291 . for large heating systems, 351 . neutral, 826 .' water supply systems, 783 Heating Ventilating Air Conditioning AIR, WATER AND STEAM Dalton's Law, Temperatures, Air Properties, Humidity, Rela tive Humidity, Specific Humidity, Relation of Dew Point to Relative Humidity, Adiabatic Saturation of Air, Total Heat and Heat Content, Enthalpy, Psychrometric Chart, Properties of Water, Properties of Steam, Rate of Evaporation AIR conditioning has for its objective the supplying and maintaining, in a room or other enclosure, of an atmosphere having a composition, temperature, humidity, and motion which will produce desired effects upon the occupants of the room or upon materials stored or handled in it. Dry air is. a mechanical mixture of gases composed, in percentage of volume, "as follows1: nitrogen 78.03, oxygen 20.99, argon 0.94, carbon dioxide 0.03, and small amounts of hydrogen and other gases. Atmospheric air at sea level is given in percentage by volume as: N, 77.08, Oj 20.75, water vapor 1.2, A 0.93, CO2 0.03 and Hj 0.01. The amount of water vapor varies greatly under different conditions and is frequently one of the most important constituents since it affects bodily comfort and greatly affects all kinds of hygroscopic materials. DALTON'S LAW A mixture of dry gases and water vapor, such as atmospheric air, obeys Dalton's Law of Partial Pressures; each gas or vapor in a mixture, at a given temperature, contributes to the observed pressure the same amount that it would have exerted.by itself at the same temperature had no other gas or vapor been present. If p = the observed pressure of the mixture 'International Critical Tables, l Heating Ventilating Air Conditioning Guide 1938 and pi, pi, pi, etc. = the pressure of the gases or vapors corresponding to the observed temperature, then p = pi + pi + Pi, etc. (1) TEMPERATURES ' Air is said to be saturated at a given temperature when the water vapor mixed with the air is in the dry saturated condition or, what is the equiva lent, when the space occupied by the mixture holds the maximum pos sible weight of water vapor at that temperature. If the water vapor mixed with the dry air is superheated, i.e., if its temperature is above the temperature of saturation for the actual water vapor partial pressure, the air is .not saturated. The starting point of most applications of thermodynamic principles to. air conditioning problems is the experimental determination of the dry-' bulb and wet-bulb temperatures, and sometimes the barometric pressure. The dry-bulb temperature of the air is the temperature indicated by any type of .thermometer not affected by the water vapor content or relative humidity of the air. The wet-bulb temperature is determined by a thermo meter with its bulb encased in a fine mesh fabric bag moistened with dean water and whirled through the air until the thermometer assumes a steady temperature. This steady temperature is the result of a dynamic equilibrium between the rate at which heat is transferred from the air to the water on the bulb and the rate at which this heat is utilized in evapora ting moisture from the bulb. The rate at which heat is transferred from the air to the water is substantially proportional to the wet-bulb depres sion (t -- /'), while the rate of heat utilization in evaporation is propor tional to the difference between the saturation pressure of the water at the wet-bulb temperature and the actual partial pressure of the water Vapor in the air (e1 -- e). Carrier's equation for this dynamic equilibrium is . e' -- e B -- e' t - t< 2800 - 1.31' (2a) In the form commonly used, , where . (B _ <') - <-) 2800 - 1.3? (2b) ' c = actual partial pressure of water vapor in the air, inches of mercury. ' -- saturation pressure at wet-bulb temperature, inches of mercury. B = barometric pressure, inches of mercury. t -- dry-bulb temperature, degrees Fahrenheit. t' -- wet-bulb temperature, degrees Fahrenheit. Formula 2b may be used to determine the actual partial pressure of the watervapor in a dry air-water vapor mixture. Then, from Dalton's Law of Partial Pressures, Equation 1, it follows that the partial pressure of the dry air is (B -- e). : If a mixture of dry air and water vapor, initially unsaturated, be cooled Chapter 1. Air. Water and Steam at constant pressure, the temperature at which condensation of the water vapor begins is called the dew-point temperature.. Clearly the dew-point is the saturation temperature corresponding to the actual partial pressure, e, of the water vapor in the mixture. ' AIR PROPERTIES Density is variously defined as the mass per unit of volume, the weight per unit of volume, or the ratio of the mass, or weight, of a given volume of a substance to the mass, or weight, of an equal volume of some other substance such as water or air under standard conditions of temperature and pressure. The term specific gravity is more commonly used to express the latter relation but, when the gram is taken as the unit of mass and the cubic centimeter as the unit of volume, density and specific gravity have the same meaning. The term specific density is sometimes used to dis tinguish the weight in pounds per cubic foot; and as here used, density is the weight in pounds of one cubic foot of a substance. The density of air decreases with increase in temperature when under constant pressure. The density of dry air at 70 F and under standard atmospheric pressure (29.921 in. of Hg) is approximately 0.075 lb (see Table 1), while that of a mixture of air and saturated water vapor at the same temperature and barometric pressure is only about 0.0742 lb. In the mixture the density of the dry air is 0.07307 and that of the vapor is 0.00115 lb (see Table 2). In order to make comparisons of air volumes or velocities it is necessary to reduce the observations to a common pressure and temperature basis. The basic pressure is usually taken as 29.921 in. of Hg, but no basic tem perature is universally recognized. Common temperatures for this purpose are 32 F, 60 F, 68 F, and 70 F. Since 70 F is the most commonly specified temperature to which rooms for human occupancy must be heated, it is usually understood, when no other temperature is specified, that 70 F is the basic temperature for measuring the volume or the velocity of air in heating and ventilating work. The specific volume of air is the volume in cubic feet occupied by one pound of. the air. Under constant pressure the specific volume varies inversely as the density and directly as the absolute temperature. . . The specific heat of air is the number of Btu required to raise the tem perature of 1 lb of air 1 F. Distinction should always be made between the instantaneous specific heat at any existent temperature and the mean specific heat, which is the average specific heat through a given tempera ture range. The. mean specific heat is the value required in most calcu lations. The specific heats at constant pressure, Cp, and the specific heats, Cv, at constant volume are different. The specific heat at constant pressure is commonly used and it varies, under a pressure of one atmos phere,from a minimum at 32 F from which it increases with either increase or decrease of temperature. The value of 0.24, as the mean specific heat at constant pressure, is sufficiently accurate for use at ordinary tem peratures. Values for instantaneous and mean specific heats are given in Table 3. The mean specific heat of water vapor at constant pressure is taken as 0.45 for all general engineering computations. 3 Heating Ventilating Air Conditioning Guide 1938 TemperaTeas Deo F Table 1. Properties of Dry Air3 Barometric Pressure 29.921 In. of Hg Weight Pounds per Cu Ft Ratio or Volume to Volume at 70 F Btu Absorbed bt One Ca Ft Drt Air per Deo F Cu Ft Drt Air Warmed One Deg per Btu 0 10 20 30 40 50 60 70 80 90 100 . 110 120 130 140 150 ' 160 180 200 220 240 260 280 300 350 400 450 500 550 600 700 800 900 .1000 0.08633 a. 08449 0.08273 0.08104 0.07942 0.07785 0.07636 0.07492 . 0.07353 0.07219 0.07090 0.06966 0.06845 0.06729 0.06617 0.06509 0.06403 0.06203 0.06015 0.05838 0.05671 0.05514 0.05365 0.05223 0.04901 0.04615 0.04362 0.04135 0.03930 0.03744 0.03422 0.03150 0.02911 0.02718' 0.8678 0.8867 0.9056 0.9245 0.9433 0.9624 0.9811 1.0000 1.0189 1.0378 1.0567 1.0755 1,0946 1.1133 1.1322 1.1510 1.1701 1.2078 1.2456 1.2832 1.3211 1.3587 1.3965 1.4344 . 1.5287 1.6234 1.7176 1.8119 1.9064 . 2.0011 . 2.1893 2.3784 2.5737 . 2.7564 0.02077 ... 0.02030 0.01986. , 0.01944 ;; . 0.01905 " 0.01868 0.01832 0.01798 0.01765 0.01733 0.01702 0.01672 0.01643 0.01616 0.01589 0.01563 0.01538 0.01490 0.01446 0.01403 0.01364 0.01326 0.01291 0.01257 0.01181 0.01114 0.01054 0.01001 0.00953 0.00908 0.00833 0.00769 0.00713 0.00668 48,15 49.26 50.35 51.44 52.49 53.36 54.44 55.62 56.66 57.70 58.75 59.81 60.86 61.88 62.93 63.98 65.02 67.11 69.24 71.27 73.31 75.41 77.46 79.55 84.67 89.67 94.87 99.01 104.93 110.13 120.05 130.04 140.25 149.70 Compiled by W. H. Severns. based on the instantaneous specific heats of air. The values for the heats . and for the cubic feet warmed one degree are for the temperatures stated and are not true over a tempera ture range of more than one degree above or below the temperatures stated. Chapter 1. Air. Water and Steam T^ble 2. Properties of Saturated Air3 Weights of Air, Vapor and Saturated Mixture of Air and Vapor at 29.921 In. of Hg Temp. Deg F Weight in a Cubic Foot or Mixture Weight of Dry Air Pounds Weight of . ' Total Weight Vapor of Mixture Pounds Pounds Btu Absorbed bt One Cubic Foot Sat. Am per Deg F Cubic Feet Sat. Am Warmed One Deg per Btu Specific Heat Btu per Pound or Mixture 0 0.08622 0.000068 0.08629 0.02078 48.12 0.2408 10 0.08431 0.000111 0.08442 0.02031 49.24 0.2406 20 0.08244 0.000177 0.08262 0.01987 50.33 0.2405 30 0.08060 0.000278 0.08088 0.01946 51.39 0.2406 40 0.07876 0.000409 0.07917 0.01908 52.41 0.2410 50 0.07692 0.000587 0.07751 0.01872 53.42 0.2415 60 0.07503 0.000828 0.07586 0.01838 54.41 0.2423 70 0.07307 0.001151 0.07422 0.01805 55.40 0.2432 80 0.07099 0.001578 0.07257 0.01775 56.34 0.2446 90 0.06877 0.002134 0.07090 0.01747 57.24 0.2464 100 0.06634 0.002851 0.06919 0.01721 58.11 0.2487 110 0.06361- 0.003762 0.06737 0.01696 58.96 0.2517 120 0.06057 0.004912 0.06548 0.01675 59.70 0.2558 130 0.05712 0.006344 0.06346 0.01657 60.35 0.2611 140 0.05317 0.008116 0.06129 0.01642 60.91 0.2679 150 0.04863 0.010284 0.05891 0.01630 61.35 0.2767 10 0.04339 0.012919 0.05631 0.01624 61.58 0.2884 170 0.03733 0.016092 0.05342 0.01621 61.69 0.3034 180 0.03033 0.019888 0.05022 0.01624 61.58 0.3234 190 0.02228 0.024384 0.04666 0.01633 61.24 0.3500 200 0.01298 0.029700 0.04268 0.01649 60.64 0.3864 210 0.00230 0.035932 0.03616 0.01672 59.81 0.4624 212 0.00000 0.037286 0.03729 0.01818 55.01 0.4875 Compiled'by W. H. Severns, based on the instantaneous specific heats of air. Temperature Deg F Table 3. Specific Heats of Dry Air3 Constant Barometric Pressure of 29.921 In. of Hg Instantaneous ' or True ' Specific Heat ' Temperature Range Deg F Mean Specific Heat -301.0 -108.4 32.0 212,0 392.0 752.0 1112.0 . ,, 0.2520 0.2430 0.2399 0.2403 0.2413 0.2430 0.2470 32 to 212 32 to 392 32 to 752 32 to 1112 0.2401 . 0.2411 0.2420 0.2430 ------------ Compiled by W. H. Severns, based on data given in the International Critical Tobies. 5 x r Heating Ventilating Air Conditioning. Guide 1938 . Pounds per C ubic Foot T a b l e 4 . W e ig h t s o f Sa t u r a t e d a n d P a r t l y Sa t u r a t e d A i r f o r V a r io u s B a r o m e t r ic a n d H y g r o m e t r ic C o n d it io n s , b -. . 6 F ro m Fatt Engineering. ' .' bA convenient and accurate c h a rt fo r q u ic k ly determ ining the w eight o f a ir under any co n d itio n of d ry -b u lb , w et-bulb, and pressure is A Chart fo r Determ ining the Weight c / M oist A ir in Pounds per Cubic Foot, b y John E. Younger. Published in M echanical Engineering, June, 1925. Chapter 1. Air. Water and Steam Table 4 is intended to aid in determining the density of moist air, taking into account its temperature, pressure, and moisture content. Example 1. To show the use of Table 4: Given air at 83 F dry-bulb and 68 F wetbulb (or a depression of 15 deg) with a barometric pressure of 29.40 in. of mercury. What will be the weight of this air in pounds per cubic foot? Solution. From Table 4 the weight of saturated air at 80 F and 29.00 in. barometer is found to be 0.07034 lb per cubic foot. There is a decrease of 0.00015 lb per degree drybulb temperature above 80 F. There is an increase of 0.00025 lb for each 0.1 in. above 29.00 in. From the last column of Table 4 it is found that there is an increase of approxi mately 0.000035 lb per degree wet-bulb depression when the dry-bulb is 83 F. Tabu lating the items: 0.07034 = weight of saturated air at 80 F and 29.00 bar,. -- 0.00045 = decrement for 3 deg dry-bulb, 3 X 0.00015. + 0.00100 -- increment for 0.4 in. bar., 4 X 0.00025. + 0.00053 = increment for 15 deg wet-bulb depression, 15 X 0.000035. 0.07142 = weight in pounds per cubic foot of air at 83 F dry-bulb, 68 F wet-bulb, 1 29.40 in. bar. . It is usual to assume that dry air, moist air, and the water vapor in the air follow the laws of perfect gases. This assumption while not absolutely true, especially with saturated vapor at temperatures much above 140'JY is sufficiently accurate for practical purposes and it greatly simplifies computations. . Boyle's Law refers to the relation between the pressure and volume of a gas, and may be stated as follows: With temperature constant, the volume of a given weight of gas varies inversely as its absolute pressure. Hence, if Pi and Pi represent the initial and final absolute pressures, and V\ and V2 represent corresponding volumes of the same mass, say one pound of V. Pi .. gas, then -- -- , or Px Vx = Pi Vi, but since Pi Vi for any given case is Vi Jr\ a definite constant quantity, it follows that the product of the absolute pressure and volume of a gas is a constant, or P V = C, when T is kept constant. Any change in the pressure and volume of a gas at constant temperature is called an isothermal change. Charles' Law refers to the relation among pressure, volume, and tem perature of a gas and may be stated as follows: The volume of a given weight of gas varies directly as the absolute temperature at constant pressure, and the pressure varies directly as the absolute temperature at constant volume. Hence, when heat is added at constant volume; Fc, the resulting r-i 11 sure, Pc, the relation is Vi Ti XV In general; .for any weight of gas, W, since volume is proportional to weight, the relation among P, V, and T is where PV = WRT P = the absolute pressure of the gas, pounds per square foot. V = the volume of the weight W, cubic feet. . .. ,: (3) .. . . ., 7 Heating Ventilating Air Conditioning Guide 1938 W = the weight of the gas, pounds. R = a constant depending on the nature of the gas. is 53.34. ' T = the absolute temperature, degrees Fahrenheit. The average value of R for air ' This is the characteristic equation for a perfect gas, and while no gases are perfect in this sense, they conform so nearly that Equation 3 will apply to most engineering computations. HUMIDITY Humidity is the water vapor mixed with dry air in the atmosphere. Absolute humidity has a multiplicity of meanings, but usually the term refers to the weight of water vapor pier unit volume of space occupied, expressed in grains or pounds per cubic foot. With this meaning, absolute humidity is nothing but the actual density of the water vapor in the mixture and might better be so called. A study of Keenan's Steam Tables* indicates that water vapor, either saturated or super-heated, at . partial pressures lower than 4 in..of mercury may be treated as a gas with a gas constant R of 1.21 in the characteristic equation of the gas pV = wR (l + 460). Within such limits, the density (d) of water vapor is d = ~r = 1.21 (/+ 460) (pOUnds PCT cub!c foot) (4a) = f (grains per cubic foot) . . (4b) where e = actual partial pressure of vapor, inches of mercury. t -- dry-bulb temperature, degrees Fahrenheit. Specific Humidity It simplifies many problems which deal with mixtures of dry air and water vapor to express the weight or the mass of the vapor in terms of the weight or the mass of dry air. If the weight of the water vapor in a mixture be divided by the weight of the dry air, and the weight of dry air be made unity, we have an expression pf the weight of water vapor carried by a unit weight of dry air. This relation has no generally accepted name. It has been variously called: mixing ratio, proportionate humidity, mass or density ratio, absolute humidity, and specific humidity. Of all these terms specific humidity is the most suggestive of the meaning which it is desired to express and it has found considerable use in this sense even though it is defined in International Critical Tables as the ratio of the mass of vapor to the total mass. It will be understood here that specific humidity refers to the weight of water vapor carried by one pound of dry air. The gas constant for dry air, when the partial pressure of the air is expressed in inches of Hg, is 0.753; so that the specific humidity, if represented by PE, is 'Published by American Society of Mechanical Engineers, see abstract in Table 8. 8 Chapter 1. Air. Water and Steam jy =_________ 5 j____________________ _____________ 1.21 (< + 460) 0.753 (1 + 460) = 0.622 (pounds) (5a) = 4354fe (grains) where e = actual partial pressure of vapor, inches of mercury. B = total pressure of mixture (barometric pressure), inches of mercury. (5b) Relative Humidity Relative humidity (3>) is either the ratio of the actual partial pressure, e, of the water vapor in the air to the saturation pressure, et, at the drybulb temperature, or the ratio of the actual density, d, of the vapor to the density of saturated vapor, dt, at the dry-bulb temperature. That is: The relative humidity of a given mixture at a given temperature is not the same as the specific humidity, W, of the mixture divided by the specific humidity, Wt, of saturated vapor at the same temperature, for from Equations 5a and 6 m -0 622 Gr^h;) -0 622 fe) - & The specific humidity of an unsaturated air-vapor mixture cannot, therefore, be accurately found by multiplying the specific humidity of saturated vapor by its relative humidity; although the error is usually small especially when the relative humidity is high. With a relative humidity of 100 per cent, the dry-bulb, wet-bulb, and dew-point temperatures are equal. With a relative humidity less than 100 per cent, the dry-bulb exceeds the wet-bulb, and the wet-bulb exceeds the dew-point temperature. RELATION OF DEW POINT TO RELATIVE HUMIDITY A peculiar relationship exists between the dew-point and the relative humidity and this is found most useful in air conditioning work. This relationship is, that for a fixed relative humidity there is substantially a constant difference between the dew-point and the dry-bulb temperature over a considerable temperature range. Table 5, giving the dry-bulb and dew-point temperatures and the dew-point differentials for 50 per cent relative humidity, illustrates this relationship clearly. Table 5. Temperatures for 50 Per Cent Relative Humidity Dry-bulb temperature._______ __________ 65.0 Dew-point temperature!............................ ...... 45.8 Difference between dew-point and drybulb temperature................... ..................... 19.2 70.0 50.5 19.5 75.0 80.0 85.0 90.0 55.25 59.75 64.25 68.75 19.75 20.25 20.75 21.25 9 Heating Ventilating Air Conditioning Guide 1938 It will be seen from an inspection of this table that the difference between the dew-point temperature and the room temperature is approxi mately 20 deg throughout this range of dry-bulb temperatures or, to be more exact, the differential increases only 10 per cent for a range of practically 25 deg. . This principle holds true for other humidities and is due to the fact that the pressure of the water vapor practically doubles for every 20 deg through this range. The approximate relative humidity for any difference between dew point and dry-bulb temperature may be expressed in. per cent as: 100 ' ? where (, = dew-point temperature. . This principle is very useful in determining the available cooling effect obtainable with saturated air when a desired relative humidity is to be maintained in a room, even though there may be a wide variation in room temperature. This problem is one which applies to certain industrial con ditions, such as those in cotton mills and tobacco factories, where re latively high humidities are carried and where one of the principal prob lems is to remove the heat generated by the machinery. It also permits the use of a differential thermostat, responsive to both the room tempera ture and the dew-point temperature, to control the relative humidity in the room. - . Table 6 gives, for different temperatures, the density of saturated vapor, dt, the weight of saturated vapor mixed with 1 lb of dry air, Wt, (at a relative humidity of 100 per cent and a barometric pressure, B, of 29.92 in. of mercury), the specific volume of dry air, and the volume of an air-vapor mixture containing 1 lb of dry air (at a relative humidity of 100 per cent and a pressure of 29.92 in. of mercury). The preceding equations or the data from Table 6 may be conveniently used in solving the following typical problems: Example S. Humidifying and Heating. Air is to be maintained at 70 F with a relative humidity of 40'per cent (4> = 0.4) when the outside air is at 0 F and 70 per cent relative humidity (4> = 0.7) and a barometric pressure, B, of 29.92 in. of mercury. Find the weight of water vapor added to each pound of dry air and the dew-point temperature of the humidified air. - ': Solution. From Equation 5a and Table 6, W, = 0.622 (^ 92^-^ 0 0264 ) = 0.000548 lb per pound of dry air. 04 y fl 700c \ " ( 2q Q2 --~ 0 295 / = ^-00618 lb per pound of dry air. The water vapor added per pound of dry air must be (W% -- Wi) or 0.005632 lb. By inspection of Table 6, Wt ~ 0.00618 at 44.5 F, so this is the dew-point temperature of the humidified air. An approximation of the same result from Table 6 is e 0.7 X 0.0007852 -- 0.00054964 lb per pound of dry air. ^ ~ 0.4 X 0.01574 = 0.006296 lb per pound of dry air. 10 Chapter 1. Air. Water and Steam The water vapor added per pound of dry air is approximately 0.00574636 lb and the dew-point temperature is approximately 45 F. The degree of approximation is evident. Example S. Dehumidifying and Cooling. Air with a dry-bulb temperature of 84 F, a wet-bulb of 70 F, or a relative humidity of 50 per cent'(<l> = 0.5),'and a barometric pressure, B, of 29.92 in. of mercury is to. be cooled to 54 F. Find the dew-point tem perature of the entering air and the weight of vapor condensed per pound of dry air. Solution. From Equation 5a and Table 6, .- W, = 0.622 = 0.01248 lb per pound of dry air. W' " 0622 ( 29.92'- 0)42003) = 000887 lb ^ pound f dry air- Since Wx = Wt when / = 63.4 F, this is the dew-point temperature of the entering air. The weight of vapor condensed is ( Wx -- Wt) or 0.00361 lb per pound of dry air. An approximate result is Wt = 0.5 X 0.02543 = 0.012715 lb per pound of dry air. '' Wt = 1 X 0.008856 = 0.008856 lb per pound of dry air, since the exit air is saturated. Since Wx = Wt at t = 64 F, this is the dew-point temperature of the entering air. The weight of vapor condensed is 0.003859 lb per pound of dry air. The degree of approxi mation is again evident. . ADIABATIC SATURATION OF AIR The process of adiabatic saturation of air is of considerable importance in air conditioning. Suppose that 1 lb of dry air, initially unsaturated but carrying W lb of water vapor with a dry-bulb temperature, t, and a wetbulb temperature, l\ be made to .pass through a tunnel containing an exposed water surface. Further assume the tunnel to be completely in.sulated, thermally, so that the only heat transfer possible is that between the air and water. As the air passes over the water surface, it will gradu ally pick up water vapor and will approach saturation at the initial wetbulb temperature of the air, if the water be supplied at this wet-bulb tem perature. During the process of adiabatic saturation, then, the dry-bulb temperature of the air drops to the wet-bulb temperature as a limit, the wet-bulb temperature remains substantially constant, and the weight of water vapor associated with each jpound of dry air increases to Wt<, as a limit, where Wtt is the weight of saturated vapor per pound of dry air for saturation at the wet-bulb temperature. Example 4. If air with a dry-bulb of 85 F and a wet-bulb of 70 F be saturated adiabatically by spraying with recirculated water, what will be the final temperature and the vapor content of the air? . Solution. The final temperature will be equal to the initial wet-bulb temperature or 70 F, and since the air is saturated at this temperature, from Table 6, W = 0.01574 lb per pound of dry air. In the adiabatic saturation process, since the heat given up by the dry air and associated vapor in cooling to the wet-bulb temperature is utilized in evaporation of water at- the wet-bulb temperature, W. H. Carrier has pointed out3 that the equation for the process of adiabatic saturation, and hence for a process of constant wet-bulb temperature, is: 1Rational Psychrometric Formulae, by W. H. Carrier (A.S.W.E. I'munctions, Vol. 33, 1911, P- 1005.) I)Table 6. Properties of Saturated Water Vapor with Air at Low Temperatures'1 (Part Tbmp., F --130 -120 -- 128 -127 -120 -125 -124 -123 -122 -121 -120 -110 -118 -117 -110 -115 -114 -113 -112 -111 -110 -100 -108 -107 -100 -105 -104 -103 -102 -101 -100 -99 -98 -97 -96 Pressure or Saturated Vapor X 10- Weight or Saturated Vapor Volume in Cu Ft Barometer, 29.92 In. Ho In. of Hg Lb per Sq In. per Cu Ft Pouods X 10- Groins per lb of Dry Air Pounds X 10- Grains of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it 0.276 .306 .338 .373 .411 0.455 .499 .542 .604 .669 0.735 .805 .892 .989 1.098 1.208 1.317 1.444 1.575 1.728 1.889 2.087 2.292 2.511 2.742 ' 2.983 3.258 3.543 3.872 4.213 4.607 5.018 5.455 5.946 6.470 0.1356 .1503 .1660 .1832 .2019 0.000693 .000766 .000843 .000928 .001019 0.000049 .000054 .000059 .000065 .000071 0.2235 .2451 .2662 .2967 .3286 0.001125 .001230 .001332 .001480 .001635 0.000079 .000086 .000093 .00010 .00012 0.3610 .3954 .4382 .4858 .5393 0.001791 .001956 .002161 .002388 .002644 0.00013 .00014 .00015 .00017 .00019 0.5934 .6469 .7093 .7736 .8488 0.002900 .003153 .003447. .003749 .004101 0.00020 .00022 .00024 .00026 .00029 0.9279 1.0251 1.1258 1.2334 1.3469 0.004471 .004925 .005393 .005892 .006415 0.00031 .00035 .00038 .00041 .00045 - 1.4652 , 1.6003 ,, 1.7403 1.9019 2.0694 0.006960 .007580 .008219 .008958 .009719 0.00049 .00053 .00058 .00063 .00068 2.2630 2.4637 2.6784 2.9196 3.1781 0.010599 .011512 .012480 .013566 .014721 0.00074 .00081 .00087 .00095 .00103 0.005738 .006362 .007027 .007755 .008545 0.009459 .01037 .01127 .01256 .01391 0.01528 .01674 .01854 .02056 .02283 0.02511 .02738 .03002 .03274 .03593 0.03927 .04339 .04765 .05220 .05701 0.06202 .06773 .07366 .08050 .08759 0.09578 .1043 .1134 .1236 .1345 0.00040 .00045 .00049 .00054 .00060 0.00066 .00073 .00079 .00088 .00097 0.00107 .00117 .00130 .00144 .00160 0.00176 .00192 .00210 .00229 .00252 0.00275 .00304 .00334 .00365 .00399 0.00434 .00474 .00516 .00564 .00613 0.00705 .00730 .00794 .00865 .00942 8.31 8.33 8.36 8.38 8.41 8.43 8.46 8.48 8.51 8.53 8.56 8.58 8.61 8.63 8.66 8.68 8.71 8.73 8.76 8.78 8.81 8.83 8.86 8.89 8.91 8^94 8.96 8.99 ' 9.01 9.04 9.06 9.09 9.11 9.14 9.16 8.31 8.33 8.36 8.38 8.41 8.43 8.46 8.48 8.51 8.53 8.56 8.58 8.61 8.63 8.66 8.68 8.71 8.73 8.76 8.78 8.81 8.83 8.86 8.89 8.91 8.94 8.96, 8.99 9.01 9.04 9.06 9.09 9.11 9.14 9.16 Compiled by W. M. Sawdon. vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air OF Datum Vapor 32 F Datum -31.71 -31.46 -31.21 -30.96 -30.71 1000.7 1001.2 1001.8 1002.1 1002.5 -30.46 -30.21 -29.96 -29.72 -29.47 1003.0 1003.4 1003.9 1004.3 1004.8 -29.22 -28.97 -28.72 -28.47 -28.23 1005.2 1005.7 1006.1 1006.6 1007.0 -27,98 -27.73 -27.48 -27.23 -26.99 . 1007.5 1007.9 1008.4 1008.8 1009.3 -26.74 -26.49 -26.24 -26.00 -25,75. ; 1009.7 1010.2 1010.6 1011.1 1011.5 -25.50 -25.26 -25.01 -24.76 -24.51 ' 1012.0 ; 1012.4 1012.9 1013.3 1013.8 -24.27 -24.02 -23.78 -23.53 ,-23.28 1014.2 1014.7 1015.1 1015.6 1016.0 Dry Air with Vapor to Saturate it' -31.71 -31.46 --31.21v -30.96 -30.71 -30.46 -30.21 -29.96 -29.72 -29.47 -29.22 -28.97 -28.72 -28.47 -28.23 -27.98 -27.73 -27.48 . -27.23 -26.99 -26.74 -26.49 -26.24 -28.00 -25.75 -25.50 -25.26 -25.01 -24.76 -24.51 -24.27 -24.02 -23.78 -23.53 -23.28 . I,Table 6. Properties of Saturated Water Vapor with Air at Low Temperatures4 (Part Continued) Temp., F Pressure or Saturated Vapor X 10-* In. of Hg Lb per Sq In. Weight op Saturated Vapor per Cu Ft Pounds X10- Grains per lb of Dry Air Pounds X 10-* Grains Volume in Cu Ft Barometer, 29.92 In. Ho of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it Heat Content per Lb Dry Air OF Datum Vapor 32 F Datum Dry Air with Vapor to Saturate it ' -95 -94 -93 -92 -91 -90 -89 -88 -87 -86 -85 -84 -83 -82 -81 -80 -79 -78 -77 -76 -75 -74 -73 -72 -71 -70 -69 -68 -67 -66 . -65 -64 ' -63 -62 -61 7.047 7.638 8.316 9.017 9.806 10.64 11.53 12.51 13.53 14J69 15.87 17.20 18.58 20.10 21.72 23.47 25.34 27.29 29.52 31.81 34.37 37.01 39.96 43.04 46.33 49.87 53.59 57.65 61.81 66.41 71.17 76.64 82.28 88.19 94.62 . 3.4604 3.7507 4.0837 4.4281 4.8156 5.2264 5.6635 6.1449 6.6459 7.2157 7.7953 8.4486 9.1265 9.8731 10.669 11.517 12.436 13.394 14.489 15.614 . 16.883 18.179 19.628 21.141 22.757 24.496 26.323 28.318 30.361 32.621 34.959 37.646 40.416 43.319 46,477 0.015990 .017284 .018767 .020292 .022009 0.00112 .00121 .00131 .00142 .00154 0.023817 .025738 .027851 .030041 .032530 0.00167 .00180 .00195 .00210 .00228 0.035049 .037885 .040817 .044037 .047463 0.00245 .00265 .00286 .00308 .00332 0.051151 .055082 .059165 .063831 .068605 0.00358 .00386 .00414 .00447 .00480 0.073933 .079405 .085510 . .091865 .098632 0.00518 .00556 .00599 .00643 .00690 0.10590 .11350 .12179 .13024 '.13959 0.00741 .00795 .00853 .00911 .00977 0.14922 .16028 .17164 .18350 .19638 0.01044 .01122 .01201 .01285 .01375 0.1465 .1588 .1729 .1875 . .2039 0.2212 .2397 .2601 .2813 .3054 0.3299 .3576 .3863 .4179 .4516 0.4879 .5268 .5674 .6137 .6613 0.7148 .7694 .8308 .8948 .9632 1.037 1.114 1.199 1.285 1.381 1.480 1.593 1.711 1.833 1.987 0.01026 .01112 .01210 .01312 .01427 0.01548 .01678 .01821 .01969' -.02138 0.02309 .02503 .02704 .02925 .03161 0.03415 .03688 .03972 .04296 .04629 0.05002 .05386 .05816 .06264 .06742 0.07259 .07798 .08393 .08995 .09667 0.10360 .11151 .11977 .12831 .13769 9.19 9.21 '9.23 9.26 9.29 9.31 9.34 9.36 9.39 9.41 9.44 .9.46 9.49 9.51 9.54 9.56 9.59 9.61 9.64 9.66 9.69 9.72 . 9.74 9.77 9.79 9.82 9.84 9.87 9.89 9.92 9.94 9.97 9.99 10.02 10.04 9.19 9.21 9.23 9.26 9.29 9.31 9.34 9.36 9.39 9.41 9.44 9.46 9.49 9.51 9.54 9.58 9.59 9.61 9.64 9.66 9.69 9.72 9.74 9.77 9.79 9.82 9.84 9.87 9.89 9.92 9.94 9.97 9.99 10.02 10.04 -23.04 -22.79 -22.55 -22.30 -22.05 -21.81 -21.56 -21.32 -21.07 -20.83 -20.58 -20.34 -20.09 -19.84 -19.60 -19.30 -19.11 -18.87 -18.02 -18.38 -18.13 -17.89 -17.64 -17.40 -17.16 -16.91 -16.67 -16.42 -16.18 -15.94 -15.69 -15.45 -15.21 -14.96 -14.72 1016.5 1016.9 1017.4 1017.8 1018.3 1018.7 1019.2 1019.6 1020.1 1020.5 1021.0 1021.4 1021.9 1022.3 1022.8 1023.2 1023.7 1024.1 1024.6 1025.0 1025.5 1025.9 1026.4 1026.8 1027.3 1027.7 1028.2 1028.6 1029.1 1029.5 1030.0 1030.4 1030.9 1031.3 1031.8 -23.04 -22.79 -22.55 -22.30 -22.05 -21.81 -21.56 -21.32 -21.07 -20.83 -20.58 -20.34 -20.09 -19.84 -19.60 -19.36 -19.10 -18.86 -18.01 -18.37 -18.12 -17.88 -17.63 -17.39 -17.15 -16.90 -16.66 -16.41 -16.17 -15.93 -15.67 -15.43-15.19 -14.94 -14.70 Compiled by W. M. Sawdon, vapor pressures converted from International Critical Tables. \ Table 6. Properties of Saturated Water Vapor with Air at Low Temperatures (Part I, Continued) Tbmp., F Pressure or Saturated Vapor X KM Id. of Hg Lb per 8q In. Weight op Saturated Vapor per Cu Ft Pounds X 10** Grains per lb of Dry Air PouodB X KM Grains Volume in Cu Ft Barometer, 29.92 In. Ho of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it -- 60 -59 -58 -57 -56 101.4 108.8 116.3 124.8 133.4 -55 -54 -53 -52 -51 143.0 163.0 163.5 174.9 187.0 -50 -49 -48 -47 -46 199.9 213.0 227.9 243.1 259.5 -45 -44 -43 -42 -41 276.7 295.0 314.7 335.3 357.6 -40 -39 -38 -37 -36 380.3 405.5 431.2 459.2 488.4 -35 -34 -33 -32 -31 . -30 -29 -28 -27 -26 519.5 652.4 586.5 623.7 661.8 701.6 742.2 791.2 841.0 892.1 49.808 53.443 57.127 61.302 65.526 0.20993 .22469 .23958 .26645 .27344 70.242 ' 75.154 80.311 85.011 91.854 0.29239 .31207 .33267 .35469. .37862 98.191 104.63 111.94 119.41 127.47 0.40370 .42917 .45808 .48744 .51905 135.92 144.90 154.58 164.70 175.65 . " 0.55213 .58722 .62493 .66426 .70672 186.80 199.18 211.81 225.66 239.90 0.7498 .7976 .8461 .8989 .9538 255.16 271.34 288.09 306.36 325.08 1.0122 1.0738 .1.1374 1.2067 1.2774 344.33 364.67 388.64 413.10 438.20- 1.3499 1.4260 1.5166 1.6083 1.7021 0.01470 .01573 .01677 .01795 .01914 . 2.108 2.262 2.418 . 2.595 2.773 0.02047 .02184 .02329 .02485 .02650 2.973 3.181 3.399 3.636 3.888 0.02826 .03004 .03207 .03412 .03633 4.156 4.428 4.738 5.054 5.395 0.03865 .04111 .04375 .04650 .04947 5.753 6.133 6.543 6.971 7.435 0.05249 .05583 .05922 .06292 .06677 7.907 8.431 8.965 0.548 10.16 0.07085 .07517 .07962 .08447 .08942 10.80 11.49 12.20 12.97 13.76 0.09449 .09982 .10616 .11258 .11914 14.58 15.43 16.45 17.49 18.55 0.14756 .15834 .16926 .18165 .19411 0.20811 .22267 .23793 .25452 .27216 0.29092 .30996 .33166 .35378 .37766 0.40271 .42931 .45801 .48797 .52045 0.55349 .69017 .62755 .66836 .71120 0.75600 -.80430 .85400 .90790 .96320 1.0206 1.0801 1.1515 1.2243 1.2985 10.07 10.09 10.12 10.14 10.17 10.19 10.22' 10.24 10.27 10.29 10.32 10.34 10.37 10.40 10.42 10.45 10.47 10.50 10.52 10.55 10.57 10.60 10.62 10.65 10.67 10.69 10.72 10.75 10.77 10.80 10.82 10.85 10.87 10.90 10.92 10.07 10.09 10.12 10.14 10.17 10.19 10.22 10.24 10.27 10.29 10.32 10.34 10.37 10.40 10.42 10.45 10.47 10.50 10.52 10.55 10.57 10.60 10.62 10.65 10.67 10.69 10.72 10.75 10.77 10.80 10.82 10.85 10.87 10.90 10.92 Compiled by W. M. Sawdon, vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air 0F Datum Vapor 12 F Datum -14.48 -14,23 -13.99 -13.75 -13.50 1032.2 1032.7 1033.1 1033.6 1034.0 -13.26 -13.02 -12.78 -12.53 -12.29 1034.5 1034.9 1035.4 1035.8 1036.3 -12.05 -11.81 -11.57 -11.32 -11.08 1036.7 1037.2 1037.6 1038.1 1038.6 -10.84 -10.60 -10.35 -10.11 -9.872 1039.0 1039.4 1039.9 1040.3 1040.8 -9.629 1041.2 -9.388 1041.7 -9.146- 1042.1 -8.905 ** 1042.6 -8:663.,-' % 1043.0 -8.422 -8.180 -7.939 -7.698 -7.457 : 1043.5 1043.9 1044.4 1044.8 1045.3 -7.216 -6.975 -6.734 -6.493 -6.251 1045.7 1046.2 1046.6 1047.1 1047.5 Dry Air with Vapor to Saturate it -14.46 -14.21 -13.97 -13.72 -13.47 -13.23 -12.99 -12.74 -12.49 -12.25 -12.01 -11.76 -11.52 -11.27 -11.02 -10.78 -10.54 -10.28 -10.04 -9.795 -9.547 -9.300 -9.053 -8.805 -8.557 -8.309 -8.060 -7.812 -7.562 -7.313 -7.064 -6.814 -6.562 -6.310 -6.057 T' TM-I,aEr~-a;r Table 6. Properties of Saturated Water Vapor with Air at Low Temperatures (Part I, Concluded) Temp., F Pressure or Saturated Vapor X 10-* In. of Hg Lb per Sq In. Weight or Saturated Vapor per Cu Ft Pounds X 1(M Grains per lb of Dry Air Pounds X 10- Grains Volume in Cu Ft Barometer, 29.92 In. Hg of I lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it -25 -24 -23 -22 -21 946.4 1003. 1064. 1126. 1192. -20 -19 -18 -17 -16 1262.0 1337. 1416. 1496. ' 1684. -15 -14 -13 -12 -11 1675.0 1772. 1874. 1980. 2093. -10 -9 -8 -7 -6 2210.0 2335. 2463. 2502. 2745. ' --5 -4 -3 . -2 -1 2898.0 3055. 3222. 3397. 3580. 0 3773.0 464.87 492.67 522.64 553.09 585.51 619.89 656.73 695.54 734.84 778.06 822.76 870.41 920.51 972.58 1028.1 1085.6 1147.0 1209.8 1229.0 1348.3 1423.5 1500.6 1582.6 1668.6 1758;5 1853.3 1.8016 1.9049 2.0162 2.1287 2.2484 2.3760 2.5105 2.6527 2.7963 2.9542 3.1168 3.2899 3.4714 3.6596 3.8599 4.0666 4.2871 4.5120 4.5734 5.0066 5.2738 5.5473 5.8379 6.1414 6.4583 6.7914 0.12611 .13334 .14113 .14901 .15739 0.16625 .17574 .18569 .19574 .20679 0.21818 .23029 .24300 .25617 .27019 0.28466 .30009 .31584 .32014 .35046 0.36917 .38831 .40865 .42990 .45208 0.47500 19.68 20.86 22.13 23.42 24.79 26.25 27.81 29.45 31.12 32.95 34.84 36.86 38.98 41.19 43.54 45.98 48.58 51.25 52.06 57.12 60.30 63.57 67.05 70.69 74.50 78.52 1.3776 1.4602 1.5491 1.6394 1.7353 1.8375 1.9467 2.0615 2.1784 2.3065 2.4388 2.5802 2.7286 2.8833 3.0478 3.2186 3.4006 3.5875 3.6442 3.9984 ' 4.2210 4.4499 4.6935 4.9483 5.2150 5.5000 10.95 10.97 11.00 11.02 11.05 . 10.95 10.97 11.00 11.02 11,05 11.07 11.10 11.13 11.15 11.18 11.07 11.10 11.13 11.15 11.18 11.20 11.23 11.25 11.28 11.30 11.21 11.24 11.26 11.29 11.31 11.33 11.35 11.38 11.40 11.43 11.34 11.36 11.39 11.41 11.44 11.45 11.48 11.50 11.53 11.55 11.46 - 11.49 11.51 11.54 11.57 11.58 11.69 Compiled by W. M. Sawdon, vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air OF Datum -6.011 -5.770 -5.629 -5.288 -5.047 -4.807 -4.566 -4.325 -4.085 -3.844 -3.604 -3.363 -3.123 -2.883 -2.642 -2.402 -2.162 -1.021 -1.681 -1.441 -1.201 -0.9604 -0.7203 -0.4802 -0.2401 0 Vapor 32 F Datum 1048.0 1048.4 1048.9 1049.3 1049.8 1050.2 1050.7 1051.1 1051.6 1052.0 1052.5 1052.9 1053.4 1053.8 1054.3 1054.7 1055.2 1055.6 1056.1 1056.5 1057.0 1057.4 1057.9 1058.3 1058.8 1059.2 Dry Air with Vapor to Saturate it -5.805 -5.661 -5,297 -5.042 -4.787 ' -4.631 -4.274 -4.015 -3.758 -3.497- -3.237 -2.975 -2.712 -2.449 -2.183 -1.917 -1.649 -1.380 -1.131 -0.8375 -0.6636 -0.2882 -0.01098 +0.2679 +0.5487 +0.8317 \A C h a p t e r 1. A i r . W a t e r a n d S ' H e a t in g V e n t il a t in g A ir C o n d it io n in g G u id e 1938 1 Table 6. Properties of Saturated Water Vapor with Air, 0 F to 200 Fa (Part II) 'emp., F 0 1. 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 Pressure op saturated Vapor In. of Hg Lb per Sq In. Weight of Saturated Vapor per Cu Ft Pounds Grains per lb of Dry Air Pounds Grains 0.03773 .03975 .04186 .04409 .04645 0.04886 .05144 .05412 .05692 .05988 0.06295 .06618 .06958 .07309 .07677 0.08067 .08469 .08895 .09337 .09797 0.1028 .1078 .1132 .1186 .1244 0.1304 .1366 .1432 .1500 .1571 0.1645 .1722 .1803 .1879 .1957 ' 0.01853 .01963 .02056 .02166 .02282 0.02400 .02527 .02658 .02796 .02941 0.03092 .03251 .03418 .03590 .03771 0.03963 .04160 .04369 .04586 .04812 0.05050 .05295 .05560 .05826 .06111 0.06405 .06710 .07034 .07368 .07717 0.08080 .08458 .08856 .09230 .09610 0.000067914 .000071395 .000075021 .000078851 .000082890 0.000087005 .000091399 .000095955 .00010070 .00010572 0.00011090 .00011634 .00012206 .00012794 .00013410 of00014062 .00014732 .00015440 * .00016174 .00016935 0.00017747 .00018564 .00019439 .00020335 .00021276 0.00022255 .00023278 .00024342 .00025445 .00026597 0.00027797 .00029043 .00030343 .00031471 ' ; 00032690 0.475 .500 .525 .552 .580 0.609 .640 .672 .705 .740 0.776 .814 .854 .896 .939 0.984 1.031 1.081 1.132 1.185 1.242 1.299 1.361 1.423 1.489 1.558 1.629 1.704 1.781 1.862 1.946 2.033 2.124 2.203 2.288 0.0007852 .0008275 .0008714 .0009179 .0009671 0.001017 .001071 .001127 .001186 .001247 0.001311 .001379 .001450 .001523 .001600 0.001682 .001768 .001855 .001947 .002043 0.002144 .002250 .002361 .002476 .002596 0.002722 .002853 .002991 .003133 .003283 0.003439 .003601 .003771 .003931 .004094 5.50 5.79 6.10 6.43 6.77 7.12 7.60 7.89 8.30 8.73 9.18 9.65 10.15 10.66 11.20 11.77 12.36 12.99 13.63 14.30 15.01 15.75 16.53 17.33 18.17 19.05 19.97 20.94 21.93 22.99 24.07 25.21 26.40 27.52 28.66 Volume in Cu Ft Barometer, 29.92 In. Ho of t lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it 11.58 11.60 11.63 11.65 11.68 11.70 11.73 11.75 11.78 11.80 11.83 11.86 11.88 11.91 11.93 11.96 11.98 12.00 12.03 12.06 12.08 12.11 12.13 12.16 12.18 12.21 12.23 12.26 12.28 12.31 12.33 12.38 12.38 12.41 12.43 11.59 . 11.62 11.64 11.67 11.70 11.72 11.75 11.77 11.80 11.83 11.85 11.88 11.91 11.93 11.96 11.99 12.01 12.04 12.07 12.09 12.12 12.15 12.18 12.20 12.23 12.26 12.29 12.32 12.34 12.37 12.40 12.43 12.46 12.49 12.51 Compiled by W.. M.-Sawdon, vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air 0F Datum Vapor 32 F Datum 0.0000 , .2401 .4801 .7201 .9601 1059.2 1059.7 1060.1 1060.6 1061.0 1.200 1.440 1.680 1.920 2.160 1061.5 1061.9 1062.4 1062.8 1063.3 2.400 2.640 2.880 3.120 3.359 1063.7 1064.2 1064.6 1065.1 1065.5 3.599 3.839 4.079 4.319 4.559 1066.0 1066.4 ' 1068.9 1087.3 1067.8 4.798 1068.2 5.038 1068.7 5.278 - 1069.1 6.518 1069.6 5.758v* / ' S 1070.0 5.9986.237 6.477 6.717 6.957 1070.5 1070.9 1071.4 1071.8 1072.3 7.197 7.437 7.677 7.917 8.157 1072.7 1073.2 1073.6 1074.1 1074.5 Dry Air with Vapor to Saturate it 0.8317 1.117 1.404 1.694 1.986 2.280 2.577 2.877 3.180 3.486 3.795 4.108 4.424 4.742 5.064 5.392 5.722 6 058 6.397 6.741 7.088 7.443 7.802 8.166 8.536 8.912 9.292 9.682 10.075 10.477 10.886 11.302 11.726 12.139 12.556 a ij g H S 0 > S3 n 0 3 O 3 o Oq o n 8 OO Table 6. Properties of Saturated Water Vapor with Air, 0 F to 200 Fa (Part II, Continued) Temp., F Pressure op saturated ., Vapor In. of Hg Lb per Sq In. 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 ' 56 57 *8 59 60 . 61 62 63 64 65 86 67 68 69 0.20360 .21195 .22050 .22925 .23842 0.1000 .1041 .1083 .1126 .1171 0.24778 .25755 .26773 .27832 .28911 0.1217 .1265 .1315 .1367 .1420 0.30031 .31191 .32393 .33635 .34917 0.1475 .1532 .1591 .1652 .1715 0.36241 .37625 .39051 .40496 .42003 0.1780 .1848 .1918 .1989 .2063 0.43570 .45179 .46828 .48538 .50310 0.2140 .2219 .2300 .2384 .2471 0.62142 . . .54035 .55970 .57985 . .60042' 0.2561 .........2654 .2749 .2848 ;,,.2949 0.62179 .64378 . .66638 -.68980 .71382 0.3054 -.3162 . .3273 .3388 .3506 Weight of Saturated Vapor , Volume in Cu Ft Barometer, 29.92 In. Hg . per Cu Ft Pounds Gridns per lb of Dry Air Pounds Grains of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it 0.0003394 .0003527 .0003662 .0003799 .0003943 2.376 2.469 2.563 2.660 2.760 0.0004090 .0004243 .0004401 .0004566 .0004735 0.0004909 .0005088 .0005274 .0005465 .0005663 2.863 2.970 3.081 3.196 3.315 3'436 3.562 3.692 3.826 3.964 0.0005866 .0006078 .0006296 .0006516 .0006746 4.106 4.255 4.407 4.561 4.722 0.0006984 .0007228 .0007477 .0007735 .0008003 4.889 5.060 5.234 5.415 5.602 0.0008278 .0008562 .0008852 .0009153 .0009460 5.795 , 5.993 6.196 6.407 6.622 0.0009778 .0010105 .0010440 .0010816 .0011140 . v 6.845 7.074 7.308 7.571 7.798 0.004262 .004438 .004618 .004803 .004996 0.005194 .005401 .005616 .005840 .006069 0.008306 .006553 .006808 .007072 .007345 . 0.007626 .007921 .008226 .008534 .008856 0.009192 .009536 v009890 -.01026 .01064 0.01103 .01144 .01186 .01229 .01274 0.01320 .01368 .01417 ;01468 .01520 29.83 31.07 32.33 33.62 34.97 36.36 37.80 39.31 40.88 42.48 44.14 45.87 47.66 49,50 51.42 53.38 55.45 57.58 59.74 61.99 64.34 66.75 69.23 71.82 74.48 77.21 . 80.08 83.02 86.03 89.18 92.40 95.76 99.19 102.8 106.4 12.46 12i.48 12.51 12.53 12.56 12.59 12.61 12.64 12.66 12.69 12.71 12.74 12.76 12.79 12.81 12.84 12.86 12.89 12.91 12.94 12.96 12.99 13.01 13.04 13.06 13.09 13.11 13.14 13.16 13.19 13.21 13.24 13.26 13.29 13.31 12.54 12.57 12.60 12.63 12.66 12.69 12.72 12.75 12.78 12.81 12.84 12.87 12.90 12.93 12.96 12.99 13.02 13.06 13.09 13.12 13.15 13.19 13.22 13.25 13.29 13.32 13.35 13.39 13.42 13.46 13.49 13.53 . 13.57 13.60 13.64 Heat Content per Lb Dry Air 0F Datum 8.397 8.636 8.876 9.116 9.356 9.596 9.836 10.08 10.32 10.56 10.80 11.04 11.28 11.52 11.76 12.00 12.23 12.47 12.71 12.95 13.19 13.43 13.67 13.91 14.15 14.39 ,14.63 14.87 15.11 15.35 15.59 15.83 16.07 16.31 16.55 Vapor 32 F Datum 1075.0 1075.4 1075.9 1076.3 1076.8 1077.2 1077.7 1078.1 1078.6 1079.0 1079.5 1079.9 1080.4 1080.8 1081.3 1081.7 1082.2 1082.6 1083.1 1083.5 1084.0 1084.4 1084.9 1085.3 1085.8 1086.2 1086.7 1087.1 1087.6 1088.0 1088.5 1088;9 1089.4 1089.8 ' 1090.3 Dry Air with Vapor to Saturate ' 12.979 13.409 13.845 14.285 14.736 15.191 15.657 16.13 16.62 17.11 17.61 18.12 18.64 19.16 19.70 20.25 20.80 21.38 21.95 22.55 . 23.15 23.77 24.40 25.05 25.70 26.37 27.06 27.76 28.48 29.21 29.96 - 30.73 31.51 32.31 33.12 Compiled by W.'' MV'Sawdon,:vap'or pressures' converted from International Critical Tables. d i H e a t in g V e n t il a t in g A ir Co n d it io n in g G u id e 1938 Table 0. Properties of Saturated Water Vapor with Air, 0 F to 200 Fa (Part II, Continued) ` - g* Pressure or saturated . , Vapor ` la. of Hg Lb per Sq la. Weigbt or Saturated Vapor ; per Cu Ft per ib of Dry Air Pounds- Grains Pounds Grains . Volume in Cu Ft Barometer. 29.92 In. Ho of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturated - 70 0.73866 71 .76431 72 .79058 73 .81766 74 .84555 75 0.87448 70 .90398 77 .93452 78 .96588 70 . .90825 80 1.0316 81 1.0661 82 1.1013 83 1.1377 84 1.1762 85 1.2135 86 1.2527 87 1.2033 88 1.3346 89 1.3774 90 91 92 93 94 1.4211 1.4661 1.5125 1.5600 . 1.6088 .95 1.6591 96 1.7108 97 1.7638 98 1.8181 99 ,1.8741 100 1.9316 101 1.9004 102 2.0507 103 2.1128 104 2.1763 0.3628 .3754 .3883 .4016 .4153 0.4205 .4440 .4590 .4744 .4903 0.5067 .6236 .5409 .5588 .5772 0.5960 .6163 .6352 .6555 .6765 0.6980 .7201 .7429 .7662 .7902 0.8149 .8403 .8663 .8930 .9205 0.9487 .9776 . 1.0072 1.0377 1.0689 0.0011507 .0012884 .0012269 .0012667 .0013075 0.0013497 .0013927 .0014371 .0014825 .0015295 0.0015777 .0016273 .0016781 .0017304 .0017841 0.0018389 .0018950 .0019531 .0020116 .0020725 0.0021344 .0021989 .0022634 .0023304 .0023992 0.0024697 .0025425 .0026164, .0026925 .0027700 0.0028506 .0029316 .0030156 .0031017 .0031887 8.055 8.319 - 8.588 8.867 9.153 9.448 9.749 10.06 10.38 10.71 11.04 11.39 11.75 12.11 12.49 12.87 13.27 13.67 14.08 14.51 14.94 15.39 15.84 16.31 16.79 17.28 17.80 18.31 18.85 19.39 19.95 20.52 21.11 21.71 22.32 0.01574 .01631 .01688 .01748 .01809 0.01873 .01938 .02005 .02075 .02147 6.02221 .02298 .02377 .02459 .02543 0.02629 .02718 .02810 .02904 .03002 0.03102 .03205 .03312 .03421 .03535 0.03652 .03772 .03896 .04024 .04156 0.04293 .04433 .04577 .04726 .04879 110.2 114.2 118.2 122.4 126.6 13L.1 135.7 140.4 145.3 150.3 155.5 160.0 166.4 172.1 m.o. 184.0 . 190.3 196.7 203.3 210.1 217.i 224.4 231.8 239.5 247.5 255.6 264.0 272.7 281.7 290.9 300.5 310.3 320.4 330.8 341.5 13.34 13.37 13.40 13.42 13.44 13.47 13.49 13.52 13.54 13.57 13.69 13.62 13.64 13.67 13.69 13.72 13.74 13.77 13.79 13.82 13.84 13.87 13.89 13.92 13.94 13.97 13.09 14.02 14.04 14.07 14.10 14.12 14.15 14.17 14.20 13.68 13.71 13.75 13.79 13.83 13.87 13.01 13.95 13.99 14.03 14.08 14.12 14.16 14.21 14.26 14.30 14.34 14.39 14.44 14.48 14.53 14.58 14.63 14.69 14.73 14.79 14.84 14.90 14.95 15.01 15.07 15.12 15.18 15.25 15.31 Compiled by-W. M. Sawdon, vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air OF Datum Vapor 32 F Datum 16.79 17.03 17.27 17.51 17.75 1090.7 1091.2 1091.6 1092.1 1092.5 17.99 18.23 18.47 18.71 18.95 1093.0 1093.4 1093.9 1094.3 1094.8 19.19 19.43 19.67 19.91 20.15 1095.2 1095.7 1096.1 1096.6 1097.0 20.39 1097.5 20.63 1097.9 20.87 - 1098.4 21.11 1098.8 21.35 1099.3 21.59 1009.7 21.83 1100.2 22.07 . 1100.6 22.32 1101.1 22.5.6 r, .'1101.5 22.80 23.04 23.28 23.52 23.70 . 1102.0 1102.4 1102.9 1103.3 1103.8 24.00 24.24 24.48 24.72 24.96 1104.2 1104.7 1105.1 1106.6 1106.0 Dry Air with Vapor to Saturate it 33.96 34.83 35.70 36.60 37.51 38.46 39.42 40.40 41.42 42.46 43.51 44.61 45.72 46.88 48.05 49.24 50.47 51.74 63.02 54.35 55.70 57.09 58.52 59.99 61.50 63.05 64.62 66.25 67.92 69.63 71.40 73.21 75.06 76.97 78.92 5 C h a p t e r 1. A ir . W a t e r a n d S' Table 6. Properties of Saturated Water Vapor with Air, O F to 200 Fa (Part II, Continued) Temp., F Pressure or saturated , Vapor Id. of Hg Lb per Sq In. ' Weight or Saturated Vapor . ` per Cu Ft per lb of Dry Air Pounds Grains PoundB Grains Volume in Cu Ft Barometer, 29.92 In. Hg of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it 105 106 107 108 .109 110 111 112 113 114 ,115 116 117 118 119 120 121 122 123 124 125 126 .127 128 129 130 131. 132 133 134 135 . 136 137 . 138 139 2.2414 2.3084 2.3770 2.4473 2.5196 2.5939 2.6692 2.7486 . 2.8280 2.9094 2.9929 3.0784 3.1660 3.2676 . 3.3492 3.4449 3.5406 3.6404 3.7422 3.8460 3.9519 4.0618 4.1718 4.2858 4.4039 4.5220 4.6441 4.7703 4.8986 6.0289 6.1633 5.2997 6.4402 . 5.5827 6.7293 . 1.1009 1.1338 1.1675 1.2020 1.2375 1.274 1.311 1.350 1.389 1.429 1.470 1.612 1.555 1.600 1.645 1.692 1.739 1.788 1.838 1.889 - 1.941 1.995 2.049 2.105 2.163 2.221 2.281 2.343 2.406 . . 2.470 2.536 2.603 2.672 2.742 2.814 0.0032786 .0033715 ;.0034650 .0035612 .0036603 0.0037622 .0038669 .0039729 .0040816 .0041911 0.0043047 .0044208 .0045372 .0046620 .0047846 0.0049115 .005040 .005173 .005311 .005450 0.005590 .005734 .005882 .006031 .006188 0.006344 . .008504 .006671 .006839 .007010 0.007185 .007364 .007547 .007732 .007923 22.05 1 23.60 24.26 24.93 25.62 0.05037 .05200 .05368 .05541 .05719 26.34 27.07 27.81 28.57 29.34 0.05904 .06092 .06292 .06493 .06700 30.13 30.95 31.76 32.63 ' 33.49 0.06913 .07134 .07361 .07600 .07840 34.38 35.28 36.21 37.18 38.16 0.08093 .08348 .08616 .08892 .09175 39.13 40.14 41.17 42.22 43.32 '44.41 45.53 46.70 47.87 49.07 0.09466 .09770 .1008 .1040 .1074 0.1107 .1143 .1180 .1218 .1257 50.30 51.55 52.83 54.12 55.46 0.1297 .1339 .1382 .1427 .1473 352.6 364.0 375.8 387.9 400.3 413.3 426.4 440.4 454.5 469.0 483.9 499.4 515.-3 532.0 548.8 566.5 584.4 603.1 622.4 642.3 662.6 683.9 705.6 728.0 751.8 774.9 . 800.1 826.0 852.6 879.9 907.9 037.3 967.4 998.0 1031.1 14.22 14.25 14.27 14.30 ;14.32 14.35 14.37 14.39 14.42 14.45 14.47 14.50 14.52 14.55 14.57 14.60 14.62 14.65 14.67' 14.70 14.72 14.75 14.77 14.80 14.83 14.85 14.88 14.90 14.03 . 14.95 14.98 15.00 16.03 15.05 15.08 15.37 15.44 15.50 15.57 15.64 15.71 15.78 15.85 15.93 16.00 16.08 16.16 . 16.24 16.32 16.41 16.60 16.58 16.68 16.77 16.87 16.96 17.06 17.17 17.27 17.38 17.49 17.61 17.73 17.85 17.97 18.10 18.23 18.36 18.60 18.65 Compiled by W. M. Sawdon, vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air OF Datum 25.20 25.44 25.68 25.92 26.16 26.40 26.64 26.88 27.12 .27,36 27.60 27.84 28.08 28.32 28.56 28.80 29.04 29.28 29.52 , 29.76 30.00 30.24 30.48 30.72 30.96 31.20 31.45 31.69 31.93 32.17 32.41 32.65 32.89 33.13 33.37 Vapor 32 F Datum 1106.5 1106.9 1107.4 1107.8 1108.3 1108.7 1109.2 1109.6 1110.1 1110.5 1111.0 1111.4 1111.9 1112.3 1112.8 1113.2 1113.7 1114.1 1114.6 1115.0 1115.5 ` 1115.9 1116.4 1116.8 1117.3 1117.7 1118.2 1118.6 1119.1 1119.5 1120.0 1120.4 1120.9 1121.3 1121.8 Dry Air with Vapor to Saturate it 80.93 ' 83.00 85.13 87.30 89.54 91.86 94.21 96.70 99.20 101.76 104.40 107.13 109.92 112.85 115.80 li8.89 122.01 125.27 128.63 132.06 135.59 139.26 143.01 146.87 150.96 154.93 . . 159.26 163.68 168.24 172.89 177.67 182.67 187.80 193.14 198.61 H e a t in g V e n t il a t in g A ir C o n d it io n in g G u id e 1938 Table 6; Properties of Saturated Water Vapor with Air, 0 F to 200 Fa (Part 11,'Continued) Temp., f; 140. 141 142 143' 144 145 146 147 148 149 . 150 ' 151 152 153 154 155 150 157 158 159 160 101 102 .. 163 164 165 166 , 107 168 169 170 171 172 173 174 Pbebsurb or saturated - 1 Vapor ` . . la. of Hg Lb per Sq la. 5.8779 6.0306 6.1874 6.3482 . 0.6111 : . 2.887 2.962 3.039 3.118 3.198 6.6781 . . 6.8471 7.0222 7.1993 7.3805 i ' 3.280 3.303 3.449 3.530 3.625 7.5658 7.7551 7.9485 8.1460 8.3470 3.716 3.809 3.904 4.001 4.100 8.5532' 4.201 8.7650' : 4.305 8.9788 4.410 9.1986 ' 4.518 9.4206 4.627 9.6486 9.8807 10.119.. 10.301 10.608 ' ' ' 4.739. 4.853 4.970 5.089 6.210 10.860 11.117 11.379 11.646 11.919 . 5,334. ' . 5.400 . 5.589 5.720 5.854,. 12.190 12.480 12.770 13.065 13.366 5.990 0.130 . 0.272 0.417 6.565 * Weight or Saturated Vapor * Volume in Cu Ft Barometer, 29:92 In. Hq Heat Content per Lb per Cu Ft . Pounds Grains per lb of Dry Air Pounds Grains of 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it Dry Air OF Datum Vapor 32 F . Datum Dry Air with Vapor to Saturate it 0.008116 .008313 .008516 .008724 .008933 0.009148 .009366 .009590 .009817 .010040 ... 0.010284 .010526 .010772 .011022 .011279 0*011539 ` .011807 .012077 .012354 .012634- 0.012919 .013211 .013509 .013812 .014120 0.014434 .014753' .015080 .015410 .015750 0.016092 .016444 .016801 .017164 .017534 56.81 58.19 59.61 61.07 62.53 . 64.04 65.50 67.13 68.72 70.28 71,99 73.68 75.40 '77.15 78.95 80.77 '82.65 84.54 86.48 88.44 90.43 92.48 94.56 96.68 98.84 101.0 103.3 105.0 107.9 110.3 112.6 115.1 117.6 120.1 122.7 0.1521 .1570 .1622 .1675 .1730 0.1787 .1846 .1908 .1971 .2037 0.2105 .2176 .2250 .2327 .2407 0.2490 .2577 .2667 .2761 .2858 0.2961 .3067 .3179 .3295 .3416 0.3544 .3677 .3817 .3964 .4118 0.4280 .4451 .4631 .4821 .5022 1064.7 1099.0 1135.4 1172.5 1211.0 1250.9 , 1292.2 1335.6 1379.7 1425.9 1473.5 : 1523.2 1575.0 . 1628.9 1684.9 1743.0 1803.9 1866.9 1032.7 2000.6 2072.7 2146.9 2225.3 2300.5 2391.2 2480.8 2573.9 2071.9 2774.8 2882.6 2996.0 3115.7 3241.7 3374.7 3515.4 15.10 15.13 15.15 15.18 15.20 18.79 18.94 19.10 19.26 19.43 15.23 15.25 15.28 15.30 15.33 * 19.60 19.78 19.96 20.15 20.35 15.35 15.38 15.40 15.43 15.45 20.55 20.76 20.97 21.20 21.43 . 15.48. 15.50 15.53 15.50 15.68 21.07 21.93 22.19 22.46 22.74 15.01 15.63 15.60 15.08 15.71 23.03 23.33 23.65 23.98 24.33 15.73 24.69 15.70 . 26.07 15.78 25.40 15.81 25.88 15.83 . 26.31 15.86 15.88 15.91 15.93 15.96 26.77 27.24 27.74 28.28 28.84 33.61 33.85 34.09 34.33 34.57 1122.2 1122.7 1123.1 1123.6 1124.0 34.81 35.05 35.29 35.53 35.77 1124.5 1124.9 1125.4 1125.8 1126.3 36.02.' 36.26 30.50 36.74 36.98 1120.7 1127.2 1127.6 1128.1 1128.5 37.22 37.46 37.70 37.94 38.18 . 1129.0 1129.4 1129.9 1130.3 1130.8 38.43 1131.2 38.07 ' 1131.7 1 38.91 . 1132.1 39.15 1132.5 39.39 ,* '.1133.0 39.63 . . 39.87 -- 40.11 40.35 40.59 1133.5 1133.9 1134.4 1134.8 1135.3 40.83 41.07 41.32 41.56 41.80 1135.7 1130.2 1136.6 - 1137.1 1137.5 204.30 210.11 216.26 222.53 229.02 235.76 242.71 250.02 257.43 ; 205.20 273.19 281.54 290.21 299.25 308.61 318.34 328.51 339.04 350.02 361.36 373.38 385.76 398.80 412.34 420.42 441.34 . 456.81 473.11 490.18 508.11 526.91 546.79 567.68 589.76 613.05 Compiled by W. M. Sawdon, vapor pressures converted from International Critical Tables. I C h a p t e r 1. A i r . W a t e r a n d S ' Table 6. Properties of Saturated Water Vapor with Air, 0 F to 200 Fa (Part II, Concluded) Temp F Pressurb oi saturated Vapor In. of Hg Lb per Sq In. Weight op Saturated Vapor per Cu Ft Pounds Grains per lb of Dry Air Pounds Grains Volume in Cu Ft Barometer, 29.92 In. Ho of, 1 lb of Dry Air of 1 lb of Dry Air + Vapor to Saturate it 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 190 197 198' 199 200 13.674 13.985 14.303 14.627 14.054 15.290 15.632 15.981 10.337 16.697 17.066 17.440 17.821 18.210 18.605 19,008 19.419 19.839 20.266 20.702 . 21.144 21.592 22.048 22.612 22.984 23.465 6.716 0.869 7.025 7.184 7.346 7.610 7.678 7.849 8.024 8.201 8.382 8.566 8.753 8.944 9.138- 6.336 9.538 9.744 9.954 10.168 10.385 10.605 10.829 11.057 11.289 11.525 0.017914 .018294 .018684 .019080 .019477 0.019888 .020304 .020729 .021159 .021598 0.022045 .022497 .022956 .023424 .023900 0.024384 .024881 .025380 .025893 .026413 0.026939 .027472 .028019 .028571 .029129 0.029700 125.4 128.1 130.8 133.6 130.3 139.2 142.1 145.1 148.1 151.2 154.3 157.5 160.7 164.0 167.3 170.7 174.2 177.7 181.3 184.9 188.6 192.3 196.1 200.0 203.9 207.9 0.5235 .5459 .6697 .5949 .0215 0.0501 .6805 .7131 .7481 .7854 0.8258 .8693 .9162 .9073 1.0227 1.083 1.150 1.224 1.306 1.397 1.499 1.013 1.742 1.890 2.061 2.261 3664.5 3821.3 3987.9 4164.3 4350.5 4550.7 ` 4703.5 4991.7 6230.7 5497.8 6780.0 6085.1 6413.4 6771.1 7158.9 7581.0 8050.0 8568.0 9142.0 9779.0 10493.0 11291.0 12194.0 13230.0 14427.0 15827.0 /15.98 10.01 10.03 16.06 16.08 16.11 16.13 16.16 16.18 10.21 16.23 16.26 16.28 16.31 16.34 16.30 ` 16.39 16.41 16.44 16.46 16.49 16.51 10.54 16.50 16.59 16.61 29.43 30.05 30.71 31.41 32.15 32.94 33.78 34.68 35.65 30.67 37.78 38.98 40.27 41.67 43.04 44.85 46.68 48.70 50.93 53.42 50.20 59.31 62.85 66.88 71.54 76.99 Compiled by W, M. Sawdon. vapor pressures converted from International Critical Tables. Heat Content per Lb Dry Air OF Datum 42.04 42.28 42.52 42.76 43.00 43.24 43.49 43.73 43.97 44.21 44.45 44.69 44.93 45.18 45.42 45.66 45.90 46.14 46.38 46.62 - 46.86 47.10 47.34 47.59 47.83 48.07 Vapor 32 F Datum 1138.0 1138.4 1138.9 1139.3 1139.8 1140.2 1140.7 1141.1 1141.6 1142.0 1142.5 1142.9 1143.4 1143.8 1144.3 1144.7 1145.2 1145.6 1140.1 1146.5 1147.0 1147.4 1147.9 1148.3 1148.8 1149.2 Dry Air with Vapor to Saturate it 637.78 663.73 691.35 720.63 761.39 784.48 819.74 857.45 898.00 941.14 987.93 1038.21 1092.51 1151.58 1210.04 1285.37 1362.88 1448.36 1543.19 1648.28 1766.21 1897.86 2046.98 2217.88 2415.51 2646.41 . Heating Ventilating Air Conditioning Guide 1938 . A'fg (BY -- m = Cpa (/ -- t<) + C^W (t -. t') (9a) and using = 0.24 and Cpj -- 0.45 . A'fg (BY - W) = (0.24 + 0.45HO (1 - <0 (9b) where . fc'fg = latent heat of vaporization at I', Btu per pound. (BY -- W) = increase in vapor associated with 1 lb of dry air when it is saturated adiabatically from an initial dry-bulb .temperature, 1, and an initial vapor, content, W. pounds. ............... . Knowing any two of the three primary variables, t, '('. or. W, the. third may be found from this equation for any process of adiabatic saturation. TOTAL HEAT AND HEAT CONTENT The total heat of a mixture of dry air and water vapor was originallydefined by W. H. Carrier as S = c^(t - 0) + W [A'fg + cPs (t - /)] (10) where S = total heat of the mixture, Btu per pound of dry air. Cpj, = mean specific heat at constant pressure of dry air. Cp, = mean specific heat at constant pressure of water vapor. t = dry-bulb temperature, degrees Fahrenheit. t' wet-bulb temperature, degrees Fahrenheit. W --- weight of water vapor mixed with each pound of dry air, pounds. ft'fg = latent heat of vaporization at t', Btu per pound. Since this definition holds for any mixture of dry air and water vapor, the total heat of a mixture with a relative humidity of 100 per cent and at a temperature equal to the wet-bulb temperature (/') is . . 2' = Cpa (f - 0) + H^t. A'fg ' (11) By equating Equation 10 to Equation 11, the equation; for the adiabatic saturation process, Equation 9a, follows. This demonstrates that the adiabatic saturation process at constant wet-bulb temperature is also a process of constant total heat. . In short, the total heat of a mixture of dry air and water vapor is the same for any two states of the mixture at the same wet-bulb temperature. This fact Furnishes a convenient means of finding the-total heat of-an-air-vapor mixture in any state. ' i Enthalpy ......................... This total heat of an air:vapor mixture" is not exactly equal to the true heat content-or (enthalpy of the mixture since the heat content of the liquid is not. included in Equation lO, ..With the meaning of heat content in agreement with present practise in other branches of thermodynamics, the true heat content of a mixture of dry air and water vapor (with 0 F as the datum for dry air, and the saturated liquid at 32 F as the datum for the water vapor) is 22 Chapter 1. Air, Water and Steam ' where A = Cpa (t -- 0) + W A, = 0.24 (I -- 0) + W A, . A = the heat content of the mixture, Btu per pound of dry air. t -- the dry-bulb temperature, degrees Fahrenheit. , W = the weight of vapor per pound of dry air, pounds. . hs = the heat content of the vapor in .the mixture, Btu per pound. (12) The heat content of the water vapor in the mixture may be found in steam charts or tables when the dry-bulb temperature and the partial pressure of the vapor are known. Or, since the heat content of steam at low partial pressures, whether super-heated or saturated, depends only upon temperature, the following empirical equation, derived from Proper ties of Saturated Steam by J'. H. Keenan, Table 8, may be used: 3 =. k 1059.2 + 0.45 <' (13) Substituting this value of ha.in Equation 12, the heat content of the mixture is . A = 0.24 (I -- 0) + W (1059.2 + 0.45 1') , (14) Example 5. Find the total heat of an air-vapor mixture having a dry-bulb tem perature of 85 F and a wet-bulb temperature of 70 F. Solution. From Table 6, for saturation at the wet-bulb temperature, BY = 0.01574, and from Equation 14, A = 0.24 (70 -0) + 0.01574 [1059.2 + (0.45 X 70)1 = 33.96 Btu per pound dry air. By considering the temperatures in Table 6 to be wet-bulb readings, the enthalpy of any air-vapor mixture may be obtained from the last column in the table. An energy equation can be written that applies, in general, to various air conditioning processes, and this equation can be used to determine the quantity of heat transferred during such processes. In the most general form, this equation may be explained with the aid of Fig. 1 as follows: The rectangle may represent any. apparatus, t.g., a drier, humidifier, dehumidifier, cooling tower, or the like, by proper choice of the direction of the arrows. In general, a mixture of air and water vapor, such as atmospheric air, enters the apparatus at 1 and leaves at 3. Water is supplied at some temperature, tr- For the flow of 1 lb of dry air (with accompanying vapor) through the apparatus, provided there is no appreciable change in the elevation or velocity of the fluids and no mechanical energy delivered to or by the apparatus, A. + h + OF, - W,) hr = A, + flc Eh -- Rc = A, -- A, -- (IF, - Wt) A, : : (15) where Eh = the quantity of heat supplied per pound of dry air, Btu...................... Rc = the quantity of heat lost externally by heat transfer from the. apparatus. Btu per pound of dry air. . Wi -- the weight of water vapor entering, per pound of. dry air.. IFi = the weight of water vapor leaving, per pound of dry.air. , . Aj = the heat content of the water supplied at It, Btu per pound. ' 23 Heating Ventilating Air Conditioning Guide 1938 ht -- A, = the increase in the heat content of the air-water vapor mixture in passing through the apparatus, Btu per pound of dry air = 0.24 (/, - /,) + W, (1059.2 + 0.451,) - Wt (1059.2 + 0.451,) The net quantity of heat added to or removed from air-water vapor mixtures in air conditioning work is frequently approximated by taking the differences in total heat at exit and entrance. For example, in Fig. 1, an approximate result is where .Eh -- Ec = S, -- Si ' .. . .. '-(10) S, = the total heat of the air-vapor mixture at exit, Btu per pound of dry air. Si = the total heat of the air-vapor mixture at entrance, Btu per pound of dry air. W3 ib. Water Vapor 1 Ib. Dry Air Fig. 1. Diagram Illustrating Energy Equation 15 From the definitions of total heat and heat content, it may be demon strated that Equation 16 is exactly equivalent to Equation 15, when, and only when, f'j = t'i = k; i.e., when the initial and final wet-bulb tempera tures and the temperature of the water supplied are equal. The one pro cess that meets these conditions is adiabatic saturation, .and either equation will give a result of zero; for other conditions, Equation 16 is approximate but satisfactory for many calculations. The following problems illustrate the application of these principles: Example 6. Heating (data from Example 2). Assuming the water to be supplied at 50 F, the net quantity of heat supplied is, from Equation 15, . Eh - Ec = 0.24 (70 - 0) + 0.000548 X 0.45 (70 - 0) + 0.005632 [1059.2 + 0.45 X 70 -- (50 -- 32)] = 22.90 Btu per pound of dry air. , Example 7. Cooling (data from Example 3). If the condensate is removed at 54 F the quantity of heat removed is found from Equation 15, by proper regard to the arrow direction in Fig. 1, ' Eh + Ec = 0.24 (84 - 54) + 0.00887 X 0.45 (84 - 54) + 0.00361 [1059.2 + 0.45 X 84 --,,(54 -- 32)] = 11.24 Btu per pound of dry air. Using Table 6, the initial total heat of the air-vapor mixture, since the wet-bulb temperature is 70 F, is 33.96 Btu per pound of dry-air. ' The final total heat is, from Table 6, since the exit air is saturated, 22.55 Btu per pound. Hence, using Equation 16, the quantity of heat removed is, approximately, (33.96 -- 22.55) or 11.41 Btu per pound of dry air. The degree of approximation to the correct result is evident in this example. ' ' Chapter 1. Air, Water and Steam PSYCHROMETRIC CHART The revised Bulkeley Psychrometric Chart4, will be found attached to the inside back cover. It shows graphically the relationships expressed in Equations 9a and 9b. It also gives the grains of moisture per pound of dry air for saturation, the grains of moisture per cubic foot of saturated air, the total heat in Btu per pound of dry air saturated with moisture, and the weight of the dry air in pounds per cubic foot. Fig. 2 shows the procedure to follow in using the Bulkeley Chart. The directrix curves above the saturation line are as follows: . A is the total heat in Btu contained in the mixture above 0 F, and is to be referred to the column of figures at the left side of the chart. Heat of the liquid is not included. A. B, C, D, E. F=Directrix lines D. B. L*Dry bulb line D. P. L=Dew pant line R. H. L=Relative humidity line W. B. L=Wet bulb line SJ.? Saturation line ' G. P. U>*Gratns moisture sat mixture per ib dry air T. H.=TotaJ heat sat mixture per tb dry air V. P.=Vapor pressure in mm mercury G. P. C. F. S. Grains moisture per cu ft sat air W. 0. A. C. F. S.=Weight dry sir per cu ft in lbs saturated R. D. 0. S-= Relative density dry air per cu ft saturated W. P. C. F. S.=Weight per cu ft in tbs saturated R. D. S.sReiative density per cu ft saturated W. P. C. F. D.aWeight per cu ft in lbs dry R. D. 0.=Relative density per cu ft dry t.P.C.F.1 Ate temp at 0. P. = a p c F ,, partial saturation Ads temp at u. o. W- P-C-F-x W- r. c.temp" nil = F. at partial saturation Abs temp at 0. P. j R. D. at partial saturation Abs temp at D..B. Fig. 2 Diagrams Showing Procedure to Follow in Using Bulkeley Chart B is the grains of moisture of water vapor contained in each pound of the saturated mixture and is to be referred to the figures at the left side of the chart. . C is the grains of moisture of water vapor per cubic foot of saturated mixture, and is to be referred to the figures at the left side of the chart which are to be divided by 10. D is the weight in decimal fractions of a pound of dry air in one cubic foot of the saturated mixture, and is referred to the first column of figures to the right of the satura tion line between the vertical dry-bulb temperature lines 170 and 180 F. The relative density of the mixture is read in a similar manner from the same curve by the column of figures between the vertical dry-bulb temperature lines 180 and 190 F. E is similar to D but is for.one cubic foot of the saturated mixture. The Bulkeley Psychrometric Chart was presented to the Society In 1926. (See A.S.H.V.E. Trans actions. Vol. 32, 1926. p. 163.) Single copy of the chart can be furnished at a cost of $ .25. 25 . Heating Ventilating Air Conditioning Guide 1938 F is similar to D but is for dry air, devoid of all moisture or water vapor. For con venience, the approximate absolute temperature of 500 F is given at 40 F on the satura tion line for the purpose of calculating volume, weight per cubic foot, and relative density at partial saturation. METHOD OF USING THE CHART Example 8. Relative Humidity: At the intersection of the 78 F wet-bulb line and the 95 F dry-bulb line, the relative humidity is read directly on the straight diagonal lines as 46 per cent. . Example 9. Dew Point: At the intersection of the 78 F wet-bulb line, the dew-point temperature is read directly on the horizontal temperature lines as 70.9 F. Example 10. Vapor Pressure: At the intersection of the 78 F .'wet-bulb line and the 95 F dry-bulb line, pass in a horizontal direction to the left of the chart and on the logarithmic scale read the vapor pressure as 19.4 millimeters of mercury. (Divide by 25.4 for inches.) Example 11. Total Heal Above 0 F in Mixture per Pound of Dry Air Saturated with Moisture: From where the wet-bulb line joins the saturation line, pass in a vertical direction on the 78 F dry-bulb line to its intersection with curve A and on the logarithmic scale at the left of the chart read 40.6 Btu per pound of mixture. The use of this curve to obtain the total heat in the mixture at any wet-bulb temperature is a great con venience, as the number of Btu required to heat the mixture and humidify it, as well as the refrigeration required to cool and dehumidify the mixture, can be obtained by taldng the difference in total heat before and after treatment of the mixture. Example IS. Grains of Moisture per. Pound of Dry Air Saturated with Moisture: From 70.9 F dew-point temperature on the saturation line, pass vertically to the inter section with curve B and on the logarithmic scale at the left read 114 grains of moisture per pound. Example 13. Grains of Moisture per Cubic Fool of Mixture, Partially Saturated: From 70.9 F dew-point temperature on. the saturation line proceed in a vertical direction to curve C, and on the logarithmic scale to the left read 83.3 which, divided by 10, gives 8.33 grains. A temperature of 70.9 F is equal to an absolute temperature of 530.9, and 95 F equals 555, absolute temperature. Therefore, X 8.33 = 7.97 grains per . cubic foot of partially saturated mixture. - Example H. Grains of Moisture per Cubic Foot of Saturated Air: Starting at the saturation line at the desired temperature, pass in a vertical direction to curve C and on the logarithmic scale at the left, read a number which, divided by 10, will give the answer. Example 15. Weight per Cubic Foot of Dry Air and Relative Density: From the point where, for example, the 70 F vertical dry-bulb line intersects curve E, pass to right side and read 0.075 lb; if cubic feet per pound are desired, divide 1 by this amount. The relative density is read immediately to the right is 1.00. Example 16. Weight of Dry Air per Cubic Foot, of Saturated Mixture and Relative Density: From the point where, for example, the 70 F vertical line intersects the curve D, pass to the right and read weight per cubic foot as 0.07316 with a relative density of' 0.9755 for saturated air at 70 F. . Example 17. Weight of Dry Air per Cubic Foot and Relative Density of Partially. Saturated Air: Air at 50 F and a wet-bulb temperature of 46 F is to be heated to 130 F. ' The wet- and dry-bulb lines intersect at a dew-point temperature of 42 F. Pass to the left where this dew-point line intersects the saturation line and then pass in a vertical direction to where the 42 F dry-bulb line intersects with curve D. Then pass directly to the right and read the weight per cubic foot of saturated air at 42 F as 0.07844 and the relative density as 1.046. The absolute temperature at 42 F is 502, and at 130 F is 590. 502 Therefore, 77^ = 0.851. The weight of 1 cu ft of air at 50 F dry-bulb and 46 F wet-bulb when heated to 130 F is 0.07844 X 0.851 = 0.06675. and the relative density is 1.046 ' , X 0.851 = 0.89. ., . 26 . Chapter 1. Air, Water and Steam PROPERTIES OF WATER Composition of Water. Water is a chemical compound (HjO) formed by the union of two volumes of hydrogen and one volume of oxygen, or two parts by weight of hydrogen and 16 parts by weight of oxygen. Density of Water. Water has its greatest density at 39.2 F, and it expands when heated or cooled from this temperature. At 62 F a U. S. gallon of 231 cu in. of water weighs approximately 8H lb, and a cubic foot of water is equal to 7.48 gal. The specific volume of water depends on the temperature and it is always the reciprocal of its density. (See Table 7.) Table 7. Thermal Properties of Water Temperature Deg F Sat. Press. Lb per Sq In. 32 0.0887 40 0.1217 50 0.1780 60 0.2561 70 0.3628 80 0.5067 90 0.6980 100 0.9487 110 1.274 120 1.692 130 2.221 140 2.887 150 3.716 160 4.739 170 5.990 180 7.510 190 9.336 200 11.525 210 14.123 212 14.696 220 17.188 240 24.97 260 - 35.43 280 49.20 300 67.01 350 134.62 400 247.25 450 422.61 500 681.09 550 1045.4 600 1544.6 700 3096.4 ' Volume Cu Ft per Lb 0.01602 0.01602 0.01602 0.01603 0.01605 0.01607 0.01610 0.01613 0.01616 0.01620 0.01625 0.01629 0.01634 0.01639 0.01645 0.01650 0.01656 0.01663 0.01669 0.01670 0.01676 0.01690 0.01706 0.01723 0.01742 0.01797 0.01865 . 0.01950 0.02050 . 0.02190 0.02410 0.03940 Weight-Lb peb Cu Ft 62.42 62.42 . . 62.42 ' 62.38 62.31 62.23 62.11 62.00 61.88 . 61.73 61.54 61.39 61.20 61.01 60.79 60.61 60.39 60.13 59.92 . 59.88 59.66 59:17 58.62 58.04 57.41 55.65 . 53.62 51.30 48.80 45.70 41.50 25.40 Specific Heat . 1.0093 1.0048 1.0015 0.9995 0.99820.9975 0.9971 0.9970 0.9971 0.9974 0.9978 0.9984 0.9990 0.9998 1.0007 1.0017 1.0028 1.0039 1.0052 1.0055 1.0068 1.0104 1.0148 1.0200 1.0260 1.0440 1.0670 1.0950 1.1300 1.2000 1.3620 -----:---- Water Pressures. Pressures are often stated in feet or inches of water column. At 62 F, with ft equal to the head in feet, the pressure of a column of water is 62.383ft lb per square foot, or 0.433ft lb per square inch. A column of water 2.309 ft (27.71 in.) high exerts a pressure of one pound per square inch at 62 F. Boiling Point of Water. The boiling point of water varies with the pressure; it is lower at. higher altitudes. A. change in pressure wi,ll .alwa,ys be accompanied by a change in the boiling-point; and there will be a cor- 27 Heating Ventilating Air Conditioning Guide 1938 Table 8. Properties op Saturated Steam: Pressure Table* Specific Volume Aba. Prui, Temp. Lb./Sq. In. Otf> F. LSiqeut.id Evtp. Sat. Vapor P t V| Vf v VV'He 5833 0.01603 1256.9 1256.9 */4"Hg 70.44 0.01605 856.5 856.S l"Hg 79.06 0.01607 652.7 652.7 W'Hg 91.75 2"Hg 101.17 0.01610 4453 44S3 0.01613 339.5 339.5 2Vi"Hg 108.73 0.01616 2753 2753 3"Hg 115.08 0.01618 2313 2313 1.0 , 2.0 3.0 4.0 101.76 126.10 141.49 152.99 . 0.01614 333.8 333.9 0.01623 173.94 173.96 0.01630 118.84 11836 0.01636 90.72 90.74 6.0 162.25 6.0 170.07 7.0 1763S 8.0 182.87 9.0 188.28 0.01641 0.01645 0.01649 0.01652 0.01*656 73.59 62.03 53.68 4738 42.42 73.61 62.05 53.70 4739 42.44 10.0 11.0 12.0 13.0 14.0 14.696 193.21 197.75 201.96 205.88 209.56 212.00 0.01658 38.44 0.01661 35.15 0.01664 32.40 0.01666 . 30.06 0.01669 28.05 0.01670 2630 38.45 3S.17 33.42 30.08 28.06 26.82 16.0 18.0 20.0 22.0 24.0 26.0 28.0 21632 222.40 227.96 233.07 237.82 242.25 246.41 0.01673 0.01678 0.01682 0.01685 0.01689 0.01692 0.01695 24.75 22.16 20.078 18363 16.924 15.701 14.647 24.76 22.18 20.095 18380 16.941 15.718 14.664 30.0 82.0 34.0 36.0 38.0 25034 254.05 257.58 260.94 264.16 0.01698 0.01701 0.01704 0.01707 0.01710 13.728 12.923 12309 11.570 10.998 13.74S 12.940 12326 11.587 11.015 40.0 42.0 44.0 46.0 48.0 267.24 270.21 273.06 275.81 278.45 0.01712 0.0171S 0.01717 0.01719 0.01722 10.480 10.010 9.582 9.189 8.829 10.497 10.027 9.599 9307 8346 60.0 281.01 62.0 283.49 64.0 - 285.90 66.0 . 28833 68.0 . 290.50 0.01724 0.01726 0.01728 0.01730 0.01732 8.496 8.189 7.902 7.636 7388 8.514 8306 7.919 7.653 7.405 60.0 62.0" 64.0 66.0 . 68.0 292.71 294.85 296.94 298.98 300.98 0.01735 0.01737 0.01739 0.01741 0.01743 7.155 6.937 6.732 6.539 6357 7.172 6.95S 6.749 6.S56 6375 70.0 72.0 74.0 76.0 78.0 302.92 304.82 306.68 308.50 310.28 0.01744 0.01746 0.01748 0.01750 0.01752 6.186 6.024 5370 5.723 . 5.584 6303 6.041 5.887 5.741 5.602 80.0 82.0 , 84.0 86.0 88.0 312.03 313.74 315.42 317.06. 318.68 0.01754 0.01756 0.01757 0.01759 0.01761 5.452 5.470 5325 . 5343 5304 5.222 5.089 5.107 4.979 4.997 90.0 92.0 94.0 96.0 98.0 320.27 321.83 32337 324.88 32637 0.01763 0.01764 0.01766 0.01768 0.01769 4.874 4.773 4.676 4.584 4.494 4.892 4.791 4.694 4.602 4.512 Total Heat Sat. Sat. Crap. Vapor hi bfg 263838.47 47.06 59.72 69.10 76.63 82.96 1058.8 1052.5 10473 10403 1035.7 1031.5 1027.9 1085.7 1091.0 1094.9 1100.6 11043 1108.1 11103 69.69 93.97 10933 12033 10353 1021.6 1012.7 1005.9 11053 1115.6 1122.0 11263 130.10 -1000.4 137.92 995.8 144.71 991.7 150.75 988.1 156.19 9843 11303 1133.7 1136.4 1138.9 1141.0 161.13 165.68 169.91 17335 177.55 180.00 9813 11433 979.1 11443 976.5 1 1146.4 974.1 1147.9 971.8 11493 9703 11503 18435 190.48 196.09 20135 206.05 210.54 214.75 967.4 963.5 959.9 956.6 953.4 950.4 947.7 11513 11543 1156.0 11573 1159.5 1161.0 1162.4 218.73 222.50 226.09 229.51 232.79 945.0 942.5 940.0 937.7 935.5 1163.7 11653 1166.1 11673 11683 235.93 238.95 241.86 244.67 24737 9333 9313 9293 9273 925.4 11693 11703 1171.1 1171.9 1172.7 249.98 252.52 254.99 25738 259.71 923.S 921.7 920.0 9183 916.6 1173.5 11743 1175.0 1175.7 1176.4 261.98 264.18 26633 268.43 270.49 915.0 913.4 911.9 910.4 908.9 1177.0 1177.6 11783 1178.8 1179.4 272.49 274.45 27637 27835 280.09 907.4 906.0 904.6 903.2 901.9 1179.9 1180.5 1181.0 1181.5 1182.0 281.90 283.67 285.42 287.13 288.80 900.5 8993 897.9 896.7 895.4 1182.4 1182.9 1183.4 1183.8 11843 290.45 292.07 293.67 -29535 396.80 894.2 893.0 8913 890.6 889.4 1184.6 11853 1185.4 11853 1186.2 Entropy Sat. Aba. Pram. Eaap. Vapor Lb./Sq. In. 81 03533 0.0754 0.0914 0.1147 0.1316 0.1450 0.1561 8lg 2.0422 1.9856 1.9451 13877 1.8468 1.8148 1.7885 8 2.0955 2.0609 2.0365 2.0024 1.9784 1.9598 1.9446 P %"Hg %"Hg l"Hg HV'Hg 2"Hg 2W Hg 3"Hg 0.1326, 1.8442 0.1750 1.7442 03009 1.6847 0.2198 1.6420 1.9769 1.9192 13856 1.8618 1.0 2.0 3.0 4.0 0.2348. 1.6088 03473 1.S814 0.2580 1.5582 0.2674 1.5379 03758 13200 1.8435 1.8287 13162 13053 1.7958 6.0 6.0 7.0 8.0 9.0 03834 03903 0.2968 03027 03082 03119 1.5040 1.4894 1.4760 1.4636 1.4521 1.4446 1.7874 1.7797 1.7727 1.7663 1.7604 1.7S64 10.0 11.0 12.0 13.0 14.0 14.696 03184 03274 03356 0.3431 0.3500 03S64 03624 1.4312 1.4127 13960 13809 13670 13542 13422 1.7496 1.7402 1.7317 1.7240 1.7170 1.7106 1.7046 16.0 18.0 20.0 22.0 24.0 26.0 28.0 03680 03732 03783 0.3830 03876 13310 13206 13107 13014 13925 1.6990 1.6938 1.6890 1.6844 1.6800 30.0 32.0 34.0 S6.0 38.0 0.3919 03961 0.4000 0.4039 0.4076 1.2840 1.2759 1.2682 1.2608 1.2537 1.6759 1.6720 1.6683 1.6647 1.6613 40.0 42.0 44.0 46.0 48.0 0.4111 0.4145 0.4178 0.4210 0.4241 1.2469 1.2404 13340 13279 13220 1.6580 1.6549 1.6518 1.6489 1.6461 60.0 62.0 64.0 66.0 68.0 0.4271 0.4300 0.4329 0.4356 0.4384 13162 13107 13053 13001 1.1950 1.6434 1.6407 1.6382 1.6357 1.6333 60.0 62.0 64.0 66.0 68.0 0.4410 0.4435 0.4460 0.4485 0.4509 1.1900 1.1852 1.1805 1.1759 1.1714 1.6310 1.6287 1.6265 1.6244 1.6223 70.0 72.0 74.0 76.0 78.0 0.4532 0.4555 0.4578 0.4599 0.4621 1.1670 1.1627 1.1586 1.1545 1.1S0S 1.6202 1.6182 1.6163 1.6144 1.6126 80.0 82.0 84.0 86.0 88.0 ~ 0.4642 0.4663 -0.4683 0.4703 0.4723 1.1465 1.1427 1.1389 1.1352 1.1316 1.6107 1.6090 1.6072 1.6055 1.6038 90.0 92.0 94.0 96.0 98.0 Abstracted from Steam Tables and Mollier Diagram, by Prof. J. H. Keenan, 1930 edition, by permission the publisher. The American Society of Mechanical Engineers. . 28l i i \ Chapter 1. Air, Water and Steam Table 8. Properties of Saturated Steam: Pressure Table--(Continued) Aba. Free*. Lb./Sq. In. p 100.0 102.0 104.0 106.0 108.0 110.0 112.0 114.0 116.0 118.0 120.0 122.0 124.0 126.0 128.0 130.0 132.0 134.0 136.0 138.0 140.0 142.0 144.0 146.0 148.0 160.0 162.0 164.0 166.0 168.0 160.0 162.0 164.0 166.0 168.0 170.0 172.0 174.0 176.0 178.0 180.0 182.0 184.0 186.0 1S8.0 190.0 192.0 194.0 196.0 198.0 200.0 206.0 210.0 216.0 220.0 226.0 230.0 236.0 240.0 246.0 Tamp. Das. F. t 327.83 329.27 330.68 332.08 333.44 Specific Volume Sat. Sat. Liquid Erap. 1Vapor Vf Vfg v* 0.01771 4.408 4.426 0.01773 4326 4344 0.01774 4347 4365 0.01776 4.171 4.189 0.01777 4.097 4.115 334.79 336.12 337.43 338.72 340.01 0.01779 4.026 0.01780 3.958 0.01782 3.892 0.01783 3.828 0.0178S 3.766 4.044 3.976 3.910 3.846 3.784 341.26 342.50 343.73 344.94 346.14 0.01786 3.707 0.01788 3.652 0.01789 3.597 0.01791 3.542 0.01792 3.487 3.725 3.670 3.615 3.560 3.505 347.31 348.48 349.64 350.78 351.91 0.01794 3.433 0.01795 3383 0.01796 3335 0.01798 3388 0.01799 3342 3.451 3.401 33S3 3306 3360 353.03 354.14 355.22 35631 35737 - 0.01801 3.198 0.01802 3.155 0.01804 3.112 0.01805 3.071 0.01806 3.031 3316 3.173 3.130 3.089 3.049 358.43 359.47 360.51 361.53 362.54 0.01808 2.992 0.01809 2.954 0.01810 2.917 0.01812 2382 0.01813 2346 3.010 2.972 2.935 2.900 2364 363.55 364.54 365.52 366.50 367.46 0.01814 2.812 0.01816 2.779 0.01817 2.746 0.01818 2.715 0.01819 2.683 2.830 2.797 2.764 2.733 2.701 368.42 36937 37031 371.24 372.16 0.01821 2.653 0.01822 2.623 0.01823 2.594 0.01825 2.566 0.01826 2.538 2.671 2.641 2.612 2.584 2.S56 373.08 374.00 374.90 375.78 376.67 0.01827 2.511 0.01828 2.484 0.01829 2.458 0.01831 2.433 0.01832 2.407 2.529 2.502 2.476 2.451 2.425 377.55 378.42 37937 380.13 380.97 0.01833 2383 0.01834 2359 0.01835 2.335 0.01837 2312 0.01838 2389 2.401 2377 2353 2330 2307 38132 383.89 385.93 387.93 389.89 0.01839 2367 0.01842 2313 0.01844 2.162 0.01847 2.113 0.01850 2.066 2385 2331 2.180 2.131 2.084 391.81 393.70 39S.56 397.40 39930 0.01853 2.0208 2.0393 0.01856 1.9778 1.9964 0.01859 1.9367 1.9553 0.01861 1.8970 1.9156 0.01864 13589 13775 Total Heat Sat. Sat. Liquid Evap. Vapor hi hf* 29833 8883 1186.6 299.83 887.1 1186.9 30130 886.0 11873 302.76 884.9 1187.6 304.19 8833 1188.0 - Entropy Sat. Sat. Liquid Evap. Vapor Sf 8fg 0.4742 1.1280 0.4761 1.124S 0.4779 ` 1.1211 0.4798 1.1177 0.4816 1.1144 8e 1.6022 1.6006 13990 13974 13959 Aba. Free*. Lb./Sq. In. P 100.0 103.0 104.0 106.0 108.0 305.61 882.7 11883 307.00 881.6 1188.6 30836 880.6 1188.9 309.71 879.5 11893 311.05 878.5 1189.5 0.4834 0.4851 0.4868 0.4885 . 0.4901 1.1111 1.1079 1.1048 1.1017 13986 13944 13930 1.5915 13901 13887 110.0 112.0 114.0 116.0 118.0 31237 877.4 11893 313.67 876.4 1190.1 314.96 875.4 1190.4 316.23 874.4 1190.6 317.49 873.4 1190.9 0.4918 0.4934 0.4950 0.4965 0.4981 1.0956 1.0926 1.0897 1.0868 1.0840 13874 13860 13847 1.5834 13821 120.0 122.0 124.0 126.0 128.0 318.73 872.4 11913 319.95 871.5 1191.4 321.17 8703 1191.7 32237 869.6 1191.9 32336 868.6 11923 0.4996 0.5011 0.5026 0.5041 0.5056 1.0812 1.0784 1.0757 1.0730 1.0703 13808' 13796 13783 13771 1.5759 130.0 132.0 134.0 136.0 138.0 324.74 867.7 1192.4 325.91 366.7 1192.6 327.06 865.8 1192.9 32830 864.9 1193.1 32932 864.0 11933 0.5070 0.5084 0.S098 0.5112 0.5126 1.0677 1.0651 1.0625 1.0600 1.0575 1.5747 1.5735 13724 13712 13701 140.0 142.0 144.0 146.0 148.0 330.44 863.1 1193.5 331.54 8623 1193.7 332.64 8613 1193.9 333.72 860.4 1194.1 334.80 859.5 11943 0.5140 0.5153 0.5166 0.5180 0.5193 1.0550 1.0526 1.0S02 1.0478 1.0454 13690 13679 13668 13658 13647 160.0 162.0 164.0 166.0 168.0 335.86 858.7 1194.5 336.91 857.8 1194.7 337.95 857.0 1194.9 338.99 856.1 1195.1 340.01 8553 11953 0.5205 0.5218 0.5230 0.5243 0.5255 1.0431 1.0408 1.0385 1.0363 1.0340 13636 1.5626 13616 13606 13596 160.0 162.0 164.0 166.0 168.0 341.03 854.4 1195.4 342.04 853.6 1195.6 343.04 852.7 1195.8 344.03 851.9 1196.0 345.01 851.1 1196.1 0.5268 03280 0.5292 0.5304 0.5315 1.0318 13586 1.0296 1.5576 1.0275 13566 1.0253 1.55S7 1.0232 1.5548 170.0 172.0 174.0 176.0 178.0 345.99 8S03 11963 346.97 849.5 1196.4 347.94 848.6 1196.6 348.89 847.9 1196.8 349.83 847.1 1196.9 0.5327 0.5339 0.5350 0.5362 0.5373 1.0211 1.0190 1.0169 1.0149 1.0129 1.5538 1.5529 13520 1.5511 1.5502 180.0 182.0184.0 186.0 188.0 350.77 8463 1197.0 351.70 845.5 11973 3S2.61 844.7 11973 353.53 844.0 1197.5 354.43 8433 1197.6 0.5384 0.5395 0.5406 0.5417 03427 1.0109 1.0089 1.0070 1.0050 1.0031 1.5493 13484 1.5475 1.5467 1.5458 190.0 192.0 194.0 196.0 198.0 35533 842.4 11973 357.56 840.5 1198.1 359.76 838.6 1198.4 361.91 8363 1198.7 364.02 835.0 1199.0 0.5438 03465 0.5491 0.5516 0.5540 1.0012 0.9964 0.9918 0.9873 0.9829 1.5450 1.5429 1.5409 1.5389 13369 200.0 206.0 210.0 216.0 220.0 366.10 8333 11993 368.14 831.4 1199.6 370.15 829.7 11993 372.13 827.9 1200.1 374*09 8263 12003 0.5S6S 0.5S88 03612 03635 . 0.5658 0.9786 0.9743 0.9702 0,9661 0.9620 1.5350 13332 13313 13295 13273 226.0 230.0 236.0 240.0 246.0 29 Heating Ventilating , Air Conditioning Guide 1938 Table 8. Properties of Saturated Steam : Pressure Table--(Concluded) Lb./Sq. In. P 250.0 260.0 270.0 260.0 290.0 TOemg.PF-. t 400.97 404.43 407.79 411.06 414.24 Specific Volume Sat. liquid Ep. Sat. Vapor I Vfg Vg 0.01867 1.8223 1.8410 0.01872 1.7536 1.7723 0.01877 1.6895 1.7083 0.01882 1.6302 1.6490 0.01887 1.5745 1.5934 Total Heat Set. Sat. Liquid Eup. Vapor hr ' - hfg bg 376.02 824.5 1200.5 379.78 821.2 120LO 383.44 8ll0 1201.4 387.02 814.7 1201.8 390.50 811.6 1202.1 300.0 320.0 340.0 360.0 417.33 423.29 423.96 43439 439.59 0.01892 1.5225 14414 0.01901 1.4279 1.4469 0.01910 1.3439 13630 0.01918 1.2689 1.2881 0.01927 1.2015 1.2208 393.90 808.5 1202.4 400.47 802.5 1203.0 406.75 796.6 1203.4 412.80 790.9 1203.7 418.61 785-3 1203.9 400.0 420.0 440.0 460.0 480.0 444.58 44938 454.01 458.48 462.80 0.0194 0.0194 0.0195 0.0196 0.0297 1.1407 1.1601 1.0853 1.1047 10345 14540 0.9881 14077 0.9456 0.9633 4243 429.6 4344 439.9 444.9 779.8 1204.1 774.5 1204.1 7693 1204.1 764.1 1204.0 759.0 1203.9 600.0 620.0 640.0 660.0 680.0 466.99 471.05 474.99 47832 48245 0.0198 0.0198 0.0199 0.0200 0.0201 0.9063 0.9261 04701 0.8899 0.8363 04562 04047 0.8247 0.7751 0.7952 449.7 454.4 4594 463.6 468.0 754.0 1203.7 749.0 1203.5 744.1 12033 7393 1202.9 734.5 1202.5 640.0 660.0 680.0 486.17 489.71 493.16 496.53 499.82 0.0202 0.0202 0.0203 0.0204 0.0205 0.7475 0.7677 0.7217 0.7419 . 0.6972 0.7175 0.6744 0.6948 0.6527 0.6732 4723 476.6 480.8 484.9 488.9 7293 1202.1 725.1 1201.7 7203 12013 715.9 12003 7113 12003 700.0 720.0 740.0 760.0 780.0 503.04 506.19 50938 51230 51537 0.0206 0.0206 0.0207 0.0208 0.0209 0.6321 0.6527 0.6128 0.6334 0.5944 0.6151 0.5769 04977 0.5602 0.5811 492.9 496.8 500.6 504.4 5083 7063 1199.7 702.4 11993 697.9 1198.6 6933 11983 6893 1197.4 800.0 820.0 840.0 860.0 680.0 518.18 521.03 52343 526.58 52939 0.0209 0.0210 0.0211 00212 0.0213 04444 04653 0.5293 04503 0.5149 04360 0.5013 0.5225 0.4881 0.5094 5114 5153 5194 522.6 5264 684.9 1196.7 680.6 1196.0 676.4 1195.4 6723 1194.7 667.9 1194.0 900.0 920.0 940.0 960.0. 980.0 531.95 S34.56 S37.13 539.66 542.14 0.0213 0.0214 0.0215 0.0216 0.0217 0.47S6 0.4969 0.4635 0.4849 0.4520 0.473S 0.4409 0.4625 0.4303 0.4520 5293 532.9 536.2 539.6 5424 6633 11933 659.7 1192.6 655.6 1191.8 652.5 1291.1 6473 11903 1000.0 1060.0 1100.0 1160.0 1200.0 544.58 55043 55638 56141 567.14 . 0.0217 - 0.4202 0.4419 0.0219 03960 0.4179 0.0222 03738 03960 0.0224 03540 03764 0.0226 03356 03582 5464 5544 561.7 5693 5763 6433 1189.6 633.6 11873 623.9 1185.6 6143 1183.5 604.9 1281.4 1260.0 1300.0 1360.0 1400.0 1460.0 57230 57732 58232 586.96 59138 0.0228 0.0230 0.0232 0423S 0.0237 03187 0341S 03029 03259 0.2684 03216 03748 03983 03621 03858 583.6 590.6 5973 6043 611.0 595.6^11793 5863 1177JO S773 1174.7 568.1 1172.4 559.1 1170.0 1600.0 1600.0 1700.0 1800.0 1900.0 596.08 604.74 612.98 62036 62839 0.0239 0.0244 0.0249 0.0254 0.0260 03502 03741 03284 03528 03089 03338 0.1913 03167 0.1754 03014 6173 5503 1167.6 6303 532.6 1162.7 6423 515-0 11573 654.7 4973 11513 666.8 478.9 1145.7 2000.0 2200.0 2400.0 2600.0 2800.0 635.6 6493 661.9 673.8 684.9 0.0265 0.1610 0.1875 0.0277 0.1346 0.1623 0.0292 0.1112 0.1404 0.0310 0.0895 0.1205 0.0333 . 0.0688 0.1021 679.0 703.7 729.4 . 756.7 786.7 4603 1139.0 420.0 1123.8 376.4 11053 3273 10843 2723 1058.9 3226.0 6953 704.9 706.1 0.0367 , 0.0477 -0.0844 ; 823.1 2023 1025.6 0.C459 0.0142 0.0601 887.0 75.9 962.9 0.0522 0 0.0522 925.0 0 925.0 Entropy Sat. Sat. Liquid Evap. Vapor SI Sfg Sg 0.5680 0.9581 1.5261 0.5723 0.9504 13227 03765 0.9430 13194 03805 0.9357 13163 03845 0.928? 13132 Aba. Prwac. Lb./Sq. In. P 260.0 260.0 270.0 280.0 290.0 0.5883 0.9220 13102 0.5957 0.9089 1.5046 0.6027 0.8965 1.4992 0.6094 0.8846- 1.4940 0.6157 0.8733 1.4.891 300.0 320.0 340.0 360.0 380.0 0.6218 0.8625 1.4843 0.6277 0.8520 1.4798 0.6334 0.8420 1.4753 0.6388 0.8322 1.4711 0.6441 0.8228 1.4670 400.0 420.0 440.0 4603 480.0 0.6493 0.8137 1.4630 0.6543 0.8048 1.4591 0.6592 0.7962 1.4SS4 0.6639 0.7878 1.4517 0.6686 0.7796 1.4482 600.0 620.0 640.0 660.0 680.0 0.6731 0.7716 1.4447 . 0.677S 0.7638 1.4413 0.6818 0.7562 1.4380 0.6861 0.7487 1.4348 0.6902 0.7414 1.4316 600.0 620.0 640.0 660.0 680.0 0.6943 0.7342 1.4285 0.6983 0.7272 1.4255 0.7022 0.7205 1.4225 0.7060 0.7136 1.4196 0.7098 0.7069 1.4167 700.0 720.0 740.0 760.0 780.0 0.713S 0.7004 1.4139 0.7171 0.6940 1.4221 0.7207 0.6877 1.4084 0.7242 0.6815 1.4057 0.7277 0.6754 1.4031 800.0 820.0 840.0 860.0 680.0 0.7311 0.6694 1.4005 0.7344 0.6635 1.3980 0.7377 0.6S77 13954 0.7410 0.6520 13930 0.7442 0.6464 13905 920.0 940.0 960.0 980.0 0.7473 0.6408 13881 0.7550 0.6273 13822 0.7624 0.6141 13765 0.769S 0.6014 13709 0.7764 0.5891 13656 1000.0 1050.0 1100.0 1160.0 1200.0 0.7831 0.5772 13603 0.7897 0.S6S4 13552 0.7962 0.S540 13501 03024 0.5428 134S2 03086 0.5318 13404 1250.0 1300.0 1350.0 1400.0 1460.0 0,8146 O.S212 13357 03262 0.5003 1326S 0.8373 0.4801 13174 0.8482 0.4601 13083 0.8589 0.4402 13990 1600.0 1600.0 1700.0 1800.0 1900.0 0.8696 0.4200 13896 03912 03788 13700 0.9133 03356 13488 0.9364 03892 13257 0.9618 03379 1.1996 2000.0 2200.0 2400.0 2600.0 2800.0 0.9922 0.1754 1.1676 3000.6 1.0461 0.0651 1.1112 3200.0 1.0785 0 13785 3226.0 Chapter 1. Air. Water and Steam responding change in the; latent heat of evaporation. These values are given in Table 8. Specific Heat. The specific heat of water, or the amount of heat (Btu) required to raise the temperature of one pound of water, one degree Fahren heit,. varies with the temperature, but it is commonly assumed to be unity at all temperatures. Steam tables are based on exact values, however. The specific heat of ice at 32 F.is 0.492 Btu per pound. The amount of heat required to raise one pound of water at 32 F through a known temperature interval depends on the average specific heat for the temperature range. ' Sensible and Latent Heat. The heat necessary to raise the temperature of one pound of water from 32 F to the boiling point is known as the heat i 4 of the liquid or sensible heat. When more heat is added, the water begins to evaporate and expand at constant temperature until the water is * I entirely changed into steam. The heat thus added is known as the latent heat of evaporation. PROPERTIES OF STEAM Steam is water vapor which exists in the vaporous condition because sufficient heat has been added to the water to supply the latent heat of evaporation and change the liquid into vapor. This change in state takes place at a definite and constant temperature which is determined solely/ by the pressure of the steam. The volume of a pound of steam is the/ specific volume which decreases as the pressure increases. The reciprocal of this, or the weight of steam per cubic foot, is the density. . (See Table 8:) Steam which is in contact with the water from which it was generated is r known as saturated steam. If it contains no actual water in the form of mist or priming, it is called dry saturated steam. If this be heated and the pressure maintained the same as when it was vaporized, its temperature will increase and it will become super-heated, that is, its temperature will be higher than that of saturated steam at the same pressure. REFERENCES Temperature of Evaporation, by W. H. Carrier (A.S.H.V.E. Transactions, Vol. 24, 1918, p. 25). The Evaporation of a Liquid into a Gas, by W. K. Lewis (A.S.M.E. Transactions, Vol. 44, 1922). The Evaporation of a Liquid into a Gas--a Correction, by W. K. Lewis (Mechanical Engineering, September, 1933). ... Temperature of Evaporation of Water into Air, by W. H. Carrier and D. C. Lindsay [A.S.M.E. Transactions, Vol. 46, 1924). '. A New Psychrometric or Humidity Chart, by C. A. Bulkeley (^.S.H.V.E. Trans actions, Vol. 32, 1926, p. 163). A Review of Psychrometric Charts, by C. O. Mackey (Heating and Ventilating, June, July, 1931). . . ; Air, Conditioning Applied to Cold Storage and.a New Psychrometric Chart, by C. A. Bulkeley (Refrigerating Engineering, February, 1932). The Psychrometric Chart, by E. V. Hill [Aerologist, April, May, June, 1932). Air Conditioning Theory, by John A. Goff (Refrigerating Engineering, January, 1933). Mixtures of Air and Water Vapor, by' C. A. Bulkeley (Refrigerating Engineering, January, 1933). - X31 . Heating Ventilating Air Conditioning Guide 1938 Basic Theory of Air Conditioning, by Lawrence Washington (Western Conference on Air Conditioning, San Francisco, Calif., February 9-10, 1933). The Theory of the Psychrometer, by J. H. Arnold (Physics, July, September, 1933). Heat Transmission in Cooling Air with Extended Surfaces, by W. L. Knaus (Refrigera ting Engineering, January, February, 1935). A New Psychrometric Chart, by F. O. Urban (Refrigerating Engineering, November 1935). Psychrometric Charts, by Donald B. Brooks ( V. S. Bureau of Standards Miscellaneous Publication No. 143). , .. The Deviation of the Actual Wet-Bulb Temperature from the Temperature of Adiabatic Saturation, by David Dropkin (Cornell University Engr. Exp. Station Bui. No. 23, July, 1936). ... . PROBLEMS IN PRACTICE 11 Given air at 70 F dry-bulb and 50 per cent relative humidity with a baro metric pressure of 29.00 in. Hg, find the weight of vapor per pound of dry air. Pressure of saturated vapor = et = 0.7387 in. Hg (Table 6). From Equation 5a, . W = 0.622 0.5 X 0.7387 ,29.00 - (0.5) X (0.7387); W = 0.008024 lb of vapor per pound of dry air at 70 F dry-bulb and 50 per cent relative humidity. Approximate Method: . Weight of saturated vapor per pound of dry air = Wt = 0.01574 lb (Table 6). 0.01574 X 0.5 = 0.00787 lb of vapor per pound of dry air at 70 F dry-bulb and 50 per cent relative humidity. . 2 Given air with a dry-bulb temperature of 80 F, relative humidity of 55 per cent, and a barometric pressure of 28.85 in. Hg, calculate the weight of a cubic foot of mixture. ;' Pressure of saturated vapor at 80 F = et = 1.0316 in. Hg (Table 6). Pressure of the vapor in the mixture = 1.0316 X 0.55 = 0.5676 in. Hg. Pressure of the dry air in the mixture = 28.85 -- 0.5676 = 28.282 in. Hg. pV = wR (<+ 460) (R = 0.753 when partial pressure of air is expressed in in. Hg). 28.282 X 1 = X 0.753 X (80 + 460) 28 282 da = o 753 X 540 = `^ lb = weight of dry air in 1 cu ft of the mixture. Likewise from Equation 4a, dy = 1 21 ^X^540 = 0.000868 lb = weight of vapor per cubic foot at 55 per cent relative humidity. Weight of 1 cu ft of the mixture = 0.06955 + 0.000868 = 0.070418 lb. ... _3 3 Given air with a dry-bulb temperature of 75 F, a relative humidity of 60 per cent, and a barometric pressure of 28.80 in. Hg, calculate the volume of 1 lb of the mixture. Pressure of saturated vapor at 75 F = et = 0.8745 in. Hg. Pressure of vapor in the mixture = 0.8745 X 0.6 = 0.525 in. Hg. Pressure of dry air in the mixture = 28.80 -- 0.525 28.275 in. Hg. . -, , . . 32 Chapter 1. Air. Water and Steam 28.275 = 0.07018 lb = weight of dry air in 1 cu ft of the mixture. " 0.753 X 535 From Equation 4a, 0.525 = 0.000811 lb = weight of vapor per cubic foot at 55 per cent v " 1.21 X 535 relative humidity. Weight of 1 cu ft of the mixture = 0.07018 + 0.000811 = 0.070991 lb. Volume of 1 lb of the mixture = q 070991 = 14-08 cu ft. 4 It is desired to maintain a temperature of 80 F and a relative humidity of 50 per cent in a factory where the equipment gives off 6,000 Btu per hour. If the entering air is at 70 F with an average barometric pressure of 29.92 in. Hg; determine the relative humidity, and the pounds of air required per hour if there is no heat interchange between the walls, windows, or floors of the building. Pressure of saturated vapor at 80 F = 1.0316 in. Hg (Table 6). Pressure of vapor in the mixture = 1.0316 X 0.5 = 0.5158 in. Hg. W " 0 622 (29.92t15085l58) " 0 01091 lb' Pressure of saturated vapor at 70 F = 0.7387 in. Hg. With the same specific humidity n0.m01n09o1i = ,,0.6o2n2* l ^29 Q2 0_-73(80773X874x \ 4> = 69.8 per cent relative humidity at 70 F. . h = 0.24 X 80 + 0.01091 [1059.2 + (0.45 X 80)] = 31.15 Btu per pound, the heat con tent of the mixture at 80 F and 50 per cent relative humidity. i = 0.24 X 70 + 0.01091 [1059.2 + (0.45 X 70)] = 28.70 Btu per pound, the heat con tent of the mixture at 70 F and the same specific humidity. 31.15 -- 28.70 = 2.45 Btu to be removed per pound of air. 6000 Btu = heat given off by equipment per hour. = 2449 lb of air required per hour. 5 Given 1 lb of dry air at 78 F and a barometric pressure of 29.92 in. Hg; calculate the volume. If the temperature is raised to 96 F and the volume remains constant, what will be the new pressure, Pt, in in. Hg? PV = wR (I + 460) R (for air) = 53.34. W = 1 lb. P = absolute pressure, pounds per square foot. 1 X 53.34 X (78 + 460) 29.92 X 0.491 X 144 V = 13.57 cu ft = volume of 1 lb. Pi Ti P, 7V ' TiPi T, (96 + 460) (29.92 X 0.491 X 144) Pi (78 + 460) (0.491 X 144) 30.90 in. Hg. 6 Given saturated air at a temperature of 75 F and a.barometric pressure of 29.92 in. Hg; determine the heat content of the mixture per pound of dry air, ' including the heat content of the liquid above 32 F. ' 33 X Heating Ventilating Air Conditioning Guide 1938 From Equation 12, . h = 0.24 (< - 0) + PFAs. where ha ~ 1059.2 + 0.451* (Empirical equation derived from Keenan's Steam Tables). -- 75 F. . W ~ 0.01873 lb of water vapor (Table 6). h = 0.24 (75 - 0) + 0.01873 [1059.2 + (0.45 X 75)]. * k = 38.46 Btu per pound of dry air. . .. 7 A building requires 50,000 cu ft of air per hour to be raised from --10 F dry-bulb and .75 per cent relative humidity to 72 F dry-bulb and 30 per cent relative humidity. Determine the amount of heat and the' weight of water which it is necessary to supply per hour if the temperature of the supply water is 50 F and the barometric pressure is 28.75 in. Hg. . . '- Assume air volume to be dry air at 70 F. '* Weight of air -- 0.075 X 50,000 = 3750 lb per hour. From Table 6, Pressure of vapor in the mixture, outside air = 0.75 X 0.0221 = 0.0166 in. Hg. Specific humidity, outside air =' 0.622 '/ , 0` 0166 28.75 - 0.0166 )=0, 0003589 lb. From Table 6, (Pressure of vapor in the mixture, inside air = 0.30 X 0.7906 = 0.2372 in. Hg. 0 2372 \ ' 75 L o 23718/ = 0.0051741b.. ' , Water to be added = 3750 (0.005174 - 0.0003589 ) = 18.06 lb per hour. Heat content, inside air = 0.24 X 72 + 0.00517411059.2 +,(0.45 X 72)] = 22.925 Btu pHeeraptocuonndt.ent, outside air = 0.24 X (-10) + 0.0003589 [1059.2 +^J(0.45) X --2.021 Btu per pound. -10)] = ' Btu added incident to the water per pound of dry air. (0.005174 - 0.0003589) (50 - 32). = 0.0867 Btu per pound. ,/* Heat requirement per hour = [22.925 -- (--2.021 + 0.0867)] X 3750 = 93,221 Btu. 8 Determine the amount of heat and water that must be extracted to cool 3750 lb of air (weighed dry) from 95 F and 60 per cent relative humidity to 50 F and 100 per cent relative humidity with a barometric pressure of 28.75 in. Hg; Pressure of vapor in the mixture, outside air = 0.6 X 1.659 = 0.995 in. Hg. Specific humidity, outside air = 0.622 (-no __ A .= 0.0223 lb. \28.75 -- 0.995/ Specific humidity, inside air = 0.007626 lb. -N Weight of water to be extracted per hour = (0.0223 -- 0.007626) X 3750 = 55.03 lb. Heat content, outside air = 0.24 X 95 + 0.0223 [1059.2 + (0.45 X 95)] = 47.37 Btu per pound. Heat content, inside air = 0.24 X 50 + 0.00764 [1059.2 + (0.45 X 50)] = 20.26 Btu per pound. ' Heat to be extracted = (47.37 - 20.26) X 3750 = 101,662 Btu. 34 Chapter 2 refrigerants and air drying agents Properties of Refrigerant Substances, Selection Factors, Solid Adsorbents, Liquid Absorbents, Nature of Processes, Tempera . ture Pressure Concentration Relations BOTH cooling and dehumidification of air are usually desirable at certain times. Cooling may be regarded as the extraction of sensible heat while dehumidification necessitates the removal of latent heat. By a suitable selection and combination of methods and equipment these two processes may be accomplished simultaneously or they may be secured independent of each other and at different times as desired. On occasion, the desired result can be secured by extracting sensible heat only while in other cases drying alone will produce the end conditions sought. Suitable substances must be available for use in every particular case. Generally, when both cooling and dehumidification are sought current practice makes use of artificially produced refrigeration in some form. The substances used as the heat-carrying agents in these applications are called refrigerants. Air drying agents are substances which permit dehumidification of air as a process separate and independent of the extraction of sensible heat from it. Refrigerants and air drying agents are treated separately, in this chapter where the aim is to present a statement of the properties of these substances which are of especial importance in air conditioning work. Little mention is made here of methods, systems, or equipment whereby these substances may be applied, which infor mation may be found in Chapter 24. REFRIGERANTS Since air cooling and dehumidification are frequently accomplished by evaporating a liquid under circumstances which will permit the heat necessary to be extracted from the air, the refrigerants are substances which, are capable of being changed into liquids or vapors within workable temperature and pressure ranges. There are many substances which might be so used but in practice the choice is limited by a wide variety of considerations including availability, cost, safety,' chemical stability and adaptability to the type of refrigerating system to be used. . In this chapter detailed consideration is limited to six substances, viz: ammonia, carbon dioxide, dichlorodifluoromethane (F12), methyl 35 Heating Ventilating Air Conditioning Guide 1938 Table I. Properties of Ammonia Sat. Temp. F AB8 Press. Lb peb So In. Liquid Vapor Heat Content and Entropt Taken From -40 F Heat Content Liquid Vapor Entropy 100 F Superheat 200 F Superheat Liquid Vapor Ht. Ct. Entrop r Ht. Ct Entropy . 0 30.4; 0.0241* 2 31.9; 0.0242' 4 33.4' 0.02431 5 34.2' 0.0243; 6 35.05 0.02431 8 36.77 0.02441 10 38.51 0.02441 12 40.31 0.02451 14 42.18 0.02457 16 44.12 0.02462 18 46.13 0.02468 20 48.21 0.02474 22 50.36 0.02479 24 52.59 0.02485 26 54.90 0.02491 28 57.28 0.02497 30 59.74 0.02503 32 62.29 0.02508 34 64.91 0.02514 36 67.63 0.02521 38 70.43 0.02527 39 71.87 0.02530 40 V3.32 0.02533 41 74.80 0.02536 42 . 76.31 0.02539 44 79.38 0.02545 46 82.55 0.02551 48 85.82 0.02558 50 89.19 0.02564 52 92.66 0.02571 54 96.23 0.02577 56 99.91 0.02584 58 103.7 0.02590 60 107.6 0.02597 62 111 .6 0.02604 64 115.7 0.02611 66 120.0 0.02618 68 124.3 0.02625 70 128.8 0.02632 72 133.4 0.02639 74 138.1 0.02646 76 143.0 0.02653 78 147.9 0.02661 80 153.0 0.02668 82 158.3 0.02675 84 163.7 0.02684 86 169.2 0.02691 88 174.8 0.02699 90 L8U.6 0.02707 92 186.6 0.02715 94 192.7 0.02723 96 98.9 0.02731 98 i 05.3 0.02739 too 11.9 0.02747 102 18.6 0.02756 9.116 8.714 8.333 8.150 7.971 7.629 7.304 6.996 42. 45. 47.; 6ii.i5 0.097. 1.335: 612.4 0.102;J1-3317 613.1 10.1065 1.327; 666.; 1.443! 720..51 5317 667. 1.440C) 721.:1 1 5277 668.4 1.436C) 722 :>1 5236 48.; 49.4 51. 53. 613.; 0.1092 1.325; 613. >0.1115 1.3234 614.; 0.1162 1.3195 614.5 0.1201 1.3157 668.8 1.434( 669.; 1.4321 670.1 1.4281 670. S 1.4242 722.1>1 5216 723.1 1 5196 724.1 1 5155 725 ()1 5115 56. ( 615.5 0.125" 1.3118 671.7 1.4205 725 5 1 5077 6.703 6.425 6.161 5.910 58.2 60.3 62.5 64.7 616.: 0.130C 1.3081 616.6 0.1346 1.3043 617.2 0.1392 1.3006 617.8 0.1437 1.2969 672.5 1.4168 673.4 1.4130 674.2 1.4093 675.0 1.4056 726.8 1 5039 727 S 1 5001 728 7 1 4963 729 6 1 4925 5.671 66.9 618.; 0.1482 1.2933 675.8 1.4021 730 5 1 4889 5.443 5.227 5.021 4.825 4.637 4.459 4.289 4.126 69.1 618.9 0.1528 1.2897 676.6 1.3985 731.4 1 4853 71.3 73.5 - 75.7 619.4 0.157; 1.2861 619.9 0.1618 1.2825 620.5 0.1663 1.2790 677.3 1.3950 678.1 1.3914 678.9 1.3879 732.4 1 4816 733 3 1 4780 734 2 1 4744 77.9 621.0 0.1708 1.2755 679.7 1.3846 735.1 1 4710 80.1 82.3 84.6 621.5 0.1753 1.2721 622. C 0.1797 1.2686 "622.5 0.1841 1.2652 680.4 1.3812 681.2 1.3779 681.9 1.3745 736.0 1 4676 736.8 1 4643 737 7 1 4609 4.048 3.971 3.897 3.823 3.682 3.547 3.418 3.294 3.176 85.7 622.7 0.1863 1.2635 682.3 1.3729 738.2 1 4592 86.8 87.9 89.0 91.2 623.0 0.1885 1.2618 623.2 0.1908 1.2602 623.4 0.1930 1.2585 623.9 0.1974 1.2552 682.7 1.3712 '738.6 1 4575 683.1 1.3696 739 0 1 4559 683.4 1.3680 739 5 1 4542 684.2 1.3648 740.4 1 4510 93.5 95.7 624.4 0.2018 1.2519 624.8 0.2062 1.2486 684.9 1.3616 685.6 1.3584 741.3 1 4477 742 2 1 4445 97.9 100.2 625.2 0.2105 1.2453 625.7 0.2149 1.2421 686.4 1.3552 687.1 1.3521 743.1 1 4412 744.0 1 4382 3.063 2.954 102.4 104.7 626.1 0.2192 1.2389 626.5 0.2236 1.2357 687.8 1.3491 688.5 1.3460 744 8 1 4351 745 7 1 4321 2.851 2.751 2.656 106.9 626.9 0.2279 1.2325 689.2 1.3430 746.5 1 4290 109.2 111.5 627.3 3.2322 1.2294 627.7 3.2365 1.2262 689.9 1.3399 690.6 1.3370 747.4 1 4260 748.2 1 4231 2.565 2.477 113.7 116.0 628.0 3.2408 1.2231 628.4 3.2451 1.2201 691.3 1.3341 691.9 1.3312 749.1 1 4202 749.9 1 4172 2.393 2.312 118.3 120.5 628.8 0.2494 1.2170 629.1 3.2537 1.2140 692.6 1.3283 693.3 1.3254 750.8 1 4143 751.6 1 4114 2.235 2.161 2.089 2.021 122.8 125.1 629.4 (3.2579 1.2110 629.8 0.2622 1.2080 694.0 1.3226 694.6 1.3199 752.4 1 4086 753.3 1 4059 127.4 630.1 3.2664 1.2050 695.3 1.3171 754.1 1 4031 129.7 630.4 0.2706 1.2020 695.9 1.3144 755.0 1 4004 1.955 1.892 1.831 132.0 630.7 3.2749 (.1991 696.6 1.3116 755.8 1 3976 134.3 631.0 3.2791 1.1962 697.2 1.3089 756.6 1 3949 136.6 631.3 3.2833 .1933 697.8 1.3063 757.4 1 3923 1.772 1.716 1.661 138.9 141.2 631.5(3.2875 .1904 631.813.2917 1.1875 698.5 1.3040 699.1 1.3010 758.3 l 3896 759.1 1.3870 143.5 632.0 1.2958 .1846 699.7 1.2983 759.9 L 3843 1.609 145.8 632.2 1.3000 . 1818 700.3 1.2957 760.7 L.3818 1.559 148.2 632.5i 1.3041 .1789 700.9 1.2932 761.5 L.3793 1.510 1.464 150.5 632.6(3.3083 .1761 701.51 .2906 762.2 .3768 152.9 632.9 1.3125 .1733 702.1 .2881 763.0 .3743 1.419 155.2 633.0 3.3166 .1705 702.7 .2855 763.81 .3718 1.375 157.6 633.2 3.3207 .1677 703.3 .2830 764.6 .3693 36 Chapter 2. Refrigerants and Air Drying Agents Table 1. Properties of Ammonia--(Continued) Sat. Temp. F Abs Press. Lb per So In. Volume liquid Vapor Heat Content and Entropy Taken From -40 F Heat Content Entropy 100 F Superheat 200 F Superheat. liquid Vapor liquid Vapor Ht. Ct. Entropy Ht. Ct. Entropy 104 225.4 0.02764 1.334 159.9 633.4 0.3248 1.1649 703.8 1.2805 765.3 1.3668 106 232.5 0.02773 1.293 162.3 633.5 0.3289 1.1621 704.3 1.2780 766.1 1.3643 108 239.7 0.02782 1.254 164.6 633.6 0.3330 1.1593 705.0 1.2755 766.9 1.3619 110 247.0 0.02790 1.217 167.0 633.7 0.3372 1.1566 705.5 1.2731 767.6 1.3596 112 254.5 0.02799 1.180 169.4 633.8 0.3413 1.1538 706.1 1.2708 768.3 1.3$73 114 262.2 0.02808 1.145 171.8 633.9 0.3453 1.1510 706.6 1.2684 769.1 1.3550 116 270.1 0.02817 1.112 174.2 634.0 0.3495 1.1483 707.2 1.2661 769.8 1.3527 118 278.2 0.02827 1.079 176.6 634.0 0.3535 1.1455 707.7 1.2636 770.5 1.3503 120 286.4 0.02836 1.047 179.0 634.0 0.3576 1.1427 708.2 1.2612 771.3 1.3479 122 294.8 0.02846 1.017 181.4 634.0 0.3618 1.1400 708.6 1.2587 772.0 1.3455 124 303.4 0.02855 0.987 183.9 634.0 0.3659 1.1372 709.1 1.2563 772.8 1.3431 126 312.2 0.02865 0.958 186.3 633.9 0.3700 1.1344 709.6 1.2538 773.5 1.3407 128 321.2 0.02875 0.931 188.8 633.9 0.3741 1.1316 710.0 1.2513 774.2 1.3383 chloride, water, and monofluorotrichloromethane (Fn), for each of which a table is presented. Each table gives the principal physical properties of the saturated substance, and all are arranged in uniform fashion. In each case columns are included which-give the heat content and entropy of the superheated vapor at two selected points. Tables 1, 2, 3 and 4 which include the refrigerants much used in reciprocating and rotary mechanical compression systems have a 2 F temperature interval. As water and Fn are much used in centrifuged compression systems the temperature interval in Tables 5 and 6 is 5 F. AIR DRYING AGENTS Moisture may be removed from air, thus accomplishing dehumidi fication, by the use of any one of a number of substances if the moist air and these substances are brought together under suitable circumstances. One class of these substances are solids at ordinary conditions and have the power of adsorbing the moisture from the air. Another class of air drying agents are liquids under ordinary conditions and absorb the mois ture from the air. Nearly all the drying agents in frequent commercial use in air conditioning installations are of one or the other of these two classes. Adsorbents - . These substances are characterized by a physical structure containing a great number of extremely small pores but still retaining sufficient mechanical strength to resist whatever wear and handling to which they are subjected. To be suitable for air drying purposes they must be widely available at economical cost, durable in use, stable in form and properties, and capable of withstanding the re-activation processes by which they are made ready for repeated use. They must also possess capacity for adsorbing and holding so sufficient a quantity of moisture that the dimensions of the beds necessary to accommodate them will be practical. 37 > *:- Heating Ventilating Air Conditioning Guide 1938 Table 2. Properties of Carbon Dioxide Sat. Temp. F ABS Press. Lb per Sq In. Heat Content and Entropt Taken From --40 F Heat Content Entropy 50 F Superheat 100 F Superheat Liquid Vapor liquid Vapor liquid Vapor Ht. Ct Entrap (t Ht CL Entropy . 0 305.5 0.01571 0.2904C 18.8 2 315.9 0.01571 0.2803C 19.8 4 326.5 0.01581 0.2707C 20.8 5 332.0 0.01591 0.2661C 21.3 6 337.4 0.01591 0.2614C 21.8 8 348.7 0.01605 0.25260 22.9 10 360.2 0.01614 0.24370 24.0 12 371.9 0.01623 0.23540 25.0 14 383.9 0.01632 0.22740 26.1 16 396.2 0.01642 0.21970 27.2 18 408.9 0.01652 0.21210 28.3 20 421.8 0.01663 0.20490 29.4 22 434.0 0.01673 0.19790 30.5 24 448.4 0.01684 0.19120 31.7 26 462.2 0.01695 0.18460 32.9 28 476.3 0.01707 0.17830 34.1 30 490.8 0.01719 0.17220 35.4 32 505.5 0.01731 0.16630 36.7 34 522.6 0.01744 0.16030 37.9 36 536.0 0.01759 0.15500 39.1 38 551.7 0.01773 0.14960 40.4 39 559.7 0.01780 0.14700 41.0 40 567.8 0.01787 0.14440 41.7 41 576.0 0.01794 0.14185 42.3 42 584.3 0.01801 0.13930 42.9 44 601.1 0.01817 0,13440 44.3 46 618.2 0.01834 0.12970 45.6 48 635.7 0.01851 0.12500 47.0 50 653.6 0.01868 0.12050 48.4' 52 671.9 0.01887 0.11610 49.8 54 690.6 0.01906 0.11170 51.2 56 709.5 0.01927 0.10750 52.6 58 728.8 0.01948 0.10340 54.0 60 748.6 0.01970 0.09940 55.5 62 769.0 0.01995 0.09545 57.0 64 789.4 0.02020 0.09180 58.6 66 810.3 0.02048 0.08800 60.2 68 831.6 0.02079 0.08422 61.9 70 853.4 0.02112 0.08040 63.7 72 875.8 0.02152 0.07654 65.5 74 898.2 0.02192 0.07269 67.3 76 921.3 0.02242 0.06875 69.4 78 944.8 0.02300 0.06473 71.6 80 968.7 0.02370 0.06064 73.9 82 993.0 0.02456 0.05648 76.4 84 017.7 0.02553 0.05223 79.4 86 043.0 0.02686 0.04789 83.3 87.81 069.9 0.03454 0.03454 97.0 138.5 0.041!10.3024 138. 0.044110.3014 138. 0.046 0.300! 138. 0.0475 0.3006 138.5 0.048510.2994 138.7 0.0504 0.2982 153';' 0.3342 153.' 0.3336 153.' 0.3318 153.' 0.3312 153.1 0.3306 153.7 0.3293 167..5 0.3612 167.65 0.3600 167. 0.3588 167.' 0.3582 167.! 0.3576 167.5 0.3563 138.7 0.0526 0.2970 153.7 0.3281 168.6 0.3550 138.6 0.0548 0.2958 153.7 0.3270 168.1 0.3538 138.6 0.0571 0.2946 153.7 0.3259 168.2 0.3526 138.5 0.0593 0.2933 138.4 0.0616 0.2921 153.7 0.3249 153.7 0.3238 168.3 0.3513 168.5 0.3501 138.3 0.0638 0.2909 153.7 0.3227 168.6 0.3489 138.2 0.0662 0.2897 153.7 0.3214 168.7 0.3479 138.1 0.0686 0.2885 153.7 0.3202 168.8 0.3470 138.0 0.0710 0.2873 153.7 0.3189 168.9 0.3460 137.9 0.0734 0.2861 153.7 0.3177 169.0 0.3451 137.8 0.0758 0.2849 153.7 0.3164 169.1 0.3441 137.7 6.0781 0.2834 153.7 0.3158 169.2 0.3431 137.4 0.0804 0.2820 153.7 0.3151 169.3 0.3421 137.2 0.0828 0.2805 153.7 0.3145 169.4 0.3411 136.9 0.0851 0.2791 153.7 0.3138 169.5 0.3401 136.8 0.0862 0.2783 153.7 0.3135 169.5 0.3396 136.7 0.0874 0.2776 153.7 0.3132 169.6 0.3391 136.5 0.0887 0.2768 153.7 0.3127 169.6 0.3386 136.3 0.0899 0.2761 153.7 0.3122 169.7 0.3381 136.1 0.0924 0.2745 153.7 0.3112 169.8 0.3371 135.7 0.0950 0.2730 153.7 0.3101 169.9 0.3362 135.4 0.0975 0.2714 153.7 0.3091 170.0 0.3352 135.0 0.1000 0.2699 153.7 0.3081 170.1 0.3342 134.5 0.1027 0.2681 153.7 0.3069 170.2 0.3333 133.9 0.1054 0.2663 153.7 0.3057 170.3 0.3324 133.4 0.1081 0.2644 153.7 0.3046 170.5 0.3315 132.7 0.1108 0.2626 132.1 0.1135 0.2608 153.7 0.3034 153.7 0.3022 170.6 0.3306 170.7 0.3297 131.3 0.1164 0.2584 153.7 0.3012 170.8 0.3289 130.6 0.1194 0.2560 153.7 0.3002 170.9 0.3281 129.7 0.1223 0.2535 153.7 0.2991 171.0 0.3273 128.7 0.1253 0.2511 153.7 0.2981 171.1 0.3265 127.5 0.1282 0.2487 126.0 0.1321 0.2450 153.7 0.2971 153.7 0.2962 171.2 0.3257 171.3 0.3250 124.510.1360 0.2414 153.7 0.2953 171.4 0.3242' 122.8 0.1398 0.2377 153.7 0.2945 171.5 3.3235 120.9 0.1437 0.2341 153.7 0.2936 171.6 3.3227 118.7(0.1476 0.2304 153.7 0.2927 171.7 3.3220 116.6(0.1578 60.2195 153.760.2920 173.8 3.3215 113.9 . 1679 0.2087 153.7 60.2914 176.0 3.3209 110.4(>.1781 0.1978 153.7 60.2907 178.213.3204 97,0C). 1880(0.1880 153.760.2901 180.1 3.3199 38 Chapter 2. Refrigerants and Air Drying Agents Aluminum Oxide, (Alumina), in a porous, amorphous form is a solid adsorbent frequently called by the common name activated alumina, and containing small amounts of hydrated aluminum oxide, and very small amounts of soda, and various metallic oxides. A good grade of activated alumina will show 92 per cent of AhOz, and its soda content will be com bined with silica and alumina into an insoluble compound. This substance also has the property of adsorbing certain gases and certain vapors other Fig. 1. Temperature--Vapor Pressure--Concentration Relation for a Silica Gel Bed at Constant Temperature than water vapor--a property which is sometimes useful in air condi tioning installations. It is available commercially in granules ranging from a fine powder to pieces approximately 1.5 in. in diameter. It has high adsorptive capacity per unit of weight, and is non-toxic. It may be repeatedly re-activated after becoming saturated with adsorbed moisture without practical loss of its adsorptive ability. In the grade frequently used for air drying the re-activation may be accomplished at temperatures under 350 F. Specific gravity is 3.25 and the pores are reported to occupy 58 per cent of the volume of each particle. For most estimating purposes 39 rjT- Heating Ventilating Air Conditioning Guide 1938 Table 3. Properties of Dichlorodifluoromethane(Fij) Sat. Temp. F Abs Press. Lb pec Sq In. Volume Liquic I Vapor Heat Content and Entbopt Taken From --40 F Heat Content liquid Vapor Entropy Liquid Vapor 25 F Superheat 50 F Superheat Ht. Ct I Entropy Ht. Ct. I Entropy i 0 2 4 5 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 39 40 41 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 111l.919199l788800076767765565455554444344l333784333530224722714722229427503791253.019846380175.3...48..105....9.6.7..43..!3..778...'.0.l7892.85...62.2..47......8.61..33435.4.7681.74...1.505..1770169500240075310478808543055919088837260879551C11C(..!i 331>5>>0000933333000000000333*00000000000000000o00..........0.0.00...0....o.......0000..000.000..0..0..000.000..00..00000000...00000..100.0.0000.1111111100.11000011111111111o111O11111111111o1211112222222222111121122211121111111111111111115u11115n334I34241112K1111100999088733K87766566665553455;;330000000000000000000000000000000000........11.1.11..111..1...11135..1114333.4404....4....44455.55....5656..766.7..8777...8.6..88.99..5..0762180030511932276435094442761955549719630717430718408853928160507394055788043235172325282769978981371331371375744222111111111111111111111111098778977666554399934322901188.0......1....3..0.7.....982...4..5.2..7...1.267838401563589270361226127537011526814025122360697)50!,] 88888888888888888888888888888888888878877788676866667577555577747744734233332222112210.01......00..0.9i.9.9.9.8..8.8.9808..853.7.16..89.4..2.083624..4..9..6.1..2.9.856.77..2...64.82.0.12.079367822441092862225123376229124252070918119375,7259,'71952,1]9369710,4,]'1,0000000000000000000000000-000000000.0...00.00....0.00..00000.....000.00..00.000...000...00..0000..0.00..0..0...000..000...0...0000..0.50555005055000550555000044400444400044343333337333332793843256220224212602522229741821391367876505324009695818326796718465520420134890389420875239830231695594417275980287561391109425653826604059751,23;333331|3]231,]057]3891]29;]|000000000000000000000000000000000.00..00.0....00.00..0...0000.01..001.1...1111..1.1.1..111.1...111..1.1.11...11.11.1..11.1161.....11.16.661166116661166166116111166666111666666666666666666666666676666667676767777777777777781887788878848828399359994699610970948000004002056651708923324086437512062263870439819755413419917567814335383813,]7561|10386,!197]14125505099999999989888888888888888888888880811888101188009888988808988899888877776766666.555554..44....3.4.33..3.92..2.22...1..21...59753718..923..56..7105.-026.9...4....7.81..3..845.4..7.7.029.0237765707813882306946444274697817992181618629111551221199548]5119,1]16074,;!1]] 21.0 3.0126 0.347 2 24.5 1 >.0126 0.338 3 28.0 C>.0126 0.328 3 31.6 C .0127 0.319 3 35.3 C>.0127 0.310 3 88.10 0.06056] 0.16608 92.16] 88.28 0.06143 0.166001 92.36] 88.45] 0.06230 0.16592 92.55 88.62 0.06316 0.16584 92.75, 88.791 0.06403 0.165761 92.93! .17829, 85.26] 0.18547 .17812, 85.51 0.18529 .17795] 85.76, 0.18511 .177861 85.89| 0.18502 17778 86.01, 0.18494 17763 86.26| 0.18477 .17747 86.51 0.18460 17733, 86.76; 0.18444 .17720] 87.01 0.18429 .17706 87.26 0.18413 17693 87.51, 0.18397 17679 87.76] 0.18382 17666] 88.00, 0.18369 17652] 88.24| 0.18355 .17639 88.49 0.18342 .17625 88.73 0.18328 17612 88.97 0.18315 17600 89.21 0.18303 17589 89.45| 0.18291 .17577 89.68 0.18280 17566 89.92 0.18268 17560 90.04 0.18262 17554 90.16 0.18256 17549 90.28 0.18251 17544, 90.40| 0.18245 17534] 90.65 0.18235 17525 90.89; 0.18224 17515 91.14 0.18214 17505, 91.38] 0.18203 17496 91.61 0.18193 17486] 91.83, 0.18184 17477 92.06] 0.18174 17467 92.28 0.18165 17458; 92.51, 0.181SS 17450| 92.741 0.18147 17442 92.97 0.18139 17433 93.20 0.18130 17425 93.43 0.18122 17417] 93.66, 0.18114 17409] 93.991 0.18106 17402 94.12 0.18098 17394 94.34] 0.1809-1 17387 94.571 0.18083 17379, 94.80] 0.18075 17372] 95.01 0.18068 17365 95.22 0.18061 17358, 95.44 0.18054 17351, 95.65 0.18047 17344 95.86, 0.18040 17337 96.071 0.18033 17330] 96.28; 0.18026 17322 96.50 0.18018 17315 96.71 0.18011 17308 96.92 0.18004 17301 97.12] 0.17998 40 Chapter 2. Refrigerants and Air Drying Agents Table 3. Properties of Dichlorodifluoromethane (Fh)--Continued Sat. Temp. F Abs Press. Lb per SqIn. Volume liquid Vapor Heat Content and Entbopt Taken Fbom --40 F Heat Content liquid Vapor Entropy 25 P Superheat 50 F Superheat Liquid Vapor Ht Ct. Entropy Ht. Ct Entropy 104 139.0 0.0128 0.302 32.15 88.95 0.06490 0.16568 93.11 0.17294 97.32 0.17993 106 108 110 142.8 0.0128 0.293 32.65 89.11 0.06577 -0.16560 93.30 0.17288 97.53 0.17987 146.8 0.0129 0.285 33.15 89.27 0.06663 0.16551 93.48 0.17281 97.73 0.17982 150.7 0.0129 0.277 33.65 89.43 0.06749 0.16542 93.66 0.17274 97.93 0.17976 112 154.8 0.0130 0.269 34.15 89.58 0.06836 0.16533 93.82 0.17266 98.11 0.17969 114 158.9 0.0130 0.262 34.65 89.73 0.069221 0.16524 93.98 0.17258 98.29 0.17961 116 163.1 0.0131 0.254 35.15 89.87 0.07008 0.16515 94.15 0.17249 98.48 0.17954 118 167.4 0.0131 0.247 35.65 90:01 0.07094 0.16505 94.31 0.17241 98.66 0.17946 120 171.8 0.0132 0.240 36.16 90.15 0.07180 0.16495 94.47 0.17233 98.84 0.17939 122 176.2 0.0132 0.233 36.66 90.28 0.07266 0.16484 94.63 0.17224 99.01 0.17931 124 180.8 0.0133 0.227 37.16 90.40 0.07352 0.16473 94.78 0.17215 99.18 0.17922 126 185.4 0.0133 0.220 37.67 90.52 0.07437 0.16462 94.94 0.17206 99.35 0.17914 128 190 .'1 0.0134 0.214 38.18 90.64 0.07522 0.16450 95.09 0.17196 99.53 0.17906 130 194.9 0.0134 0.208 38.69 90.76 0.07607 0.16438 95.25 0.17186 99.70 0.17897 132 199.8 0.0135 0.202 39.19 90.86 0.07691 0.16425 95.41 0.17176 99.87 0.17889 134 204.8 0.0135 0.196 39.70 90.96 0.07775 0.16411 95.56 0.17166 100.04 0.17881 136 209.9 0.0136 0.191 40.21 91.06 0.07858 0.16396 95.72 0.17156 100.22 0.17873 138 215.0 0.0137 0.185 40.72 91.15 0.07941 0.16380 95.87 0.17145 100.39 0.17864 140 220.2 0.0138 0.180 41.24 91.24 0.08024 0.16363 96.03 0.17134 100.56 0.17856 the volume-weight relation on a dry basis may be taken as 50 lb per cubic foot although in the smaller sizes the packed weight may be as much as 64 lb per cubic foot. . Silicon Dioxide, (Silica), in a special form obtained by suitably mixing sulphuric acid with sodium silicate, is another solid adsorbent and is commonly called silica gel. Its capillary structure is exceedingly small, so small that its exact structure has to be deduced rather than observed. The gel is available commercially in a "wide variety of sizes of granules ranging from 4 to 300 mesh*. > It has high adsorptive capacity per unit of weight and is non-toxic, may be repeatedly re-activated without practical deterioration. Re-activation may be accomplished at tem peratures of air up to 600 F although it is frequently accomplished with air or other gases at temperatures not over 350 F. Volume of the capillary pores is reported to be from 50 to 70 per cent of the total solid volume. For most estimating purposes the volume-weight relation can be assumed as from 38 to 40 lb per cubic foot on a dry basis. Other substances having properties which make them available as solid adsorbents include lamisilate and charcoal but details of their physical properties are not available. Nature of Adsorption Process Adsorption is accomplished without chemical change between the air and the adsorbent substance. The adsorbent does not go into solution but water vapor is extracted from the air-vapor stream passing through the bed of adsorbent material and is caught and retained in the capillary pores. The exact nature of the process which goes on during adsorption 41 Heating Ventilating Air Conditioning Guide 1938 Chapter 2. Refrigerants and Air Drying Agents Table 4. Properties of Methyl Chloride Table 4. Properties of Methyl Chloride--(Continued) Sat. Temp. F Ass Press. Lb peb Sq In. Volume Liquid - Vapor Heat Content and Entbopt Taken From --40 F Heat Content Entropy . 100 F Superheat 200 F Superheat liquid Vapor liquid Vapor HtCt Entropy Ht. Ct Entropy Sat. Temp. F Abb Press. Lb per bQ In. Volume liquid Vapor Heat Content and Entbopt Taken Fbom --4-0 F Heat Content Entropy 100 F Superheat 200 F Si perheat liquid Vapor liquid Vapor Ht Ct Entropy Ht Ct Entropy 0 18.73 0.0162 5.052 14.4 192.4 0.0328 0.4197 215.6 0.467 237.2 0.507 2 19.60 0.0162 4.856 15.1 193.1 0.0344 0.4196 216.2 0.466 237.7 0.505 4 20.47 0.0163 4.661 15.8 193.8 0.0360 0.4195 216.7 0.465 238.2 0.504 5 20.91 0.0163 4.563 16.2 194.1 0.0368 0.4195 -217.0 0.464 238.5 0.503 6 21.39 0.0163 4.476 16.6 194.4 0.0376 0.4194 217.3 0.464 238.8 0.502 8 22.34 0.0164 4.303 17.3 195.1 0.0391 0.4193 ' 217.9 0.463 239.4 0.501 10 23.30 0.0164 4.129 18.1 195.8 0.0407 0.4192 218.5 0.463 240.0 0.500 12 24.38 0.0164 3.984 18.8 196.3 0.0423 0.4184 219.0 0.462 240.5 0.499 14 25.46 0.0164 3.839 19.6 196.7 0.0439 0.4176 219.5 0.462 241.0 0.498 16 26.55 0.0165 3.693 20.3 197.2 0.0454 0.4168 220.0 0.461 241.5 0.498 104 106 108 122.60 QJU83 126.20 n 0184 129.80 0 0184 110 133.40 n 0185 112 137.42 0 0185 114 141.44 0 0185 116 145.46 6 0186 118 149.48 6 0186 120 . 153.50 6.0187 0.8712 53.1 0.8471 53.8 0.8231 54.6 0.7990 55.3 0.7786 56.1 0.7583 56.8 0.7379 57.6 0.7176 58.3 0.6972 59.1 211.3 0.1090 0.3897 236.8 0.430 263.2 0.473 211.4 0.1103 0.3890 237.1 0.429 263.5 0.473 211.6 0.1117 0.3884 237.5 0.429 263.9 0.472 211.8 0.1130 0.3877 237.9 0.428 264.3 0.472 212 .C 0.1144 0.3871 238.1 0.427 264.6 0.471 212.2 0.1157 0.3864 238.3 0.427 264.8 0.470 212.4 0.1171 0.3858 238.6 0.426 265.1 0.470 212.6 0.1184 0.3851 238.8 0.426 265.3 0.469 212.8 0.1198 0.3845 239.0 0.425 265.6 0.468 18 27163 0.0165 3.548 21.1 197.6 0.0472 0.4160 220.5 0.461 242.0 0.497 20 28.71 0.0166 3.403 21.8 198.1 0.0486 0.4152 221.0 0.460 242.5 0.496 22 29.98 0.0166 3.288 22.5 198.5 0.0501 0.4148 221.5 0.459 243.0 0.495 24 31.25 0.0166 3.172 23.3 198.9 0.0516 0.4143 222.0 0.459 243.6 0.495 26 32.53 0.0167 3.057 24.0 199.3 0.0532 0.4139 222.4 0.458 244.1 0.494 is not known but it is stated that the action is brought about by surface condensation, and also by a difference between the vapor pressure of the 28 33.80 0.0167 2.941 24.8 199.7 0.0547 0.4134 222.9 0.458 244.7 0.494 water condensing inside the pores and the partial pressure of the water 30 35.07 0.0168 2.826 25.5 200.1 0.0562 0.4130 223.4 0.457 245.2 0.493 vapor in the air-vapor mixture. The adsorbing process in the bed can 32 36.55 0.0168 2.734 26.2 200.5 0.0577 0.4124 223.9 0.456 245.7 0.492 34 38.03 0.0169 2.642 27.0 200.9 0.0592 0.4118 224.3 0.455 246.2 0.492 36 39.51 0.0169 2.549 27.7 201.4 0.0607 0.4111 224.8 0.455 246.7 0.491 continue until the vapor.pressures come into equilibrium. The amount of vapor adsorbed will depend on the adsorbent substances being used 38 40.99 0.0169 2.457 28.5 201.8 0.0622 0.4105 225.2 0.454 247.2 0.491 but for any single substance the amount depends on the temperature of 39 41.73 0.0170 2.411 28.8 202.0 0.0629 0.4102 225.5 0.453 247.4 0.490 the bed as well as on the partial pressure of the air-vapor mixture being 40 42.47 0.0170 2.365 29.2 202.2 0.0637 0.4099 225.7 0.453 247.7 0.490 41 43.33 0.0170 2.328 29.6 202.4 0.0644 0.4096 225.9 0.453 248.0 0.490 passed over it. . 42 44.18 0.0171 2.290 29.9 202.6 0.0651 0.4093 226.1 0.452 248.3 0.489 As the process of adsorption goes on heat is liberated in the bed. The 44 45.89 0.0171 2.216 30.7 203.0 0.0666 0.4087 226.6 0.451 248.8 0.489 heat so liberated is the latent heat of the water vapor condensed together 46 47.61 0.0171 2.141 31.4 203.3 0.0680 0:4081 227.0 0.451 249.4 0.488 48 so 49.32 0.0172 51.03 0.0172 2.067 32,2 203.7 0.0695 0.4075 227.5 0.450 249.9 0.488 1.992 32.9 .204.1 0.0709 0.4069 227.9 0.449 250.5 0.487 with the so-called heat of wetting. For a pound of water vapor at 60 F the latent heat released by condensation is approximately 1057 Btu.. 52 53.00 0.0172 1.931 33.7 204.4 0.0724 0.4063 228.2 0.448 251.0 0.486 The heat of wetting for silica gel, for example, is about 200 Btu, making a 54 54.97 0.0173 1.870 34.4 204.7 0.0739 0.4056 228.6 0.448 251.5 0.486 total heat of adsorption of approximately 1257 Btu per pound of water 56 56.94 0.0173 1.810 35.2 .205.1 0.0754 0.4050 228.9 0.447 252.0 0.485 58 58:91 0.0173 1.749 35.9 205.4 0.0769 0.4043 229.3 0.447 252.5 0.485 60 60.88 0.0174 1.688 36.7 205.7 0.0784 0.4037 229.6 0.446 253.0 0.484 adsorbed from the air-vapor mixture passing through the silica gel bed. The heat of wetting varies with the substance being used as the adsorbent .62 63.13 0.0174 1.638 37.4 206.0 0.0798 0.4030 229.9 0.445 253.5 0.483 while the latent heat of condensation depends only on the temperature 64 65.37 0.0174 1.588 38.2 206.3 0.0812 0.4024 230.3 0.444 254.0 0.483 66 67.62 0.0175 1.539 38.9 206.6 0.0827 0.4017 230.6 0.443 254.5 0.482 and pressure of the water vapor. 68 69.86 0.0175 1.489 39.7 206.9 0.0841 0.4011 231.0 0.442 255.0 0.482 70 72.11 0.0176 1.439 40.4 207.2 0.0855 0.4004 231.3 0.441 255.5 0.481 Temperature-Pressure-Concentration Relations . 72 74 76 78 74.66 0.0176 77.21 0.0177 79.76 0.0177 82.31 0.0178 1.398 1.357 1.315 1.274 41.1 41.9 42.6 43.4 207.$ 0.0869 0.3998 231.6 0.440 256.0 0.480 207.7 0.0883 0.3992 232.0 0.439 256.5 0.480 208.0 0.0898 0.3985 232.3 0.439 256.9 0.479 208.2 0.0912 0.3979 232.7 0.438 257.4 0.479 Since the adsorptive ability of an adsorbent depends on the temperature of the bed and on the partial pressure difference between the pores and the air-vapor mixture it is important to know the pressures and temperatures 80 84.86 0.0178 1.233 44.1 208.5 0.0926 0.3973 233.0 0.437 257.9 0.478 at which pressure equilibrium is reached. . 82 87.74 0.0178 1.199 44.8 208.7 0.0940 0.3967 233.3 0.436 258.4 0.478 84 90.62 0.0179 1.165 45.6 209.0 0.0953 0.3960 233.6 0.435 258.9 0.477 86 93.50 0.0179 1.130 46.3 209.2 0.0967 0.3954 233.9 0.435 259.4 0:477 Evidently the equilibrium conditions represent the limits beyond which adsorption of vapor cannot continue. The relationship can .be i 88 96.38 0.0180 90 99.26 0.0180 92 102.49 0.0180 94 105.72 0.0181 1.096 1.062 1.033 1.005 47.1 47.8 48.6 49.3 209.5 0.0980 0.3947 234.2 0.434 259.9 0.476 209.7 0.0994 0.3941 234.5 0.433 260.4 0.476 209.9 0.1008 0.3935 234.8 0.433 260.8 .0.476 210.2 0.1022 0.3929 235.1 0.432 261.2 0.475 shown graphically and Fig. 1 is such a chart for silica gel. Charts of like nature can be plotted for other adsorbent materials. Fig. 1 shows the equilibrium conditions for a gel bed maintained at 96 108.94 0.0181 0.9764 50.1 210.4 0.1035 0.3922 235.4 0.432 261.6 0.475 constant temperature while the water vapor adsorption is allowed to : 98 112.17 0.0182 100 115.40 0.0182 102 119.00 0.0183 0.9478 50.8 210.7 0.1049 0.3916 235.7 0.431 262.0 0.474 0.9193 51.6 210.9 0.1063 0.3910 236.0 0.431 262.4 0.474 0.8952 52.3 211.1 0.1076 0.3903 236.4 0.430 262.8 0.474 continue until pressure equilibrium is reached. Each curve on the chart show a certain dew-point temperature, and therefore a certain pressure, of the saturated water vapor. 42 43 Heating Ventilating Air Conditioning Guide 1938 Table 5. Properties of Monofluorotrichlorombthane (Fn) 8aT. Temp. F A.. p la pcs Sq In. Volume liquid Vapor Heat Content and Entropt Taken Fbom -40 F Heat Content liquid Vapor Entropy 25 F Superheat 50 F 8nperfaeat liquid Vapor Ht Ct Entropy Ht Ct. Entropy 0 2.59 0.01020 13.700 7.81 90.4 0.0178 0.1975 93.9 0.2049 97.4 0.2120 s 2.96 0.01024 12.100 8.81 91.2 0.0200 0:1974 94.7 0.2047 98.2 0.2117 10 3.38 0.01028 10.700 9.82 92.0 0.0222 0.1973 95.5 0.2045 99.0 0.2114 15 3.85 0.01032 9.530 10.80 92.8 0.0243 0.1971 96.3 0.2043 99.8 0.2111 20 4.36 0.01036 8.490 11.90 93.7 0.0264 0.1970 .97.2 0.2041 100.7 0.2109 25 4.94 0.01040 7.580 12.90 94.5 0.0286 0.1969 98.0 0.2039 101.5 0.2107 30 5.57 0.01045 6.770 13.90 95.3 0.0307 0.1969 98.8 0.2038 102.3 0.2105 35 6.27 0.01049 6.080 14.90 96.1 0.0328 0.1968 99.6 0.2037 103.1 0.2103 40 7.03 0.01053 5.460 16.00 96.8 0.0349 0.1968 100.3 0.2036 103.8 0.2101 45 7.88 0.01057 4.920 17.00 97.6 0.0370 0.1967 101.1 0.2035 104.6 0.2099 SO 8.79 0.01062 4.440 18.10 98.4 0.0391 0.1967 101.9 0.2034 105.4 0.2098 55 9.80 0.01066 4.020 19.10 99.2 0.0412 0.1967 102.7 0.2033 106.2 0.2097 60 10.90 0.01071 3.640 20.20 100.0 0.0432 0.1967 103.5 0.2033 107.0 0.2096 65 12.10 0.01076 3.300 21.30 100.8 0.0453 0.1967 104.3 0.2032 107.8 0.2094 70 13.40 0.01081 3.000 22.40 101.5 0.0473 0.1967 105.0 0.2032 108.5 0.2093 75 14.80 0.01086 2.740 23.50 102.2 0.0493 0.1967 105.7 0.2031 109.2 0.2092 80 16.30 0.01091 2.500 24.50 102.9 0.0513 0.1966 106.4 0.2030 109.9 0.2090 85 17.90 0.01096 2.280 25.60 103.6 0.0533 0.1966 107.1 0.2029 110.6 0.2089 90 19.70 0.01101 2.090 26.70 104.4 0.0553 0.1966 107.9 0.2028 111.4 0.2088 95 21.60 0.01106 1.918 27.80 105.1 0.0573 0.1966 108.6 0.2028 112.1 0.2087 100 23.60 0.01111 1.761 28.90 105.7 0.0593 0.1965 109.2 0.2027 112.7 0.2085 105 25.90 0.01116 1.620 30.10 106.4 0.0613 0.1965 109.9 0.2026 113.4 0.2084 As an example in the interpretation of the chart consider the case when moist air at a temperature of 80 F and a partial vapor pressure of 0.5 in. of mercury flows through a bed of silica gel which is at a temperature of 80 F. The chart indicates that the equilibrium of pressure between the air-vapor mixture and the bed is reached when the dry bed has adsorbed moisture to the extent of 31 per cent of the weight when dry. When this happens the bed can adsorb no more moisture unless its temperature is changed. In practice however the adsorbent bed is seldom held at a steady tem perature in air conditioning applications and neither is the adsorption process permitted to continue until moisture equilibrium is reached. . Instead, the bed temperature varies and the bed-is re-activated before equilibrium is .approached. While charts of this kind can show the limiting properties of the substances they are seldom directly applicable to the solution of air conditioning problems unless considerable additional information is available. This takes the form of performance data cover ing the characteristics of the equipment in which the adsorbent bed, is placed. Such performance data are beyond the scope of this chapter. Liquid Absorbents Any absorbent substance may be used as an air drying agent if it has a vapor pressure lower than the vapor pressure in the air-vapor mixture from which the moisture is to be removed. Absorbents are character istically water solutions of materials in which the vapor pressure is 44 Chapter 2. Refrigerants and Air Drying Agents reduced to a suitable level by governing the concentration of the solution. In addition to having a,suitable low vapor pressure, a practical absorbent must also be widely available at economical cost, be non-corrosive, odorless, non-toxic, chemically inert against any impurities in the air stream, stable over the range of use and especially it must not precipitate out at the lowest temperature to which the apparatus is exposed. It must have low viscosity and be capable of being economically regenerated or concentrated after having been diluted by absorbing moisture. Water solutions, or brines, of the chlorides of various inorganic elements such as calcium chloride and lithium chloride are the absorbents most frequently used in connection with air conditioning applications and de tailed attention is confined to these two in this chapter. Nature of Absorption Process The application consists of bringing the air-vapor stream into intimate contact with the absorbent, permissably by passing the air stream through a finely divided spray of the brine but more generally by passing the air over a metal surface coil where the liquid absorbent presents a large surface to the air stream. The difference in vapor pressures causes some of the vapor in the air-vapor mixture to migrate into the brine. Here it condenses into liquid water and decreases the concentration of the absor bent. In order that the process be continuous means must be provided for counteracting the diluting effect of the extracted moisture and also for maintaining the temperature of the brine sufficiently low to hold the desired vapor pressure. ' As the water vapor is added to the absorbent and condenses, it gives up its latent heat of condensation which tends to raise the temperature of both the absorbent and the moist air stream. For every pound of water absorbed and condensed the heat added to the air stream and the brine Table 5. Properties of Water Sat. Temp. F Abs Press. Lb per Sq In. Volume liquid Vapor Heat Content and Entropt Taken From +32 F Heat Content liquid Vapor Entropy liquid Vapor 50 F Superheat 100 F Superheat Ht. Ct. Entropy Ht Ct. Entropy 32 0.0887 0.01602 3296.0 0.00 1073.0 0.0000 2.1826 1096.9 2.2277 1120.8 2.2688 35 0.1000 0.01602 2941.0 3.02 1074.4 0.0062 2.1724 1098.3 2.2172 1122.2 2.2581 40 0.1217 0.01602 2441.0 8.05 1076.8 0.0163 2.1555 1100.6 2.2000 1124.5 2.2406 45 0.1475 0.01602 2034.0 13.07 1079.2 0.0262 2.1390 1102.9 2.1832 1126.7 2.2234 50 0.1780 0.01602 1702.0 18.08 1081.5 0.0361 2.1230 1105.2 2.1667 1129.0 2.2066 55 0.2140 0.01603 1430.0 23.08 1083.9 0.0459 2.1073 1107.5 2.1506 1131.3 2.1902 60 0.2561 0.01603 1206.0 28.08 1086.2 0.0556 2.0920 1109.8 2.1349 1133.5 2.1742 65 0.3054 0.01604 1021.0 33.08 1088.6 0.0652 2.0771 1112.2 2.1196 1135.8 2.1585 70 0.3628 0.01605 868.0 38.07 1090.9 0.0746 2.0625 1114.5 2.1046 1138.1 2.1432 75 0.4295 0.01606 740.0 43.06 1093.2 0.0840 2.0483 1116.7 2.0900 1140.3 2.1283 80 0.507 0.01607 632.9 48.05 1095.5 0.0933 2.0344 1119.0 2.0758 1142.5 2.1138 85 0.596 0.01609 543.3 53.04 1097.8 0.1025 2.0208 1121.2 2.0619 1144.7 2.0996 90 0.698 0.01610 467.9 58.03 1100.0 0.1116 2.0075 1123.4 2.0483 1146.8 2.0857 95 0.815 0.01612 404.2 63.01 1102.3 0.1206 1.9946 1125.6 2.0350 1148.9 2.0721 100 0.949 0.01613 350.3 68.00 1104.6 0.1296 1.9819 1127.9 2.0220 1151.1 2.0588 105 1.101 0.01615 304.4 72.98 1106.8 0.1384 1.9695 1130.2 2.0093 1153.2 2.0458 For properties of steam at high temperatures, see Page 28. Heating Ventilating Air Conditioning Guide 1938 Table 7. Dew-Point of Air in Equilibrium with Lithium Chloride Solutions Concentration in gram mols of Lithium Chloride per 1000 Grains Water 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0 320 315.2 308.7 299.9 290.2 279.7 269.4 259.6 251.5 244.1 236.5 230.0 223.8 218.6 214.5 210.3 300 295.4 289,1 280.5 270.9 260.6 250.5 240.8 232.6 225.4 218.C 211.8 205.8 1200.8 196.9 192.8 280 275.6 269.5 261.1 251.7 241.5 231.6 222.2 214.C 206.7 199.7 193.5 187.8 183.2 179.3 175.2 260 255.8 250.0 241.9 232.6 222.7 212.8 203.5 195.5 188.4 181.7 175.4 170.C 165.6 162.C 158.4 240 236.0 230.4 222.5 213.5 203.8 194.2 185.0 177.1 170.C 163.6 157.5 152.2 148.3 144.6 140.5 220 216.2 210.8 203.2 194.4 184.9 175.5 166.4 158.6 151.6 145.3 139.6 134.6 130.7 127.3 124.2 200 196.4 191.2 183.9 175.4 166.1 156.7 148.0 140.3 133.5 127.3 121.9 117.0 113.3 110.1 180 176.6 171.6 164.7 146.4 147.3 138.1 129.6 122.1 115.5 109.4 104.2 99.6 96.0 160 156.8 152.1 145.4 137.4 128.6 119.7 111.3 103.9 97.4 91.6 86.6 82.2 140 137.0 132.6 126.1 . 118.4 109.9 101-3 93.1 85.9 79.5 73.8 69.0 120 117.2 113.0 106.8 99.4 91.1 82.7 74.7 67.8 61.5 56.0 110 107.3 103.2 97.2 89.9 81.9 73.5 65.6 58.8 52.6 47.1 100 97.4 93.4 87.5 80.5 72.7 64.4 56.6 49.8 43.7 38.2 90 87.5 83.6 77.9 71.0 63.3 54.2 47.6 40.8 34.8 29_3 80 77.6 73.8 68.4 61.6 54.0 46.1 38.5 31.8 25.9 20.6 70 67.7 64.0 58.7 52.2 44.8 37.0 29.5 22.9 17.2 12.0i 60 57.8 54.3 49.1 42.7 35:5 27.9 20.5 14.0 8.3 40 38.0 34.7 29.9 23.9 16.9 9.6 2.4 -3.9 20 15.1 10.7 5.0 -1.7 -8.7 -15.4 0 -4.5 -8.6 -13.9 -20.2 -27.0 -33.3 combined is obtainable from steam tables. For instance, at 60 F the amount of this heat, is about 1057 Btu. In addition to this heat there is involved also the so-called heat of mixing which is frequently, considerable. Temperature-Pressure-Concentration Relations Since the absorption process can continue only as long as there is a difference in vapor pressure between the absorbent and the air-vapor mixture and since at a given temperature of the absorbent the vapor pressure depends on the concentration of the solution, evidently there Table 8. Density of Lithium Chloride Solutions 46 Chapter. 2. Refrigerants and Air Drying Agents Table 9. Viscosity of Lithium Chloride Solutions (millipoise) Concentration in Molal - TEMP- Deg F 0 2 4 6 8 10 12 14 16 18 20 22 24 -- 56.75 72.44 97.05 136.8 199.5 28.91 37.07 47.42 63.09 84.94 1233 178.6 19.91 25.53 32.58 43.05 58.48 81.10 116.1 165.6 11.02 14.26 18.37 23.55 30.90 41.40 56.62 79.80 111.2 156.3 320 8-61 11.19 14.42 18.62 24.32 6-82 8.89 11.48 14.94 19.36 S 60 7.31 9.51 12.30 15.92 4 70 6.15 8.07 10.42 13.43 4.01 5.25 6.92 8.93 11.51 3 4 4.56 6.01 7.78 10.00 *os 4.01 5.28 6.86 8.79 ? 77 3.58 4.72 6.14 7.83 ? 4-3 3.21 4.25 5.50 7.02 2.19 2.90 3.84 4.94 6.46 2.00 2.66 3.52 4.51 5.75 1.86 2.48 3.28 4.17 5.32 1.74 2.32 3.08 3.89 4.94 32.28 25.59 20.99 17.66 15.00 12.91 11.22 9.93 8.83 7.91 7.19 6.67 6.19 43.45 33.96 27.67 22.96 19.36 16.56 1432 12.59 11.12 9.91 8.97 8.28 7.73 60.26 46.13 36.64 30.06 25.06 21.28 18.28 16.00 14.09 12.47 11.27 10.38 9.64 82.04 1133 61.52 84.72 118.3 48.31 65.77 89.95 38.99 52.48 71.12 95.94 32.14 42.76 56.89 75.86 106.2 27.10 35.48 46.45 60.67 84.33 23.12 29.92 38.55 50.70 67.92 20.14 25.64 32.96 43.05 56.49 17.62 22.18 28.31 36.98 47.42 15.50 1936 24.60 31.92 40.55 14.00 17.22 21.78 28.05 35.56 12.82 15.70 19.68 25.12 31.92 11.86 14.45 18.03 22.80 29.11 must be a relation between these quantities which if known would state the limits of the process. The relationship would also depend on the absorbent being used, and would have to be determined for each substance used as an absorbent. Fig. 2 shows this relationship graphically for lithium chloride. It will be noted that this chart is essentially similar to that shown in Fig: 1 and its direct usefulness is limited by much the same considerations. In order to permit numerical calculations of air conditioning problems it is desirable to have tables for use instead of a chart like Fig. 2, and -Tables 7, 8, 9 and 10 can be used in making calculations for lithium chloride. . Table 10. Properties of Lithium Chloride Solutions Concentration Mols (42.4 {hums LiCl per 1000 Gra<N3 Water) Partial Heat or Mixing at 0 F BTU PER LB Temperature Coef. op Partial Heat op Mixing BTU per LB PER F Specific Heat at 70 F Boiling Point F Freezing (at 760 MM Point Ho) 0 o.o 0.0 0.998 212.0 32 2 2.04 -0.014 0.901 215.8 16.3 4 7.24 -0.036 0.831 221.5 ' -5.8 6 16.7 -0.069 0.778 228.9 -34.2 8 31.9 -0.109 0.739 238.1 -69 10 51.1 -0.143 0.710 248.4 -90 12 75.7 -0.160 0.687 258.8 -40 14 90.8 -0.167 0.666 268.9 1 16 124.8 -0.176 0.647 277.9 36.5 18 145 -0.186 0.631 285.8 58.1 20 162 -0.194 0.617 293.2 86.4 22 171 -0.20 0.604 300.2 1-33 24 177 -0.20 0.59 307 156 26 182 -0.21 0.58 313 180 28 191 --0.21 0.575 318 190 30 194 -0.21 0.57 323 195. 32 198 -0.22 0.56 328 280 Substance that First Separates Out on Freezing Ice Ice Ice Ice ( Ice Ice LiCl-ZH) LiCISHiO UO-2H-P LiCUiH-P LiCl-HiO LiClrH-f) LiCl-HiO LiCLB-0 LiCl-lW Lid-HiO " LiCl 47 Heating Ventilating Air Conditioning Guide 1938 Instead of tabulating the vapor pressure of the solution of lithium chloride it is preferable to tabulate the dew-point of air in equilibrium with lithium chloride, since it is easy to interpolate between values of the dew-point and not so easy to interpolate accurately between values of vapor pressure. The values for dew-point may be converted to vapor CONCENTRATION, PER CENT Fig. 2. Temperature--Pressure--Concentrations for Lithium Chloride pressures, relative.humidity, and wet-bulb of air in equilibrium by means of the usual psychrometric chart or formula. In Tables 7, 8, 9 and 10 the unit of concentration is the mol. A `M-molal solution is defined as a solution containing M X 42.37 grains of anhydrous lithium chloride per 1000 grains of water. The formula con necting concentration in mols with weight in per cent is equivalent to: [100 X M X 42.37] -f- [1000 + (M X 42.37)]. 48 LOG VAPOR PRESSURE, MM.HG. Chapter 2. Refrigerants and Air Drying Agents PROBLEMS IN PRACTICE X What is the heat content above --40 F of 2.5 lb of ammonia when under a pressure of 92.9 lb per square inch gage and a temperature of 160 F? First determine the condition of the ammonia at the stated temperature and pressure. Do this by finding the absolute pressure which in this case is 92.9 lb gage plus 14.7 or 107.6 lb per square inch absolute. From Table 1 note that the saturation temperature at this pressure is 60 F. Therefore, the ammonia is superheated 100 F, and the total heat per pound can be read directly from the Table as 689.9 Btu. In the 2.5 lb of ammonia there are 2.5 X 689.9, or 1724.75 Btu. 2 What volume is necessary to accommodate 0.27 lb of saturated F12 vapor when compressed to 99.6 lb gage? The absolute pressure is 99.6 plus 14.7 or 114.3 lb. In Table 3 find that one pound of Fu vapor saturated occupies 0.368 cu ft. Then the 0.27 lb would occupy 0.27 X 0.368, or 0.099 cu ft. 3 0 How much heat would be removed from air passing over a coil through which 2 lb of methyl chloride per minute is forced? The coil Is under a gage pressure of 64 lh per square inch and the liquid refrigerant is completely vapor ized in passing through the coil. Find that the absolute pressure is 64 plus 14.7 or 78.7 lb per sq in. From Table 4 note that the saturation temperature at this pressure is 75 F (nearly) and that the heat content per pound of the vapor is 207.8 Btu. Also that the heat content of the liquid is 42.2 Btu per pound. Subtract 42.2 from 207.8 and 165.6 Btu per pound is the heat necessary to change the liquid refrigerant to a vapor (latent heat). As the heat to accomplish this change comes from the air around the coil, the heat removed from the air is 165.6 Btu per pound of methyl chloride evaporated in the coil. When the refriger ant is circulated at 2 lb per minute, 2 X 165.6, or 331.2 Btu per minute are removed from the air, or refrigerating effect is produced at the rate of 331.2 -s- 200, or 1.65 tons. 4 Calculate the dew-point, wet-bulb, relative humidity and absolute hu - midity of air in equilibrium at 100 F with pure lithium chloride solution of density 1.270. From Table 8 the concentration of a solution of density 1.270 at 100 F is 18.0 M. From Table 7 the dew-point of 18 M lithium chloride at 100 F is 43.7 F. From Table 6, Chapter 1, the partial pressure of water over the solution is 0.2858 in. of Hg, the absolute humidity is 42.00 grains per pound dry air, and the wet-bulb is 65.8 F. The relative humidity is 14.0 per cent. 5 # Calculate the boiling point, and freezing point of 18 M lithium chloride solutions. From Table 10, boiling point (standard) is 285.8 F, freezing point is 58.1 F. The salt precipitated on cooling to this temperature has the composition LiCl-2HjO. 6 t Calculate the heat of vaporization of 1 lb of water from a large amount of lithium chloride solution at the boiling point. . The heat of boiling is equal to the heat of mixing plus the heat of boiling pure water at the same temperature. The heat of mixing from Table 10 at 18 M and 285.8 F is (145 -- 0.186 X 285.8) = 92 Btu per pound. The heat of vaporization of water from steam tables at 285.8 F is 920 Btu per pound. Therefore the heat of vaporization of water from the solution is 920 + 92 = 1012 Btu per pound. 7 0 One thousand pounds of air per minute at 100 F dry-bulb with a dew-point of 70 F and a relative humidity of 39 per cent is passed over 18 M lithium chloride solution. The rate of flow of the solution is 200 gpm and the entering tempera ture is 80 F, The air leaves the absorber at 85 F dry-bulb and dew-point of 35 F. Calculate (a) the heat to be removed from the lithium chloride solution y49 Heating Ventilating Air Conditioning Guide 1938 to maintain these conditions, and (6) the temperature rise of the solution in passing through the absorber. a. The heat content of the entering air: From Table 6, Chapter 1, weight of vapor at 70 F dew-point is 0.01574 lb times heat content of steam at 100 F. dry-bulb is 1104.2 (Table 8, Chapter 1) equals 17.41 Btu per pound plus heat content of dry air at 100 F is 24.0 (Table 6, Chapter 1) resulting in heat content of mixture as 41.41 Btu per pound. Similarly, the heat content of the leaving air: Weight of vapor at 35 F dew-point is 0.004262 X 1097.5 = 4.68 Btu per pound plus heat content of dry air at 85 F is 20.39 resulting in heat content,of mixture as 25.07 Btu per pound. Heat to be extracted from air is 1000 :X'.(41'.41'25.07) =-16,340 Btu per minute. Add to this the heat of mixing of 18M lithium chloride at 80 F equals 145 -- (0.186 X 80) = 130 Btu per pound (Table 10) or for 1000 lb of air X, (0.01574 - 0.00426) X 130 = .1494 Btu per minute. Heat to be removed from solution is. 16,340 + 1494 = 17,834 Btu per minute. .. ' , b. The weight of solution circulated is 200 X 1.275 (Table 8) X 8.33 = 2124 lb per minute. Its heat capacity is 2124 X 0.631 (Table 10) = 1340 Btu per minute per degree Fahrenheit. The temperature rise is 17,834 -5- 1340 = 13.31 F. ... . . Chapter 3 PHYSICAL AND PHYSIOLOGICAL PRINCIPLES OF AIR CONDITIONING Vitiation of Air, Heat Regulation in Man, Effects of. Heat, Effects of Cold and Temperature Changes, Acclimatization, Effective Temperature Index of Warmth, Optimum Air Condi tions, Winter, and Summer Comfort Zone, Optimum Humid ity, Air Quality and Quantity, Air Movement and Distribution, Natural and Mechanical Ventilation, Heat and Moisture Losses, Ultra-Violet Radiation and Ionization, Recirculation - and Ozone, Ventilation Standards . - VENTILATION is defined in part as "the process of supplying or removing air by natural or mechanical means to or from any space." (See Chapter 45.) The word in itself implies quantity but not necessarily quality. From the standpoint of comfort and health, however, the problem is now considered to be one of securing air of the proper quality rather than of supplying a given quantity. The term air conditioning in its broadest sense implies control of any or all of the physical or chemical qualities of the air. More particularly, it includes the simultaneous control of temperature, humidity, movement, and purity of the air. The term is broad enough to embrace whatever ' other additional factors may be found desirable for maintaining the atmosphere of occupied spaces at a condition best suited to the physio logical requirements of the human body. VITIATION OF AIR Under the artificial conditions of indoor life, the air undergoes certain physical and chemical changes which are brought about by the occupants themselves. The oxygen content is somewhat reduced, and the carbon dioxide slightly increased by the respiratory processes. Organic matter, which is usually perceived as odors, comes from the nose, mouth, skin and clothing. The temperature of the air is increased by the metabolic processes, and the humidity raised by the moisture emitted from the skin and lungs. There is also a marked decrease in both positive and negative ions in the air of occupied rooms but the significance of this factor is still questionable1. Contrary to old theories, the usual changes in oxygen and carbon dioxide are of no physiological concern because they are much too small even under the worst conditions. The amount of carbon dioxide in air is ^Changes in Ionic Content in Occupied Rooms Ventilated, by Natural and Mechanical Methods, by C. P. Yaglou, L. C. Benjamin and S. P. Choate (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 191). 51 Heating Ventilating Air Conditioning Guide 1938 often used in ventilation work as an index of odors of human origin, but the information it affords rarely justifies the labor involved in making the observation2,3. Little is known of the identity and physiological effects of the organic matter given off in the process of respiration. The former belief that the discomfort experienced in confined spaces was due to some toxic volatile matter in the expired air is now limited, in the light of numerous researches, to the much less dogmatic view that the presence of such a substance has not been demonstrated. The only certain fact is that expired and transpired air is odorous and offensive, and it is capable of producing loss of appetite and a disinclination for physical activity. These reasons, whether esthetic or physiological, call for the introduction of a certain minimum amount of clean outdoor air to dilute the odoriferous matter to a concentration which is not objectionable. A certain part of the dissemination of disease in confined spaces is caused by the emission of pathogenic bacteria from infected persons. Droplets sprayed into the air in talking, coughing, sneezing, etc., do not all fall immediately to the ground within a few feet from the source, as it was formerly believed. The large droplets do, of course, but minute droplets less than 0.1 mm. in diameter evaporate to dryness before they fall the height of a man. Nuclear residues from such sources, which may contain infective organisms drift long distances with the air currents and the virus may remain alive long enough to be transmitted to other persons in the same room or building. Wells4 recovered droplet nuclei from cultures of resistant micro-organisms a week after inoculation into a tight chamber of 300 cu ft capacity. Typical organisms of infections of the upper respiratory tract (pneumococcus type I, B. diphtheriae, Strep tococcus hemolyticus, and Streptococcus viridans) were found to die out quite soon when exposed to light and air, and could be recovered from the air in small numbers only 48 hours after inoculation. Organisms typical of the intestinal tract (B. coli, B. typhosus, B. paratyphosus, A. and B. dysenteriae) were not recovered 12 hours after inoculation. The significant factors in infection are believed to be the numbers of infective organisms encountered, the frequency of exposure, and the resistance of the individual including the degree of acquired immunity. The probability of encountering a sufficient number of organisms to break down the natural body defense is related to the air space per person and the quantity of clean air supplied. Except in badly ventilated rooms, the danger is believed to be "much contracted in space, limited in time and . restricted to comparatively few diseases."3 Practical possibilities in sterilizing air supplies by the use of ultra violet light are now being studied6. The primary factors in air conditioning work, in the absence of any specific contaminating source, are temperature, radiation, drafts and' indices of Air Change and Air Distribution, by F. C. Houghten and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 261). Ventilation Requirements, by C. P. Yaglou, E. C. Riley and D. I. Coggins (A.S.H.V.E. Transactions,VoL 42, 1936. p. 133). Air-Borne Infection and Sanitary Air Control, by W. F. Wells, {Journal Industrial Hygiene, November, 1Q9M ' Preventive Medicine and Hygiene, by Milton J. Rosenau (6th edition, pp. 909-917, D. Appleton- Century Co., N. Y., 1935). . Viability of B. Coli Exposed to Ultra-Violet Radiation in Air, by W. F. Wells, and G. M. Fair CScience, 1935. 82 p. 280). 52 &Chapter 3. Physical Physiological Principles of Air Conditioning body odors. As compared with these physical factors, the chemical factors are, as a general rule, of secondary importance. HEAT REGULATION IN MAN The importance of the thermal factors arises from the profound in fluence which they exert upon body temperature, comfort and health. Body temperature depends on the balance between heat production and heat loss. The heat resulting from the combustion of food within the body maintains the body temperature well above that of the surrounding air. At the same time, heat is constantly lost from the body by radiation, conduction and evaporation. Since, under ordinary conditions, the body temperature is maintained at its normal level of about 98.6 F, the heat production must be balanced by the heat loss. In healthy persons this takes place automatically by the action of the heat regulating mechanism. According to the general view, special areas in the skin are sensitive to heat and cold. Nerve courses carry the sense impressions to the brain and the response comes back over another set of nerves, the motor nerves, to the musculature and to all the active tissues in the body, including the endocrine glands. In this way, a two-sided mechanism controls the body temperature by (1) regulation of internal heat production (chemical regulation), and (2) regulation of heat loss by means of automatic varia tion in the rate of cutaneous circulation and the operation of the sweat glands (physical regulation). The mechanisms of adjustment are complex and little understood at the present time. Coordination of these dif ferent mechanisms seems to vary greatly with different air conditions. With rising air temperatures up to 75 F or 80 F, metabolism, or internal heat production, decreases slightly7, probably by an inhibitory action on heat producing organs, especially the adrenal glands, which seem to exert the major influence on basic combustion processes in the body. The blood capillaries in the skin become dilated by reflex action of the vasomotor nerves, allowing more blood to flow into the skin, and thus increase its temperature and consequently its heat loss. The increase in peripheral circulation is at the expense of the internal organs. If this method of cooling is not in itself sufficient, the stimulus is extended to the sweat glands which allow water to pass through the surface of the skin, where it is evaporated. This method of cooling is the most effective of all, as long as the humidity of the air is sufficiently low to allow for evaporation. In high humidities, where the difference between the dew-point temperature of the air and body temperature is not sufficient to allow rapid evapora tion, equally good results may be obtained by increasing the air move ment, and hence the heat loss by conduction and evaporation. In cold environments, in order to keep the body warm there is an actual increase in metabolism brought about partly by voluntary muscular con tractions (shivering) and partly by an involuntary reflex upon the heat producing organs. The surface blood vessels become constricted, and the blood supply to the skin is curtailed by vasomotor shifts to the internal organs in order to conserve body heat. The sweat glands become inactive. THeat and Moisture Losses from the Human Body and Their Relation to Air Conditioning Problems, c.by F. Houghten, W. W. Teague. W. E. Miller and W. P. Yant (A.S.H.V.E. Transactions. Vol. 35, 1929, n. 245). - 53 Heating Ventilating Air Conditioning Guide 1938 EFFECTS OF HEAT Although the human organism is capable of adapting itself to variations in environmental conditions, its ability to maintain heat equilibrium is limited. The upper limit of effective temperature to which the human organism is capable of adapting itself without serious discomfort or injury to health is 90 deg ET for men at rest and between 80 and 90 deg ET for men at work depending upon the rate of work. Within these limits a new equilibrium is established at a higher body temperature level through a chain of physiological adjustments. The heat regulating center fails, when, the external temperature is so abnormally high that bodily heat cannot be eliminated as fast as it is produced. Part of it is retained in the body, causing a rise in skin and deep tissue temperature, an increase in the heart.rate, and accelerated respiration. (See Table 1.) In extreme Table 1. Physiological Responses to Heat of Men at Rest and at Work* Effective Temp. Actual Cheek Tekp. (Deo Fahb) Men at Rest . Men at'Wohk ' . 90,000 FT-LB OF'.WoBK PER HOUR ' ' . '. Rise in Rectal Temp. ` (Deg Fahrper -Hour) Increase , in Pulse ' Rate (Beats per Min per Hour) - Approximate Loss in Body Weight by Perspiration (Lb per Hr) Total Work ` Accomplished' (Ft-Lb) ' Rise in Body Temp. . (Deg Fahr per Hr) Increase in Pulse' Rate (Beats per Min per Hr) Approximate Loss in Body Wt. by Per spiration (Lb per Hr) . 60 . 70 80 85 90 95 100 105 110 __ __ 96.1 96.6 97.0 97.6 99.6 104.7 ------ - . .. 0.0 0.0 0.1 0.3 0.9 2.2 4.0 5.9b __ 0 0 1 4 15 40 83 137b 0.2* 0.3 0.4 0.5 0.9 1.7 , 2.7 4.0b 225,000 225,000 209,000 190;000 153,000 102,000 67,000 49,000 37,000 0.0 0.1 0.3 : 0.6 1.2 2.3 4.0 6.0b 8.5b 6 7 11 17 31 61 103b 158b 237b 0.5 0.6 0.8 1.1 1.5 ' 2^0 2.7 3.5b 4.4b . Data by A.S.H.V.E. Research Laboratory. ^Computed value from exposures lasting less than one hour. heat, the metabolic rate is markedly increased owing to the excessive rise in body temperature8, and a vicious cycle results which may eventually lead to serious physiologic damage. . Examples of this are met with in unusually hot summer weather and in hot industries where the radiant heat from hot objects renders heat loss from the body by radiation and convection impossible. Consequently, the workers depend entirely on evaporation for the elimination Of body heat. They stream with perspiration and drink liquids abundantly to replace the loss. ' One of the deleterious effects of high temperatures is that the blood is" diverted! from the internal organs to the surface capillaries, in order to serve in the process of cooling. This affects the stomach, heart, lungs and other vital organs, and it is suggested that the feeling of lassitude and discomfort experienced is due in part to the anaemic condition of the brain. The stomach loses some of its power to act upon the food, owing to a w `?aSl^'^mDBei6?e,and Kxiiosure to High Temperatures and Various Humidities, by W. J. McConnell. C. P. Yaglou and W. B. Fulton (A.S.H.V.E. Transactions. Vol. 31. 1925,'p. 123): 54 Chapter 3. Physical & Physiological Principles or Air Conditioning diminished secretion of gastric juice, and there is a corresponding loss in the antiseptic and antifermentive action which favors the growth of bacteria in the intestinal tract9. These are considered to be the potent factors in the increased susceptibility to gastro-intestinal disorders in hot summer weather. The victim may lose appetite and suffer from indiges tion, headache and general enervation, which may eventually lead to a premature old age. . In warm atmospheres, particularly during physical work, a considerable amount of chloride is lost from the system through sweating. The loss of this substance may lead to attacks of cramps, unless the salts are replaced in the drinking water. In . order to relieve both cramps and fatigue, Moss19 recommends the addition of 6 grams of sodium chloride and 4 grams of potassium chloride to a gallon of water. .. The deleterious physiologic effects of high temperatures exert a power ful influence upon physical activity, accidents, sickness and mortality. Both laboratory and field data show clearly that physical work in warm atmospheres is a great effort, and that production falls progressively as the temperature rises. The incidence of industrial accidents reaches.a minimum at about 68 F, increasing above and below that temperature'. Sickness and mortality rates increase progressively as the temperature rises. , ., EFFECTS OF COLD AND TEMPERATURE CHANGES The action of cold on human beings is not well known. Cold affects the human organism in two ways: (1) through its action on the body as a whole, and (2) through its action on the mucous membranes of the upper respiratory tract. Little exact information is available on the latter. On exposure to cold, the loss of heat is increased considerably and only within certain limits is compensation possible by increased heat produc tion and decreased peripheral- circulation. The rectal temperature often rises upon exposure to cold but the pulse rate and skin temperature fall. The blood pressure increases, owing to, constriction in the peripheral vessels. Just how cold affects health is not well understood. It imposes an extra load upon the heat-producing organs to maintain body tempera ture. The strain falls largely upon digestion, metabolism, blood circu lation, and the kidneys, and indirectly upon the nervous system11. Although the seasonal increase in morbidity and mortality sets in with the approach of cold weather, and subsides in the warm summer months, little is known of the specific causative factors and their mechanism, of action. Over-crowding of buildings, overheated rooms, lack of . venti lation, and close personal contacts are frequently held responsible for our ` winter ills, but the evidence is not conclusive. . In extremely cold atmospheres compensation by increased metabolism becomes inadequate. The body temperature falls and the reflex irritability of the spinal cord is markedly affected. The organism may finally pass into an unconscious state which ends in death. ,. Influence of Effective Temperature upon Bactericidal Action of Gastro-intestinal Tract, by Arnold and Brody (Proceedings Society Exp. Biol. Med. Vol. 24,1927. p. 832). *Some Effects of High Air Temperatures upon the Miner, by K. N. Moss (Transactions Institute of Mining Engineers, Vol. 66, 1924, p. 284). "Loc. Cit. Note 5. ' 55 Heating Ventilating Air Conditioning Guide 1938 Cannon showed that excessive loss of heat is associated with increased activity of the adrenal medulla12. The extra output of adrenin hastens heat production which protects the organism against cooling. Bast13 found a degeneration of thyroid and adrenal glands upon exposure to cold. A moderate amount of variability in temperature is known to be beneficial to health, comfort, and the performance of physical and mental work. On the other hand, extreme changes in temperature, such as those experienced in passing from a warm room to the cold air out-of-doors, appear to be harmful to the tissues of the nose and throat which are the portals for the entry of respiratory diseases. '** Experiments show that chilling causes a constriction of the blood vessels of the palate, tonsils, throat, and nasal mucosa, which is accom panied by a fall in the temperature of the tissues. On re-warming, the palate and throat do not always regain their normal temperature and blood supply. This anaemic condition favors bacterial activity and it probably plays a part in the disposition of common cold and other respiratory diseases. It is believed that the lowered resistance is due to a diminution in the number and phagocytic activity of the leucocytes (white blood cells) brought about by exposure to cold and by changes in temperature. . Sickness records in industries seem to strengthen this belief. The Industrial Fatigue Research Board of England14 found that in workers exposed to high temperatures and to changes in temperature, namely, steel melters, puddlers, and general laborers, there is an excess of all sickness, the excess among the puddlers being due chiefly to respiratory diseases and rheumatism. The causative factor was not the heat itself but the sudden changes in temperature to which the workers were exposed. The tin-plate millmen who were not exposed to chills, since they work almost continuously throughout the shift, had no excess of rheumatism and respiratory diseases. On the other hand, the blast-furnacemen, who work mostly in the open, showed more respiratory sickness than the steel workers. This experience in British factories is well in accord with the findings in American industries15, 16. According to these data the highest pneumonia death rate is associated with dust, extreme heat, exposure to cold, and to sudden changes in temperature. ACCLIMATIZATION ' Acclimatization, and the factor of psychology are two important in fluences in air conditioning which cannot be ignored. The first is man's ability to.adapt himself to changes in air conditions; the'second is an intangible matter of habit and suggestion. Some persons regard the unnecessary endurance of cold as a virtue.- ``Studies on the Condition of Activity of Endocrine Glands, by W. B. Cannon, A. Guerido, S. W. Britton and E. M. Bright (American Journal of Physiology, Vol. 79, 1926, p. 466). ' . ``Studies in Exhaustion Due to Lack of Sleep, by T. H. Bast, J. S.Supernaw, B. Lieberman and J. Munro (American Journal of Physiology, Vol.-85, 1928. p. 135). - "Fatigue and Efficiency in the Iron and Steel Industry, by H. M. Vernon (Industrial Fatigue Research Board, Report No. 5, 1920, London). ' "Iron Foundry Workers Show Highest Percentage of Deaths from Pneumonia (Statistical Bulletin, Metropolitan life Insurance Company. 1928). ' "The Pneumonia Problem in the Steel Industry, by D. K. Brundage and J. J.' Bloomfield, (Journdl of Industrial Hygiene, 14, December, 1932). Chapter 3 Physical & Physiological Principles or Air Conditioning They believe that the human organism can adapt itself to a wide range of air conditions with no apparent discomfort or injury to health. In the light of the present knowledge of air conditioning these views are not justified. Acclimatization to extreme conditions involves a strain upon the heat regulating system and it interferes with the normal physiologic functions of the human body. Thousands of years in the heat of Africa do not seem to have acclimatized the Negro to a temperature averaging 80 F. The same holds true of northern races with respect to cold, although the effects are mitigated by artificial control. All this seems to indicate that adaptation to an environment averaging between 60 and 80 F is a very primitive trait17. Within these limits, however, there does occur a definite adaptation to external temperature level. People and animals raised under conditions of tropical moist heat have a lower rate of heat production than do those who grow up in cooler environments. This causes them to stand chilling poorly as they are unable to quickly increase internal combustion to keep up the body temperature. For this reason they have trouble standing the cold, stormy weather of the temperate zones, and when exposed to it are very susceptible to respiratory infections. Likewise, people living in cool climates suffer greatly in the moist heat of the tropics until their adrenal activity has slowed down. Within a couple of years, however, they find themselves standing the heat much better and disliking cold. They become acclimated by a definite change in the combustion level within the body18. In certain individuals the psychologic factor is more powerful than acclimatization. A fresh air fiend may suffer in a room with windows closed regardless of the quality of the air. As a matter of fact, instances are known in which paid subjects refused to stay in a windowless but properly conditioned experimental chamber because the atmosphere felt suffocating to them upon entering the room. EFFECTIVE TEMPERATURE INDEX OF WARMTH Sensations of warmth or cold depend, not only on the temperature of the surrounding air as registered by a dry-bulb thermometer, but also upon the temperature indicated by a wet-bulb thermometer. Dry air at a relatively high temperature may feel cooler than air of considerably lower temperature with a high moisture content. Air motion makes any moderate condition feel cooler. On the other hand, in cold environments an increase in humidity produces a cooler sensation. The dividing line at which humidity has no effect upon warmth varies with the air velocity and is about 46 F (drybulb) for still air and about 51, 56 and 59 F for air velocities of 100, 300 and 500 fpm, respectively. Radiation from cold or warm surfaces is another important factor under certain conditions. ' Combinations of temperature, humidity and air movement which induce the same feeling of warmth are called thermo-equivalent con- "Civilization and Climate, by Ellsworth Huntington, Yale University Press, 1924. "Air Conditioning in its Relation to Human Welfare, by C. A. Mills (A.S.H.V.E. Transactions,..Vol. 40,1934. p. 289). ' .............. ._ 57 EMPERATURE. Temperature Chart Showing Normal Scale of'Effective APPLICABLE TO INHABITANTS OF THE UNITED STATES UNDER Following .Conditions: : 58 Chapter 3. Physical & Physiological Principles or Air Conditioning ditions. A series of tests19,201 !1,22 at the A.S.H.V.E. Research Labora tory, Pittsburgh, established the equivalent conditions met with in general air conditioning work. This scale of thermo-equivalent conditions not only indicates the sensation of warmth, but also determines the physiological effects on the body induced by heat or cold. For this reason, it is called the effective temperature scale or index. Effective temperature is ah empirically determined index of the degree of warmth perceived on exposure to different combinations of tempera ture, humidity, and air movement. It was determined by trained subjects who compared the relative warmth of various air conditions in two ad joining conditioned rooms by passing back and forth from one room to the other. . Effective temperature is not in itself an index of comfort, except under ordinary humidity conditions (30 to 60 per cent) when the individual is least conscious of humidity. Moist air at a comparatively low tem perature, and dry air at a higher temperature may each feel as warm as air of an intermediate temperature and humidity, but the comfort ex perienced in the three air conditions would be different, although the effective temperature is the same. . Air of proper warmth may, for instance, contain excessive water vapor, and in this way interfere with the normal physiologic loss of moisture from the skin, leading to damp skin and clothing and producing more or less discomfort; or the air may be excessively dry, producing appreciable discomfort to the mucous membrane of the nose and to the skin which dries up and becomes chapped from too rapid loss of moisture. The numerical, value of the effective temperature index for any given air condition is fixed by the temperature of calm (15 to 25 fpm air move ment) and saturated air which induces a sensation of warmth or cold like that of the given condition. Thus, any air condition has an effective ' temperature of 60 deg, for instance, when it induces a sensation of warmth like, that experienced in calm air at 60 deg saturated with moisture. The effective temperature index cannot be measured directly but it is com puted from the dry- and wet-bulb temperature and the velocity of air using charts (see Figs. 1 or 2, 3 and 4) or tables. The accuracy in esti mating. effective temperature is 0.5 F, because the human organism cannot perceive smaller temperature differences. Therefore, there is no justification in trying to read chart values closer than 0.5 F, as this implies fictitious accuracy. -. The charts shown in Figs. 1, 2, 3 and 4 apply to average normal and healthy persons adapted to American living and working conditions. Application is limited to sedentary or light muscular activity, and to rooms heated by the usual American convection methods (warm air, central fan and direct hot water and steam heating systems) in which the difference between the air and wall surface temperatures may not be too `Determining Lines of Equal Comfort, by F. C. Houghten and C. P. Yaglou (A.S.H.V.E. Trans actions, "Vol. 29. 1923, p. 361). / Effect on Human Beings by Various Air Velocities, by F. C. Houghten and C. P. Yaglou (A.S.H.V.E. Transactions. Vol. 30. 1924, p. 193). . aEffective Temperature with Clothing, by C. P. Yaglou and W. E. Miller (A.S.H.V.E. Trans actions, Vol. 31. 1925, p. 89). ^Effective Temperature for Persons Lightly Clothed and Working in Still Air.by F. C. Houghten, W-.'W. Teague and W. E. Miller (A.S.H.V.E. Transactions, Vol. 32. 1926, p;315). .... * 59 Heating Ventilating Air Conditioning Guide 1938 great. The charts do not apply to rooms heated by radiant method such as British panel system, open coal fires and similar usages. They will probably not apply to races other than the white or perhaps to inhabitants of other countries where the living conditions, climate, heating methods, and clothing are materially different than those of the subjects employed in experiments at the Research Laboratory. Physical & Physiological Principles of Air Conditioning CHAPTER 3. passing back and forth from a small experimental room having three cold walls to a control room with walls and air at the same temperature. It can be seen in Fig. 5 that with air and walls at 70 F in the control --n mami. the cooling effect of three cold walls at 55 F of the - ' *-------- c-------------- In rooms in which the average wall surface temperature is considerably below or above air temperature, a correction must be applied to the' readings of the dry-bulb thermometer to allow for such negative or positive radiation. In Fig. 5 is given the cooling effect of cold walls as determined at the A.S.H.V.E. Research Laboratory23 by trained subjects - "Cold Walla and Their- Relation to the Reeling of Warmth, by F. C. Houghten and Paul McDermott (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 83). 60 the temperature in the experimental room should be increased to 74 F. The reverse would hold in rooms with high-wall surface temperature; a lower air temperature would be required to compensate for positive radiations to the occupants. 61 Heating Ventilating Air Conditioning Guide 1938 OPTIMUM AIR CONDITIONS No single comfort standard can be laid down which would meet every need. There is an inherent individual variation in the sensation of warmth or comfort felt by persons when exposed to an identical atmos pheric condition. The state of health, age, sex, clothing, activity, and Chapter 3- Physical & Physiological Principles of Air Conditioning heat regulating mechanism of the body. This belief is strengthened by results of studies on premature infants over a four-year period24. By adjusting the temperature and humidity so as to stabilize the body tem perature of these infants, the incidence of diarrhoea and mortality was decreased, gains in body weight increased and infections were reduced to a minimum. . Winter Comfort Zone and Comfort Line In Fig. 6 is shown the A.S.H.V.E. winter comfort zone which was determined experimentally with large groups of men and women subjects wearing customary indoor winter clothing. The extreme comfort zone includes conditions between 60 and 74 deg ET in which one or more of the experimental subjects were comfortable. The average comfort zone s ' g o- SIV ABO JO ONnOd S3J SMIUSIOI'V JO SNiVHO the degree of acquired adaptation seem to be the important factors affecting the comfort standards. Since the prolonged effects of temperature, humidity and air move ment on health are not known to the same extent as their effects on com fort, the optimum conditions for health may not be identical with: those for comfort. On general physiologic grounds, however, the two do not differ greatly since this is in accordance with the efficient operation of the 62 Fig. S. Cooling Effect of Three Cold Walls in a Small Experimental Room, as Determined by Comparison with Sensations in a Room of Uniform Wall and Air Temperature includes conditions between 63 and 71 deg ET conducive to comfort in 50 per cent or more of the experimental subjects. The most popular effective temperature was found to be 66 deg, and was adopted by the Society26 as the "winter comfort line for individuals at rest wearing custom ary winter clothing. . The comfort line separates the cool air conditions to its left from the warm air conditions to its right. Under the air conditions existing along or defined by the comfort line, the body is able to maintain thermal ^Application of Air Conditioning to Premature Nurseries in Hospitals, by C. P. Yaglou, Philip Drinker and R. D. Blackfan (A.S.H.V.E. Transactions, Vol. 36, 1930. p. 383), . " *How to Use the Effective Temperature Index and Comfort Charts (A.S.H.V.E. Transactions, Vol. 38. 1932. p. 410). 63 / Heating Ventilating Air Conditioning Guide 1938 Chapter 3. Physical & Physiological Principles or Air Conditioning i made in rooms with wall surface temperatures approximately the same as the room dry-bulb temperature. For walls of large area having unusually high or low surface temperatures, however, a somewhat lower or higher range of effective temperature is required to compensate for the increased gain or loss of heat to or from the body by radiation as shown in Fig. 5. (See also Chapter 41). The average winter comfort line (66 deg ET) applies to average American men and women living inside the broad geographic belt across the United States in which central heating of the convection type is generally used during four to eight months of the year. It does not apply to rooms heated by radiant energy, rooms with excessive glass area or rooms with poorly insulated or cold walls. Even in the warm south and southwestern climates, and in the very cold north-central climate of the United States, the comfort chart would probably have to be modified according to climate, living and working conditions, and the degree of acquired adaptation. . In densely occupied spaces, such as classrooms, theaters and audi toriums, somewhat lower temperatures may be necessary than those indicated by the comfort line on account of counter-radiation between the bodies of occupants in close proximity28. The sensation of comfort, insofar as the physical environment is con cerned, is not absolute but varies considerably among certain individuals. Therefore, in applying the air conditions indicated by the comfort line, it should not be expected that all the occupants of a room will feel per fectly comfortable. When the winter comfort line is applied in accordance with the foregoing recommendations, the majority of the occupants will be perfectly comfortable, but there will always be a few who would feel a bit too cool and a few a bit too warm. These individual differences among the minority should be counteracted by suitable clothing. Air conditions lying outside the average comfort zone but within the extreme comfort zone may be comfortable to certain persons. In other words, it is possible for half of the occupants of a room to be comfortable in air conditions outside the average comfort zone, but in the majority of cases, if not in all, these conditions will be well within the extreme comfort zone as determined experimentally. . Ntfe.--Both summer and winter comfort zones apply to inhabitants of the United States only. Applica tion of winter comfort line is further limited to rooms heated by central station systems of the convection .The line does not apply ta rooms heated by radiant methods. Application of summer comfort line v?lTM^Th..hftale)i' fPiS th,e ft6, ,whH5 the_pccupants become fuUy adapted to the artificial air con! 3 horns Th U d 1 PP tD theatera' department stores, and the like where the exposure is less than equilibrium with its environment with the least conscious sensation to the individual, or with the minimum phsyiologic demand on the heat regulat ing mechanism.. This environment involves not only the condition of the air with respect to temperature and humidity, but also the condition of the surrounding objects and wail surfaces. The. comfort zone tests were The comfort chart (Fig. 6) applies to adults between 20 and 70 years of age living in the northeastern parts of the United States. For pre maturely bom infants, the optimum temperature varies from 100 F to 75 F, depending upon the stage of development. The optimum relative humidity for these infants is placed at 65 per cent29. No data are yet available on the optimum air conditions for full term infants and young, children up to school age. Satisfactory air conditions for these age groups are assumed to vary from 75 F to 68 F with natural indoor humidi ties. For school children, the studies of the New York State Commission on Ventilation place the optimum air conditions at 66 F to 68 F tempera ture with a moderate humidity (not specified) and a moderate but not excessive amount of air movement (not specified)30. "determination of the Comfort Zone With Further Verification of Effective Temperatures Within This Zone, by F. C. Houghten and C. P. Yaglou (A.S.H.V.E. Transactions, Vol. 29, 1923, p. 361). TR^CTloMmVoh03^19M!npe.:2Mrte C`thinE' by C P: YagIoa and PhiU>> ?rinker (A.S.H.V.E. 64 "Loc. Cit. Note 27. . "Loc. Cit. Note 24. "Ventilation (Report N. Y. State Commission on Ventilation. E. P. Dutton and Co., N. Y,, 1923). 65 1 Heating Ventilating Air Conditioning Guide 1938 Satisfactory comfort conditions for men at work are found to vary from 40 deg to 70 deg ET, depending upon the rate of work and amount of clothing worn31. In hot industries, 80 deg ET is considered the upper limit compatible with efficiency, and, whenever possible, this should be reduced to 70 deg ET or less. Summer Comfort Zones The summer comfort zone is much more difficult to fix than the winter zone owing to the complicating factor of sweating in warm weather. A given air condition which is comfortable for person's with dry skin and clothing may prove too cold for those, perspiring, as is the case, for instance, with employees and customers in a cooled store, restaurant, or theater, on a warm summer day. The conditions to be maintained in . different types of public buildings depend to a large extent upon the oc cupants' length of stay and upon the prevailing outdoor condition. In Fig. 6 is shown the summer comfort zone for exposures of 3 hours or more, after adaptation has taken place. The average zone extends from 66 to 75 deg ET, with a comfort line at 71 deg ET, as determined at the Harvard School of Public Health32. These effective temperatures average about 4 deg higher than those found in winter when customary winter clothing was worn. The variation from winter to summer is probably due partly to adaptation to seasonal weather and partly to differences in the clothing worn in the two seasons. The best effective temperature (for exposures lasting 3 hours or more) was found to follow the average monthly outdoor temperature more closely than the prevailing outdoor temperature. It remained at approxi mately the same value in July, August and September, and although the average monthly temperature did not vary much, the prevailing outdoor temperature ranged from 70 F to 99.5 F. A decrease in the optimum temperature became apparent only when the prevailing outdoor tempera ture fell to 66 F, which is below the customary room temperature in the United States for summer and winter. ' . Crowding the experimental chamber lowered the comfortable effective temperature from 70.8 deg when the gross floor area per occupant was 44 sq ft and the air space 380 cu ft, to 69.4 deg when the floor area was reduced to 14 sq ft and the air space to 120 cu ft per occupant. ' The basic summer comfort zone, shown in Fig. 6 has more academic than practical significance. It prescribes conditions of choice for con tinuous exposures, as in homes, offices, etc., without regard to costs, prevailing outdoor air conditions, and temperature contrasts upon entering or leaving the cooled space. A great number of persons seem to be content with a higher plane of indoor temperature, particularly when the matter of first cost and cost of operation of the cooling plant is givendue consideration. According to previous investigations33, an indoor temperature of about 80 F with relative humidities below 55 per cent, or 74.5 deg ET and lower, result in satisfactory comfort conditions in the living quarters of a residence," "Loc. Cit. Note 22. "Loc. Cit. Note 27. . .,, ,,,, "Study of Summer Cooling in the Research Residence for the Summer of 1934, by A. P. Kratz, S. Konzo, M. K. Fahnestock and E. L. Broderick (A.S.H.V.E. Transactions, Vol. 41.1935. p. 207). 66 Chapter 3 Physical & Physiological Principles of Air Conditioning and while this condition is not representative of optimum comfort it provides for sufficient relief in hot weather to be acceptable to the majority of users. Experience in a number of air conditioned office buildings, including the New Metropolitan Life Building in New York31, indicates that a temperature of about 80 F with a relative humidity between 45 and 55 per cent (73 to 74.5 deg ET) is generally satisfactory in meeting the requirements of the employees. In artificially cooled theaters, restaurants, and other public buildings where the period of occupancy is short, the contrast between outdoor and indoor air conditions becomes the deciding factor in regard to the tem perature and humidity to be maintained. The object of cooling such places in the summer is to provide sufficient relief from the heat without causing sensations of chill or intense heat on entering and leaving the building. Effective temperatures as high as 75 F at times have been found satis factory in very warm weather. There are two schools of thought con cerning the relation between temperature and humidity to be maintained. For a given effective temperature some engineers including the operators of coojing plants favor a comparatively low temperature with a high humidity as this results in a reduction of refrigeration requirements. Preliminary experiments at the A.S.H.V.E. Laboratories36 would seem to indicate no appreciable impairment of comfort with relative humidities as high as 80 per cent, provided the effective temperature is between 70 and 75 deg. The second school favors a higher dry-bulb temperature, according to the prevailing outdoor dry-bulb, with a comparatively low humidity (well below 50 per cent); the main purpose being to reduce temperature contrasts upon entering and leaving the cooled space and. to keep the clothing and skin dry. This second scheme requires more refrigeration with the present conventional type of apparatus. Current practice in theatres, restaurants, etc.,' follows a schedule similar to that shown in Table 2. This schedule should be usedywith con siderable judgment depending on the occupancy and local climatic conditions. There are some indications that a definite indoor effective temperature may be applicable throughout the cooling season, but other observations seem to show that changing indoor conditions are desirable with violently changing outdoor weather conditions. It is, in fact, questionable whether entirely satisfactory air conditions could be adduced for practical use to meet the changing requirements of patrons from the time they enter to the time they leave a cooled space. Too many uncontrollable variables enter into the problem. Work how going on at the A.S.H.V.E. Laboratories and other interested institutions may throw considerable light on this complex problem. For cooled banks and stores where the customers come and go spending** **The Air Conditioned System of the New Metropolitan Building--First Summer's Experience, by W. J. McConnell and I. B. Kagey (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 217). Comfort Standards for Summer Air Conditioning, by F. C. Hougbten and Carl Gutbcrlct (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 215). Cooling Requirements for Summer Air Conditioning, by F. C. Houghten, F. E. Giesecke, Cyril Tasker and Carl Gutberlet (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, December, 1936, p. 681). 67 Heating Ventilating Air Conditioning Guide 1938 Table 2. Desirable Inside Conditions in Summer Corresponding to Outside Temperatures3 Occupancy Over Ifi Min Chrrsids Dbt-Bulb FDeo Effective Temperature AmInside Conditions Dry-Bulb Deg F Wet-Bulb Deg F Dew-Point Deg F 100 75 83 66 56 75 82 67 59 75 81 . 68 , 61 75 80 70 65 95 74 82 64 53 -74 81 66 57 74 80 67 60 74 79 68 62 74 78 70 66 90 73 81 63 52 . 73 80 64 54 73 79 66 59 73 78 67 61 85 72 80 61 48 72 79 63 53 72 78 64 56 72 77 66 60 80 71 78 61 49 71 77 63 54 71 76 64 57 . . J 71 75 66 61 "Applicable to individuals engaged in sedentary or light muscular activity. ' Relative Humid ity Per Cent 40 45 51 60 36 44 51 57 68 36 41 50 56 32 41 46 56 36 45 52 .61 but a few minutes in the cooled space, observations36 indicate a schedule about 1 deg dry-bulb or effective temperature higher than that shown in Table 2. Laboratory experiments with exposures of 2 to 10 min indicate temperatures 2 to 10 F higher than those in Table 2 but with much lower ^ relative humidities. It should be kept in mind that southern people, with their more sluggish heat production and lack of adaptability, will demand a comfort zone several degrees higher than that for the more active people of northern climates. Instead of the summer comfort line standing at 71 deg as here given, it was found to be much higher for foreigners in Shanghai where climatic conditions are similar to those of our gulf states. This difference in adaptability of people forms a very real problem for air conditioning engineers. Cooling of theaters, restaurants, and other public buildings in southern climates cannot be based on northern standards without con siderable modification. - Optimum Humidity Just what the optimum range of humidity is, is a- matter of conjecture. There seems to exist a general opinion, supported by some experimental and statistical data, that warm, dry air is less pleasant than air of a andVMi&S'l Ctetolier,TI932LratUre ShU`d DePend UPn Type f ""paIICy- b* J-* Walker (HcatUi 68 - --mi 3 physical & Physiological Principles or Air Conditioning Chapter moderate humidity, and that it dries up the mucous membranes in such a way as to increase susceptibility to colds and other respiratory dis orders ** 38' Owing to the cooling effect of evaporation, higher tem peratures are necessary, and this condition may lead to discomfort and lassitude. Moist air, on the other hand, interferes with the normal evaporation of moisture from the skin, and again may cause a feeling of oppression and lassitude, especially when the temperature is also high. For the premature infant, a high relative humidity of about 65 per cent is demonstrably beneficial to health and growth40 until the infants reach a weight of about 5 lb. No such clear-cut evidence exists in the case of adult persons. In the comfort zone experiments of the A.S.H.V.E. Research Laboratory, the relative humidity was varied between the limits of 30 and 70 per cent approximately, but the most comfortable range has not been determined. In similar experiments at the Harvard - School of Public Health, the majority of the subjects were unable to detect sensations of humidity (i.e., too high, too low, or medium) when the relative humidity was between 30 per cent and 60 per cent with_________. ordinary room temperatures. This is in accord with studies by Howell41, --I Miura42 and others. . The limitation of the comfort zones in Fig. 6 with respect to humidity must not be taken too seriously. Relative humidities below 30 per cent may prove satisfactory from the standpoint of comfort, so long as ex tremely low humidities are avoided. From the standpoint of health, however, the consensus seems to favor a relative humidity between 40 and 60 per cent. In mild weather such comparatively high relative humidi ties are entirely feasible, but in cold or sub-freezing weather they are objectionable on account of condensation and frosting on the windows. They may even cause serious damage to certain building materials of the exposed walls by condensation and freezing of the moisture accumulating . inside these materials. Unless special precautions are taken to properly insulate the affected surfaces, it will be necessary to reduce the degree of artificial humidification in sub-freezing weather to less than 40 per cent, according to the outdoor temperature. Information on the prevention of condensation on building surfaces is given in Chapter 7. The principles ' underlying humidity requirements and limitations are discussed more fully elsewhere4?. The purpose of artificial humidification may be easily defeated by failure to change the spray water of the humidifier at least daily. Where this condition occurs, the air is characterized by a lack of freshness, and under extreme conditions by a musty, sour odor in the conditioned space. "Reactions of the Nasal Cavity and Post-Nasal Space to Chilling of the Body Surface, by Mudd, Stuart, et al {Journal Experimental Medicine, 1921, Vol. 34, p. 11). "Reactions of the Nasal Cavity and Post-Nasal Space to Chilling of the Body Surfaces, by A. Goldman, et al and Concurrent Study of Bacteriology of Nose and Throat {Journal Infectious Diseases, 1921, Vol. 29, p. 151). "The Etiology of Acute Inflammations of the Nose, Pharynx and Tonsils, by Mudd, Stuart, et al {Am. Otol., Rhinol., and Laryngol., 1921). "Loc. Cit. Note 24. "Humidity and Comfort, by W. H. Howell {The Science Press, April, 1931). "Effect of Variation in Relative Humidity upon Skin'Temperature and Sense of Comfort, by U. Miura (American Journal of Hygiene, Vol. 13, 1931, p. 432). "Humidification for Residences, by A*. P. Kratz, University of Illinois {Engineering Experiment Station Bulletin No. 230, July 28, 1931). 69 . / Heating Ventilating Air Conditioning Guide 1938 Air Quality AIR QUALITY AND QUANTITY In occupied spaces in which the vitiation is entirely of human origin, the chemical composition of the air, the dust, and often the bacteria con tent may be dismissed from consideration so that the problem consists in maintaining a suitable temperature with a moderate humidity, and in keeping the atmosphere free from objectionable odors. Such unpleasant odors, human or otherwise, can be easily detected by persons entering the room from clean, odorless air. In industrial rooms where the primary consideration is the control of air pollution (dusts, fumes, gases, etc.), or contamination not removable at the source of production, the clean air supply must be sufficient to dilute the polluting elements to a concentration below the physiological threshold (see Chapters 4 and 26). Air Quantity The air supply to occupied spaces must always be adequate to satisfy the physiological requirements of the occupants. It must be sufficient to maintain the desired temperature, humidity, and purity with reasonable uniformity and without drafts. In many practical instances there are two air quantities to be considered, (a) outdoor air supply, and (b) total air supply. The difference between the two gives the amount of air to be recirculated. When the only source of contamination is the occupant, the minimum quantity of outdoor air needed appears to be that necessary to remove objectionable body odors, or tobacco smoke. The concentration of body odor in a room, in turn, depends upon a number of factors, including socio-economic status of occupants, outdoor air supply, air space allowed per person, odor adsorbing capacity of air conditioning processes, tem perature, and other factors of secondary importance. With any given group of occupants and type of air conditioner the intensity of body odor perceived upon entering a room from relatively clean air was found to vary inversely with the logarithm of outdoor air supply and the logarithm of the air space allowed per. person. The minimum outdoor air supply necessary to remove objectionable body odors under various conditions, as determined experimentally at the Harvard School of Public Health44, is given in Table 3. Outdoor air requirements for the removal of objectionable tobacco smoke odors have yet to be determined. Practical values in the field vary from 5 to 15 cfm per person; this air quantity may and should be a part of that necessary for other requirements, i.e., removal of body odors, heat, moisture, etc. . _ The total quantity of air to be circulated through an enclosure'is governed largely by the needs for controlling temperature and air dis tribution when either heating or cooling is required. The factors which determine total air quantity include the type and nature of the building, locality, climate, height of rooms, floor area, window area, extent of occupancy, and last but not least, the method of distribution. Serious difficulties are often encountered in attempting to cool a room "Loc. Cit. Note 3. 70 Chapter 3. Physical & Physiological Principles of Air Conditioning with a poor distribution system or with an air supply which is too small to result in uniform distribution without drafts. Some systems of distribu tion produce drafts with but a few degrees temperature rise, while other systems operate successfully with a temperature rise as high as 35 F.: The total air quantity introduced in any particular case is inversely pro portional to the temperature rise, and depends largely upon the judgment and ingenuity of the engineer in designing the most suitable system for the particular conditions. Table 3. Minimum Outdoor Air Requirements to Remove Objectionable Body Odors {Provisional values subject to revision upon completion of work) Ttpe of Occupants Am Space per Person Co Ft Outdoor* Am Supply CFM per Person Heating season with or without recirculation. Air not conditioned. ^pHpntarv adults of average socio-economic status.__ Sedentary adults of average socio-economic status.-- Sedentary adults of average socio-economic status.-- Sedentary adults of average socio-economic status___ 100 200 300 500 25 16 12 7 Laborers........................1........ -......... -.................................. 200 23 Grade school children of average class............................ Grade school children of average class............................ Grade school children of average class............................ Grade school children of average class............................ 100 200 300 500 . 29 21 17 11 Grade school children of poor class........... ...................... 200 38 Grade school children of better class. .......................... 200 18 Grade school children of best class...........................,...... 100 22 Heating season. Air humidified by means of centrifugal humidifier. Water atomization rate 8 to 10 gph. Total air circulation 80 cfm per .person. Sedentary Adults..... 200 12 Summer season. Air cooled and dehumidified by means of a spray dehumidifier. . Spray water changed daily. Total air circulation 80 cfm per person. Sedentary Adults. 200 <4 Impressions upon entering room from relatively clean air at threshold odor intensity. The changes in moisture content resulting from occupation in the atmosphere of a room supplied with various volumes of outside air is shown in Fig. 7. Data are given for an adult, 5 ft 8 in. in height, weighing 150 lb and, having a body surface of 19.5 sq ft and for a child, 12 years of age, 4 ft 7 in. in height weighing 76.6 lb and having a body surface area of 12.6 sq ft. Also given in Fig. 7 is the temperature of incoming air necessary to maintain a room temperature of either 70 or 80 F as indicated assuming that there is no heat gain or loss to the room by transmission through the walls, solar radiation or other sources. 71 Heating Ventilating Air Conditioning Guide 1938 AIR MOVEMENT AND DISTRIBUTION Stagnant warm air, no matter how pure, is not stimulating and it detracts to some extent from'the quality of air. Experience, and recent field studies by the A.S.H.V.E. Research Laboratory45 place the desirable air movement between 15 and 25 fpm under ordinary room temperatures during the heating season. Objectionable drafts are likely to occur when the velocity of the air current is 40 fpm and the temperature of the air current 2 F or more below the customary winter room temperature. Higher velocities are not objectionable in the surnmer time when the air of Enclosure, and Dry-Bulb Temperature of Incoming Air temperature exceeds 80 F. Variations in air movement and temperature in different parts of occupied rooms are often indicative of relative air distribution. The work of the A.S.H.V.E. Research Laboratory indicates that an air movement between 15 and 25 fpm with a temperature variation of 3 F or less in different parts of a room, 36 in. above floor, insure satis factory distribution. Considerable evidence was obtained in these tests to show that measurements of carbon dioxide are not essential for the study of air distribution, or for indirect measurements of outdoor air "ClassToom Drafts in Relation to Entering Air Stream Temperature, by F. C. Houghten. H. H. Trimble, Carl Gutberlet and M. F. Lichtenfels (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 268). Chapter 3- Physical & Physiological Principles of Air Conditioning Table 4. Relation Between Metabolic Rate and Activity Houblt Meta bolic Rate por Avo. Person or Total Heat Dissipated, Btu per Hour Hourly Sensible Heat Dissipated, Btu per Hour Hourly Latent Heat Dissipated, Btu per Hour Average Person Seated at Rest1- 384 Average Person Standing at Rest1 Tailor*. Office Worker Moderately Active 431 482 490 Clerk, Moderately Active, Standing at Counter.-- 600 Book Binder*........ ................ 626 Shoe Maker*; Clerk, Very Active Standing at Counter -- 661 Pool Player.............. ------ 680 Walking 2 mph*. 4; Light Dancing........................... Metal Worker* 761 862 Painter of Furniture*--------------- 876 Restaurant Serving; Very Busy. 1000 Walking 3 mph*............ --........... . 1050 Walking 4 mph** 4; Active Dancing, Roller Skating......... 1390 Stone Mason*:................................ 1490 Bowling--........................................ 1500 Man Sawing Wood*----------------- 1800 Slow Run4....................................... 2290 Walking 5 mph*.....--..............-- 2330 Very Severe Exercise5.-................ 2560 Maximum Exertion Different People4.............................. .......... 3000 to 4800 225 225 225 225 225 225 225 230 250 277 280 325 346 452 490 490 590 159 206 257 265 375 401 436 450 511 585 596 675 704 938 1000 1010 1210 Moisture Dissipated, per Hour Grains 1070 1390. 1740 1790 2530 2710 2940 3040 3450 3950 4020 4560 4750 6330 6750 6820 8170 Lb 0.153 0.199 0.248 0.256 0.362 0.387 0.420 0.434 0.493 0.564 0.575 0.651 0.679 0.904 0.964 0.974 1.167 ^Metabolism rates noted based on tests actually determined from the following authoritative sources: `A.S.H.V.E. Research Laboratory;1Becker and Hamalainen; *Douglas, Haldane. Henderson and Schneider; ^Henderson and Haggard; and `Benedict and Carpenter. Metabolic rates for other activities estimated. Total heat-dissipation integrated into latent and sensible rates by actual tests for metabolic rates up to .1250 Btu per hour, and extrapolated above this rate. Values for total heat dissipation apply for all atmos pheric conditions in a temperature range from approximately 60 to 90 F dry-bulb. Division of total heat dissipation rates into sensible and latent heat holds only for conditions having a dry-bulb temperature of 79 F. For lower temperatures, sensible heat dissipation increases and latent heat decreases, while for higher temperatures the reverse is true. . Table 5. Degrees of Perspiration for Persons Seated at Rest Under Various Atmospheric Conditions Degree of Perspiration* Atmospheric Condition 95 Per Cent Relative Humidity ' 20 Per Cent Relative Humidity E.T. Forehead clammy... ......................... _................. 73.0 Bodv clammy 73.0 Body damp......... 79.0 Beads on forehead.......... 80.0 Body wet 84.5 Perspiration on forehead runs and drips.____ 88.0 Perspiration runs down body_______________ 88.5 D. b. 73.6 73.6 79.7 80.8 85.4 89.0 89.5 W.B. 72.4 72.4 78.4 79.4 84.0 87.6 88.1 RT. 75.0 75.0 81.0 87.0 86.5 94.0 90.0 D. b. 87.0 87.0 97.5 109.4 108.5 125.2 116.0 W. B. 60.7 60.7 67.5 75.2 74.6 85.4 79.5 "Forty per cent of subjects registered degree of perspiration equal to or greater than indicated. 73 Heating Ventilating Air Conditioning Guide 1938 74 Chapter 3. Physical & Physiological Principles or Air Conditioning Table 6. Degrees of Perspiration for Persons at Work Under Various . Atmospheric Conditions Work Rate 33,000 Ft Lb per Hour Atmospheric Condition assDeo or Perspiration* 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity E.T. D. B. W. B. E.T. D. B. W. B. Forehead clammy---------------------- ----------------- Body clammy--------------------------------------------- Body damp------------------------------------------------- Beads on forehead----------------------------:--........ Body wet...................................... .................... Perspiration on forehead runs and dripa------ Perspiration runs down body................. . 59.0 50.0 60.0 68.0 69.0 78.5 79.0 59.4 50.2 60.3 68.5 69.6 79.3 79.8 58.3 49.3 59.3 67.5 68.5 78.0 78.5 69.5 57.0 62.5 76.0 71.0 82.0 81.0 80.5 61.6 69.6 91.0 82.8 100.5 99.8 56.5 44.2 49.5 63.4 53.0 70.2 69.0 Forty per cent of subjects registered degree of perspiration equal to or greater than indicated. supply, which can be obtained more conveniently from the increase in moisture content of the ventilating current. HEAT AND MOISTURE GIVEN UP BY HUMAN BODY In conditioning air for comfort and health it is necessary to know the rate of sensible and latent heat liberation, from the human body, which in conjunction with other heat loads (see Chapters 5 and 7) determine the capacity of the conditioner. The data in common use are those of the A.S.H.V.E. Research Laboratory46 shown in Figs. 8, 9, 10 and 11. Other useful data are given in Tables 4, 5 and 6, which are self-explanatory. ULTRA-VIOLET RADIATION AND IONIZATION In spite of the rapid advances in the field of air conditioning during the past few years, the secret of reproducing indoor atmospheres of as stimulating qualities as those existing outdoors under ideal weather con ditions, has not as yet been found. Extensive studies have failed to elucidate the cause of the stimulating quality of country air, qualities which are lost when such air is brought indoors and particularly when it is handled by mechanical means. Ultra-violet light and ionization have been suggested but the evidence so far is inconclusive or negative47. `'Thermal Exchanges between the Bodies of Men Working and the Atmospheric Environment, by F. C. Houghten, W. W. Teague. W. E. Miller and W. P. Yant (American Journal of Hygiene, Vol.'XIII, No. 2. March. 1931, pp. 415-431). 4?Changes in Ionic Content in Occupied Rooms, Ventilated by Natural and Mechanical Methods, by C. P. Yaglou, L. C. Benjamin and S. P. Choate (A.S.H.V.E. Transactions. Vol. 38.1932. p. 191). Physio logic Changes During Exposure to Ionized Air. by C. P. Yaglou, A. D. Brandt and L. C. Benjamin (A.S. H.V.E. Transactions, Vol. 39, 1933, p. 357). Diurnal and Seasonal-Variations in the Small Ion Content of Outdoor and Indoor Air, by C. P. Yaglou and L. C. Benjamin (A.S.H.V.E. Transactions, Vol. 40, J34, p. 271). The Nature of Ions in Air and Their Possible Physiological Effects, by L. B. Loeb (A.S. H-V.E. Transactions, Vol. 41, 1935, p. 101). The Influence of Ionized Air upon Normal Subjects, by *- P; Herrington ([Journal Clinical Investigation, 14, January, 1935). The Effect'of High Concentrations of Light Negative Atmospheric Ions on the Growth and Activity of the Albino Rat, by L. P. Herrington and Karl L. Smith (Journal Ind. Hygiene, 17, November. 1935). Subjective Reactions.of/Human Beings to Certain Outdoor Atmospheric Conditions, by C.-E. A. Winslow and L. P; .Herrington (A.S.H.V.E. Transactions. Vol. 42. 1936, p. 119). .- .. 75 Heating Ventilating Air Conditioning Guide 1938 Chapter 3. Physical & Physiological Principles of Air Conditioning natural and mechanical ventilation Under favorable conditions natural ventilation methods properly com bined with means for heating may be sufficient to provide for the fore going objectives in homes, uncrowded offices, small stores, etc. In large offices, large school rooms, and in public and industrial build ings, natural ventilation is uncertain and makes heating difficult. The chief disadvantage of natural methods is the lack of control; they depend largely on weather and upon the velocity and direction of the wind. Rooms on the windward side of a building may be difficult to heat and ventilate on account of drafts, while rooms on the leeward side may not receive an adequate amount of air from out-of-doors. The partial vacuum produced on the leeward side under the action of the wind may even reverse the flow of air so that the leeward half of the building has to take the drift of the air from the rooms of the windward half. Under such conditions no outdoor air would enter through a leeward window opening, but room air would pass out. In warm weather natural methods of ventilation afford little or no control of indoor temperature and humidity. Outdoor smoke, dust and noise constitute other limitations of natural methods. RECIRCULATION AND OZONE The amount of recirculated air may be varied to suit changes in weather and seasonal requirements, so as to conserve heat in winter and refrig eration in summer, but the saving in operating cost should not be obtained at the' expense of air quality. Ozone has been used for deodorizing recirculated air by oxidation or masking. Under favorable conditions some success is possible but from the practical standpoint it is difficult to regulate the ozone output so as to just neutralize undesirable odors at all times during the occupancy of a room. The difficulties appear to be mainly due to a wide variability in the rate of ozone disappearance in different rooms, or in the same room at different times, according to the characteristics of a room, the absolute humidity, impurities in the air, number and type of occupants, and probably other factors which require considerable study before ozone can be safely and economically applied. The allowable concentrations in the breathing zone are very small; between 0.01 to 0.05 parts of Os per million parts of air. These are much too small to influence bacteria. Higher concentrations are associated with a pungent unpleasant odor and considerable discomfort to the occupants. One part per million causes respiratory discomfort in man, headaches and depression, lowers the metabolism, and may even lead to coma48. Toilets, kitchens, and similar rooms, in buildings using recirculation, should be ventilated separately by mechanical exhaust in order to prevent objectionable odors from diffusing into other parts of the building............. ttThe British Medical Journal. Editorial, June 25, 1932, p. 1182. See also Loc. Cit. Note 5. 77 Heating Ventilating Air Conditioning Guide 1938 PROBLEMS IN PRACTICE 1 What are the most comfortable air conditions? Comfort standards are not absolute, but they are greatly affected by the physical con dition of the individual, and the climate, season, age, sex, clothing, and physical activity. For the northeastern climate of the United States, the conditions which meet the require ments of the majority of people consist of temperatures between 68 and 72 F in winter and between 70 and 85 F in summer, the latter depending largely upon the prevailing outdoor temperature. The most desirable relative humidity range seems to be between 30 and 60 per cent. 2 Are the optimum conditions for comfort identical with those for health? There are no absolute criteria of the prolonged effects of various air conditions on health. For the present it can be only inferred that bodily discomfort may be an indication of adverse conditions leading to poor health. 3 # Given dry-bulb and wet-bulb temperatures of 76 F and 62 F, respectively, and an air velocity of 100 fpm, determine: (l) effective temperature of the condition; (2) effective temperature with calm air; (3) cooling produced by the movement of the air. (1) In Fig. 1 draw line AB through given dry- and wet-bulb temperatures. Its inter section with the 100 ft velocity curve gives 69 deg for the effective temperature of the condition. (2) Follow line AB to the right to its intersection with the 20 fpm velocity line, and read 70.4 deg for the effective temperature for this velocity or so-called still air. (3) The cooling produced by the movement of the air is 70.4 -- 69 = 1.4 deg ET. . 4 i Assume that the design of an air conditioning system for a theater is to be based on an outdoor dry-bulb temperature of 95 F and a wet-bulb temperature of 78 F with an indoor relative humidity of 50 per cent. According to Table 2, the dry-bulb temperature in the auditorium should be 80 F. Estimate the sensible and latent heat given up per person. - . ' The sensible heat given up per person per hour may be obtained from Fig. 9. With ah abscissa value of 80 F, Curve D for men seated at rest gives a value (on the ordinate scale) of 220 Btu per person per hour as the sensible heat loss. The latent heat given up by a person seated at rest may be obtained from Fig. 10. With an abscissa value of 80 F, Curve D indicates a latent heat loss of 175 Btu per hour (left hand scale) or a moisture loss of 1190 grains per hour (right hand scale). 5 0 Neglecting the gain or loss of heat by transmission or infiltration through walls, windows and doors, how many cubic feet of outside air, with dry- and wet-bulb temperatures of 65 F and 59 F, respectively, (63.1 deg ET) must be supplied per hour to an auditorium containing 1000 people in order that the inside temperature shall not exceed 75 F dry-bulb and 65 F wet-bulb? Figs. 9 and 10 give 265 Btu sensible heal; and 905 grains of moisture per person with a dry-bulb temperature of 75 F in the auditorium. Therefore, 265,000 Btu of sensible heat and 905,000 grains of moisture will be added to the air in the auditorium per hour. Taking 0.24 as the specific heat of air, 2.4 Btu per pound of air will be absorbed in raising the dry-bulb temperature from 65 to 75 F, and 265,000 -s- 2.4 = 110,400 lb of air or 110,400 X 13.4 = 1,479,000 cfh of air will be required. This is equivalent to 1,479,000 -r- (1000 X 60) = 24.7 cfm per person. . The moisture content of the inside air is 76 grains per pound of dry air and that of the outside condition is 65 grains. From a psychrometric chart the increase in moisture content will therefore be 11 grains per pound of dry air. Hence 905,000 -f- 11.0 = 82,300 lb of air at the specified condition will be required. This is equivalent to 82,300 X 13.4 = 1,103,000 cfh of air or 1,103,(KK) -s- (1000 X 60) = 18.4 cfm of air per person. The higher volume of 24.7 cfm per person will be required to keep the dry-bulb tem perature from rising above the 75 F specified. The wet-bulb* temperature will therefore not rise to the maximum of 65 F. 78 Chapter 4 AIR POLLUTION Classification of Air Impurities, Dust; Concentrations, Air Pollution and Health, Occlusion o Solar Radiation, Smoke and Air Pollution Abatement, Dust and Cinders,. Nature's . Dust Catcher . THE particulate impurities which contribute to atmospheric pollution include carbon from the combustion of fuels, particles of earth, sand, ash, rubber tires, leather, animal excretion, stone, wood, rust, paper, threads of cotton, wool, and silks, bits of animal and vegetable matter, and pollen. Microscopic examination of the impurities.in city air shows that a large percentage of the particles are carbon. CLASSIFICATION OF AIR IMPURITIES The most conspicuous sources of atmospheric pollution may be classi fied arbitrarily according to the size of the particles as dusts, fumes, and smoke. Dusts consist of particles of solid matter varying from 1.0 to 150 microns in size, (micron = 0.001 millimeter or 1/25,000 in.) Fumes include particles resulting from chemical processing, combustion, explo sion, and distillation, ranging from 0.1 to 1.0 micron in size. The word fumes may be applied also to mixtures of mists (liquid droplets) and gases as acid mists. Smoke is composed of fine soot or carbon particles, usually less than 0.1 micron in size, which result from incomplete combustion of carbonaceous materials, such as coal, oil, tar, and tobacco. In addition to carbon and soot, smoke contains unconsumed hydrocarbon gases, sulphur dioxide, carbon monoxide, and other industrial gases capable of injuring property, vegetation, and health. The lines of demarcation in these three classifications are neither sharp nor positive, but the distinction is descriptive of the nature and origin of of the particles, and their physical action. Dusts settle without appre ciable agglomeration, fumes tend to aggregate, smoke to diffuse. Particles which approach the common bacteria in size--about 1 micron--are difficult to remove from air and are apt to remain in suspension unless they can be agglomerated by artificial means. The term fly-ash is usually applied to the microscopic glassy spheres which form the principal solid constituent of the effluent gases from powdered-coal fired furnaces.. Cinders denote the larger solid constituents which may be entrained by furnace gases. - It is well .established that particles larger than, about 1 micron are unlikely to remain suspended in air currents of moderate strength.- Only 79 Heating Ventilating Air Conditioning Guide 1938 violent air motion will sustain them in air long enough for them to be breathed. This means that, in hygenic problems, the engineer is con cerned mostly with suspensions of particles comparable to the common F . orig 1. Sizes and Characteristics Air-Borne Solids bacteria in size. A notable exception to this size limitation is the common hay-fever producing pollen such as that from rag-weed. Pollen grains may be anything from fragments 15 microns in diameter to whole pollens 25 microns or more in size. Since the lower limit of visability to the 80 Chapter 4. Air Pollution Table 1 1 Approximate Limits' of Inflammability of Single Gases and Vapors in Air at Ordinary Temperatures and Pressures1 Gas oa Vapor Lower Limit ' Volume in Per Cent Higher Limit Volume m Peb Cent Hydrogen...................................... Ammonia..... ---.......... -............... Hydrogen sulphide..................... Carbon disulphide..................... Carbon monoxide....................... Methane................ -....... ;......... ` Methane (turbulent mixture).. Ethane...--.................................. Propane......................................... Butane---.......... -................ -...... Pentane.............. -...............--...... Ethylene........................................ Acetylene..................... -............... Acetylene (turbulent mixture) Benzene--..................................... Toluene............... -....................... Cyclohexane........... ..................... Methyl cyclohexane................... Methyl alcohol........ .................... Ethyl alcohol................................ Ethyl ether................................... Benzine.... .......... .......................... Gasoline----- ......----- 1..... ,--........ Water gas.................-.................... Ethylene oxide........................... Acetaldehyde........ ....................... Furfural (125 C)................ :........ Acetone......................................... Acetone (turbulent mixture)__ Methyl ethyl ketone............:..... Methyl formate......... -................. Ethyl formate.............................. Methyl acetate..... ........ Ethyl acetate...................... ........ Propyl acetate.............................. Butyl acetate (30 C)._............... Ethyl nitrite.............................. Methyl chloride......................... Methyl bromide.... ...................... Ethyl chloride.............................. Ethyl bromide.....:........:...... Ethylene dichloride......... Dichlorethylene........................ Vinyl chloride ...............,........ Pyridine (70 C)............................ Natural gas______ :....... ............... Illuminating gas........................... Blast-furnace gas........................ 4.1 16.0 4.3 1.0 12.5 5.3 5.0 3.2 2.4 1.9 1.45 3.0 3.0 2.3 1.4 1.4 1.3 1.2 7.0 4.0 1.7 1.1 1.4 6 to 9 3.0 4.0 2.0 3.0 2.5 2.0 6.0 3.5 4.1. 2.5. 2.0 . 1.7 3.0 8.0 13.5 4.0 ' 7.0 6.0 10.0 4.0 1.8 . 4.8 5.3 .35.0 74.0 27.0 46.0 50.0 74.0 14.0 15.0 12.5 9.5 8.5 7.5 29.0 7.0 7.0 8.3 19 0 26.0 , "6.0 55 to 70 80.0 57.0 11.0 12.0 20.0 16.5 14.0 11.5 19.0 14.5 - 15.0 11.0 16.0 13.0 22.0 12.5 13.5 31.0 74.0 . aLimits of Inflammability of Gases and-Vapors, by H. F. Coward-and G. W. Tories! CU. S. Bureau of Mines, Bulletin No. 279, 1931). .. , .- ' ... . 81 S IS i^E si; w 1 i a I 1 Heating Ventilating Air Conditioning Guide 1938 average eye is around 50 microns all air floated material of this kind is too small to identify without the aid of the microscope. Mineral particles, such as grains of sand, bits of rock, volcanic ash, or fly-ash, can be transported long distances under unusual circumstances. Thus, the dust storms of 1935 in the Kansas district resulted in vast amounts of fine top soil being thrown high into the air. Solar illumination as far east as Boston was affected noticeably and particles as large as 40 to 50 microns were actually carried half way across the continent before they settled out. In similar manner volcanic ash has been carried even further. It is not surprising, therefore, that fly-ash from furnace gases, cement dust and the like, can be carried fpr considerable distances and occasionally the engineer is confronted with the problem of removing such material before the air in question is suitable for use in building venti lation. The physical properties of the particulate impurities of air are summar ized conveniently in the chart of Fig. 1. . In the case of gases the physical property which is probably of most importance is inflammability. The best data available at present.on this subject are given in Table 1. Dust Concentrations . It is customary to report dust concentrations as grains per 1000 cu ft or milligrams per cubic meter. Gas concentrations are commonly re corded as milligrams per cubic meter or as parts per million or as per cent by volume. Typical ranges in dust concentrations as now found in practical applications are given in Table 2. Table 2. Dust Concentration Ranges in Practical Applications3 Application . CuGrains Per 1000 Ft Mgs Per Cu M Dusty factories or mines........ ...................................... Explosive concentrations (as of flour or soft coal).. 0.2 to .0.4 0.4 to 0.8 0.8 to 1.5 4.0 to 80.0 4000 to 8000 0.4 to 0.8 0.9 to 1.8 .1.8 to 3.5 . 10 to.200 . 10,000 to 20,000 sl grain per 1000 cu ft = 2.3 mgs per cubic meter; 1 oz per cubic foot =1 gram per liter. ... The engineer frequently desires information regarding the effects of various concentrations of gases or dusts upon man, as the success of a particular installation may depend upon the maintenance of air which is adequately clean. At the present time there are a number of organi- s zations working on this problem all of them publishing literature of various kinds.1 References to books covering the hygienic significance, determination and control of dust are listed at the end of this, chapter. 1National Institute for Health, U. S. Public Health Service;'Division of Labor Standards. U. S. Depart- ment'of Labor; University of Toronto' Medical School, Canada; Saranac Laboratories, Saranac Lake, N.Y.; Air Hygiene Foundation, Inc., Pittsburgh. Pa.; Harvard School of Public Health,'Boston, Mass.; Haskell Laboratory, Wilmington, Del.; and the Departments of Health and of Labor in the United States and in various provinces-of Canada. . 82 Chapter 4. Air Pollution AIR POLLUTION AND HEALTH The prevention of various diseases which result from exposure to atmospheric impurities is an engineering problem. It is important for the engineer to insure, by proper ventilation, suitable environments for working or for general living. If the equipment used is to be successful, it must operate automatically as in the modern air conditioned theatre or railroad train. In Table 3 are given data on permissable concentrations of various substances, gases and dusts, which occur in industry. The prudent Table 3. Toxicity of Gases and Fumes in Parts per 10,000 Parts of Air3 Vapor or Gas Rapidly Fatal Maximum Concentration F08 FROM H to 1 Hour Maximum Concentration fob l Hour Maximum Allowable fob Prolonged ' Exposure Carbon monoxide........--. Hydrocyanic acid.............. Ammonia............................ Hydrochloric acid gas...... . Chlorine........ ..................... Hydrofluoric acid gas-----Sulphur dioxide................. Hydrogen sulphide............ Carbon bisulphide.--....... Phosgene.................... ---- Nitrous fumes.................... Benzene.............................. Aniline................................ Nitrobenzene...................... Carbon tetrachloride;....... Chloroform.......i................. Tetrachlorethane............. . Methyl chloride. _............. Methyl bromide................. Lead dust Quartz dust......................... 40 800-1000 30 50-100 10-20 10 2 4-5 . 10-30 20 2'A Over H 2H-7H 190 190 480 ' 250 . 73 370 . 1500-3000 200-400 v 15-20 m 25 A A Ho H-i 5-7 11 4-6 h A 1-iH 240 140 200-400 20-40 10 i A 3 2-3 5 1-2 h 31-47 31-47 i-ih Hoo 40 50 . H l Ho Hoo As Ho l .A . . Hoo H. IA-3 Ho 1 2 Ho' ` 70 5-10 10 2 0.15 mg/cu m 1 mg/cu m ^Adapted from Y. Henderson and H. Haggard. (See Noxious Gases, 19S7, and Lessons Learned from. Industrial Gases and Fumes, Institute of Chemistry of Great Britain and Ireland, London,- 1930.) . engineer will design equipment using these bench marks as the upper limits of pollution. In general it is good practice to avoid recirculation of air which contains originally toxic substances. Obviously there may be exceptions to this rule, but it is one. which is generally being followed in current practice. ' . Bronchitis is the chief condition associated with exposure to thick dust; and follows upon inhalation of practically any kind of insoluble and noncolloidal dust.. Atmospheric dust in itself cannot be blamed for causing tuberculosis, but it may aggravate the disease once it has started.* ^Physiological Response of .the Peritoneal Tissue to Dusts Introduced as Foreign Bodies, by Miller and Sayers (7. 5. Public Health Reports, 49:80, 1934); . .. 83 Heating Ventilating Air Conditioning Guide 1938 Chapter 4. Air Pollution The sulphurous fumes and tarry matter in smoke are more dangerous than the carbon. In foggy weather the accumulation of these substances in the lower strata may be such as to cause irritation of the eyes, nose, and respiratory passages, leading to asthmatic breathing and bronchitis and, in extreme cases, to death. The Meuse Valley fog disaster will probably become a classic example in the history of gaseous air pollution. Re leased in a rare combination of atmospheric calm and dense fog, it is believed that sulphur dioxide and other toxic gases from the industrial region of the valley caused 63 sudden deaths, and injuries to several hundred persons. `` Carbon monoxide from automobiles and from chimney gases consti tutes another important source of aerial pollution in busy cities. During heavy traffic hours and under atmospheric conditions favorable to con centration, the air of congested streets is found to contain enough CO to menace the health of those exposed over a period of several hours, par ticularly if their activities call for deep,and rapid breathing. In open air under ordinary conditions the concentration of CO in city air is insufficient to affect the average city dweller or pedestrian. a much higher level than is possible in the case of buildings that operate their own boiler plants. In general, time, temperature and turbulence are the essential require ments for smokeless combustion. Anything that can be done to increase any one of these factors will reduce the quantity of smoke discharged. Especial care must be taken in hand-firing bituminous coals. (See Chapter 9.) ... . . Checker or alternate firing, in which the fuel is fired alternately on separate parts of the grate, maintains a higher furnace temperature and thereby decreases the amount of smoke. . _ Coking and firing, in which the fuel is first fired close to the firing door "and the coke pushed back into the furnaCe just before firing again, pro duces the same effect. The volatiles as they are distilled thus have to pass over the hot fuel bed where they will be burned if they are mixed with sufficient air and are not cooled too quickly by the heat-absorbing surfaces of the boiler. ... Steam or compressed air jets, admitted over the fire, create turbulence in the furnace and bring the .volatiles of the fuel more quickly into contact Occlusion of Solar Radiation . . with the air required for, combustion. These jets are. .especially helpful The loss of light, particularly the occlusion of solar ultra-violet light due to smoke and soot, is beginning to be recognized as a health problem in many industrial cities. Measurements of solar radiation in Baltimore3 by actinic methods show that the ultra-violet light in the country was 50 per cent greater than in the city. In New York City4 a loss as great as 50 per cent in visible light was found by the photo-electric cell method. Recent studies5 in Pittsburgh indicate that heavy smoke pollution is definitely unhealthful. Heretofore adequate proofs on this point were lacking. The aesthetic and economic objections to air pollution are so definite, and the effect of air-borne pollen can be shown so readily as the cause of hay fever and other allergic diseases, that means and expenses of pre vention or elimination of this pollution are justified. for the first few..minutes after each firing. ..Frequent firings' of small charges shorten the smoking period and reduce the density. TTiinner, fuel beds on the grate increase the effective combustion space in the furnace, supply more air for combustion, and are sometimes effective in reducing the smoke emitted;'but care should be taken that holes are not formed in the fire. A lower volatile coal or a higher gravity oil always produces less smoke than a high volatile coal or low gravity oil-used in the same furnace and fired in the same manner. . The installation of more modern or better designed fuel burning equip ment, or a change in the construction of the furnace, will often reduce smoke. . The installation of a Dutch oven which will increase the furnace volume and raise the furnace temperature often produces satisfactory results. : ' In the case of new installations, the problem of smoke abatement can SMOKE AND AIR POLLUTION ABATEMENT be solved by the selection of the proper fuel-burning equipment and furnace design for the particular fuel to be burned and by the proper Successful abatement of atmospheric pollution requires 'the combined efforts of the combustion engineer, the public health officer, and. the public itself. The complete electrification of industry and railroads, and., the separation of industrial and residential - communities would aidw operation of that equipment. Constant vigilance is necessary to make certain that the equipment is properly operated. In old installations the solution of the problem presents many difficulties, and a considerable investment in special apparatus is necessary. . materially in the effective-solution of the'problem. . - . - ?. . . Legislative measures at the present time are largely concerned with the - In the large cities where the nuisance from 'snioke, dust and cinders is the most serious, limited areas obtain-some relief by the use of district' heating. The boilers in these plants are of large size designed and oper ated to burn the fuel without smoke, and some of them are equipped with smoke discharged from the chimneys of , boiler plants. Practically all of the ordinances limit the number of minutes in any one hour, that snioke of a specified density, as measured by comparison with a Ringelmann Chart (Chapter 44), may be discharged. .. , dust catching devices. The gases of combustion are usually discharged at \ These ordinances do not cover the smoke discharged at low levels, by automobiles, and, although they have been instrumental in reducing the Effects of Atmospheric Pollution Upon Incidence of-Solar Ultra-Violet Light, by J. H. Shrader, M. H. Coblentz and F. A. Korff (American Journal of Public Health, p. 7, Vol. 19, 1929). ^ smoke emitted by boiler plants, they have, in many.instances, increased the^output of chimney dust and cinders due to the use of more excess air- Studies in Illumination, by J. E. Ives (U. S. Public Health Service Bulletin No. 197, 1930). ' Pneumoconiosis in the Pittsburgh district; Based on a Study'of 2,500 Post Mortem Examinations made in Pittsburgh Hospitals, by Schnurer et al (Journal Industrial Hygiene, 17:294, March, 1935). and .to greater turbulence in the furnaces. . *] Legislative measures in general have not as yet covered the noxious 84 85 X' Heating Ventilating Air Conditioning Guide 1938 gases, such as sulphur dioxide and sulphuric acid mist, which are dis charged with the gases of combustion. Where high sulphur coals are burned, these sulphur gases present a serious problem. . DUST AND CINDERS The impurities in the air other than smoke come from so many sources that they are difficult to control. Only those which are produced in large quantities at a comparatively few points, such as the dust, cinders and fly-ash discharged to the atmosphere along with the gases of com bustion from burning solid fuel, can be readily controlled. : Dusts and cinders in flue gas may be caught by various devices on the market, such as fabric filters, dust traps, settling chambers, centrifugal separators, electrical precipitators, and gas scrubbers, described in Chapter 26. - The cinder particles are usually larger in size than the dust particles; they are gray or black in color, and are abrasive. Being of a larger size, the range within which they may annoy is limited. The dust particles are usually extremely fine; they are light gray or yellow in color, and are not as abrasive as cinder particles. Being ex tremely fine, they are readily distributed over a large area by air currents. The nuisance created by the solid particles in the air is dependent on the size, and physical characteristics of the individual particles. The difficulty of catching the dust and cinder particles is principally a function of the size and specific gravity of the particles. , Lower rates of combustion per square foot of grate area will reduce the quantity of solid matter discharged from the chimney with the gases of combustion. The burning of coke, coking coal, and sized coal from which the extremely fine coal has been removed will not as a general rule produce as much dust and cinders as will result from the burning of non-coking coals and slack coal when they are burned on a grate. Modem boiler installations are usually designed for high'capacity per Square foot of ground area because such designs give the lowest cost of construction per unit of capacity. Designs of this type discharge a large quantity of dust and cinders with the gases of combustion, and if pollution of the atmosphere is to be%prevented, some type of catcher must be installed: ' ' , NATURE'S DUST CATCHER Nature has provided means for catching solid particles in the air and depositing them upon/the earth. A dust particle.forms the nucleus-for each rain drop and the rain picks up dust as it falls from the clouds to the ' earth. In fact, without.dust in the air to form the nuclei for rain drops it would never rain, and the earth would be continually enveloped in a cloud of vapor. However, it was found in recent studies8 that rain was not a good air cleaner of'the material below about 0:7 micron. `Atmospheric Pollution of American Cities for the years 1931-1933, by J. E. lyes et al (U. S. Public Health Bulletin No. 224'; .March*' 1936). . - * 86 Chapter 4. Air Pollution REFERENCES Bulletin, Air Hygiene Foundation, Inc., Pittsburgh, Pa. nofermi'nation and Control of Industrial Dust, by J. J. Bloomfield and J. M. Dalla ValhT(U S Public Health Bulletin, No. 217, 1935). Journal of Industrial Hygiene and Toxicology, Harvard School of Public Health, Boston, Mass. Reports of the National Silicosis Conference, Washington, D. C. To be published by the U. S. Department of Labor. Saranac Symposium on Silicosis, 1937, Saranac Laboratories, Saranac, N. Y. Industrial Dust, by Philip Drinker and Theodore Hatch, McGraw Hill'Co., N. Y. Noxious Gases, by Y. Henderson and H. Haggard, Chemical Catalog Co., N. Y. Occupation and Health, International Labour Office. Preventive Medicine and Hygiene,, by Milton J. Rosenau, D. Appleton-Century Co., N. Y. PROBLEMS IN PRACTICE 1 Classify the detrimental aspects of air pollution as it affects large industrial communities. - Air pollution may be classified (a) medical, as it affects the physiological functions of people; (ft) botanical, as it affects vegetation, trees, plants, shrubs and flowers; and (c) physical, as it affects the discoloration' and deterioration of buildings, and the nuisance of soiled interior furnishings, clothes, merchandise, etc. ,. 2 Distinguish between dusts, fumes, and smokes. Solid particles ranging in size from l.O micron to 150 microns are called dusts (micron = KsiOOO.in.). Particles resulting from sundry chemical reactions and ranging from 0.1 to 1.0 micron in size are called fumes. ." . Carbon particles less than 0.1 micron in size which generally arise from the incomplete combustion of such materials as coal, oil, or tobacco are called smokes. 3 What are some of the more important physical properties of these various groups of foreign bodies which are of importance in ventilation? . - In slowly moving air, dusts tend to settle out by gravity without agglomerating to form, larger particles; fumes have the tendency'to form larger particles which will settle when they attain the size of approximately 1.0 micron; while smokes tend to diffuse and remain in the air as permanent impurities. , 4 Why is atmospheric pollution an important engineering problem? ' a. Certain impurities, when present in too. great concentrations, cause ill health or even death. ' .... ft. High concentrations of solids occlude solar radiations. c: Some materials cause permanent injury to'parts of buildings, as sulphur fumes corrode exposed metal'.' ,, \ :s '.! ; !..' 1 d. Extra cleaning expense is incurred in dusty localities. ' ` " " e. Internal combustion engines are damaged by abrasive dusts. i i ':'. ! 5 How may the hazards of dust-producing industrial operations best be curtailed? . ' By providing mechanical exhaust ventilation sufficient to keep dust concentration at a safe level (see Table 3) and then removing foreign bodies to reduce the pollution of out side air. .: 87 Heating Ventilating Air Conditioning Guide 1938 6 How may the pollution of the atmosphere be lessened? By compelling industrial plants to install dust catching and smoke controlling devices. In many cities the domestic heating plant is one of the most serious offenders, but these plants are too small to justify the installation of dust catchers. Public education in improved firing methods would be of considerable help in this field. 7 What size particles are detrimental to health? While fairly large particles may enter the upper air passages, those found in the lungs are seldom more than 10 microns in size, and comparatively few of them are- more than 5 microns. It is agreed that particles between l/2 and 2 microns may be harmful; some authorities place the upper limit at about 5 microns, and some incline to extend the lower limit to 0.1 of a micron. ' 8 Is the shape of the particle of any significance? ' Hard particles with sharp corners or edges have a cutting effect on the delicate mucous membranes of the upper respiratory tract which may lower the resistance of the nose and throat to acute infections. This is aggravated by the irritating effects of some chemical compounds which may be taken in with the air and which act to reduce resistance. 9 What are the principal meteorological effects of smoke and dust? a. The reduction in the amount of light received. Measurements have shown that visible light may be as much as 50 per cent less intense in a smoky section of a city than in a section that is free from smoke. Ultra-violet light is reduced as much or more, and in some cases is cut out entirely for a time. : b. Smoke and dust aid in the formation and prolongation of fogs. City fogs accumulate smoke and become darker in color and very objectionable. The sun requires a longer time to disperse them, and when the water is evaporated, there is a rain of smoke and soot particles that have been entrained. .. . ... 10 Why has not smoke abatement been more effective? . Because communities have not .been made sufficiently aware of the possibilities of buriiihg high volatile fuels smokelessly and of separating cinder and ash from the stack gases to a degree that will prevent a nuisance. ' 11 Is the abatement of dust and cinders important? ' Yes. Only a small percentage of the solid emission from stacks is smoke, in the accepted popular sense; the remainder is fly-ash and cinders. While black smoke is disagreeable and its tarry matter and carbon particles soil anything with which they come in contact, the cinders and some of the ash are hard and destructive. They also, together with dusts-from industrial processes, make up the irritating, air-borne solids that are breathed by individuals not working in a dusty mill or factory. . 12 0 Are air-borne impurities causative factors in hay fever, bronchial asthma, and allergic disorders? .\ -, . Yes. Recent medical investigations indicate that 90 per cent of seasonal hay fever and 40 per cent of bronchial asthma are caused by air-borne pollens, tree dusts, and other allergic irritants. > 13 0 Name some essential requirements for the smokeless combustion of fuels. Time, temperature, and turbulence. A study of these factors is usually of value in overcoming a smoke nuisance. ' 14 t What is the Ringelmann Chart Method of comparing smoke densities? See Chapter 44. The Ringelmann Chart consists of four cards ruled with lines having different degrees of blackness. These cards, together with a white card and a black one, are hung in a horizontal row 50 ft from the observer. At this distance the lines become invisible and the cards appear to be different shades of gray, ranging from white to black. The observer, by matching the cards against the shades of smoke coming from a stack, is able to estimate the blackness of the smoke as compared with the chart. / : 88 ' Chapter 5 heat transmission coefficients AND TABLES Methods of Heat Transfer, Coefficients, Conductivity of Homogeneous Materials, Surface Conductance Coefficients, Air Space Conductance, Practical Coefficients, Table of Con ductivities and Conductances, Tables of Over-all Coefficients of Heat Transfer for Typical Building Construction, Combined . Coefficients of Transmission IN order to maintain comfortable living temperatures within a building it is necessary to supply heat at the.same rate that it is lost from the building. The loss of heat occurs in two ways, by direct transmission through the various parts of the structure and by air leakage or filtration between the,inside and outside of the building. The purpose of this chapter is to show methods of calculation and to give practical trans mission coefficients which may be applied to various structures to deter mine the heat loss by direct transmission. The amount. lost by air filtration is determined by different methods, as outlined in Chapter 6, and must be added to that lost by direct transmission to obtain the total heating plant requirements. METHODS OF HEAT TRANSFER Heat transmission between the air on the two sides of a structure takes place by three methods, namely, radiation, convection and conduction. In a simple wall built up of two layers of homogeneous materials separated to give an air space between them, heat will be received from the high temperature surface by radiation, convection and conduction. It will then be conducted through the homogeneous interior. section by con duction and carried across to the opposite surface of the air space by radiation, conduction and convection. From here it will be carried by conduction through to the outer surface and leave the outer surface by radiation, convection and conduction. - The process of heat transfer through a built-up wall section is complicated in theory, but in practice it is simplified by dividing a wall into its component parts and considering the transmission through each part separately. Thus the average wall may be divided into external surfaces, homogeneous materials and interior air spaces. Practical heat transmission coefficients may be derived which will give the total heat transferred by radiation, conduction and convec tion through any of these component parts and if the selection arid method of applying these individual coefficients is thoroughly understood it is usually a comparatively simple matter to calculate the. over-all heat transmission coefficient for any combination of materials. 89 Heating Ventilating Air Conditioning Guide 1938 HEAT TRANSFER COEFFICIENTS The symbols representing the various coefficients of heat transmission and their definitions are as follows: V -- thermal transmittance or over-all coefficient of heat transmission; the amount of heat expressed in Btu transmitted in one hour per square foot of the wall, floor, roof or ceiling for a difference in temperature of 1 deg F between the air on the inside and that on the outside of the wall, floor, roof or ceiling. k = thermal conductivity; the amount of heat expressed in Btu transmitted in one hour through 1 sq ft of a homogeneous material 1 in. thick for a difference in temperature of 1 deg F between the two surfaces of the material. The eonductivity of any material depends on the structure of the material and its density. Heavy or dense materials, the weight of which per cubic foot is high, usually transmit more heat than light or less dense materials, the weight of which per cubic foot is low.N . . C = thermal conductance; the amount of heat expressed in Btu transmitted in one hour through 1 sq ft of a non-homogeneous material for the thickness or type under consideration for a difference in temperature of 1 deg F between the two surfaces of the material. Conductance is usually used to designate the heat transmitted through such heterogeneous materials as plaster board and hollow clay tile. / = film or surface conductance; the amount of heat expressed in Btu transmitted by radiation, conduction and convection from a surface to the air surrounding it, or vice versa, in one hour per square foot of the surface for a difference in temperature of 1 deg F between the surface and the surrounding air. To differentiate between inside and outside wall (or floor, roof or ceiling) surfaces, fi is used to designate the inside film or surface conductance and/o the outside film or surface conductance. . a = thermal conductance of an air space; the amount of heat expressed in Btu trans mitted by radiation, conduction and convection in one hour through an area of 1 sq ft of an air space for a temperature difference of. 1 deg F. The conductance of an air space depends on the mean absolute temperature, the width, the position and the character of the materials enclosing it. . , R = resistance or resistivity which is the reciprocal of transmission, conductance, or conductivity, i.e.: - 0 . '* -j1j- = over-a,,ll or a.ir-to-a.ir res.istance. = internal resistivity. -i- = internal resistance. y - = film or surface resistance. ^ air-space resistance. - . a. \ . -. . . As an example in the application of these coefficients assume a wall with over-all coefficient U. Then,. . ' where U =`AUit-to) . - . . . :. . ' (1) '. -H = Btu per hour transmitted through the material of the wall, glass, roof or . flqor. . . ' A = area in square feet of wall, glass, roof, floor, or material, taken from building . . plans or actually measured. (Use the net inside or heated surface dimensions . in all cases.) .. . . -- t0 = temperature difference between inside and outside air, in which t must always be taken at the proper level. Note that t may not be the breathing-line temperature in all cases. '. ' 90 Chapter 5. Heat Transmission Coefficients and Tables If the heat transfer between the air and the inside surface of the wall is being considered, then, ., H = A fi (t - t,) (2) where fi = inside surface conductance. t and <i = the temperatures of the inside air and the inside surface of the wall re ' spectively. In practice it is usually the over-all heat transmission coefficient that is required. This may be determined by a test of the complete wall, or it may be obtained from the individual coefficients by calculation. The simplest method of combining the coefficients for the individual parts of the wall is to use the reciprocals of the coefficients and treat them as resistance units. The total over-all resistance of a wall is equal numeri cally to the sum of the resistances of the various parts, and the reciprocal of the over-all resistance is likewise the over-all heat transmission coef ficient of the wall. For a wall built up of a single homogeneous material of conductivity k and x inches thick the over-all resistance, J V T+T + fo (3) If the coefficients/i, f0 and k, together with the thickness of the material x are known, the over-all coefficient U may be readily calculated as the reciprocal of the total heat resistance. For a compound wall built up of three homogeneous materials having conductivities ki, fe and k3 and thicknesses xi} xt and x3 respectively, and laid together without air spaces, the total resistance, . .. U 1_ fi .+ 4kis- + 'tkt * + ; (41 For a walk with air space construction consisting of two homogeneous materials of thicknesses xt and Xj and conductivities ki and k3, respectively, separated to form an air space of conductance a, the over-all'resistance, V (51 Likewise any combination of homogeneous materials and air. spaces- can be put into the wall and the over-all resistance of the combination may be calculated by adding the resistances of the individual sections of the wall. In certain special forms of construction such as tile with irregular air spaces it is necessary to consider the conductance C of the unit as built instead of the unit conductivity k, and the resistance of the section is equal to The method of calculating the over-all heat transmission coefficient for a given wall is comparatively simple, but the selection of the proper coefficients is often complicated.' In some cases the construc tion of the wall is such that the substituting of coefficients in the accepted formula will give erroneous results. This is the case with irregular cored 91 Heating Ventilating Air Conditioning Guide 1938 out air spaces in concrete and tile blocks, and walls in which there are parallel paths for heat flow through materials having different heat resistances. In such cases it is necessary to resort to test methods to check the calculations, and in practically all cases it has been necessary to determine fundamental coefficients by test methods. Conductivity of Homogeneous Materials The thermal conductivity of homogeneous materials is affected by several factors. Among these are the density of the material, the amount of moisture present, the mean temperature at which the coefficient is determined, and for fiberous materials the arrangement of fiber in the . material. There are many fiberous materials used in building construc tion and considered as homogeneous for the purpose of calculation, whereas they are not really homogeneous but are merely considered so as a matter of convenience. In general, the thermal conductivity of a material increases directly with the density of the material, increases with the amount of moisture present, and increases with the mean temperature at Which the coefficient is determined. The rate of increase for these various factors is not the same for all materials, and in assigning proper coef ficients one should make certain that they apply for the conditions under which the material is to be used in a wall. Failure to do this may result in serious errors in the final coefficients. Surface Conductance Coefficients ' Heat is transmitted to or from the surface of a wall by a'combination of radiation, convection and conduction. The coefficient will be effected by any factor which-has an influence on any one of these three methods of transfer.. The amount of heat by radiation is controlled by the character of the surface and the temperature difference between' it and' the sur rounding objects. The amount of heat by conduction and convection is controlled largely by the roughness of the surface, by the air movement over the surface and by the temperature difference between the air and the surface. Because of these variables the surface coefficients may be subject `to wide fluctuations for different materials and different con ditions. The inside and outside coefficients/, and/0 are in general affected to the same extent by these various factors and test coefficients deter mined for inside surfaces will apply equally well to outside surfaces under like conditions. Values for / in still and moving air at different mean temperatures have been determined for various building materials at the University of Minnesota under a cooperative agreement with the Society.1 The relation obtained between surface conductances for different materials at.mean temperatures of .20 F is shown in Fig. 1. These values were obtained with air flow parallel to the surface and from other tests in which the angle of incident between the direction of air flow and the surface was varied from zero to 90 deg it would appear that these values might be lowered approximately 15 per cent for average conditions. While for average building materials there is a difference due to mean temperature, the greatest variation in these coefficients is caused by the character of the surface and the wind velocity. If other surfaces, such as 'Surface Conductances as Affected by Air Velocity, Temperature and Character of Surface, by F. B. Rowley; A. B. Algren and Ji L. Blackshaw (A.S.H.V.E.' Transactions. Vol. 36.' 1930. p. 429). 92 |i 3 Chapter 5. Heat Transmission Coefficients and Tables aluminum foil with low emissivity coefficients were substituted, a large oart of the radiant heat would be eliminated. This would reduce the total coefficient for all wind velocities by about 0.7 Btu and would make but very little difference for the higher wind velocities. In many cases in building construction the heat resistance of the internal parts of the wall is high as compared with the surface resistance and the surface factors become of small importance. In other cases such as single glass windows the surface resistances constitute practically the entire resistance of the structure, and therefore become important factors. Due to the wide variation in surface coefficients for different conditions their selection for Fig. 1. Curves Showing Relation Between Surface Conductances for Different Surfaces at 20 F Mean Temperature a practical building becomes a matter of judgment. . In calculating the over-all coefficients for the walls of Tables 3 to 12, 1.65 has been selected as an average inside coefficient and 6.0 as an average outside coefficient for a 15-mile wind velocity. In special cases where surface coefficients become important factors in the over-all rate of heat transfer more, selective coefficients may be required. .-. ... Air Space Conductance .. . Heat is conducted across an air space by a combination of radiation,, conduction and convection.,. The amount of heat by radiation is governed, largely by the nature of the surface and the temperature differencebetween'.the boundary surfaces of the air space. -Conduction and con- 93 Heating Ventilating Air Conditioning Guide 1938 vection are controlled largely by the width and shape of the air space and the roughness of the boundary surfaces. The thermal resistances of air, spaces bounded by extended parallel surfaces perpendicular to the direction of heat flow and at different mean temperatures have been determined for average building materials at the University of Minnesota in a cooperative research program with the Society. . The values given in Table 1 show the results of this study and apply to air spaces bounded by such materials as. paper, wood, plaster, etc., having emissivity coefficients of from 0.9 to 0.95. The conductivity coefficients decrease with air space width until a width of about % in. has been reached, after which the width has but very little effect. In these Table 1. Conductances of Air Spaces a at Various Mean Temperatures Mean Temp Deo Fabs 0.128 Conductances op Ajb Spaces pob Various Widths in Inches 0.250 0.364 0.493 0.713 1.00 1.500 20 2.300 1.370 1.180 1.100 1.040 1.030 1.022 30 2.385 1.425 1.234 1.148 1.080 1.070 1.065 40 2.470 1.480 1.288 1.193 1.125' 1.112 1.105 50 2.560 1.535 1.340 i.242 1.168 1.152 1.149 60 2.650 1.590 .1.390 1.295 1.210 1.195 1.188 70 2.730 1.648 1.440 1.340 1.250 1.240 1.228 80 2.819 1.702 1.492 1.390 1.295 1.280 1.270 90 2.908 1.757 1.547 1.433 1.340 1.320 1.310 100 2.990 1.813 1.600 1.486 1.380 1.362 1.350 110 3.078 1.870 1.650 1.534 1.425 1.402 1.392 120 3.167 1.928 1.700 1.580 1.467 1.445 1.435 130 3.250 1.980 1.750 1.630 1.510 1.485 1.475 140 3.340 2.035 1.800 1.680 1.550 1.530 1.519 150 3.425 2.090 1.852 1.728 1.592 1.569 1.559 Thermal Resistance of Air Spaces by F. B. Rowley and A. B. Algren (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 165). ; coefficients radiation is a large factor, and if surfaces with low emissivity coefficients are substituted for ordinary building materials the total amount of radiant heat will be reduced. The reduction in radiant heat caused by the low emissivity surface is independent of width of air space. Air spaces properly formed in combination with metallic surfaces such as aluminum foil, coated sheet steel, and other materials having a reflective surface, possess heat repelling characteristics. Values of air spaces lined with aluminum foil on one or both sides for widths of %in. and %.in., are shown, in Table 2 of conductivities. A low emissivity coefficient is, dependent on the permanency of the reflective surface: If a bright clean surface is covered with a thin layer of corrosive material its reflectivity is appreciably reduced2. ., . r. ' In comparing the conductance coefficients for air spaces with and with out bright metallic surface lining it should be noted that the reduction in heat transfer is substantially as great when one surface is lined as it is, when both surfaces are lined. The reason for this is that practically 95 per cent of the total radiant heat is intercepted by one surface linings Aluminum Foil Insolation (National Bureau of Standards Letter Circular No. LC465,-June, 1936). - 94. Chapter 5. Heat Transmission Coefficients and Tables d there is but a small amount left to be stopped by the second surface -phe effect of any low emissivity surface in stopping the trans mission of radiant heat is the same regardless of whether it is on the high or low temperature side of the air space. For materials such as aluminum oairit or bronze paint which stop only a small percentage of radiant heat there is a greater percentage of gain by addition of a second surface lining: PRACTICAL COEFFICIENTS For practical purposes it is necessary to have average coefficients that may be applied to various materials and types of construction without the necessity of making tests on the individual material or combination of materials. In Table 2 coefficients are given for a group of materials which have been selected from various sources. Wherever possible the proper ties of material and conditions of tests are given. However, in selecting and applying these values to any construction a reasonable amount of caution is necessary; variations will be found in the coefficients for the same materials, which may be partly due to different test methods used, but which are largely due to variations in materials. The recommended coefficients which have been used for the calculation of over-all coefficients as given in Tables 3 to 12 are marked by an asterisk. It should be recognized in these tables of calculated coefficients that space limitations will not permit the inclusion of all the combinations of materials that are used in building construction and the varied applications of insulating materials to these constructions. Typical examples are given of combinations frequently used, but any special construction not given in Tables 3 to 12 can generally be computed by using the conductivity values given in . Table 2 and the fundamental heat transfer formulae. For example, the tabulation of all of the values for multiple layers of insulating . materials would present extensive and detailed problems of calculations for the varied application combinations, but the engineer having the fundamental conductivity values can quickly obtain the proper coefficients. Attention is called to the fact that the conductivity values per inch of thickness do not afford a true basis for. comparison between insulating materials as applied, although they are frequently used for that purpose. The value of an insulating material is measured in terms of its heat resistance, which not only depends upon the thermal conductivity coef ficient per inch but also upon the thickness as installed and the manner of installation. For instance the material having a coefficient of 0.50 and 1 in. thick is equal in value to a material having a coefficient of 0.25 and a thickness of ^ in. Certain types of blanket installations are designed to be installed between the studs, of a frame building in such manner as to give two air spaces. In order to'get the full value of such materials they should be so installed that each air space is approximately I in. or more in thickness and the air spaces should be sealed at the top and bottom to prevent the circulation of air from one space to the other. Another common error in installing such a material is to nail the blanket on the outside of the studs underneath the sheathing, in which case one air space is lost and also the thickness of the insulating material is materially reduced at the studs. There are certain other types .of insulation which are very porous, allowing air circulation within the material if not 95 Heating Ventilating Air Conditioning Guide 1938 properly installed. The architect or engineer must carefully evaluate the economic considerations involved in the selection of an insulating material as adapted to various building constructions. Lack of good judgment in the intelligent choice of an insulating material, or its improper installation; frequently represents the difference between good or unsatisfactory results. Refer to Chapter 7 for a discussion of wall condensation. Computed Transmission Coefficients Computed heat transmission coefficients of many common types of building construction are given in Tables 3 to 13, inclusive, each con struction being identified by a serial number. For example, the coefficient of transmission (/) of an 8-in. brick wall and 34 in. of piaster is 0.46, and the number assigned to a wall of this construction is 1-B, Table 3. Example 1. Calculate the coefficient of transmission (U) of an 8-in. brick wall with 'A in. of plaster applied directly to the interior surface, based on an outside wind exposure of 15 mph. It is assumed that the outside course is of hard (high density) brick having a conductivity of 9.20, and that the inside course is of common (low density) brick having a conductivity of 5.0, the thicknesses each being 4 in. The conductivity of the plaster is assumed to be 3.3, and the inside and outside surface coefficients are assumed to average 1.65 and 6.00, respectively, for still air and a 15 mph wind velocity. ! Solution, k (hard high density brick) = 9.20; x = i.O in.; k (common low density brick) = 5.0; x -- 4.0 in.'; k (plaster) = 3.3; x = A in.;/i = 1.65;/o = 6.0. Therefore. U= 1 4.0 ^0 6.0 + 9.20 + 5.0 0. 3.31 + 1 1.65 = ,___________ 1 0.167 + 0.435 + 0.80 + 0.152. + 0.606 ; = 0.46 Btu per hour per square foot per degree Fahrenheit difference in tempera ture between the air on the two sides. \ - The coefficients in the tables were determined by calculations similar to those shown in Example 1, using Fundamental. Formulae .3, 4 and .5 and the values of k (or C),f;, fa and a indicated in Table 2 by asterisks. In computing heat transmission coefficients of floors laid directly on the ground (Table 10), only one surface coefficient ,(/i) is used. For example, the value of U for a 1-in. yellow pine floor (actual thickness, 25/32 in.) placed directly on 6-in. concrete on the ground, is determined as follows: V = 1 = 0.48 Btu per hour per square foot per degree difference 1 + 0.781 + 6.0 , 1.65 1 0.80 1 12.62 in temperature between the ground and the air immediately above the floor. Rigid insulation refers to the so-called board form which may be used structurally, such as for. sheathing. Flexible insulation refers to the blankets, quilts or semi-rigid types of insulation. !' Actual thicknesses of lumber are used in the computations rather than nominal thicknesses. The computations for wood shingle, roofs applied over wood stripping are based on 1 by 4 in. wood strips, spaced 2 in. apart. Since no reliable figures are available concerning the conductivity of Spanish and French clay roofing tile, of which there are many varieties, the figures for such types of roofs were taken the same as for slate roofs, as 96 Chapter 5. Heat Transmission Coefficients and Tables Table 2 Conductivities (k) and Conductances (C) of Building .' Materials and Insulators are expressed in Bin per hour per square fool per degree Fahrenheit per 1 in. thickness. 1 he coejjto*TM-* r unless otherunse indicated. Description Material Fine Coarse Cement Aggre gate Aggre gate Slump 0-No. 4 No. 4-M Per Cent Voids Sard and Gravel, - Concrete------------------------ 1 1 1 1 1 1 1 1 2.00 2.75 3.50 2.00 2.00 2.75 2.75 3.50 3.50 2.75 4.50 5.50 2.75 2.75 4.50 4.50 5.50 5.50 0 11.5 0 10.9 0 11.2 5 13.9 5 13.9 5 14.6 5 14.6 5 14.7 5 14.7 O O || a Se 144.7 145.7 144.5 142.5 142.5 141.1 141.1 139.2 139.2 aS Ij sS s -I-* -|o H* Os Ez E 1 h DP g OO OO |gI I& % K 1 75.06 74.77 75.00 75.50 74.74 73.30 74.89 74.50 75.15 13.10 12.90 13.20 12.10 12.40 12.40 12.10 12.8S 12.50 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 ft W (4) ( (4) (4) (4) (4) Avg. Value for Sand and Gravel Concrete____ 142.3 12.62* 1 2.00 2.75 0 16.6 135.3 74.87 11.20 0.09 w 1 2.75 4.50 0 15.4 137.8 75.18 12.00 0.08 (4) 3.50 5.50 0 16.3 136.4 74.75 11.50 0.09 (4) 1 2.00' 2.75 3 20.9 130.1 74.85 10.50 0.10 (4) 1 2.75 4.50 3 23.4 126.0 74.45 10.00 0.10 (4) 1 3.50 5.50 3 23.4 127.3 75.26 9.79 0.10 (4) Avg. Value for Limestone Concrete _ _ 132.15 -- 10.83 -- - Hatdite_____ __ . 2.00 2.75 . 0 18.2 1 2.75 4.50 0 19.9 3.50 5.50 0 21.4 1 2.00 2.75 3 22.8 1 2.75 4.SO 3 26.0 3.50 5.SO 3 24.4 Avg. Value for Cinder Concrete _. _ -- 2.00 2.75 0 18.0 1 2.75 4.50 0 19.8 1 3.50 5.50 0 21.8 1 2.00 2.75 4 21.2 1 2.75 4.SO 4 22.2 2.75 4.50 4 22.2 1 3.SO 5.SO 4 23.9 Avg. Value for Haydite ------- .. 103,6 98.7 92.0 101.4 94.0 94.4 75.26 75.71 75.72 74.95 75.20 75.55 97.35 80.7 75.0 71.7 78.8 72.4 72.4 71.0 74.82 75.75 74.82 74.76 75.39 75.49 75.46 74.57 4.63 4.30 3.73 4.89 4.38 4.24 4.86 4.15 3.78 3.67 4.38 3.89 3.86 4.00 3.96 0.22 0.23 0.27 0.20 0.23 0.24 -- 0.25 0.26 0.27 0.23 0.26 0.26 0.25 -- !*> 4) (4) 4) (4) (4) - (4) (4) (4) (4) (4) (4) (4) -- Authorities: #U. S. Bureau of Standards, tests based on samples submitted by manufacturers. 'A. C. Willard, L. C. Lichty, and L. A. Harding, tests conducted at the University of Illinois. *J. C. Peebles, tests conducted at Armour Institute of Technology, based on samples submitted by manufacturers., . _. 4F. B. Rowley, tests conducted at the University of Minnesota. *A.S.H.V.E. Research Laboratory. E. A. Allcut, tests conducted at the University of Toronto. rLees and Charlton. . G. B. Wilkes, tests conducted at the Massachusetts Institute of Technology. Recommended conductivities and conductances for computing heat transmission coefficients. fFor thickness stated or used on construction, not per 1-in. thickness. For additional conductivity data see Chapters 3 and 15, 1937 Data Book. If outside surface of block is painted with an impervious coat of paint, add 0.07 to resistance for sand and gravel blocks. Add 0.18 to resistance for cinder blocks. Add 0.17 to resistance for haydite blocks. Recommended value. See Heating, Ventilating and Air Conditioning, by Harding and Willard, revised edition, 1932. ^See A.S.H.V.E. Research Paper, Conductivity of Concrete, by F. C. Houghten and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 38. 1932. p. 47). . ` -The 6-in., 8-in., and 10-in. hollow tile figures are based on two cells in the direction of heat flow. The 12-in. hollow tile is based on three cells in the direction of heat flow. The 16-in. hollow tile consists of one 10*in. and one 6-in. tile, each having two cells in the direction of heat flow. ' /Not compressed. ' Roofing, 0.15-in. thick (1.34 lb per sq ft), covered with gravel (0.83 lb per sq ft), combined thickness assumed 0.25. `Surface values were obtained on vertical surfaces and varying with the'temperature differences. A foil lined air space in a horizontal position will have a coefficient roughly three times greater if the heat flow is upward rather than downward. . 97 . / Heating Ventilating Air Conditioning Guide 1938 Table 2. Conductivities () and Conductances (C) of Building Materials and Insulators--Continued The coefficients are expressed in Btu Per hour per square foot Per degree Fahrenheit per 1 in. thickness unless otherwise indicated. Material Description Cement Fine Aggre gate 0-No. 4 Coarse Aggre gate. Slump No.4-M Per Cent Voids Rtpanded Burned Clat_____ Steam Treated Limestone Slap,. PlTMICR MfWF.n TN Cai.tv By-Product op Manufacture op Phosphates____ _ Hatditr......... 1 1 ! 1 j 1 8.00 7.00 8.00 8.00 8.00 8.50 8.50 Fineness Modulus 3.75 18.4 27U 26.5 25.5 21.1 21.8 21.8 57.9 74.6 6S.0 86.6 91.1 67.1 67.1 Sand and gravel aggregate-. 126.4 Sand and gravel aggregate used for calcu lations Cores filled with S.14 lb density cork Crushed limestone aggregate-___ _ 134.3 Cinder aggregate= 86.2 Cinder aggregate used for calculations______ Cores filled with 69.7 lb density cinders____ Cores filled with 5:12 lb density oork______ Cores filled with 14.2 lb density rock wooL__ Haydite aggregate__________________ ____L_ ' 67.7 . Cores.filleawith 5.06 lb density cork__-___ ; iiUiuhmii M<n Sand and gravel aggregate Sand and gravel aggregate used for calcu lations: Cinder aggregate___________ -________ Cores filled with 5.24 lb density cork____. Haydite aggregate Cores filled with 5.6 lb density cork 124.9 86.2 "76.7 75.57 2.28 74.49 2.27 74.68 2.42 74.62 3.19 74.43 3.42 75.89 2.89 74.60 2.815 40 0.900t l.OOOf 40 0.560f 40 0.8S6f` 40 0.577f 0.600V 40 0.390T 40 0.250V 40 0.266f 40 0.495V 40 0.206f 40 0.777! 0.800!' 40 0.531f' 40 0.237V 40 0.468! 40 0.168f 0.44 0.44 0.41 0.31 0.29 0.35 0.34 1.11 1.00 1.79 1.17 1.73 1.66 2.56 4.00 3.76 2.02 4.85 1.29 4.22 2.13 5.94 (4) (4) (4) (4) 4) (4) (4) (4) (4) (4) (4) (4) 4) 4) 4) 4) h^ri pri f^rV x I ---------- r----------- Cinder aggregate______ ____ _ 100.0 Double wall with 1 in. air spaee between. 100.0 1 in. space filled with 9.97 lb density rode wool 100.0 40 40 40 l.OOOf 0.358f 0.204f 1.00 2.70 4.90 gravel,aggregate-- 0.380f- (4) r------ J 5 z 8 x 12 block sand and gravel aggregate6. 0.947! (4) rr Chapter S. Heat Transmission Coefficients and Tables (C)Table 2 Conductivities (ft) and Conductances of Building 1 ` Materials and Insulators--Continued expressed in Bin per hoar per square foot per degree Fahrenheit per 1 in. thickness. The coefficients ore express.* unless otherwise indicated. Material Description s -I- Ho D si's? i Io H E Is i&0. 3s egg PP 1 OO OO 1; a0a ll o0ms E masonry materials Blue*- Low density...................... .................................. High density____--....................................... -- Brickwore----------------- -- ---- Cement Mortar----------------- Concrete--------------------------- Cellular-........................... .........------------------Cellular......--............. ........ ..................... ......... Cellular.--:--------------------------- -----------------Typical fiber gypsum, 87.5% gypsum and Special concrete made with an aggregate of 40.0 50.0 60.0 70.0 51.2 101.0 Tile__ --------............. -- Tile or Tbrrazzo-------- - Hollow day (2 'm-)H-in- plaster both sides.-- 120.0" Hollow clay (4 in.) J^r-in. plaster both sides-- 127.0 Hollow day (6 in.) }4-in. plaster both sides.-- 124.3 51.8" 75.6 75 75 75 75 74 70 no" 100 105 "70" 76 5.00* 9.20* 5.00* 12.00* 11.35lo 16.36 1.06 1.44 1.80 2.18 1-66* 3.98 12.50* 12.00* 1.00!* 0.64!* 0.60!* 0.58!* 0.40!* 0.31!* 1.00! 0.60! 0.47! 0.46!* 1.66 2.96 12.00* 1NSULATION--BLANKET OR FLEXIBLE TYPES Fui Chemically treated wood fibers held between layers of strong papa-/---------------------------- mu-Eel grass between strong paper'------------------ Flax fibers between strong paper/. ' .. . Chemically treated hog hair between kraft Chemically treated hog hair between kraft paper and asbestos paper/----------------------- Hair felt between layers of paper/ . Kapok between burlap or paper/. Jute fiber/.-- . -- ----------------------------Ground paper between two layers, each H*in- thick made up of two layers of kraft paper (sample J^-in. thick)_____ ----------- ;--------- 3.62 4.60 3.40 4.90 5.76 7.70 11.00 1.00 6.70 12.1 70 90 90 90 71 71 75 90 75 75 0.27* 0.25 0.26 0.25 0.28 0.26 0.28 0.25 0.24 0.25 0.40! INSULATION-SEMIRIGID TYPE Flax/ _ . Felted hair and asbestos/-- 75% hair and 25% jut/------------------------50% hair and 50% jut/ . Felted jute and asbestos/----- -- Compressed peat moss---------------------- -------- 13.00 11.00 12.10 13.60 7.80 6.30 6.10 6.70 10.00 11.00 90 90 70 90 90 90 90 75 90 70 0.26 0.26 0.30 0.32 0.28 0.27 0.26 0.25 0.37 0.26 INSULATION--LOOSE FILL OR BAT TYPE mm* ' 1.90 .1.60 75 75 0.23 0.24 0.20 0.11 0.20 0.08 0.94 0.69 0.56 0.46 0.60 0.25 0.08 0.08 1.00 1.57 1.67 1.72 2.50 3.23 1.00 1.67 2.13 2.18 0.60 0.34 0.08 3.70 4.00 3.85 4.00 3.57 3.85 3.57 4.00 4.17 4.00 2.50 3.84 3.84 3.33 3.12 3.57 3.70 3.85 4.00 2.70 3.84 4.35 4.17 (2) (5) (3) 3) (3) (3) (4). (3) (2) (2) (2) (4) (4) (3) (1) (1) ID (3) (3) W (1) (3) (4) (1) (1) (3) (1) (1) (1) (1) (3) (1) (3) (3) (3) For notes see page 97. 99 1 Heating Ventilating Air Conditioning Guide 1938 Table 2. Conductivities (k) and Conductances (C) of Building Materials and Insulators--Continued The coefficients are expressed in Btu per hour per square foot Per degree Fahrenheit per 1 in. thickness, unless otherwise indicated. , Material Description "EP P O Eg S3 g. a* od i? 5s sS Ss fc t aS Eg3 SP tP aZo Zoa oo E- 8' H< 1 1 8 at, as B ao < INSULATION--LOOSE FILL OR BAT TYPE --Continued Glass Worn. Gramjlab______ , __ oiTim Fibrous material made from slap . Fibrous material 25 to 30 microns in dia- meter, made from virgin bottle glass__ Made from combined silicate of lime and Alumina Made from expanded aluminum-magnesium silicate _ *a a* Flaked, dry and fluffy/___ * ** " , 1.50 75 9.40 103 1.50 75 4.20 72 6.20 42 24.00 18.00 12.00 34.00 26.00 24.00 19.80 18.00 90 90 90 90 90 75 90 75 0.27 0.27 0.27 0.24 0.32 0.77 0.59 0.44 0.60 0.52 0.48* 0.35 0.34 INSULATION--RIGID BUILDING BOARDS Asbestos a a aa a am** Rock wool with a binding agent Rock wool with flax, straw pulp, and binder Rock wool with vegetable fibers___ From maple, beech and birch (coarse) Redwood hark - 18.00 14.00 10.00 14.50 14.50 11.50 8.80 13.20 3.00 90 90 90 77 75 72 90 90 0.29 0.28 0.27* 0.33 0:38 0.31 0.41 0.36 0.31 Nao adaded bin*der_____________ ** * m * Asphaltic binder.. __ . 14.00 10.60 7.00 5.40 14.50 Chemically treated hog hair covered with film of asphalt____ ___ , Made from corn stalks ____ ___ * " exploded wood'fibers__ * * hard wood fibers- Insulating plaster 9/10-in. thick applied to H-in, plaster board has* ___ Made from licorice root* Made from 85% magnesia and 15% asbestos Made from shredded wood and cement.. Rii^op ni> fihor Sugar cane fiber insulation blocks encased in asphalt membrane__ Made from wheat straw__ . *a "a wood fiber ** . ** "* aa aa *a aa aa aa 10.00 15.00 17.90 15.20 54.00 16.10 19.30 24.20 13.50 13.80 17.00 15.90 15.00 8.50 15.20 16.90 90 0.34 90 0.30 90 0.27 90 0.25 90 0.32 .0.33* 75 0.28 71 0.33 78 0.36 70 0.32 75 1.07f 81 0.34 86 0.51 72 . 0.46 70' 0.33 70 0.30 68 0.33 72 0.33 70 0.33 52 0.33 72 0.29 0.33 90 0.34 Compressed cement ami asbestos sheets- _ Oomurated asheston hoard 123.00 86 20.40 110 2.70 0.48 3.70 3.70 (3) (0 3.70 (3) 4.17 (3) 3.12 (3) 1.30 1.69 (1) in 2.27 1) 1.67 .. (l) 1.92 . u 2.08 (3) 2.86 2.94 (1) (3) (1) 3.33 m 3.45 (i) 3.57 CD 3.70 . (1) 3.03 1) 2.63 3) 3.22 . (3) 2.44 (L) 2.44 (1) 2.78 a) 3.22 . 0) 3.33 2.94 3.33 3.70 4.00 3.12 0) (1) (1) (l> (1) 3.57 3.03 3.12 3.12 0.93 2.94 1.96 2.17 3.03 ) (3) S4> (3) j (3) (3) (1) (3) (3) 3.33.,-' 3.03 3.03 3.03 3.03 3.45 3.03 2.94 (3) (3) (3) (3) (6) (3) (3) ) 0.37 2.08 0) ( For notes see Page 97. 100 1 Chapter s. Heat Transmission Coefficients and Tables Table 2 Conductivities (k) and Conductances (C) of Building Materials and Insulators--Continued Material Description - 5 g . g e* H *5 cid s * a i? BS os g* t "If 15 i Is sS pp gg oo OO ggS gS BJ < building boards --Continued nUT--TTW Pressed asbestos milt board________________ Sheet asbestos------------------ -- Gypsum between layers of heavy paper_____ Rifnd, prvpsum between layers of heavy paper (j^-in. thick)-- . . . ---------- Gypsum mixed with sawdust between layers of heavy paper (0.39-in. thick)-- -- (^in.) .... ... .. (H in-)-----................... ...................................... 60.50 48.30 62.80 53.50 60.70 _____ -- 86 110 70 90 90 __ -- ROOFING CONSTRUCTION Asphalt, composition or prepared___________ Built up--54-iu- thick .. .... .......... Built up, bitumen and felt, gravel or slag surfaced*- ..... ...............--.................... Plaster board, gypsum fiber concrete and 3-ply roof covering 2M in. thick Asphalt -- Slate Wood- ' . --. ... . .. . -- 70.00 __ 52.40 65.00 70.00 201.00 -- 7_5 76 75 75 ~ 0.84 0.29 1.41 2.60f 3.60f 3.73f* 2.82f* 6.50f* 3.S3f` 1.33 0.58f 6.00t* 6.50t* 10.37* 1.28f 1.19 3.45 0.71 0.38 0.28 0.27 0.35 0.1S 0.28 0.75 1.72 0.17 0.15 0.10 0.78 id (2) (3) (1) (1) __ ~ (3) __ (2) (4) (3) (3) (7) " PLASTERING MATERIALS 8.00 0.13 (2) _Gypsum, typical .... ...... --- 3.30* 0.30 __Thickness $4 in.--____--............................ ............ 73 8.80f 0.11 (4) _Metal Lath and Plaster.--. Total thickness K in................. . __ 4.40f* 0.23 Wood Lath and Piaster____ %-in. plaster, total thickness in. 70 2.50f* 0.40 (4) BUILDING CONSTRUCTIONS Frame .. _.. _____ 1-in. fir sheathing and building paper...:-._____ 1-in. fir sheathing, building paper, and yellow pine lap aiding____ 1-in. fir sheathing, building paper and stucco Pine lap aiding and building japer--siding 4 in. wide________ Yellow pine lap riding------------- Battleship linoleum 0-in.)- __ 40.00 30 . 20 20 _16 75 0.71f* O.SOf 0.55 0.85f* 1.28t* 1.20 1.36f* .1.41 2.00 1.82 1.18 0.78 0.83 0.74 W- (4) (4) (4) (3) AIR SPACE AND SURFACE COEFFICIENTS Am Spaces Over faced with ordinary building materials____ . 40 l.lOt* 0.91 (4) Surfaces, Ordinary____ __ Still air (/i) - . ,, 1.65f* 0.61 (4) 15 mph--(/o). ___ ___ 6.00t* 0.17 (4) Surface, Rough Stucco 15 mph--(Jo) __ Surface. Bright Aluminum Still air (/i")b____ __ ' 9.00+* 0.11 (4) --- 0.80f 1.25 (8) AIR SPACES FACED WITH BRIGHT ALUMINUM FOIL Air apace, faced one side with bright alumi- num foil, over -in. wide Air space, faced one side with bright alumi- 50 0.46f* 2.17 (4) num foil, %-ia. wide- 50 0.62f 1.61 (4) Air space, faoed both aides with bright aluminum foil, over $i-in. wide Air space, faced both sides with bright 50 0.41f* 2.44 (4) aluminum foil, %-m. wide___ . -- 50 0.57f 1.75 (4) For notes see Page 97. 101 r"  Heating Ventilating Air Conditioning Guide 1938 Table 2. Conductivities (4) and Conductances (C) of Building Materials and Insulators--Continued The coefficients ore expressed in Btu per hour per square foot Per degree Fahrenheit per l in. thickness, unless otherwise indicated. Material Description oD t5<c *aB, oSd* Is EJ ii is os Ps 5a oo oo sV as 1gi &a0t t3f 3 1 < AIR SPACES FACED WITH BRIGHT ALUMINUM FOIL--Continued . Air space divided in two with single curtain of bright aluminum foil (both sides bright) Each space over J^-in. wide 50 0.23f* 4.35 ) Each space H4n. wide -- 50 0.31f 3.23 (4) Air space with multiple curtains of bright aluminum foil, bright on both sides, curtains more than rin. apart, air circu lation between spaces prevented: 2 curtains, forming 3 spacra ........ ....... 50 O.lSf* 6.78 (4) 3 curtains, forming 4 spaces--___________ 50 O.ilf* 9.22 (4) 4 curtains, forming 5 spaces--___________ -- 50 0.09f* 11.66 (4) SPACES FACED WITH NONMETALLIC REFLECTIVE SURFACE Fabric with non-metallic reflective surface (J6 in* thick) placed in center of a in. air space Core at fibs' board coated two rides with non-metallic reflective surface (% in. thick) placed in space having approxi mately $ in. air space on each ride_____ fiber board coated one ride with nonmetallic reflective surface (% in. thick) Air spaoe divided in two with fabric faoed both rides with non-metallic reflective surface, each space over M-in. wide Air space over %-in. wide faced one side with non-metallic reflective surface 23.4 -- ____ --. 70 70 75 40 40 0.33f 3.03 (4) 0.27f 3.70 , (3) 0.49f 2.04 0.33f 0.67f .3.03 1.49 (4) (4) WOODS (Aeroes Grain) Bai.ha ___________ Caupobnia Redwood.. 0% moisture-- Ctprbss- Douglas Fm_. Eahtebn Hemlock-^.- Hian Maple__ 8% 16% 16% 0% mdstore-- 0% * - 8% * 8% 16% * _. 16% * ,, 0% moisture-- 0% " 8% 8% 16% *- "- 16% ` ,, 0% moisture-- 0% 8% 8% 16% *- *_ *_ "_ 16% ' ' For notes see Page 97. 102 20.0 90 8.8 90 7.3 90 22.0 7S 28.0 75 22.0 7S 28.0 75 22.0 75 28.0 75 28.7 86 26.0 75 34.0 * 75 26.0 ` 75 34.0 75 26.0 75 34.0 75 22.0 75 30.0 75 22.0 75 30.0 75 22.0 75 30.0 75 40.0 75 46.0 75 40.0 75 46.0 75 40.0 75 46.0 75 0.58 0.38 0.33 0.66 0.70 0.70 0.75. 0.74 0.80 0.67 0.61 0.67 0.66 0.75 0.76 0.82 0.60 0.76 0.63 0.81 0.670.85 1.01 1.05 1.08 1.13 1.15 1.21 1.72 (1) 2.63 U> 3.03 Cl) 1.53 (4) 1.43 (4) 1.43 (4) 1.33 (4) 1.35 (4) 1.25 HI 1.49 U) 1.64 (4) .1.49 (4) 1.S2 4) 1.33 (*) ` `1.32 (4) 1.22 (4) 1.67 (4) 1.32 " 4) 1.59 (4) 1.23 14} 1.49 (41 1.18 (4) 0.99 (4) 0.95 (4) 0.93 (4) 0.89 (4) 0.87 (4) 0.83 (4) - chapter 5. Heat Transmission Coefficients and Tables Table 2 iA Conductivities (4) and Conductances..(C) of Building Materials and Insulators--Continued --The coefficients --arc .e.xpMreesssseeds in Bln puenrlehsosuroptheerrsaqisueareinfdoiocat tpeedr.degree F..a...h..r..e..n...h..e...it.. per 1 in. thickness. Material Description S Q. -i- iTio i OP $ a5 5 M 55 lg i | * fc Hg la s s 6m cw <s gS PP oo oo g as h CSCKO* O0*SB5O as < WOODS--Continued LoitOLKAr Yellow Pine----- 30.0 40.0 40.0 30.0 40.0 34.3 44.3 Nobwat Pine------------- --- *<% . Red Ctpeess.---------- ---- 8% o1L&U ouu.-. not i i/rt Sbobtleap Yellow Pine..--. n% R% i fi% '1/5% ' R% R% 1/5% Sorr Maple______________ n% R% 8% 1/5% 1/5%' n% % VmniNiA Prw 8% lrf% lfi% West Coast Hemlock_____ 0% . 8%. White Prw* ' 8% 1 fi% 16% * Yellow Ptw* Yellow Pm* on Fn ' 22.0 22.0 ' ............. 32.0 22.0 32.0 32.0 22.0 .................................... ' 22.0 32.0 38.0 48.0 38.0 48.0 38.0 48.0 26.0 36.0 ' ' 26.0 36.0 - .. 26.0 ' 36.0 28.0 34.0 s 28.0 34.0 28.0 34.0 . 36.0 42.0 * 36.0 *................. ` '' 42.0 36.0 42.0 2210 28.0 - 22.0 ". 28.0 . 22.0 28.0 34.3 22.0 ' 30.0 - 22.0 : 30.0 * *' 22.0 30.0 31.2 75 75 75 75 75 75 86 86 75 75 75 75 75 75 75 '75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 ' 75 75 75 75 75 7S 75 75 75 75 75 75 86 7S 75 - 75 75 75 75 86 0.76 0.86 0.83 0.95 0.89 1.03 0.90 1.10 1.15* 0.62 0.74 0.6S 0.83 0.74 0.91 0.67 0.79 0.71 0.84 0.74 0.90 0.98 1.18 1.03 1.24 1.07 1.29 0.74 0.91 0.79 0.97 0.84 1.04 0.73 0.88 0.77 0.93 0.81 0.97 0.89 0.95 0.96 1.02 1.01 1.09 0.54 0.64 0.59 0.71 0.65 0.78 0.96 0.68 0.79 0.73 0.85 0.78 0.91 0.78 0.80* 1.32 1.16 1.21 1.05 1.12 0.97 1.11 0.91 0.87 1.61 1.35 1.47 1.21 1.35 1.10 1.49 1.27 1.41 1.19 1.35 1.11 1.02 0.85 0.97 0.81 0.94 0.78 1.35 1.10 1.27 1.03 1.19 0.96 1.37 1.14 1.30 1.08 1.24 1.03 1.12 1.05 1.04 0.98 0.99 0.92 1.85 1.56 1.70 1.41 1.54 1.28 1.04 1.47 1.27 1.37 1.18 1.28 1.10 1.28 1.00 1.25 (4) (4) (4) (4) (4) (4) ain) (4) (4) (4) (4) (4) (4) 4) (4) (4) (4) (4) (4) (4) (4) (4) (4) 4) 4) (4) (4) (4) (4) (4' (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (4) (1) (4) (4) (4) (4) (4) (4) (1) (3) For notes see Page 97. 103 Heating Ventilating Air Conditioning Guide 1938 Table 3. Coefficients of Transmission (U) of Masonry Walls Coefficients are expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature between the air on the two sides, and are based on a wind velocity of 16 mph. TYPICAL CONSTRUCTION TYPE OF WALL Thickness OF Masonbt (Inches) Na Solid Brick Based on 4-in. hard brick and the remainder common brick. 8 12 16 1 2 3 Chapter S. Heat Transmission Coefficients and Tables Plain walla--no in terior finish Plaster on wood la th --furred Decorated building board (M in-) with out plaster--furred Plaster (M in.) on rigid insulation (1 in .) -- furred Plaster iM in.) on oorkboard (1M in.) setin cementmortar (M in.) Plaster on metal lath attached to fur ring strips (2 in.6) -- rock wool fill (1M in.6)* INTERIOR FINISH Uninsulated Walls Iksul&teq.Wauh o g-s a Ij -3 !-T a! ss-~ sa oJ3 .1.1 si's ru JCT si-3 CLTE.S ABCD E F GH jl-jMs "8 " sif!'1'Sg iWi-ilf Ii ijflift ll^ii|1 Ess-sS-S-s KL 0.50 U.3ti 0.28 0.27. 0.20 0.21 0.30 0.24 0.20 0.23 0.19 0.17 0.22 0.16 0.19 0.14 0.16 0.13 0.14 0.12 0.11 0.23 0.19 0.17 0.12 0.11 0.10 0.20 0.17 0.15 Hollow Tile Stucco Exterior Finish. The 8-in. and 10-in. tile figures are based on two cells in the direction of flow of heat. The 12-in. tile is based on three cells in the direction of flow of heat. The 16-in. tile consists of one 10-in. tile and one 6-in. tile each having 8 10 12 16 . 4 5 6 7 0.25 0.24 0.26 0.22 0.19 0.28 9.27 0.22 0.19 0.26 0.26 0.22 0.19 0.20 0.20 0.17 0.16 0.20 0.19 0.17 0.15 0.15 0.15 0.14 0.12 0.13 0.13 0.12 0.11 . 0.20 0.20 0.18 0.16 0.11 0.11 0.10 0.097 0.18 0.18 0.16 0.14 two cells in the direction of heat flow. Limestone or Sandstone ' 8 12 16 24 8 9 0.37 0.39 0.37 0.53 0.33 0.34 0.33 0.26 0.24 0.25 0.18 0.15 0.23 0.17 0.14 0.26 0.24 0.13 0.13 0.23 0.21 10 11 0.45 0.30 0.31 0.30 0.37 0.35 0.25 0.26 0.25 0.22 0.20 0.22 0.16 0.14 0.19 0.15 0.13 0.22 0.20 0.12 0.11 0.20 0.18 Concrete (Monolithic) ' These figures may be used with sufficient accuracy for concrete walls with stucco exterior 6nh- Cinder (Monolithic) Conductivity k = 4.36 Haydite (Monolithic) . Conductivityk = 3.96 \ Cinder Blocks v Cores filled with dry cinders, 69.7 lb per cu ft. Cores filled with granulated cork, 5.12 lb per cu ft. Cores filled with rock wool, 14.2 lb per cu ft. Based on one air cell in direction of heat flow. Cores filled with granulated cork, 5.24 lb per cu ft. Concrete Blocks Cores filled with granulated cork, 5.14 lb per cu ft. Based on one air cell in direction of heat flow. Haydite Blocks Cores filled with granulated cork, 5.06 lb per cu ft. Haydite Blocks Cores filled with granulated cork, 5.6 lb per cu ft. Computed from factors marked by * in Table 2. 6Based on the actual thickness of 2-in. furring strips. 6 10 16 20 6 10 16 20 6 10 16 20 8 8 8 8. 12 12 8' 8 12 8 8 12 12 12 . 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 0.79 0.62 0.48 0.41 0.70 0.57 0.44 0.39 0.39 0.34 0.29 0.27 0.42 0.37 0.31 0.28 0.39 0.34 0.29 0.27 0.27 0.25 0.22 0.21 0.26 0.24 0.21 0.20 0.19 0.18 0.16 0.15 0.16 0.15 0.14 0.13 . 0.27 0.25 0.22 0.21 0.13 0.13 0.12 0.12 0.23 0.22 0.20 0.18 0.46 0.33 0.22 0.19 0.43 0.31 0.22 0.18 0.29 0.23 0.17 0.15 0.30 0.24 0.18 0.15 0.29 0.23 0.17 0.15 0.22 0.18 0.15 0.13 0.21 0.18 0.14 0.13 0.16 0.14 0.12 0.11 0.14 0.12, 0.10 0.09 0.22 0.18 0.15 0.13 0.12 0.11 0.09 0.09 0.19 0.16 0.13 0.12 0.44 0.30 0.21 0.17 0.41 0.29 0.20 0.17 0.28 0.22 0.16 0.14 0.29 0.23 0.17 0.14 0.28 0.22 0.16 0.14 0.21 0.17 0.14 0.12 0.21 0.17 . 0.14 0.12 0.16 0.14 0.11 0.10 0.13 0.12 0.10 0.09 0.21 0.18 0.14 0.12 0.12 0.10 0.09 0.08 0.19 0.16 - 0.13 oai 0.42 0.39 0.27 0.28 0.27 0.31 0.29 0.23 0.23 0.22 0.21 0.18 0.20 0.16 0.13 0.17 0.14 0.12 0.21 0.18 0.12 0.11 0.19 0.16 0.22 0.21 0.17 0.18 0.17 0.23 0.22 0.19 0.18 0.18 ' 0.37 0.35 0.25 0.26 0.25 0.14 0.15 0.19 0.14 0.12 0.14 0.12 0.19 0.15 0.11 0.10 0.13 0.14 0.15 0.19 0.09 0.09 0.11 0.13 0.14 0.17 0.20 0.19 0.17 0.16 0.16 0.13 0.13 0.11 0.10 0.14 0.09 0.13 0.56 0.52 0.32 0.34 0.32 0.24 0.23 0.17 0.14 0.24 0.12 0.21 0.41 0.39 0.27 0.28 0.27 0.49 0.46 0.30 0.32 0.30 0.21 0.23 0.20 0.15 0.13 0.22 0.16 0.14 0.21 0.23 0.12 0.12 0.18` 0.20 0.36 0.34 0.26 0.26 0.24 0.19 0.19 0.15 0.13 0.19 0.11 0.17 0.18 0.17 0.15 0.15 0.14 0.34 0.32 0.25 0.25 0.24 0.15 0.14 0.13 0.13 0.12 0.13 0.19 0.11 0.12 0.10 0.18 0.14 0.11 0.09 0.09 0.12 0.08 0.13 0.19 0.11 0.08 0.11 0.08 0.12 0.17 0.10 ' waterproof membrane should be provided between the outer material and the insulation fill to prevent possible wetting by absorption and a subsequent lowering of efficiency. . .. -- . * 105 Plaster (M in.) on metal lath attached to furring strips-- furred apace (over %-\n. wide) faced oneaids with bright aluminum foil ! Plaster (M, In.) on metal lath attached ; to furring strips i (2 in.6)--flexible in| sulation (} In.) be tween furring stripe (one air space) Heating Ventilating Air Conditioning Guide 1938 Table 4. Coefficients of Transmission (U) of Masonry Walls .. with Various Types of Veneers . Coefficients ore expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature between the air on the two sides, and are based on a wind velocity of 16 mph. TYPICAL CONSTRUCTION TYPE OF WALL . Facing Backing WiU, Na 4 in. Brick Veneer* 6 in. ,5iu "in. Hollow Tile- 6 12 in. 37 38 39 40 Chapter 5. Heat Transmission Coefficients and Tables INTERIOR FINISH Uninsulated Walls Insulated Walls i oa 1 oaa If If Ijsi X .2 o s.s g Plaster Id.) od metal lath--furred gx 3-, 3*1 If! sis No plaster--deco rated rigid or build ing board interior finish (H in.)-- furred gx a-w* 31 Sg dj a-Xg x|| i=l sfl fiT -s* 5 a .CsL'STE'T.SJ gjJ&g .g-S slip Is V lisssa A B C D E F GH I J K L 0.34 0.24 0.25 0.24 0.33 0.24 0.25 0.24 0.34 0.27 0.32 0.26 0.23 0.20 0.24 0.21 0.23 0.20 0.19 0.19 0.19 0.16 0.19 0.16 0.18 0.14 0.18 0.14 0.16 0.13 0.13 0.12 0.12 0.11 0.19 0.19 0.19 0.16 0.11 0.11 0.11 0.10 0.17 * 0.17 0.17 0.15 4 in. Brick Veneer* 6 in. 10 in. Concrete 16 in. 41 . 42 43 4 in- Brick Veneer* \ 4 in. Cut-Stone Veneer* 8 in. Cinder Blocks 8 in. Cinder Blocks -- Cores filled with granulated cork. 5.12 lb per cu ft. 12 in. Cinder Blocks 12 in. Cinder Blocks -- Cores filled with granulated cork, 5.24 lb per cu ft. 8 in. Concrete Blocks ' 8 in. Concrete Blocks--Cores filled with . granulated cork. 5.14 lb per cu ft. 12 in. Concrete Blocks 8 in. Haydite Block 8 in. Haydite Block--Cores filled with granulated cork. 5.06 lb per cu ft. 12 in. Haydite Block 12 in. Haydite Block--Cores filled with granulated cork, 5.6 per cu ft. 44 45 46 47 48 49 50 51 52 53 54 8 in. 12 in. Common Brick 16 in. 55 56 57 0.57 0.53 0.33 0.35 0.33 0.48 0.45 0.30 0.31 0;30 0.39 0.37 0.26 0.27 0.26 0.24 0.22 0.20 0.23 0.17 0.14 0.22 0.16 0.14 0.19 0.15 0.13 0.24 0.22 0.20 0.35 0.33 0.24 0.25 0.24 0.19 0.18 0.14 0.12 0.19 0.20 0.19 0.16 0.16 0.16 0.13 0:13 0.11 0.10 0.31 0.30 0.22 0.23 0.22 0.18 0.17 0.14 0.12 0.13 0.18 0.18 0.18 0.15 0.15 0.15 0.44 0.42 0.28 0.30 0.28 0.13 0.21 0.12 0.10 0.09 0.21 0.16 0.13 ' 0.13 0.21 0.34 0.32 0.24 0.25 0.23 0.40 0.38 0.26 0.28 0.26 0.31 0.29 0.23 0.23 0.22 0.19 0.20 0.18 0.18 0.14 0.12 0.20 0.15 0.13 0.17 0.14 0.12 0.19 0.20 0.18 0.17 0.16 0.14 0.14 0.14 0.29 0.28 0.21 0.22 0.21 0.12 0.17 0.12 0.10 0.09 0.17 0.13 0.12 0.12 0.17 0.14 0.14 0.12 0.12 0.12 0.10 0.10 0.09 0.08 0.10 0.37 0.35 0.25 0.26 0.25 0.28 0.27 0.21 0.21 0.21 0.23 0.22 0.18 0.18 0.18 0.19 0.17 0.15 0.19 0.15 0.13 0.16 0.13 0.12 0.14 0.12 0.11 0.19 0.17 0.15 0.13 0.12 0 11 0.21 0.20 0.18 0.11 0.09 0.11 0.08 0.12 0.11 0.11 0.11 0.08 0.10 0.07 0.11 0.10 0.095 0.17 0.12 0.16 0.12 0.19 0.17 0.18 0.16 o:u 0.16 0.10 0.17 0.15 0.14 4 in. Cut-Stone Veneer* 6 in. .!" Hollow Tile6 iu in. 12 in. 58 ' 59 60 61 4 in. Cut-Stone Veneer* 6 in. ' 10 in. Concrete 16 in. . '62 63 64 Computed from factors marked by * io Table 2. . *Based on the actual thickness of 2-in. furring strips. . *The 6-in.. 8-in. and 10-in.tile figures are based on two cells in the direction of heat flow. tile is based on three cells in the direction of heat flow. . - i no . The 12-ia- 0.37 0.35 0.25 0.26 0:25 0.34 0.24 0.25 0.24 0.3d 0.33 0.24 0.25 0.24 0.20 0.20 0.21 0.20 0.20 0.19 0.19 0.17 0.19 0.15 0.19 0.15 0.18 0.14 0.16 0.13 0.13 0.13 0.12 0.11 0.20 0.19 0.19 0.17 0.11 0.11 0.11 0.10 0.18 0.17 0.17 0.15 0.61 0.51 0.41 0.56 0.47 0.38 0.34 0.31 0.26 0.36 0.32 0.28 0.34 0.31 0.26 0.25 0.23 0.20 0.24 0.18 0.15 . 0.25 0.22 0.17 0.14 0.23 0.20 0.15 0.13 0.21 . 0.13 0.12 0.11 0.22. 0.20 0.18 ^Calculations include cement mortar (H in.) between veneer or facing and backing. /a ^ on one 811 In direction of heat flow. .. nr>-..i^crP?xrf mm^.rane should be provided between the outer material and the insulation fill to evcDl possible wetting by absorption and a subsequent lowering of efficiency. 107 Heating Ventilating Air Conditioning . Guide 1938 Table 5. Coefficients of Transmission (U) of Various Types of Frame Construction^ These coefficients ore expressed in Btu Per hour per square foot per degree Fahrenheit difference in temperature between the air on the two sides, and are based on a wind velocity of 16 mph. Based on the actual width of 2 by 4-in. studding, namely, 3% in. Chapter 5. Heat Transmission Coefficients and Tables INTERIOR FINISH . No Insulation Between Studding ' Insulation Between Studding ,0c u 2 o i '3 3 1H 1 oa 1 ao 3 T3 a. aM c s *1 CO efi l. c 2 2'-3 2.S a J* Ph AB C ao . 2 3 J a 2 ' gs d5 XM<o3! 8 eo - s! k o i. 1cuC Is ft DE F 0.25 0.26 0.25- 0.19 0.15. 0.11 Plaster ( K in.) on rigid insulation ( K in .) on studding No plaster--decorated rigid or build ing board interior finish ( K in.) Plaster (% in.) on metal lathb on | studding--flexible insulation ( K in.) ; between studding-- 2 air spaces Plaster i} /i in.) on metal lath6 on studding--flexible insulation (1 in.) between studding-- 2 air spaces G 0.19 .1 la S-3 ^g sS 3a s.s gS T3 sS, F -J' ' ^_ c d ss 51-2 f-sf 3^a3a 33 3 3-3 g.il -2 aW'O .s a as1 2'-3 3j{j ft* S' a HJ K nh. 3a 1gg,, >1? 0*6 sri hOg 1-1.2 LM 0.17 0.20 0.17 0.15 0.12 0.072 0.23 0.24 0.23 . 0.18 0.14 0.11 0.18 0.14 0.19 0.17 0.13 0.10 0.070 0.31 0.33 0.31 0.22 0-17 0.13 0.23 0.19 0.24 0.20 0.17 0.13 0.076 0.25 0.26 0.25 '0.19 , 0.15 0.11 0.19 0.17 0.20 0.17 0.15 0.12 0.072 0.19 0.20 0.19 0,15 0.12 0.10 0.16 0.14 0.16 0.14 0.11 o;o94 0.066 0.24' 0.25 0.24 0.19 0.15 0.11 0.19 0.19 0.19 0.17 0.15 . 0.12 0.071 0.3a 0.31 0.30 0.22 0.16 . 0.12 0.22 0.19 0.23 0.20 0.17 0.13- 0.076 . 0.27 0.29 0.27 . 0.20 0.16 0.12 0.21 0.15 0.22 0.19 0.14 0.11 0.074 0.40 0.43 0.40 ' 0.26 . 0.19,, 0.14 0.28 0.22 0.29 0i24 . 0^20 0.14 0.081 0.27 0.28 0.27 0.2Q 0.15 0.12 0.21 0.17 0.21 0.18 0.16 0.12 0.074 0.25 0.26 0.25 0.19 0.15 0.11 0.19 0.15 0.20 ,0.18 0.13 0.11 0.072. 0.35 0.37 0.35 0.24 0.18 0.13 0.25 0.21 0.26 0.22 0.18' 0.14 ' 0.079 'Yellow pine or fir--actual thickness about % in- . `Furring strips between wood shingles and sheathing.' > ...... .- - 'Small air space and mortar between building paper and brick veneer neglected: . .. nr-^,^terRT,^ me.mt|rane should be provided between the outer material and the insulation fill to P ^IP^ ^ssible wetting by absorption and a subsequent lowering of efficiency......... , . . "Mud and rock wool fill areas combined. ; . .1 109 Heating Ventilating Air Conditioning Guide 1938 Table 6. Coefficients of Transmission (Z7) of Frame Interior Walls and Partitions^ Coefficients ore expressed in Btu per hour per square foot Per degree Fahrenheit difference in temperature between the air on the two sides, and are based on sttU air {no wind) conditions on both sides. TYPICAL CONSTRUCTION /n-ft/TeB. yStOTS IfU/TER, DOUBLE PARTITION (Finished on Both Sides of Studding) SmoLB Pabsttiok Wall (Finish No. on One Air. 8n>B or Space Studding) Between Studding Flaked GST Between Studding Rock Wool FID* Between Studding H-in. Flexible Insulation Between Studding (One Air Stud Space Faced One Side with Bright Aluminum Foil Space) Type of Wall Wood Lath and Plaster On Studding Metal Lath and Plaster* On Studding Plaster Board in.) and Plaster4 On Studding H in* Rigid Insulation and Plaster4 On Studding 1 in. Rigid Insulation and Plaster4 On Studding 1H in. Corkboard and Plaster4 On Studding 2 in. Corkboard and Plaster4 On Studding 77 78 79 80 81 82 83 .A 0.62 B 0.34 C 0.11 0.69 0.39 0.11 0.61 0.34 0.10 0.35 0.18 0.083 0.23 0.12 0.066 0.16 0.081 0.052 0.12 0.063 0.045 D 0.076 E 0.21 0.078 .0.23 0.075 0.21 0.063 0.14 0.054 0.097 0.044* 0.070 0.038 0.057 F 0.24 0.26 0.24 0.15 0.10 0.073 0.059 Computed from factors marked by in Table 2. Thickness nnwl Z$i in. `Plaster on metal lath assumed H-in- thick. ^Plaster assumed M-in. thick. Table 7. Coefficients of Transmission (IT) of Masonry Partitions'! Coefficients are expressed in Btu Per hour per square foot Per degree Fahrenheit difference in temperature between the air on the two sides, and are based on still air (no wind) conditions on both sides. ' TYPICAL CONSTRUCTION flfU/ffKIC^ ___ ' Walia ~ Walls Plain Wails PlAWHlHWI Plastered No. (No Plasteb) on One Side on Both Sides - Type of Wall 4-in. Hollow Clay Tile' 4-in. Common Brick 4-in. Hollow Gypsum Tile 2-in. Solid Plaster . 84 85 86 87 Computed from factors marked by * in Table 2. .A 0.45 0.50 0.30 -- B 0.42 0.46 0.28 '-- C 0.40 0.43 ' 0.27 0.53 Chapter 5. Heat Transmission Coefficients and Tables 111 T a b l e 8 . C o e f f ic ie n t s o f T r a n s m is s io n { U ) o f F r a m e C o n s t r u c t io n F l o o r s a n d C e i l i n g s ** Coefficients are expressed in B tu per hour per square fo o t per degree Fahrenheit difference in tem perature between the a ir on the two sides, and are based on s till a ir (n o w in d ) conditions on both sides. separated fro m la th and plaster ceiling b y 1-in. fu rrin g strips* A ir space faced on one side w ith b rig h t alum inum fo il. "1 H e a t in g V e n t il a t in g A ir C o n d it io n in g G u id e 1938 112 Table 9. Coefficients of Transmission (U) of Concrete Construction Floors and Ceilings Coefficients are expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature between the air on the two sides, and are based on still air (no wind) conditions on both sides. . TYPICAL CONSTRUCTION TYPE OF FLOORING Type of Ceiling No Gelling - .v in. Plaster Applied Directly to Under Side of Concrete .. 1 . , V* Suspended or Furred Metal Lath and Plaster m In.) Celling Suspended or Furred Celling of Plaster Board (ft in.) and Plaster (H in.) Suspended or Furred Celling of Rigid Insulation ($ in.) and Plaster {H in.) Plaster (H In.) on Corkboard (1M in.) Spt in Cement Mortar (>$ in.) on Concrete -Thickness or Concrete (Inches) No. ' 4 6 8 10 1 2 3 4 45 66 87 10 8 49 e 10 8 11 10 12 4 13 6 ' 14 8 15 10 16 4 17 6 18 8 19 10 20 4 6 8 10 21 22 23 24 No Flooring (Concrete Bare)6 Yellow Pine Flooring* on Wood 81eepers Embedded in Concrete* Maple or Oak Flooring* on Yellow Pine Sub-Flooring* on Wood Sleepers Embedded in Concrete Tile or Terrauo/ Flooring on Concrete A B .C D 0.65 0.59 0.53 0.49 0.40 0.37 0.35 0.33 0.31 0.30 0.28 0.27 0.61 0.56 0.51 0.47 0.59 0.54 0.50 0.45 0.38 0.35 0.33 0.32 0.30 0.28 0.27 0.26 0.56 0.52 0.47 ,, 0.44 0.37 0.35 0.33 0.32 0.28 O*. 26 0.25 0.24 0.23 0.22 0.21 0.21 0.36 0.34 0.32 0.31 0.35 0.33 0.31 0.30 . 0.26 0.25 0.24 0.23 . 0.22 0.21 0.21 0.20 ' 0.34 0.32 0.30 Q.29 0.24 0.23 0.22 . 0.22 0.20 0.19 0.18 0.18 0.17 0.17 0.16 0.16 0.24 ' 0.23 0.22 0.21 0.15 0.14 0.14 . 0.14, 0.13 0.13 0.12 0.12 0.12 0.12 0.11 0.11 0.14 0.14, 0.14 0.14 k-m. Battleship linoleum Directly on Concrete E 0.44 0.41 0.38 0.36 0.41 0.38 0.36 0.34 0.29 0.28 0.27 0.25 0.28 0.26 0.25 0.24 0.21 0.20 0.19 0.19 0.14 0.13 0.13 0.13 Computed from factors marked by * in Table 2. .... ,. ' *The figures in Column A may be used with sufficient accuracy for concrete floors covered with carpet. Thickness of yellow pine flooring assumed to be % in. -` ' 1 *The figures'in Column B may be. used with sufficient accuracy for maple or oak flooring* applied directly over the concrete on wood sleepers. Thickness of maple or oak flooring assumed to be % in. /Thickness of tile or terrazzo assumed 1 in. -* UTable 10. Coefficients of Transmission ( ) of Concrete Floors on Ground with Various Types of Finish Flooring. < Coefficients are expressed in Btu per hour per square foot Per degree Fahrenheit difference in temperature between the ground and the air over the floor, . and ore based on still air (no wind) conditions. TYPICAL CONSTRUCTION COIftRtTft ../fUHUUrtfi ''CBtUfttTE iN/ULATldN fiE.TWt,N TWO nUM&JtANE. / Thickness . or - Concrete . (Inches) No. ; No Flooring (Concrete Bare) TYPE OF FINISH FLOORING - Yellow Pine Flooring6 on Wood Sleepers Resting on Concrete Maple or Oak Flooring* on YellowPine Sub*Flooring on Wood Sleepers Resting on Concrete Tile or Terrasso* on Concrete . K-in. Battleship Linoleum Directly on Concrete ' Type and Thickness or-Insulation . ! v. 1 In. Rigid Insulation* 1 in. Rigid Insulation* 2 in. Corkboard* 2 in. Corkboard* . i 8 10 . 4 8 1 2 3 4 5 6 '4 7 88 49 8 10 A 1.07 O.OOv 0.79 0.70 ,, . 0.66 . ,0.64;. 0.22 0.21 0.12 0.12 B# 0.35 0.33 0.32 0.30.. 0.29 0.27 0.16 0.15 0.099 0.096 C 0.28 0.27 0.26 0.25 0.24 0.23 0.14 0.13 0.093 , 0.090 - . D 0.98 0.84 0.74 0.66 0.63 0.52 0.22 0.20 6.12 0.12 E 0.60 0.54 0.50 0.46 0.44 0.39 0.19 0.18 0.11 ' 0.11 Computed from factors marked by * in Table 2. ^Assumed % In. thick. ' , '. `Assumed % in. thick. ^Assumed 1 in. thick. . ' ;` The figures for Nos. 5 to 10, Inclusive, include 3-in. cinder concrete placed directly on the ground. The insulation is applied between the cinder concrete and the stone concrete. Usually the insulation is protected on both sides by a waterproof membrane, but this is not considered in the calculations. 1 't Heating Ventilating Air Conditioning Guide 1938 Table 11. Coefficients of Transmission (17) of Various Types of Flat Roofs Covered with Built-Up Roofing typical construction Without Ceilings With Metal Lath AND ' Plaster Ceilings4 TYPE OF ROOF DECK Thickness or Root Deck (Inches) No. /tur KOOFlKCi /`hit 'Vgppor.t/^' HOOf-liHnfji-Ui tA4tlM cowatTe.' ROOFINfi /ft *T/ortor.T/jr` CULlVtf^" Precast'Cement Tile IK I ^HCRtTa' lipl Uun<j7 Concrete Concrete Concrete ' ,2.2 4- 3 `6 . 4 Wood Wood Wood Wood 5 6 7 4k 8 RflOHiNrtJeOj LjfflOtt/ PLAJTR SOARP Ifl/ULATtfty EOOFlMCi. / hiiiu.u j Jinmirmy l&rJWK?. . PLA/TCfc M:V ClLlH ^ Gypsum fiber Concrete0 (2 in.) on Plaster Board (H in-) Gypsum Fiber Concrete0 (3 in.) on Plaster Board IK in.) Gypsum Fiber Concrete0 (2 in.) on Rigid Insula* lation Board (W in.) Gypsum Fiber Concrete0 (2 in.) on Rigid Insula tion Board (1 in.) , Flat Metal Roofs ' Coefficient of transmis sion of bare corrugated iron (no roofing) is 1.50 Btu per hour per square foot of projected area per degree Fahrenheit dif ference in temperature, based on an outside wind velocity of 15 mph.______ X / ^Computed from factors marked by ihrTable 2. - - `Nominal thicknesses specified--actual thicknesses used in calculations. ` *Gypsum fiber concrete---87M per cent gypsum. 12K per cent wood fiber. m m 2K 3 9 10 11 '12 13 114 Chapter 5. Heat Transmission Coefficients and Tables Coefficients are expressed in Btu Per hour per square foot per degree Fahrenheit difference in temperature between the air on the two sides, and are based on an outside wind velocity of 16 mph. 115 1 T a b l e 12. C o e f f ic ie n t s o f T r a n s m is s io n V) o f P it c h e d R o o f s ( Coefficients ore expressed in B tu per h o u r per square fo o t Per degree F ahrenheit difference in tem perature between the a ir on the tw o sides, '* . and are based on a n outside w in d velocity o f 16 m ph. . Heating Ventilating Air Conditioning Guide 1938 (hi H) rawd ptre (*m z) pjreoqV0 (ai zairejj pue (hi Hi) P"W0 (hi h) pm> (nt i) not^Bjnsni pdhry (HI H) P (hi H) nouBpisnj pisgj (hi H) nopeptsni ptSrg bjssjj pus ibhi pooij (HjH)n(BiiIdpire (HiH)("w>aWd (HI H) sld pi qir t*H (pvsodrj anlH30N *i e * oz| <H< s OO 25 g Ew op SP3 at; op ' N o o ci 2 wg B3 O s .| JsiSl^S CO.fi -o b2*2^f*3w8C.tfSco <Bfi 03 - 1 || -S JS S5 a sit -- *0 C c - --.2 2H "DS.'04) ^ -O*- Oca.-$?5.>0 . .Mo 'SS' ** a^ tag's M5 3 12 =iH3 -*N1:35> y<a ifc/2 o 5 .25?-Sv 1 Jm3 - ^ 2-c&"S*t tio- '2 Ou -"uTM\jjw S-=-3#g 2t^p-S = S* o ^ C f-o s c-o^ .g o 3 5? a . 116 Chapter 5. Heat Transmission Coefficients and Tables Table 13- (U)Coefficients of Transmission of Doors, Windows, Skylights 1` . and Glass Walls _ are based on a wind velocity of 16 mph, and ore expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature between the air inside and outside of the door, window, skyhght or wall A. Windows and Skylights Description - u Single-............ -..........................................................................-.............. Tiiplt----........ B. Solid Wood Doorsb. c Nominal Thickness Inches i m m m .2 2 34 3 Actual Thickness Inches % lHs 1^6 m. m 256 1.13. c 0.45 0.281 u 0.69 0.59 0.52 0.51 0.46 0.38 . 0.33 C. Glass Walls Description Hollow glass tile wall, 6 x 6 x 2 in. thick blocks Wind velocity 15 mph, outside surface; still air, inside surface.--.. Still air, outside and inside surface:................ --...'....................... .... - ' V 0.60 0.48 See Heating, Ventilating and Air Conditioning, by Harding and Willard, revised edition, 1932. ^Computed using C = 1.15 for wood;/i *=* 1.65 and/o = 6.0. *It is sufficiently accurate to use the same coefficient of transmission for doors containing thin-wood panels as that of single panes of glass, namely, 1.13 Btu per hour per square foot per degree difference between inside and outside air temperatures. '- it is probable that the values of U for these two types of roofs , will compare favorably. . . The thicknesses upon which the coefficients in Tables 3 to 13, inclusive, are based are as follows: . Brick veneer___ ____________________ :____________________________ 4 " in. Plaster and metal lath______1________________ ____________________ 56 in. Plaster (on wood lath, plasterboard, rigid insulation, board form, or corkboard)............... ..................................... ......................... 34 in. Slate (roofing)___________________________________________________ 34 in. Stucco on wire mesh reinforcing 1 in. Tar and gravel or slag-surfaced built-up roofing.________________ 56 in. 1-in. lumber (S-2-S)256z m. 13'6-in. lumber (S-2-S).-. :, .154e in. 2-in. lumber (S-2-S) : _________________________ ________ :____ 156 in. 234-in. lumber (S-2-S)________________.'.__________________________234 in. 3-in. lumber (S-2-S) 2% in. 4-in. lumber (S-2-S) 356.in. . Finish flooring (maple or oak)1.in. . . Solid brick walls are based on 4-in. hard brick (high density) and the remainder common brick (low density). Stucco is assumed to be 1-in. thick on masonry walls. Where metal lath and plaster are specified, the metal lath is neglected. : - . 117 Heating Venturing Air Conditioning Guide 1938 The coefficients of transmission of the pitched roofs in Table 12 apply where the roof is over a heated attic or top floor so the heat passes directly through the roof structure including whatever finish is applied to the underside of the roof rafters. Combined Coefficients of Transmission If the attic is unheated, the roof structure and ceiling of the top floor must both be taken into consideration, and the combined coefficient of transmission determined. The formula for calculating the combined coefficient of transmission of a top floor ceiling, unheated attic space, and pitched roof, per square foot of ceiling area, is as follows: . Ut X Uc u= . .n where U = combined coefficient to be used with ceiling area. Ur = coefficient of transmission of the roof. Uce = coefficient of transmission of the ceiling. n = the ratio of the area of the roof to the area of the ceiling. (6) Stating the formula in terms of the total heat resistance of the ceiling and roof, += R~U~ U 1 Ur X n (7) In selecting the values to be used for UT and C/ce it should be noted that the under surface of the roof and the upper surface of the ceiling are more nearly equivalent to the boundary surfaces of an internal air space than they are to the external surfaces of a wall. It would be more nearly correct to use a value of 2.2 rather than the usual value of 1.65 as coef ficients for these surfaces. In most cases this would make only a minor change in U. It should be noted that the over-all coefficient should be multiplied by the ceiling and not the roof area. .. If the unheated attic space between the roof and ceiling has no dormers, windows or vertical wall spaces the combined coefficients may be used for determining the heat loss through the roof construction between the attic and top floor ceiling. If the unheated attic contains windows and vertical wall spaces these must be taken into consideration in calculating the roof area and also its coefficient Z7r. In this case an approximate value of Ur may be obtained as the summation of the coefficient of each individual section such as the roof, vertical walls or windows times its percentage of total area. This coefficient may be used with reasonable accuracy in the above formulae. If, however, there are roof ventilators such that the attic air is substantially at outside temperature, then the roof should be neglected and only the coefficient for the top floor ceiling construction used. ' Basements and Unheated Rooms . The. heat loss through floors into basements and into unheated rooms kept closed may be computed by assuming a temperature for these rooms 118 Chapter 5. Heat Transmission Coefficients and Tables f 32 F. Additional information on the inside and outside temperatures to be used in Heat loss calculations is given in Chapter 7. REFERENCES FfTw-ts of Air Velocities on Surface Coefficients, by F. B. Rowley, A. B. Algren and J L. Blackshaw (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 123). Wind Velocity Gradients Near a Surface and Their Effect on Film Conductance, by F C Houghten and Paul McDermott (A.S.H.V.E. Transactions, Vol. 37,1931, p. 301). Tnqnlatine Effect of Successive Air Spaces Bounded by Bright Metallic Surfaces, by L W. Schad (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 285). Conductivity of Concrete, by F. C. Houghten and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 47). Surface Coefficients as Affected by Direction of Wind, by F. B. Rowley and W. A. Eckley (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 33). Importance of Radiation in Heat Transfer Through Air Spaces, by E. R. Queer (A.S.H.V.E. Transactions, Vol; 38, 1932, p. 77).' The Heat Conductivity of Wood at Climatic Temperature Differences, by F. B. Rowley (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 329). Insulating Value of Bright Metallic Surfaces, by F. B. Rowley (A.S.H.V.E. Trans actions, Vol. 40, 1934, p. 413). Thermal Properties of Concrete Construction, by F. B. Rowley, A. B. Algren and Clifford Carlson (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 33). Properties of Metal Foil as an Insulating Material, by J. L. Gregg (Refrigerating Engineering, May, 1932). Thermal Insulation with Aluminum Foil, by R. B. Mason (Industrial and Engineering Chemistry, March, 1933). Thermal Insulation of Buildings, Technical Paper No. 11. (American Architect, May, 1934). Thermal Properties of Concrete Construction, by F. B. Rowley, A. B. Algren and Robert Lander (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, November, 1936, p. 621). ' Radiation and Convection Across Air Spaces in Framed Construction, by G. B. -Wilkesand C. M. F. Peterson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, August, 1937, p. 505). . . . ,. Heat Insulation as Applied to Buildings and Structures, by E. A. Allcut, University of Toronto, 1934. . House Insulation, Its Economies and Application, by Russell E. Backstrom (Report of the National Committee on Wood Utilization,. United States Government Printing Office, 1931). . Heat Transmission Through Building Materials, by F. B. Rowley and A. B. Algren, University of Minnesota Engineering Experiment Station Bulletin No. 8. Calculation of Heat Transmission, by Margaret Fishenden and Owen A. Saunders. , Heating, Ventilating and Air Conditioning, by Harding and Willard, Revised Edition, 1932. . Heat Transmission, by W. H. McAdams. Industrial Heat Transfer, by Shack. PROBLEMS IN PRACTICE 1 What is the coefficient U and how is it applied? The coefficient U is the heat loss through walls, ceilings, and floors and the value depends upon the construction and material, expressed in Btu per hour per square foot per degree difference in temperature between the inside and outside. To determine the total heat loss, multiply U for each material by the square feet of surface and the temperature difference. Heating Ventilating Air Conditioning Guide 1938 2 Find the value of U for a 6-in. concrete wall with plaster on metal lath attached to 2-in. furring strips with flanged blanket insulation. 0.23 (Table 3, Wall 12L). 3f 'A wall is built with two layers of J^-in. insulating material spaced 1 in. apart; the air space is lined on one side with bright aluminum foil; mean temperature is 40 F; still air on both sides of wall; h for insulating material Is 0.34. Calculate the value of U. fi = 1.65;/0 = 1.65; a = 0.46 R - _L. + _2i- + _L_ + -M. 1.65 T 0.34 T 0.46 . 0.34 + _J_ ^ 1.65 = 6.327 1 U = ~ = 0.158 4 What is the inside surface temperature of a 6-in. solid concrete wall? Inside air, 70 F; outside air, --20 F with 15 mph wind. The temperature drop from point to point through a wall is directly proportional to the heat resistance. fi -- 1.65; k for concrete 12.62;/0 = 6.0 Over-all resistance R = 1 1.65 + 6 12.62 + <no=1-27 i Temperature drop, inside air to surface = 1.65 Temperature drop, air to air 1.27 Temperature drop, inside air to surface = 90 = 43 1.27 X 1.65 70 -- 43 = 27 F, inside surface temperature of wall. 5 How many inches of insulating material having a conductivity of 0.30 would be required, for the wall of Question 4, to raise the inside surface tem perature to 60 F? Temperature drop, air to inside surface = 10 F; temperature drop, inside Surface to out side air = 80 F. Therefore, the heat resistance from inside wall surface to outside air . must be eight times that from inside air to inside wall surface, or 8 X , * = 4.85. The . -. - -. ... 1.65 . resistance,for added material is, therefore, + 1) =4-19 ./ .: ' 4.19 X 0.30 = 1.25 in. of insulation. ' 6 An unheated attic space in a residence has an equivalent pitched roof area of 1560 sq ft and-a ceiling area of 1200 sq ft. If 15 per cent of the roof area is composed of vertical wall spaces having a value of U = 0.52,' determine the total heat loss per hour through the ceiling and roof for a temperature dif ference of 85 F, if U = 0.46 for the roof and U = 0.38 for the ceiling. An approximate value of U for the roof is equivalent to the summation of coefficients for each individual section times its percentage of total area. * UT = (0.52 X 0.15) + (0.46 X 0.85) = 0.47. ^ .- Ratio of roof area to ceiling = 1560 -s- 1200 = 1.3,. Substituting in Formula 6: . . 0.47 X 0.38 U= 0.47 + 0.38 = 0.235 1.3 * H = A U (ft - to) = 1200 X 0.235 X 85 = 23,900 Btu per hour. 120 Chapter 6 AIR LEAKAGE Nature of Air Infiltration, Infiltration Through Walls, Window Leakage, Door Leakage, Selection of Wind Velocity, Crack Length used for Computations, Multi-Story Buildings, Heat Equivalent of Air Infiltration IR leakage losses are those resulting from the displacement of heated A air in a building by unheated outside air, the interchange taking place through various apertures in the building, such as cracks around doors and windows, fireplaces and chimneys. This leakage of air must be considered in heating and cooling calculations. (See Chapters 7 and 8.) NATURE OF AIR INFILTRATION The natural movement of air through building construction is. due to two causes. One is the pressure exerted by the wind; the other is the difference in density of outside and inside air because of differences in temperature.. The wind causes a pressure to be exerted on one or two sides of a building. As a result, air comes into the building on the windward side through cracks or porous construction, and a similar quantity of air leaves on the leeward side through like openings. In general the resis tance to air movement is similar on the windward to that on the leeward side. This causes a building up of pressure within the building and a lesser air leakage than that experienced in single wall tests as determined in the laboratory. It is assumed that actual building leakages owing to this building up of pressure will be 80 per cent of laboratory test values. While there are cases where this is not true, tests in actual buildings substantiate the factor for the general case. Tests on mechanically ventilated ' classrooms of average construction have shown that air infiltration acts quite independently of the planned air supply. Accor dingly, the heating or cooling load owing to air infiltration from natural causes should be considered in addition to the ventilating load. The air exchange owing to temperature difference, inside to outside, is not appreciable in low buildings. In tall, single story buildings with openings near the ground level and near the ceiling, this loss must be considered. Also in multi-story buildings it is a large item unless the sealing between various floors and rooms is quite perfect. This tempera ture effect is a chimney action, causing air to enter through, openings at lower levels and to leave at higher levels. A complete study of all of the factors involved in air movement through building constructions would be very complex. Some of the complicating 121 Heating Ventilating Air Conditioning Guide 1938 factors are: the variations in wind velocity and direction; the exposure of the building with respect to air leakage openings and with respect to adjoining buildings; the variations in outside temperatures as influencing the chimney effect; the relative area and resistance of openings on the windward and leeward sides and on the lower floors and on the upper floors; the influence of a planned air supply and the related outlet vents; and the variation from the average of individual building units. A study of infiltration points to the need for care in the obtaining of good building construction, or unnecessarily large heat losses will result. INFILTRATION THROUGH WALLS Table 1 gives data on infiltration through brick and frame walls. The brick Weills listed in this table are walls which show poor workmanship and which are constructed of porous brick and lime mortar. For good workmanship, the leakage through hard brick walls with cement-lime mortar does not exceed one-third the values given. These tests indicate that plastering reduces the leakage by about 96 per cent; a heavy coat of cold water paint, 50 per cent; and 3 coats of oil paint carefully applied, 28 per cent. The infiltration through walls ranges from 6 to 25 per cent of that through windows and doors in a 10-story office building, with imperfect sealing of plaster at the baseboards of the rooms. With perfect sealing the range is from 0.5 to 2.7 per cent or a practically negligible quantity, which indicates the importance of good workmanship in proper sealing at the baseboard. It will be noted from Table 1, that the in filtration through properly plastered walls can be neglected. The value of building paper when applied between sheathing and shingles is indicated by Fig. 1, which represents the effect on outside construction only, without lath and plaster. The effectiveness of plaster properly applied is no justification for the use of low grade building paper or of the poor construction of the wall containing it. Not only is it . Table 1. Infiltration through Walls'1 ., Expressed in cubic feet Per square foot Per hour .s Ttph or Wall ' . Wind Velocity, Miles pbb Hour 5 ' . 10 IS 20 25 . 30 8^ in. Brick WalL--r-|PI,,atpred 1.75 . 4.20 7.85 12.2 18.6 22.9 0.017 0.037 0.066 0.107 0.161 0.236 13 in. Brick WalL._._.{P^7; 1.44 3.92 7.48 11.6 16.3 21.2 0.005 0.013 0.025 0.043 0.067 0.097 Frame Wall, with lath and plaster*1 0.03 0.07 0.13 0.18 0.23 0.26 "The values given in this table are 20 per cent less than test values to allow for building up of pressure in rooms and are based on test data reported in the papers listed at the end of this chapter. bWall construction: Bevel siding painted or cedar shingles, sheathing, building paper, wood lath and 3 coats gypsum plaster. -' 122 Chapter 6. Air Leakage Fig. 1. Infiltration through Various Types of Shingle Construction difficult to secure and maintain the full effectiveness of the plaster but also it is highly desirable to have two points of high resistance to air flow 'with ah air space between them. . The amount of infiltration that may be expected through simple walls used in farm and other shelter buildings, is shown in Fig. 2. The infil tration indicated in Figs. 1 and 2 is that determined in the laboratory and should be multiplied by the factor 0.80 to give proper working values. Fig. 2. Infiltration through Single Surface Walls Used in Farm and Other Shelter Buildings . 123 Heating Ventilating Air Conditioning Guide 1938 WINDOW LEAKAGE The amount of infiltration for various types of windows is given in Table 2. The fit of double-hung wood windows is determined by crack and clearance as illustrated in Fig. 3. The length of the perimeter opening or crack for a double-hung window is equal to three times the width plus two times the height, or in other words, it is the outer sash perimeter length plus the meeting rail length. Values of leakage shown in Table 2 for the average double-hung wood window were determined by setting the average measured crack and clearance found, in a field survey of a large number of windows on nine windows tested in the laboratory. In addition, the table gives figures for a poorly fitted window. All of the figures for double-hung wood windows are for the unlocked condition. Just how a window is closed, or fits when it is closed, has considerable influence on the leakage. The leakage will be high if the sash are short, if the meeting rail members are warped, or if the frame and sash are not Chapter 6. Air Leakage fitted squarely to each other. It is possible to have a window with approximately the average crack and clearance that will have a leakage at least double that of the figures shown. Values for the average doublehung wood window in Table 2 are considered to be easily obtainable" figures provided the workmanship on the window is good. Should it be known that the windows under consideration are poorly fitted, the larger leakage values should be used. Locking a window generally decreases its leakage, but in some cases may push the meeting rail members apart and increase the leakage. On windows with large clearances, locking will usually reduce the leakage. Wood casement windows may be assumed to have the same unit leakage as for the average double-hung wood window when properly fitted. Locking, a normal operation in the closing of this type of window, maintains the crack at a low value. ' For metal pivoted sash, the length of crack is the total perimeter of the movable or ventilating sections. Frame leakage on steel windows may be neglected when they are properly grouted with cement mortar into brick work or concrete. When they are not properly sealed, the linear feet of sash section in contact with steel work at mullions should be figured at 25 per cent of the values for industrial pivoted windows as given in Table 2. 124 Fig. 4. Infiltration through Sash Perimeter of Window with and without Storm Sash--in. Crack and H2-1N. Clearance Leakage values for storm sash are given in Figs. 4 and 5. When storm sash are applied to well fitted windows, very little reduction in infiltration is secured, but the application of the sash does give an air space which reduces the heat transmission and helps prevent the frosting of the windows. When storm sash are applied to poorly fitted windows, a reduction in leakage of 50 per cent may be secured. Fig. 5. Infiltration through Sash Perimeter of Window with and without. 34-IN-Storm Sash-- Crack and 34-in. Clearance ,. 125 Heating; Ventilating Air Conditioning Guide 1938 Table 2. Infiltration Through Windows Expressed in Cubic Feet per Foot of Crack per Hour Ttp* or Window Remarks Wind Velocxtt, Miles pkb Hour S 10 15 20 25 30 Around frame in masonry.wall--not calkedb 3.3 8.2 14.0 20.2 27.2 34.6 Around frame in masonry wall--calkedb____ 0.5 1.5 2.6 3.8 4.8 5.8 Around frame in wood frame constructionb__ 2.2 Double-Hung Wood Sash Total for average window, non-weatherstripped, 56-iu. crack and 56-in- clearancec. Windows Includes wood frame Iftnkiurcd (Unlocked) Ditto, weatherstrippedd 6.6 4.3 6.2 10.8- 21.4 39.3 15.5 23.6 16,6 59.3 35.5 23.0 30.3 80.0 103.7 48.6 63.4 Total for poorly fitted window, non-weather- stripped, 56-in. crack and 56-in. clearance.* Includes wood frame lcakaged 26.9 69.0 110.5 153.9 199.2 249.4 Ditto, weatherstrillnedd 5.9 18.9 34.1 51.4 70.5 91.5 Double-Hung Non-weatheretrinned. locked Metal Non-weatherstripped, unlocked______ Windows* WeatherstriDoed. unlocked 20 45 70 96 125 154 20 47 74 104 137 170 6 19 32 46 60 76 Rolled Section Steel Sash Windows^ Industrial mvotedz. 14-in. crack Architectural projected, 56-in. crackh______ Architectural projected. 56-in. crackh Residential casement. 14-in. crarki Residential casement 14-ln crarki Heavy casement section, projected, J6*in. crackL ' Heavy casement section, projected 56-in. crarki--_________________ ____ 52 15 20 6 . 14 3 8 108 36 52 18 32. 10 24 176 62 88 33 52 18 38 244 86 116 47 76 26 54 304 112 152 60 100 36 72 372 139 182 74 128 48 92 Hollow Metal, vertically pivoted windowf.___ 30 88 145 186 221 242 The values given in this table are 20 per cent less than test values to allow for building up of pressure in rooms, and are based on test data reported in the papers listed at the end of this chapter. bThe values given for frame leakage are per foot of sash perimeter as determined for double-hung wood windows. Some of the frame leakage in masonry walls originates in the brick wall itself and cannot be prevented by calking. For the additional reason that calking is not done perfectly and deteriorates with time, it is considered advisable to choose the masonry frame leakage values for calked frames as the average determined by the calked and not-calked tests. - The fit of the average double-hung wood window was determined as J-in. crack and %-in. clearance by measurements on approximately 600 windows under heating season conditions. dThe values given are the totals for the window'opening per foot of sash perimeter and include frame leakage and so-called elsewhere leakage. The frame leakage values included are for wood frame construction but apply as well to masonry construction assuming a 60 per cent efficiency of frame calking A 56-in. crack and clearance represents a poorly fitted window, much poorer than average. (Windows tested in place in building. elndustria! pivoted window generally used in industrial buildings. Ventilators horizontally pivoted at center or slightly above, lower part swinging out. . hArchitectural projected made of same sections as industrial pivoted except that outside framing member is heavier, and refinements in weathering and hardware. Used in semi-monumental buildings such as schools. Ventilators swing in or out and are balanced on side arms. 16-in. crack is obtainable in the best practice of manufacture and installation, 5-in. crack considered to represent average practice. *Of same design and section shapes as so-called heavy section casement but of lighter weight, kj-in. crack is obtainable in the best practice of manufacture and installation, 56-in- crack considered to represent average practice. . jMade of heavy sections. Ventilators swing in or out and stay set at any degree of opening! 56-in. crack is obtainable in the best practice of manufacture and installation. 56-in. crack considered to represent average practice. kWith reasonable care in installation, leakage at contacts where windows are attached to steel frame work ana at mulkons is negligible. . With &-in. crack,_representing poor installation, leakage at contact with steel framework is about one-third, and at mulhons about one-sixth of- that given for industrial pivoted windows in the table.. - . \. " i..' - - . ~~ 126 Chapter 6. Air Leakage i POOR LEAKAGE Doors vary greatly in fit because of their large size and tendency to rn For a well fitted door, the leakage values for a poorly fitted doubler hung wood window may be used. If poorly fitted, twice this figure should be used. If weatherstripped, the values may be reduced one-half. A Single door which is frequently opened, such as might be found in a store, hould have a value applied which is three times that for a well fitted door This extra allowance is for opening and closing losses and is kept from" being greater by the fact that doors are not used as much in the coldest and windiest weather. The infiltration rate through swinging and revolving doors is generally a matter of judgment by the engineer making cooling load determinations and in the absence of adequate research data the values given in Table 3 represent current engineering practice. These values are based on the average number of persons in a room at a specified time, which may also be the same occupancy assumed for determining the outside ventilation requirements outlined in Chapters 3 and 8. / Table 3. Infiltration Through Outside Doors for Cooling loads Expressed in Cubic Feet per Minute per Person in Room . . Application Pam 36 in. Swinging Doors, Single ENTRANCBb 7.5 4.5 7.0 6.0 25.0 8.0 2.5 7.0 . 2.5 3.5 5.0 3.5 3.0 2.0 2.5 2.5 3.5 For doors located in only one wall or where doors in other walls are of revolving type. . bVestibules with double pair swinging doors, infiltration may be assumed 75 per cent of swinging door values. - .. Infiltration for 72 in. revolving doors may be assumed 60 per cent of swinging door values. SELECTION OF WIND VELOCITY Although all authorities do not agree upon the value of the wind veloc ity that should be chosen for any given locality, it is common engineering practice to use the average wind velocity during the three coldest months of the year. Until this point is definitely established the practice of using average values will be followed. Average wind velocities for the months of December, January and February for various cities in the United States and Canada are given in Table 2, Chapter 7. 127 S Heating Ventilating Air Conditioning Guide 1938 In considering both the transmission and infiltration losses, the more exact procedure would be to select the outside temperature and the wind velocity corresponding thereto, based on Weather Bureau records, which would result in the maximum heat demand. Since the proportion of transmission and infiltration losses varies with the construction and is different for every building, the proper combination of temperature and wind velocity to be selected would be different for every type of building, even in the same locality. Furthermore, such a procedure would necessi tate a laborious cut-and-try process in every case in order to determine the worst combination of conditions for the building .under consideration. It would also be necessary to consider heat lag due to heat capacity in the case of heavy masonry walls, and other factors, to arrive at the most accurate solution of the problem. Although heat capacity should be con sidered wherever possible, it is seldom possible to accurately determine the worst combination of outside temperature and wind velocity for a given building and locality. The usual procedure,'as explained in Chapter 7, is to select an outside temperature which is not more than 15 F above the lowest recorded, and the average wind velocity during the months of December, January and February. The direction of prevailing winds may usually be included within an angle of about 90 deg. The windows that are to be figured for prevailing and non-prevailing winds will ordinarily each occupy about one-half the perimeter of the structure, the proportion varying to a considerable extent with the plan of the structure. (See discussion of wind movement in Chapter 36.) CRACK LENGTH USED FOR COMPUTATIONS In no case should the amount of crack used for computation be less than half of the total crack in the outside walls of the room. Thus, in a room with one exposed wall, take all the crack; with two exposed walls, take the wall having the most crack; and with three or four exposed walls, take the wall having the most crack; but in no case take less than half the total crack. For a building having no partitions, whatever wind enters through the cracks on the windward side must leave through the cracks on the leeward side. Therefore, take one-half the total crack for com puting each side and end of the building. The amount of air leakage is sometimes roughly estimated by assuming . a certain number of air changes per hour for. each room, the number of . changes assumed being dependent upon the type, use and location of . the room, as indicated in Table 4. This method may be used to advantage as a check on the calculations made in the more exact manner. MULTI-STORY BUILDINGS In tall buildings, infiltration may be considerably influenced by tem perature difference or chimney effect which will operate to produce a head that will add to the effect of the wind at lower levels and subtract from it at higher levels. . On the other hand, the wind velocity at lower levels , may be somewhat abated by surrounding obstructions. ,Further more, the chimney effect is reduced in multi-story buildings by the partial isolation of floors preventing free upward movement, so that wind and 128 Chapter 6. Air Leakage _ 4 Air Changes Taking Place under Average Conditions Exclusive 1AB ' of Air Provided for Ventilation ' Kind or Room ob Building Number or Am Changes Taking Place per Hour i . Churches, Factories, Lofts, etc......... ....... -........................-........... 2 2 Kto M 2 to 3 2 1 to 2 1 to 2 2 2 to 3 1 K to 3 temperature difference may seldom cooperate to the fullest extent. Making the rough assumption that the neutral zone is located at mid height of a building, and that the temperature difference is 70 F, the following formulae may be used to determine an equivalent wind velocity to be us6d in connection with Tables 1 and 2 that will allow for both wind velocity and temperature difference: . Me = VM' - 1.75 a ; (1) where . Me = VM' + 1.75 b (2) Me = equivalent wind velocity to be used in conjunction with Tables 1 and 2. M = wind velocity upon which infiltration would be determined if tem perature difference were disregarded. a = distance of windows under consideration from mid-height of building if above mid-height. . b -- distance if below mid-height. ' The coefficient 1.75 allows for about one-half the temperature difference head. For buildings of unusual height, Equation 1 would indicate negative infiltration at the highest stories, which condition may, at times, actually exist. . Sealing of Vertical Openings In tall, multi-story buildings, every effort should be made to seal off vertical openings such as stair-wells and elevator shafts from the re mainder of the building. Stair-wells should be equipped with self-closing doors, and in exceptionally high buildings, should be closed off into sections of not over 10 floors each. Plaster cracks should be filled. Elevator enclosures should be tight and solid doors should be used. . ; If the sealing of the vertical openings is made effective, no allowance heed be made for the chimney effect. Instead, the greater wind move ment at the high altitudes makes it advisable to install additional heating surface on the upper floors above the level of neighboring buildings, this additional surface being increased as the height is. increased. . One 129 Heating Ventilating Air Conditioning Guide 1938 arbitrary rule is to increase the heating surface on floors above neighboring buildings by an amount ranging from 5 per cent to 20 per cent. This extra heating surface is required only on the windward side and on windy days, and hence automatic temperature control is especially desirable with such installations. . In stair-wells that are open through many floor levels although closed off from the remainder of each floor by doors and partitions, the strati fication of air makes it advisable to increase the amount of heating surface at the lower levels and to decrease the.amount at higher levels even to the . point of omitting all heating surface on the top several floor levels. One rule is to calculate the heating surface of the entire stair-well in the usual way and to place 50 per cent of this in the bottom third, the normal amount in the middle third and the balance in the top third. HEAT EQUIVALENT OF AIR INFILTRATION Sensible Heat Loss The heat required to warm cold outside air, which enters a room by infiltration, to the temperature of the room is given by the equation: where Hs = 0.24 Q d (ti -- to) (3) HB = heat required to raise temperature of air leaking into building from to to ft Btu per hour. . 0.24 = specific heat of air. Q = volume of outside air entering building, cubic feet per hour, d = density of air at temperature to, pounds per cubic foot, ti = room air temperature, degrees Fahrenheit, = outside air temperature, degrees Fahrenheit. Latent Heat Loss When it is intended to add moisture to air leaking into-a room for the maintenance of proper winter comfort conditions, it is necessary to determine the heat equivalent to evaporate the required amount of water vapor, which may be calculated by the equation: where < Hi = heat required to increase moisture content of air leaking into building from M0 to Mi, Btu per hour. .' Q = volume of outside air entering building, cubic feet per hour. ' d = density of air at temperature ti, pounds per cubic foot. ,' Mi = vapor density of inside air, grains per pound of dry air. M0 = vapor density of outside air, grains per pound of dry air. L = latent heat of vapor at Mi, Btu per pound. It is sufficiently accurate to used = 0.075 lb, in which case equation 3 reduces to 5 and if the latent heat of vapor is assumed for general condi tions as 1060 Btu per pound equation 4 reduces to 6. . Hs = 0.018 Q (k -- h) Hi = 0.0114 Q (Mi - M0) . (5) (6) While a heating reserve must be provided to warm inleaking air on the windward side of a building, this does not necessarily, mean that the 130 Chapter 6. Air Leakage heating plant must be provided with a reserve capacity, since the inleaking air, warmed at once by adequate heating surface in exposed rooms, will move transversely and upwardly through the building, thus relieving other radiators of a part of their load. The actual loss of heat of a building, caused by infiltration is not to be confused with the necessity for pro viding additional heating capacity for a given space. Infiltration is a disturbing factor in the heating of a building, and its maximum effect (maximum in the sense of an average of wind velocity peaks during the heating season above some reasonably chosen minimum)must be met by a properly distributed reserve of heating capacity, which reserve, how ever, is not in use at all places at the same time, nor in any one place at all times. REFERENCES Air Leakage, by F. C. Houghten and C. C. Schrader (A.S.H.V.E. Transactions, Vol. 30, 1924, p. 105). Air Leakage around Window Openings, by C. C. Schrader (A.S.H.V.E. Transactions, Vol. 30, 1924, p. 313). . Neutral Zone in Ventilating, by J. E. Emswiler (A.S.H.V.E. Transactions, Vol. 32, 1926, p. 59). Infiltration through Plastered and Unplastered Brick Walls, by F. C. Houghten and Margaret Ingels (A.S.H.V.E. Transactions, Vol. 33, 1927, p. 377). Effect of Frame Calking and Storm Sash on Infiltration around and through Windows, by W. M. Richtmann and C-. Braatz (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 547). Air Leakage on Metal Windows in a Modern Office Building, by F. C. Houghten and M. E. O'Connell (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 321). The Weathertightness of Rolled Section Steel Windows, by J. E. Emswiler and W. C. Randall (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 527). Air Leakage through a Pivoted Metal Window, by F. C. Houghten and M. E. O'Connell (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 519). Air Infiltration through Various Types of Brick Wall Construction, by G. L. Larson, D.W. Nelson and C. Braatz (A.S.HiV.E. Transactions, Vol. 35, 1929, p. 183). Pressure Differences across Windows in Relation to Wind Velocity, by J. E. Emswiler . and W. C. Randall (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 83). Air Infiltration Through Various Types of Wood Frame Construction, by G. L. Larson, D. W. Nelson and C. Braatz (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 99). Air Infiltration Through Double-Hung Wood Windows, by G. L. Larson, D. W. Nelson and R. W. Kubasta (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 571). . Flue Action in Tall Buildings, by H. L. Alt (Heating, Piping and Air Conditioning, May, 1932). ... Air Infiltration Through Steel Framed Windows, by D. O. Rusk, V. H. Cherry and L. Boelter (Heating, Piping and Air Conditioning, October, 1932). Investigation of Air Outlets in Class Room Ventilation, by G. L. Larson, D. W. Nelson and R. W. Kubasta (A.S.H.V.E. Transactions, Vol., 38, 1932, p. 463). Influence of Stack Effect on the Heat Loss in Tall Buildings, by Axel Marin (A.S.H. V.E. Transactions, Vol. 40, 1934, p. 377). Wind Velocities Near a Building and Their Effect on Heat Loss, by F. C. Houghten, J. L. Blackshaw, and Cart Gutberlet (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 387). Fuel Saving Resulting from the Use of Storm Windows and Doors, by A. P. Kratz and S. Konzo (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 87). The Infiltration Problem of Multiple Entrances, by A. M. Simpson and K. B. Atkinson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, June, 1936). Infiltration Characteristics of Entrance Doors, by A. M. Simpson (Refrigerating Engineering, June, 1936). Heating Requirements of an Office Building as Influenced by the Stack Effect, by F. C. Houghten and Carl Gutberlet (AiS.H.V.E. Journal Section, Heating, Piping and Air Conditioning, July, 1937). . 131 X Heating Ventilating Air Conditioning Guide 1938 PROBLEMS IN PRACTICE 1 # What two natural forces cause infiltration? a. Wind causes pressure to be exerted on one or two sides of a building with consequent movement of air through openings. b. Temperature difference inside to outside causes a difference in density with con sequent entrance of air at lower openings and exit of air at higher openings. 2 What is the neutral zone as applied to infiltration in buildings? Due to temperature difference inside air tends to flow out of openings near the top of the building and is replaced by outside air coming in at lower openings. At some height no flow occurs in or out. This is referred to as the neutral zone and often is taken at the mid-height of the building but may be higher or lower than this depending on several factors. 3 In what type of structure is infiltration due to temperature difference of importance? In tall open buildings.^ in multi-story buildings inadequately sealed, between floors and in stair-wells for multi-story buildings the temperature difference effect is important. .4 What procedure is sometimes used to compensate for this temperature or chimney effect in stair-wells? . One rule is to place 50 percent of the calculated radiation in the bottom third, the normal amount in the middle third and the remainder in the top third. 5 t Why is it customary to apply a correction factor to laboratory values before calculating infiltration in buildings? . Most, if not all, laboratory values have been determined by exerting a certain wind pressure across a single thickness of building construction. In actual building con struction the pressure drop due to wind velocity takes place in two steps, one through the windward and the other through the leeward wall- Tests indicate that the leakage in actual construction will be about 80 per cent of laboratory values and therefore" this factor has been applied in making up the tables in this chapter. . The curves represent laboratory data as taken with no correction applied. . .. 6 Is Infiltration through walls of Importance? ' In the case of compound walls of good construction'the heat loss due to infiltration is usually negligibly low. In the case of single thickness walls without building paper properly applied, the heat loss due to air leakage may be very high. . 7 How are the wind velocities and outside temperatures selected for infil tration calculations in heating? . ... - . , It is common practice to take the average wind velocity for the three coldest rnonths and the temperature as 15 F above the coldest recorded by the Weather Bureau during the preceeding 10 years. . ^; 8 4 Show the probable combined effects of infiltration due to temperature difference and wind velocity oh the ground floor- and on the 15th floor of a 20story building 200 ft high with a 12 mph wind blowing. At the ground floor the effective velocity is increased to: . .. Me = V122 + 1.75 X 100 = 17.8 mph At the 15th floor level it would be reduced to: : Afe = V125 - 1.75 X 50 = 7.5 mph ' 9 .What is the value of storm sash in reducing infiltration? The reduction depends on the relative fit of the window and the storm sash. Fig. 4 indicates for storm sash buttoned on a reduction at 20 mph from about 52 cfh per foot of crack to 42 cfh. . Fig. 5 indicates a reduction for a storm sash buttoned over a loosely fitted window from 185 to 90 cfh. . .. 132 Chapter 7 HEATING LOAD Heat Demand Design Factors, Method of Procedure, Inside and Outside Temperatures, Wind Velocity Effects, Auxiliary Heat Sources,' Wall Condensation, Heat Loss Computation TO design any system of heating, the maximum probable heat demand must be accurately estimated in order that the apparatus installed shall be capable of maintaining the desired temperature at all times. The factors which govern this maximum heat demand--most of which are seldom; if ever, in equilibrium--include the following: 1. Outside temperature. 2. Rain or snow. 3. Sunshine or cloudiness. 4. Wind velocity. Outside Conditions (The Weather) 5. Heat transmission of exposed parts of building. 6. Infiltration of air through cracks, crevices and open doors and windows. 7. Heat capacity of materials. . - 8. Rate of absorption of solar radiation by exposed materials. " Building Construction . 9. Inside temperatures. 10. Stratification of air. 11. Type of heating system. 12. Ventilation requirements. . 13. Period and nature of occupancy. 14. Temperature regulation. . Inside Conditions The inside conditions vary from time to time, the physical properties of the building construction, may change with age, and the outside conditions are changing constantly. Just what the worst combination of all of these variable factors is likely to be in any particular case is therefore con jectural. Because of the nature of fhe problem, extreme precision in estimating heat losses at any time, while desirable, is hard of attainment. The procedure to be followed in determining the heat loss from any building can be divided into seven consecutive steps, as follows: 1. Determine on the inside air temperature, at the breathing line or the 30-in. line, which is to be maintained in the building during the coldest weather. (See Table 1.) 2. Determine on an outside air temperature for design purposes, based on the minimum temperatures recorded in the locality in question, which will provide for all .but the most severe weather conditions. Such conditions as may exist for only a few. consecu tive hours are readily taken care of by the heat capacity of the building itself. (See Table 2.) ` 133 Heating Ventilating Air Conditioning Guide 1938 3. Select or compute the heat transmission coefficients for outside walls and glass* also for inside walls, floors, or top-floor ceilings, if these are next to unheated space; include roof if next to heated space. (See Chapter S.) ' 4. Measure up net outside wall, glass and roof next to heated spaces, as well as any cold walls, floors or ceilings next to unheated space. Such measurements are made from building plans, or from the actual building. 5. Compute the heat transmission losses for each kind of wall, glass, .floor, ceiling and roof in the building by multiplying the heat transmission coefficient in each case by the area of the surface in square feet and the temperature difference between the inside and outside air. (See Items 1 and 2.) 6. Select unit values and compute the heat equivalent of the infiltration of cold air taking place around outside doors and windows; These unit values depend on the kind or . width of crack and wind velocity, and when' multiplied by the length of crack and the temperature difference between the inside and outside air, the result expresses the heat required to warm up the cold air leaking into the building per hour. (See Chapter 6.) 7. The sum of the heat losses by transmission (Item 5) through the outside wall and glass, as well as through any cold floors, ceilings or roof, plus the heat equivalent (Item 6) of the cold air entering by infiltration represents the total heat loss equivalent for any building. Item 7 represente the heat losses after the building is heated and under stable operating conditions in coldest weather. Additional heat is required for raising the temperature of the air, the building materials and the material contents of the building to the specified standard inside temperature. The rate at which this additional heat is required depends upon the heat capacity of the structure and its material contents and upon the time in which these are to be heated. This additional heat may be figured and allowed for as conditions re- Table 1. Winter Inside Dry-Bulb Temperatures Usually Specified3 Tm or Building DeqFahb Ttph or Building Deo Fahb Schools ' Class rooms__ ....................................... - Assembly rooms................... . Gymnasiums.............. Wardrobe and locker rooms____ Kitchens... \ Playrooms. Natatoriums. _ Hospitals-- Private rooms Private rooms (surgical). ... Operating rooms______ Wards ' .. __ Kitchens and laundries__________ Toilets.____ . ................ Bathrooms............. 70-72 68-72 55-65 70 65-68 66 65-70 60-65 75 70-72 70-80 70-95 68 66 68 70-80 Theaters--' Hotels-- \ Bedrooms and baths. _____ ____ . Toilets and service rooms............... Homrr Storrs Pitrt.ic Rim.nmr.s Steam baths Factories and machine shops_____ Foundries and boiler shops. ___ Paint shops. .................. 68-72 68-72 68 70 70 66 65-68 68 70-72 65-68 68-72 126 110 60-65 50-60 80 The most comfortable dry-bulb temperature to be maintained depends on the relative humidity and air motion. These-three factors considered together constitute what is termed the effective temperature. See Chapter 3. 134 Chapter 7. Heating Load quire, but inasmuch as the heating system proportioned for taking care of the heat losses will usually have a capacity about 100 per cent greater than that required for average winter weather, and inasmuch as most buildings may either be continuously heated or have more time allowed for heating-up during the few minimum temperature days, no allowance is made except in the size of boilers or furnaces. INSIDE TEMPERATURES The inside air temperature which must be maintained within a building and which should always be stated in the heating specifications is under stood to be the dry-bulb temperature at the breathing line, 5 ft above the floor, or the 30-in. line, and not less than 3 ft from the outside walls. Inside air temperatures, usually specified, vary in accordance with the use to which the building is to be put and Table 1 presents values which con form with good practice. The proper dry-bulb temperature to be maintained depends upon the relative humidity and air motion, as explained in Chapter 3. In other words, a person may feel warm or cool at the same dry-bulb temperature, depending on the relative humidity and air motion. The optimum winter effective temperature for sedentary persons, as determined at the A.S.H. V.E. Research Laboratory, is 66 deg.1 According to Fig. 6, Chapter 3, for so-called still air conditions, a relative humidity of approximately 60 per cent is required to produce an effective temperature of 66 deg when the dry-bulb temperature is 70 F. However, even where provision is made for artificial humidification, the relative humidity is seldom maintained higher than 40 per cent during the extremely cold weather, and where no provision is made for humidifica tion, the relative humidity may be 20 per cent or less. Consequently, in using the figures listed in Table 1, consideration should be given to whether provision is to be made for humidification, and if so, the actual relative humidity to be maintained. Temperature at Proper Level: In making the actual heat-loss compu tations, however, for the various rooms in a building it is often necessary to modify the temperatures given in Table 1 so that the air temperature at the proper level will be used. By air temperature at the proper level is meant, in the case of walls, the air temperature at the mean height be tween floor and ceiling; in the case of glass, the air temperature at the mean height of the glass; in the case of roof or ceiling, the air temperature at the mean height of the roof or ceiling above the floor of the heated room; and in the case of floors, the air temperature at the floor level. In the case of heated spaces adjacent to unheated spaces, it will usually be sufficient to assume the temperature in such spaces as the mean between the temperature of the inside heated spaces and the outside air tempera ture, excepting where the combined heat transmission coefficient of the roof and ceiling can be used, in which case the usual inside and outside' temperatures should be applied. (See discussion regarding the use of combined coefficients of pitched roofs, unheated attics and top-floor ceilings Chapter 5.) `See Chapter 3. p. 63. 135 Heating Ventiuiting Air Conditioning Guide 1938 High Ceilings: Research data concerning stratification of air in build ings are lacking, but in general it may be said that where the increase in temperature is due to the natural tendency of the warmer or less dense air to rise, as where a direct radiation system is installed, the temperature of the air at the ceiling increases with the ceiling height. The relation, however, is not a straight-line function, as the amount of increase per foot of height apparently decreases as the height of the ceiling increases, ac cording to present available information2. Where ceiling heights are under 20 ft, it is common engineering practice to consider that the Fahrenheit temperature increases 2 per cent for each foot of height above the breathing line: This rule, sufficiently accurate for most cases, will give the probable air temperature at any given level for a room heated by direct radiation. Thus, the probable temperature in a room at a point 3 ft above the breathing line, if the breathing line temperature is 70 F, will be (1.00 + 3 X .02) 70 = 74.2 F. With certain types of heating and ventilating systems, which tend to oppose the natural tendency of warm air to rise, die temperature differ ential between floor and ceiling can be greatly reduced. These include unit heaters, fan-furnace heaters, and the various types of mechanical ventilating systems. The amount of reduction is problematical in certain instances, as it depends upon many factors such as location of heaters, air temperature, and direction and velocity of air discharge. In some cases it has been possible to reduce the temperature between the floor and ceiling by a few degrees, whereas, in other cases, the temperature at the ceiling has actually been increased because of improper design, instal lation or operation of equipment. So much depends upon the factors enumerated that it is not advisable to allow less than 1 per cent per foot (and usually more) above the breathing line in arriving at the air tem perature at any given level for any of these types of heating and ventilating systems, unless the manufacturers are willing to guarantee that the par ticular type of equipment under consideration will maintain a smaller temperature differential for the specific conditions involved. Temperature at Floor Level: In determining mean air temperatures just above floors which are next to ground or unheated spaces, a tempera ture.5 deg lower than the breathing-line temperature may be used, pro vided the breathing-line temperature is not less than 55 F. OUTSIDE TEMPERATURES ' . The outside temperature used in computing the heat loss from a build ing is seldom taken as the lowest temperature ever recorded in a given locality. Such temperatures are usually of short duration and are rarely repeated in successive years. It is therefore evident that a temperature somewhat higher than the lowest on record may be properly assumed in making the heat-loss computations. Temperature Gradient Observations in a Large Heated Space, by G. L. Larson, D. W. Nelson and O. C. Cromer (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 243). Tests of Three Heating Systems in an Industrial Type of Building, by G. L. Larson, D. W. Nelson and John James (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 185). , .. 136 Chapter 7. Heating Load The outside temperature to be assumed in the design of any heating system is ordinarily not more than 15 deg above the lowest recorded tem perature as reported by the Weather Bureau during the preceding 10 years for the locality in which the heating system is to be installed. In the case of massive and well insulated buildings in localities where the minimum does not prevail for more than a few hours, or where the lowest recorded temperature is extremely unusual, more than 15 deg above the minimum may be allowed, due primarily to thefly-wheel effect of the heat capacity of the structure. The outside temperature assumed and used in the design should always be stated in the heating specifications. Table 2 lists the coldest dry-bulb temperatures ever recorded by the Weather Bureau at the places listed. If Weather Bureau reports are not available for the locality in question, then the reports for the station nearest to this locality are to be used, unless some other temperature is specifically stated in the specifications. In computing the average heat transmission losses for the heating season in the United States the average outside temperature from October 1 to May 1 should be used. . WIND VELOCITY EFFECTS The effect of wind on the heating requirements of any building should be given consideration under two heads: 1. Wind movement increases the heat transmission of walls, glass, and roof, affecting poor walls to a much greater extent than good walls. .. 2. Wind movement materially increases the infiltration (inleakage) of cold air through the cracks around doors and windows, and even through the building materials them selves, if such materials are at all porous. Theoretically as a basis for design, the most unfavorable combination of temperature and wind velocity should be chosen. It is entirely possible that a building might require more heat on a windy day with a moderately low outside temperature than on a. quiet day with a much lower outside temperature. However, the combination of wind and temperature which is the worst would differ with different buildings, because wind velocity has a greater effect on buildings which have relatively high infiltration losses. It would be possible to work out the heating load for a building for several different combinations of temperature and wind velocity which records show to have occurred and to select the worst combination; but designers generally do not feel that such a degree of refinement is justified. Therefore, pending further studies of actual buildings, it is recommended that the average wind movement in any locality during December, January and February be provided for in computing (1) the heat transr mission of a building, and (2) the heat required to take care of the infiltra tion of outside air. . The first condition is readily taken care of, as explained in Chapter 5, by using a surface coefficient f0 for the outside wall surface which is based on the proper wind velocity. In case specific data "are lacking for any given locality, it is sufficiently accurate to use an average wind velocity of approximately 15 mph which is the velocity upon which the heat trans mission coefficient tables in Chapter 5 are based. In a similar manner, the heat allowance for infiltration through cracks 137 Heating VentuiAting Air Conditioning Guide 1938 Table 2. Climatic Conditions Compiled from Weather Bureau Records3 Col. A State Col. B City Col. C Average Temp., Oct. 1st-. May 1st Col. D Col. E Lowest ' Tempera- / . tare . Ever Reported Average Wind Vel ocity Dec., , Jan., Feb., * Miles per Hour. Col. F Direction ' of Prevail ing Wind,. Dec., Jan., . Feb. . Ala Birmingham;---------------- ' Flagstaff ..................... Ark._............ Fort Smith____________ Little Rock...................... Calif Los Angeles..................-- Colo.. -....... Denver........................___ Grand Junction. ____i~ D. C_______ Washington_____ ____ :... Fla Ca Savannah______________ Idaho............ Lewiston_________.--.1__ Pocatello______________ Ill Springfield........................ Ind- _____ Indianapolis_______ ___ Evansville......................... Iowa--.......... Dubuque........... ............... Sioux City........................ Ky-------------Ta Me________1. MH Dodge City Louisville.. Shreveport... ................... Eastport..... ................... Portland__ ` ................. Detroit.............................. Marquette...........--___ Miss___ ____ Vicksburg_________ ;....... Mo.:............. St. Joseph__ ______ ____ St. Louis--..... .......... Springfield........................ Nphr. Havre____ ..:..................... North Platte_............-- N. H.__ N. J...... '....... N. V........ Buffalo_______ l________ 58.9 . ' -i ' 10.4 . N 53.8 -10 " :S.5 N " 59.5' 12 6.4 E 35.8 -25 . 7.8* SW 50.4 -15 . 8.1 E 51.6 -- 12 8.7 NW 54.2 27 7.6 N 58.5 28 6.3 NE ' 38.9 -29 7.5 S 38.9 -21 5.3 NW 38.4- -15 9.7 N ` 43.4 -15 7.1 - NW, ;. 62.0 10 9.2 NE 51.5 -8 12.1 NW 58.5 8 9.5 NW 42.3 -23 5.3 E 35.7 -28 9.6 SE 36.4 . -23 12.5 W 39.8 -24 10.1 . . ' NW 40.3 -25 11.5 SW 45.1 -^-16 9.8 s 33.9 -32 7.1 NW- 32.6 -35 11.6 - NW. 39.8 --25 r 8.1 S. 41.4 -. -26 9,8 NW- 45.3 -20 9.9 SW 61.6 7 8.8 N ; 56.2 -5 8.9 SE -1 31.5 -23 12.0 w 33.8 -21 9.2 NW 43.8 -7 - : 7.8 :NW - 38.1 . -18 11,2 . : w 29.6 -28 - 12.4 . ,w 35.8 -24'' 12.7 SW 28.3 -27 11.1 NW 24.3 ' -41 12.6 SW 29.4 -33 : 11.3 NW . 56.8 -1 8.3 SE 40.7 -24 .. 9.3 NW' 43.6, -22 '-11.6 S. 44.3 -29 . 10.8 SE 34.0 -49 w. 27.6. -57 . 9.5 . -SW 37.0 -29. 10.5 s 35.4 -35 ,8.5 , w 39.4 -10 10.0 SE --28 ' 8.7 NE 33.3 -35 6.6 NW 41.6 . -9 15.9 NW 35.2 -24 - ' 8.1- S 34.8 - -20 . 17.2 W 40.7 -14 17.1 NW aUnited States data from U. S. Weather Bureau. - Canadian data from Meteorological Service of Canada. 138 Chapter 7. Heating Load Table 2. Climatic Conditions^ Compiled from Weather Bureau Records3--- ; (Continued) : .. Col. A - State or _ . Province Col. B : ' City _ . Col.C .. Col. D. . ,,Coi. E , COL.F Average " Lowest ' - Temp., .. Tempera* - Oct 1st ture Ever ' : 'May 1st Reported Average Wind Vel ocity Dec., Jan., Feb., Miles per ' Hoar Direction of Prevail- ` ing Wind, * Dec., Jan.. ( Feb. N. M...........- Santa Fe.-- . -................. 38.3 . -13 7.8 NE N. C______ - Raleigh- ________ ___ ___ 50.0 Wilmington.................. ..... - 54.2 -2 . - 8.2 .. 5 ... 8.5 SW ; SW 24.6 -45 ' '9.1 NW Devils Lake....................... 20:3 . -44 10.6 W Cleveland........................... 37.2 -17 13.0 SW Columbus. ........... 39.9 . -20 12.0 SW 47.9 -17 12.0 N 35.2 -24 6.9 SE Portland--........................ 46.1 -2 7.5 S Pfl 42.7 --6 11.0 NW Pittsburgh______________ 41.0 -20 11.7 w R. I............... Providence.__________ __ 37.2 . -17 12.8 NW <; r Charleston-- . ______ 1 57.4 ' 7, 10.6 SW Columbia-........... ......-..... 54;0 .. -2 8.1 ' NE ' S. Dak.;---- Huron.......... . ............ ...... 28.2. . -43. . 10.6 NW Rapid City...... .................. 33.4-. -34 8.2 W Tenn.---- ------ Knoxville....... .................... 47.9 -16 . .7.8. SW Memphis............................ 51.1 -9 9.7 S Texas_______ El Paso________ ......... :..... '53.5 . -5 10.4 NW ' Fort Worth______ .'.......... 55.2 -8; 10.4 NW San Antonio. ................ 60.6 . .4 ' 8.0 NE TTfah 36.3 -24 8.8 w Salt Lake City. ........... 40.0 -20 6.7 SE Vt . 31.5 : -29.- : 11.8 -S Va.................. 49.3 2 12.5 N Lynchburg......................... 46.8. . -7 .. 7.1 NW - . 47;0 --3 . 79 SW Wash Seattle........ .................... .... -.44.8 3 11.3 SE Spokane.....;..____ _______ 37.7 -30 .7.1 SW W Va. 39.4 --28 : 6.6 w Parkersburg. .................. .42.6 . . -27 . 7.5 SW Wis............... 30.0 --36 10.4 . SW La Crosse............. ;!......... 3i.7- -43 7.3 S Milwaukee... .:....... 33.4 . -25 . 11.5 W Wyo--_____ Sheridan..-............... ______ - 30.7 -41 6.0 NW Lander..... . .................... : 30.0 -40 5.0., , SW Alta........ Edmonton...... ................... b. c______ Victoria.----.................:1.i. 23.0 43.9 -57; - ; 6.5 . - SW - 1.5 12.5 N Vancouver-.:...;..:!...:..--..*. ' . 42.0 Man. - 'Winnipeg..!....... 17.5 N..B............ Fredericton.................... - 27.0 n: s________ Yarmouth___ 35.0 . ` 2, -47 : -t35 -12 '4.5 10'. 0` 9.6 14.2 E NW NW NW ; , Ont..;........... London____ 1..... ........... .. 32.6 -27 10.3 sw : Ottawa.......J!;.!................... 26.5 -34 8.4 NW ' Port Arthur....................... 22.4 -37 7.8 NW Toronto.............................. P. E. I_____ Charlottetown 32.9 29.0 -26.5 -27 13.0 9.4 sw sw Que................ 27.8 --29 14 2 SW Oueber,, - Sask________ Prince Albert-- ................ Yukon______ Dawson__________ !___..... 24.2 15.8 ' 2.1 -34 -70 -68' 13.6 5.1 3.7 sw , .w s aUnited States data from U. S. Weather Bureau. Canadian data from Meteorological-Service of. Cahada. 139 Heating Ventilating Air Conditioning Guide 1938 and walls (Tables 1 and 2, Chapter 6) must be based on the proper wind velocity for a given locality. In the case of tall buildings special attention must be given to infiltration factors. (See Chapter 6). In the past many designers have used empirical exposure factors which were arbitrarily chosen, to increase the calculated heat loss on the side or sides of die building exposed to the prevailing winds. It is also possible to differentiate among the various exposures more accurately by calcu lating the infiltration and transmission losses separately for the different sides of the building, using different assumed wind velocities. Recent investigations show, however, that the wind direction indicated by Weather Bureau instruments does not always correspond with the direction of actual impact on the building walls, due to deflection by surrounding buildings. . The exposure factor, which is still in use by many engineers, is usually taken as 15 per cent, and is added to the calculated heat loss on the side or sides exposed to what is considered the prevailing winter wind. There is a need for actual test data on this point, and pending the time when it can be secured, the question must be left to the judgment of the designing engineer. It should be remembered that the values of U in the tables in Chapter 5 are based on a wind velocity of 15 mph arid that the infiltration figures are supposed to be selected from the tables in Chapter 6 to cor respond to the wind velocities given in Table 2 of the present chapter. The Heating, Piping and Air Conditioning Contractors National Associ ation has devised a method3 for calculating the square feet of equivalent direct radiation required in a building. This method makes use of ex posure factors which vary according to the geographical location and the angular situation of the construction in question in reference to pre vailing winds and the velocity of them. AUXILIARY HEAT SOURCES The heat supplied by persons, lights, motors and machinery should always be ascertained in the case of theaters, assembly halls, and in dustrial plants, but allowances for such heat sources must be made only after careful consideration of all local conditions. In many cases, these heat sources should not be allowed to affect the size of the installation at all, although they may have a marked effect on the operation and con trol of the system. In general, it is safe to say that where audiences are involved, the heating installation must have sufficient capacity to bring the building up to the stipulated inside temperature before the audience arrives. In industrial plants, quite a different condition exists, and heat sources, if they are always available during the period of human occu pancy, may be substituted for a portion of the heating installation. In no case should the actual heating installation (exclusive of heat sources) be reduced below that required to maintain at least 40 F in the building. Electric Motors and Machinery Motors and the machinery which they drive, if both are located in the room, convert all of the electrical energy supplied into heat, which is See Standards of Beating, Piping and Air Conditioning Contractors National Association. ' 140 Chapter 7. Heating Load retained in the room if the product being manufactured is not removed until its temperature is the same as the room temperature. If power is transmitted to the machinery from the outside, then only the heat equivalent of the brake horsepower supplied is used. Iri the first case the Btu supplied per hour X 2546, and in the second case Btu per hour = bhp X 2546, in which 2546 is. the Btu equivalent of 1 hp-hour. In high-powered mills this is the chief source of heating and it is frequently sufficient to overheat the building even in zero weather, thus requiring cooling by ventilation the year round. The heat (in Btu per hour) from electric lamps is obtained by multi plying the watts per lamp by the number of lamps and by 3.415. One cubic foot of producer gas gives off about 150 Btu per hour; one cubic foot of illuminating gas gives off about 535 Btu per hour; and one cubic foot of natural gas gives off about 1000 Btu per hour. A Welsbach burner averages 3 cu ft of gas per hour and a fish-tail burner, 5 cu ft per hour. For information concerning the heat supplied by persons, see Chapter 3. In intermittently heated buildings, besides the capacity necessary to care for the normal heat loss which may be calculated according to customary rules, additional capacity should be provided to supply the heat necessary to warm up the cold material of the interior walls, floors, and furnishings. Tests have shown that when a cold building has had its temperature raised to about 60 F from an initial condition of about 0 F, the heat absorbed from the air by the material in the structure may vary from 50 per cent to 150 per cent of the normal heat loss of the building. It is therefore necessary, in order to heat up a cold building within a reasonable length of time, to provide such additional capacity. If the interior material is cold when people enter a building, the radiation of heat from the occupants to the cold material will be greater than is normal and discomfort will result. (See Chapter 3.) ': WALL CONDENSATION Condensation in the interior surfaces4 of buildings may cause irrep arable damage to manufactured articles and machinery. .It often results in short-circuiting of electric power, and causes disintegration of roof structures not properly protected. The prevalence of moisture on a surface is caused by the contact of the warm humid air in a building with surfaces below' the dew-point temperature. It can be eliminated by (1) raising the surface temperature with increased air velocities passing over the surface, or adding a sufficient thickness of insulation, and (2) by lowering the humidity which is often not possible due to manufacturing processes. - The condensation of moisture within walls6 is an important problem with may types of construction under adverse conditions. The tempera- i7i*PiT!ve,'i.oSg Condensation on Interior Building Surfaces, by Paul D. Close (A.S.H.V.E. Transactions, voi. oo, iyju, p. 153). . c,,,!?nde21sation 'S'h!n Walls, by F. B. Rowley, A. B. Algren and C. E. Lund (A.S.H.V.E. Journal section. Heaitng, Ptptng and Air Conditioning, January, 1938). 141 Heating Ventilating Air Conditioning Guide 1938 tures of the various parts of a wall are controlled by the type and amount of insulation used and the vapor densities in the corresponding sections are controlled by the type of vapor barriers installed. The transmission of hejat and vapor through a wall should be considered together, and- in most cases the . proper .combination of insulation and vapor barriers will eliminate the possibilities of condensation within walls. A consideration often overlooked in problems of condensation within walls is that a vapor barrier should be placed on the warm side and not on the cold side of a wall. . '. HEAT LOSS COMPUTATION EXAMPLE 1. Location.;---------------------------------------------------------------------------------------........--------- Philadelphia, Pa. 2. Lowest outside temperature, (Table 2)--------- ---!--L;-- --------- _------------- --. --. 6 F 3. - Base temperature:. In this example a design temperature 10 F above lowest on record instead of 15 F is used. Hence the .base temperature = , 1 (- 6 + 10) = + 4 F. 4. Direction of prevailing wind (during Dec., Jan., Feb.)':_Northwest 5. Breathing-line temperature (5 ft from floor)--------------------------------------------------------60 F 6. Inside air temperature at roof: - " . ' ... The air temperdture \ast below roof is higher than at the breathing line. . . Height of roof is 16 ft, or it is 16 -- 5 = 11 ft above breathing line:. Allowing ` '2 per cent per foot above 5 ft, or 2 X.U = 22 per cent, makes the tem- ' : perature of the air under the roof = 1.22 X 60 = 73.2 F. ' 7. Inside temperature at walls: . . -. . . ' The air temperature at the mean height of the walls is greater than at the breathing line. The mean height of the walls is'8 ft and allowing 2 per cent per foot above 5 ft, the average mean temperature of the walls is 1.06 X-60 = 63.6 F. By similar assumptions and calculations, the mean temperature of the glass will be found, to be 64.2 F and that of the doors 61.2 F. . 8. Average wind velocity (Table 2)--------------------------------- .----------- 1------------i-------- 11.0 mph 9. Over-all dimensions (See Fig. 1):_;--.............................. ............................ --120 x 50 x 16 ft 10. Construction: . . .' . . Walls--12-in. brick, with H-in. plaster applied directly to inside surface. Roof--3-in. stone concrete and built-up roofing. 142 . . Chapter 7. Heating Load Floor--5-in. stone concrete on 3-in. cinder concrete on dirt. . Doors--One 12 ft x 12 ft wood door (2 in. thick) at each end. Windows--Fifteen, 9 ft x 4 ft single glass double-hung windows on each side. 11. Transmission coefficients: Walls--(Table 3, Chapter 5, Wall 2B)......_________________________ U -- 0.34 Roof--(Table 11, Chapter 5, Roofs 2A and 3A)_________________U ' = 0.77 ' Floor--(Table 10, Chapter 5, Floors 5A and 6A)U = 0.63 Doors--(Table 13B, Chapter 5)^____________________....... ....... U -- 0.46i Windows--(Table 13A, Chapter 5).__U = 1.13 , 12. Infiltration Coefficients: ' * Windows--Average windows, non-weatherstripped, Jf6-in. crack and %4-in. clearance. The leakage per foot of crack for an 11-mile wind velocity is 25.0 cfh. (Determined by interpolation of Table 2, Chapter 6.) The heat equivalent per hour per degree per foot of crack is taken from Chapter 6. . ' 25.0 X 0.018 = 0.45 Btu per deg Fahrenheit per foot of crack. Doors--Assume infiltration loss through door crack twice that of windows.. or 2 X 0.45 = 0.90 Btu per deg.Fahrenheit per foot of crack. ` Walls--As shown by Table 1, Chapter 6, a plastered wall allows so little infiltration that in this problem it may be neglected. - .- 13. Calculations: See calculation sheet, Table 3. . Table 3. Calculation Sheet Showing Method of Estimating Heat Losses of Building Shown in Fig. 1 ' Part of Building . North Wall: . Brick. H-in. plaster_________ Doors (2-in. wood)..... K in. Crack. ....... ................... West Wall: Brick. H~in. plaster Glass fSineie) .. .. J6 in. Crack South Wall East Wall Roof. 3-in. concrete and slag surfaced built-up roofing____ Floor, 5-in. stone concrete on 3-in. cinder concrete.________ Width IN Feet Height in Feet Net Sur face Area or Crack Length Coeffi cient 50 16 12 12 .1 pair doors 656 ' 144 60 0.34 0.46 0.90 120 16 15x4 9 Double Hung Windov79 (15) 1380 540 450 Same as North Wall Same as West Wall . 0.34 : 1.13 0.45 50 120 6000 0.77 50 120 6000 0.63 Grand Total of heat reauired for hin'Minv In Rt.n nw hour Temp. Diff. Total Btu 59.6 57.2 57.2' 13.293 3,789 1,544* 59.6 60*2 60.2 27,964 36,734 6,095* 18,626 70.793 69.2 5b 319.704 18,900 517,442 , ha3 ? partitions and whatever air enters through the cracks on the windward aide must ism urough the cracks on the leeward side. Therefore, only one-half of the total crack will be used in computing infiltration for each side and each end of building. . . temperature differential is commonly assumed to exist between the air on one side of a large noor lard on the ground and the ground. .. 143 Heating Ventilating Air Conditioning Guide 1938 PROBLEMS IN PRACTICE 1 What is the relation between the sensible heat loss from a building and the heat required for humidification? A house with a volume of 14,000 cu ft has a heat loss 120 Mbh for standard uninsulated frame construction and a 70 F temperature difference. Assuming a leakage rate of 13^ air changes per hour it would require about 10 Mbh to maintain a relative humidity of 45 per cent when the outside air is 0 F and 50 per cent relative humidity. By using an insulation such as rock wool, the sensible heat loss of this house may be reduced to approximately 77 Mbh. The insulation does not affect the humidification load, which now assumes greater importance. -- 2 What inside dry-bulb temperatures are usually assumed, for: (a) homes, (b) schools, (c) public buildings? Referring to Table 1: a. 70 to 72 F. b. Temperature varies from 55 to 75 F, depending on the room. Classrooms, for instance, are usually specified as 70 to 72 F. c. 68 to 72 F. 3 How is the outside temperature selected for use in computing heat losses? The outside temperature used in computing heat losses is generally taken from 10 to 15 F higher than the lowest recorded temperature as reported by the Weather Bureau during the preceding 10 years for the locality in which the heating system is to be installed. In some cases where the lowest recorded temperature is extremely unusual, the design temperature is taken even higher than 15 F above the lowest recorded temperature. 4 What are the effects of wind movement on the heating load? - '' a. Wind movement increases the heat transmission of walls, glass, and roof; it affects poor walls,to a much greater extent than good walls. . b. Wind movement materially increases the infiltration (inleakage) of cold air through the cracks around doors and windows, and even through the building materials them selves if such materials are at all porous. ' 5 Calculate the heat given off by eighteen 200-watt lamps. 200 X 18 Jx 3.415 = 12,294 Btu per hour. ' 6 A two-story, six-room, frame house, 28-ft by 30-ft foundation, has the following proportions: i ' Area of outside walls, 1992 sq ft. ,, Area of glass, 333 sq ft. ' Area of outside doors, 54 -sq ft. Cracks around windows, 440 ft. . . .. * ' Cracks around doors, 54 ft. . : Area of second floor ceiling, 783 sq ft. Volume, first and second floors, 13,010 cu ft. . Ceilings, 9 ft high. . The minimum temperature for the heating season is. --34 F, and the required inside temperature at the 30-in. level is 70 F. The average number of degree days for a heating season is 7851, and the average wind velocity is 10 mph, northwest. The walls are constructed of 2-in. by 4-in. studs with wood sheathing, building paper, and wood siding on the outside, and wood lath and plaster on the inside. Windows are single glass, double-hung, wood, without weatherstrips. The second floor ceiling is metal lath and plaster, without an attic floor. The roof is of wood shingles on wood strips-with rafters exposed.' The area of the roof is 20 per cent greater than the area of the ceiling. Select values for the following: (a) U for walls; (b) V for glass; (c) U for second floor ceiling; (d) U for roof; 144 Chapter 7. Heating Load (e) U for ceiling and roof combined; (f) air leakage, cubic feet per hour per foot of window crack; (g) air leakage, cubic feet per hour per foot of door crack. a. 0.25 (Table 5, Chapter 5). ....... . .. b. 1.13 (Table 13, Chapter 5). .. . c. 0.69 (Table 8, Chapter 5). . d. 0.46 (Table 12, Chapter 5). .- e. 0.31 (Equation 6, Chapter 5). /. 21.4 (Table 2, Chapter 6). . g. 42.8, which is double the window leakage. . 7 Using the data of Question 6, calculate the maximum Btu loss per hour for the various constructions, and show the percentage of the total'heat which is lost through each construction described. .' . Assume 2 per cent rise in temperature for each foot in height. The average temperature will be 72.8 F for walls, doors, and windows, and 79.1 F for the second floor ceiling. a. Outside walls 46,200 Btu loss b. Glass 34,950 Btu loss c. Doors 5,670 Btu loss d. Second floor ceiling 24,050 Btu loss e. Air leakage, windows 15,750 Btu loss / Air leakage, doors . 3,865 Btu loss 35.4 per cent of total 26.7 per cent of total 4.4 per cent of total 18.4 per cent of total 12.1 per cent of total " 3.0 per cent of total , ; . . Total 130,485 Btu loss 100.0 per cent of total - , 8 For the house in Question 6, place 1-in. insulation in the outside walls and second floor ceiling; k for insulation = 0.34. Use weatherstrip on doors and windows, and double glass on the windows; C = 0.55. Calculate or select the following values: (a) U for walls; (b) U for glass; (c) U for second floor ceiling; (d) U for combination of ceiling and roof; (e) air leakage, cubic feet per hour per foot of door crack; (f) air leakage, cubic feet per hour per foot of window crack. a. 0.144 b. 0.55 c. 0.23 d. 0.16 e. 15.5 /. 31.0 9 Calculate the maximum Btu loss per hour and show.the percentage loss-by. each channel for the house as insulated in Question 8. - _ - , ; a. Outside walls b. Glass c. Doors d. Ceiling e. Air leakage, windows /. Air leakage, doors 26,650 Btu loss 17,000 Btu loss 5,670 Btu loss 12,420 Btu loss 11,400 Btu loss 2,795 Btu loss 35.1 per cent of total 22.4 per cent of total 7.4 per cent of total 16.4 per cent of total 15.1 per cent of total 3.6 per cent of total Total 75,935 Btu loss 100.0 per cent of total 10 i From the results of Questions 7 and 9, calculate the Btu saved and the percentage saved by each change in construction. a. Outside walls.. b. Glass................ c. Doors_____ d. Ceiling:___ e. Air leakage, windows /. Air leakage, doors. . Uninsulated Insulated 46,200 34,950 5,670 24,050 15,750 3,865 , 26,650 17,000 5,670 12,420 11,400 2; 795 Btu8ato> Per Cent Savbd 19,550 17,950 6 11,630 4,350 1,070 42.3 51.4 0 48.3 27.6 27.7 145 Heating Ventilating Air Conditioning Guide 1938 11 From the results of Questions 7 and 9, calculate the heat loads per heating season in.Btu and note the savings by better construction. ' - The 7851 degree days for the heating season multiplied by 24 hours, times the Btu loss per hour for 1 F drop in temperature gives the Btu load per heating season. Saving = 262,000,000 - 152,500,000 = 109,500,000 Btu. 12 The dry-bulb temperature and the relative humidity at the ceiling of a mixing room in a bakery are 80 F and 60 per cent, respectively. The roof is a 4-in. "concrete deck covered with built-up roofing. If the lowest outside tem perature to be expected is --10 F, what thickness of rigid fiber insulation will be required to prevent condensation? - From Table 11, Chapter 5, U for the uninsulated roof = 0.72. From Table 2, Chapter 5, i.for rigid fiber insulation = 0.33. From the.psychrometric chart the dew-point of air at 80 F and 60 per cent relative humidity is 65 F. The ceiling temperature, therefore, must not drop below 65 F if condensation is to be prevented. . . When equilibrium is established, the amount of heat flowing through any component part of a construction is the same for each square foot of area. Therefore, / [SO -- (-10) ] .= 1.65 (80 - 65) where V is the transmittance of the insulated roof. Solving the equation, U -- 0.275. 1 The resistance of the insulated roof .= 0.275 = 3.64. : .1 The resistance of the uninsulated roof ~ 0.72 = 1.39. . The resistance of the insulation = 3.64 -- 1.39 =. 2.25. Resistance per inch of insulation 1 0.33 3)0. , Since a resistance of 2.25 is required, and 1 in. of insulation has a resistance of 3, one inch will be sufficient to prevent condensation. . The same result might have been obtained by selecting an insulated 4-in. concrete slab having a f/ of less than. 0:275 from Table 11, Chapter 5. ' This 4-in. concrete slab with 1-in. rigid insulation has a. f/ of 9.23 which is safe. - : - ;' 146 Chapter 8 COOLING LOAD Conditions of Comfort, Design Outside Temperatures, Com* ponents of Heat Gain, Normal Heat Transmission, Solar . Heat .Transmission, Sun Effect Through Windows, Heat.. Emission of Occupants, Heat Introduced by Outside Air, Heat Emission of Appliances , ... . LOAD calculations for summer air conditioning are more complicated than heating load calculations for the reason that there are several more factors to be considered. Because of the variable nature of some of the contributing load components and the fact that they do not neces sarily impose their maximum effect simultaneously, considerable care must be exercised in determining their.phase relationship in order that equipment of proper capacity may be selected to maintain specified indoor conditions. .................... CONDITIONS OF COMFORT The conditions to be maintained in an enclosure are variable and depend upon several factors, especially the outside design! conditions, duration of occupancy and relationship between air motion, dry-bulb and wet-bulb temperatures. Information concerning the proper effective temperature to be maintained is given in Chapter 3, where) are also tabu lated the most desirable indoor conditions.to be maintained in.summer for exposures over 40 min (see Table 2, Chapter 3). ' ... . .. DESIGN OUTSIDE TEMPERATURES ,......... Summer dry-bulb and wet-bulb . temperatures of various cities are given in Table 1. It will be noted that the temperatures-are riot the maximums but the design temperatures which should be used, in air condition ing calculations. The maximum outside wet-bulb temperatures as given in Weather Bureau reports usually occur only from 1 to 4 per cent of the time, and they are therefore of such short duration that it is not practical to design a cooling system covering this range. The temperatures shown in Table 1 are in part based on available design conditions known to' be successfully applied and for those localities where; this information is lacking they are based on a study of the hourly temperatures in New York *fom which factors were derived and applied to. the average maxi mum dry- and wet-bulb temperatures for other cities. This study covered a twenty-year- record-of Weather- Bureau--temperaturesr - -The^-design .1.47 Heating Ventilating Air Conditioning Guide 1938' Table 1. Design Dry- and Wet-Bulb Temperatures, Wind Velocities, and Wind Directions for June, July, August, and September Stats City Design Dbt-Bulb Design Wet-Bulb Velocity MPH Prevailing Summer Wind Direction Ala............. .... Birmingham....................... -- 95 95 78 80 Phoenix..................................... 105 76 Ark 95. 78 Pallf 90 70 90 65. Colo... ........ -- 95 64 95 75 95 78 nr 95 78 Fla 95 78 94 79 Ha 95 75 Savannah............. ....-........ -- 95 78 95 65 Til - 95 75 95 76 Ind... Iowa______.... Kansas..____ Ky...._--------Tn " Indianapolis...... ........ ............. 95 . 95 100 95 95 76 77 75 76 79 MH Portland--...................................-....... Boston.................. .................... .-- 90 95 92 95 73 78 75 75 Minn._______ - Miss.. ____ Mo______________ Vicksburg................... -.............. 95 95 100 95 75 78 76 78 Monti-- . Nebr-------------- 95 67 95 75 Nev-------------------- 95 65 N. H. Manchester...... ...... ;-------------------- 90 73 NT 95 .. 78 NV 92 . - 75 93 75 95 75 . N M. Santa Fe...... :...___ ----- ------- N. C.......... - 90 90 95 65 75 79 N Dale 95 73 Cleveland-------- :-------------- -- . 95 Cincinnati.................. --......-- 95 101 75 78 76 Oreg----------- Pa 90 65 95 78 95 . 75 R. I......... .... ....... sr q Half Providence.------- ------------ --Charleston................. --:-- Greenville_____________________ __ 93 95 .95 95 75 80 76 75 Tenn....... ..... 95 77 95 ' 78 5.2 8.6 6.0 7.0 6.0 11.0 6.8 7.3 9.7 6.2 8.7 7.0 7.3 7.8 5.8 10.2 8.2 9.0 6.6 11.0 8.0 7.0 7.3 6.9 9.2 10.3 8.4 6.2 9.5 9.4 7.3. 9.3 7.4 5.6 10.0 . 7.1 12.2 12.9 6.5 . 5.6 7.8 .8.8 9.9 6.6 10.1 6.6 9.7 9.0 10.0 9.9 6.8 7.6 6.5 7.5 . s sw w NE SW sw s s sw s sw E NW SW NW NE S SW sw s sw sw s sw sw sw SE sw s sw sw s w NW sw s sw sw SE SE SW NW S SW s NW SW NW NW . SW NE s sw sw 148 Chapter 8. Cooling Load Table 1. Design Dry and Wet-Bulb Temperatures, Wind Velocities, and Wind Directions for June, July, August, and September (Continued) . State City Design Dht-Bulb Design Wet-Bulb Summer Wind Yelocety MPH Prevailing Summer Wind Direction 100 78 9.4 s Galveston. --.......................... 95 80 9.7 s San Antonio............................ 100 78 7.4 SE Houston.................................... 95 78 7.7 S El Paso................. .................... 100 69 6.9' E Salt Lake City. ................... 95 67 8.2 SE 90 73 ft, 9 . s Norfolk -................................. 95 78 10.9 s Richmond........ ........................ 95 85 78 65 6.2 sw 79 s Spokane............ -...................... 90 65 6.5 . sw W. Va........ Parkersburg. .......................... 95 75 5.3 SE Wise.............. Madison................................... 95 75 8.1 sw Milwaukee................................ 95 75 10.4 s Wyo.. -....... Cheyenne* .............................. 95 65 9.2 s temperatures given are not exceeded more than 5 to 8 per cent of the time during a cooling season of 1200 hours in June, July, August and September for an average year. . COMPONENTS OF HEAT GAIN A cooling load determination is composed of five components which may be classified in the following manner: 1. Normal heat transfer through windows, walls, partitions, doors, floors, ceilings, etc. ' 2. Transfer of solar radiation through windows, walls, doors, skylights, or roof. 3. Heat emission of occupants within enclosures. 4. Heat introduced by infiltration of outside air or controlled ventilation. . 5. Heat emission. of mechanical, chemical, gas,'steam, hot water and electrical appliances'!ocated within enclosures. The components of heat gain, classified by source are further classified as sensible and latent heat gain. The first two components fall into the classification of sensible heat gain, that is, they tend to raise the temperature of the air within the structure. The last three components not only produce sensible heat gain but they may also tend to increase the moisture content of the air within the structure. Normal Heat Transmission By normal heat transmission, as distinguished from solar heat trans mission is meant the transmission of heat through windows, walls, partitions, etc. from without to interior of enclosure by virtue of difference between outside and inside air temperatures. This load is calculated in a 149 Heating Ventilating Air Conditioning Guide 1938 .8 10 ^ A.M.I P.M. 2 :4 ; SUN TIME AUG I ' .: i F ig . 1. C u r v e s G iv in g S o l a r n t e n s it y N o r m a l t o . S u n , o n H o r iz o n t a l .I Surface and on W alls for A ugust 1 Chapter 8. Cooling Load manner similar to that described in Chapter 7 (except-that flow of heat is reversed) by means of the formula: .' : , //t ^ AU (to -t) -. (1) where Hi = heat transmitted through the material of wall, glass, floor, etc., Btu per hour, A = net inside area of wall; glass, floor, etc., square feet, / = inside temperature, degrees Fahrenheit. ' U> " outside temperature, degrees Fahrenheit. ' ......................... ' u = coefficient of transmission of wall, glass, floor, etc., Btu per hour per square foot per degree Fahrenheit difference in temperature (Tables 3 to 13, Chapter 5). Solar Heat Transmission . Calculations of the solar heatjtransmitted through walls and roofs are difficult to determine because of periodical character of heat flow and time lag due to heat capacity of construction. ' , The variation in solar intensity normal to sun in Btu per square foot per hour-on a horizontal surface, and on east, west, and south walls is given in Fig. 1. The curves arfe drawn from A.S.H.V.E. Laboratory data obtained by pyrhelioiiieter, are based on sun time and apply for a per fectly clear day on August 1 at a north latitude of 40 deg.. A study of these curves discloses the periodic relationship and wide variation, in solar intensity on various surfaces. It will be observed that both the roof and south wall radiation curves are in exact phase relationship with each other and that whereas the east and west wall radiation curves overlap those for roof and south wall, they do not overlap each other. This phase relationship has an important bearing on the cooling load. .Failure to consider the periodical character of heat flow- resulting rfrom diurnal movement of the sun and the lag due to heat capacity of the structure, which determine'the timing and magnitude of the heat wave flowing through the wall, may result in a large error in load calculations........... The values of solar intensity appearing in Fig. 1 must not be confused with the actual heat transmission through the wall for much of this heat intensity-on an outside surface is in part reflected and in part wiped off by convection to the outside air. A mathematical solution for the deter mination of solar heat transmission has been developed but the equations involved are too complex for practical application.1, From results of this investigation and earlier studies,2 the Research Laboratory has prepared Tables 2, 3, 4 and 5 which give the solar intensity (7) for various hours of the day against walls of various orientations and horizontal surfaces and the solar radiation (Zg ) transmitted, through windows of various orien tations as well as skylights at various hours of the day. These values are shown for north latitudes from 30 to 45 deg; : It should be noted that the values for (7) represent the rate of solar intensity impinging against and not transmitted through walls and roofs whereas values for (IG) represent actual rate of heat transmission through, windows and skylights. Since the amount of solar intensity actually `Heat Transmission as Influenced by Heat Capacity and Solar Radiation, by F. C. Houghten, J. L. Blackshaw, E. W. Pugh and Paul McDermott (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 231). a** Absorption of Solar Radiation in its Relation to the Temperature, Color, Angle and Other Character- `s-0? the Absorbing Surface, by F.'C. Houghten and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. ,36... 1930. n 1ST! . 151 Heating Ventilating Air Conditioning Guide 1938 Table 2. Solar Radiation Impinging against Walls having several Orientations, and a Horizontal Surface, and the Radiation Transmitted through Glass FOR THE SAME ORIENTATIONS Table 3. Solar Radiation Impinging against Walls having several Orientations, and a Horizontal Surface, and the Radiation Transmitted Through Glass ` FOR THE SAME ORIENTATIONS For SB Deg Latitude on the twenty-first of July, in Btu per sq ft per hour. Chapter 8. Cooling Load Table 4. Solar Radiation Impinging against Walls having several Orientations and a Horizontal Surface, and the Radiation Transmitted through Glass A FOR THE SAME ORIENTATIONS For 40 Deg Latitude on the twenty-first of July, in Btu per sq ft per hour. Sun NORTHEAST Time / East Southeast / 'a / 4:31 0 0 0 0 0 0 5:00 14 12 14 12 5 3 6.-0C 72 63 . 80 70 40 29 7:00 143 120 180 1S8 112 87 8:00 143 111 211 182 155 124 South Southwest / *G I *G 82 West Horizontal Northwest Surface . I la I *G I *G 0 1 19 82 ' 152 0 0.2 11 57 121 9:00 104 69 192 158 168 133 46 22 10:00 46 22 143 104 156 117 77 45 11:00 75 43 121 83 95 60 15 4 12:00 73 42 103 67 73 42 213 178 258 225 284 249 293 258 1:00 2:0C 3:0C 4:00 15 4 95 60 121 83 75 43 284 249 77 45 156 117 143 104 46 22 258. 225 46 22 168 133 192 158 104 69 213 178 8 2 155 124 211 182 143 111 152 121 5:00 112 87 180 158 143 120 82 57 6:00 40 29 80 70 72 63 19 11 7:00 5 3 14 12 14 12 1 0.2 7:29 0 0 0 0 0 0 0 0 Table 5. Solar Radiation Impinging against Walls having several Orientations and a Horizontal Surface, and the Radiation Transmitted through Glass FOR THE SAME ORIENTATIONS For 46 Deg Latitude on the twenty-first of July, in Btu per sq ft per hour. 152 Heating Ventilating Air Conditioning Guide 1938 transmitted through a surface depends upon the nature of the exterior surface of wall or roof construction, it is necessary, in order-to determine actual amount of solar heat transmission; to apply correction factors to the values of (/). Solar radiation factors and solar absorption coefficients have'been determined3 as indicated in Fig. 2 and Table 6 respectively.. The solar heat conduction through a wall or.roof exposed to the sun may be expressed by the formula: % i : ! ; Hr = A F a I ; (2) where ' .' . Hr = Solar heat transmission, Btu per hour. -: ; A = Area of wall or roof, square feet. 1: F =. Percentage (expressed as a decimal) of the absorbed solar radiation which is transmitted to the inside (Fig. 2). ; : a = Percentage (expressed as a decimal) of the incident solar radiation which is absorbed by the surface (Table 6). ' I -- Actual intensity of solar radiation striking surface, Btu per hour per square foot (Tables 2,3, 4 and 5): ' .. *A Rational Heat Gain Method for the Determination of Air Conditioning Cooling Loads, by F. H. .Faust, L..Levine and.F. O. Urban-(A.S.H.V.E. -Transactions, Vol. 41, .1935, p. 327)_ . .. ...,, ....... Chapter 8. Cooling Load The total amount of heat conducted through a wall exposed to the sun is the sum of Ht and HR from Formulas 1 and 2. . The calculation of heat transmission through walls and roofs does not take into consideration the heat capacity of the structure nor the con- Table 6. Solar Absorption Coefficients for Different Building Materials Surface Material Very Light Colored Surfaces White stone ' Very light colored cement White or light cream-colored paint Medium Dark Surfaces Asbestos shingles Unpainted wood ' Brown stone . Brick and red tile . Dark-colored cement Stucco Red, green or gray paint Very Dark Colored Surfaces Slate roofing Tar roofing materials Very dark paints ' ' . Absorption Coefficient (a) . . 0.4 ' ' ' . 0.7 '' 0.9 sequent time lag in the transmission of heat. In the case of massive walls the time lag may amount to several hours*4. Thus in many cases the wall transmission cannot be added directly to the cooling load from other sources because the peak of the wall transmission load may not coincide Table 7. Time Lag in Transmission of Solar Radiation through Walls and Roofs .. Tips and Thickness of Wall oh Roof ' . . Time Lao, , .. Hours 3 . 2J4 2 2H 7M 19 . 10 : with the peak of the total cooling load and may even occur after the cooling, system has been shut down for the day. The data in Table 7. were taken from'A.S.H.V.E. research papers and whereas they result from a study of experimental slabs, they give an approximate idea of the time lag to be expected in various structures. ' . . ', 4Loc. Cit. Notes 1 and 2. 155 Heating Ventilating Air Conditioning Guide 1938 Sun Effect Through Windows Windows present a problem somewhat different from that of opaque walls, because they permit a large percentage of the solar energy to pass through undiminished; only a small percentage (approximately 10 per cent) is reflected. This fact permits the solar heat gain through windows to be expressed by the simple formula: Hq - Ac IG (3) where Hg = Solar radiation transmitted through a window, Btu per hour. ^G = Area of glass, square feet. . ^G = Amount of solar radiation transmitted directly through the glass, Btu per hour per square foot (Tables 2, 3, 4 and 5). . Values for solar heat transmission through glass as determined by Formula 3 apply only to unshaded windows. Tests at the A.S.H.V.E. Research Laboratory6 have determined the percentages of heat from solar radiation actually delivered to a room with bare windows and with various types of outdoor and indoor shading. The data in Table 8 are taken from these tests. Table 8. Solar Radiation Transmitted through Bare and Shaded Windows Type of Appurtenance Finish ` Facing Sun - Per Cent Delivered to Room Bare window glass...................................................................... ........... Canvas awning._........................... I.............._......................................... Canvas awning Inside shade, fully drawn ... . Inside shade, one-half drawn................................................................ Inside Venetian blind, fully covering window, slats at 45 deg._..... Outside Venetian blind, fully covering window, slats at 45 deg__ Buff Aluminum Aluminum 97 28 22 45 68^ 58 22 The percentage values in this table were obtained by dividing the total amount of heat actually entering through the shaded window by the total amount of heat calculated to enter through a bare window (solar radiation plus glass transmission based on observed outside glass temperature). For bare windows on which the sun shines, the transmission of heat from outside air to glass is small or negative because the glass temperature is raised by the solar radiation absorbed. Therefore, in calculating the total heat gain through windows on the sunny sides of buildings, it is sufficiently accurate to determine the total cooling load due to the win dow, as the solar radiation times the proper factor from Table 8 and to neglect the heat transmission through the glass caused by the difference between the temperatures of the inside and outside air. Although Table 8 shows that 97 per cent of the heat from solar radia tion is delivered' to a room through bare window glass, more recent tests* `Radiation of Energy Through Glass, by J. L. Blackshaw and F. C. Houghten (A.S.H.V.E. Trans actions, Vol. 40, 1934, p. 93). Studies of Solar Radiation Through Bare and Shaded Windows, by F. C. Houghten, Carl Gutberlet, and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 101). `Cooling Requirements of Single Rooms in a Modern Office Building, by F. C. Houghten, Carl Gutberlet. and Albert J. Wahl (A.S.H.V.E. Transactions, VoL 41, 1935, p. 53). . 156 Chapter 8. Cooling Load have indicated that in the case of a building having floors of high heat capacity such as concrete floors on which the solar radiation falls, approxi mately one-half of the heat entering a bare window is absorbed by the ' floor and does not immediately become a part of the cooling load but is delivered back to the air in the building at a slow rate over a period of 24 hours or longer. The maximum solar intensity on any surface is of limited duration as shown in Fig. 1. In the case of windows the total energy impinging on the glass before and after the time of maximum intensity is further reduced by increased shading of the glass from the frame, or wall. The cooling load due to solar radiation therefore does not have to be calculated as a steady load. Another point which should be noted is that the maximum solar radiation load on the east wall occurs early in the morning when the outside temperature is low. In a paper7 by the A.S.H.V.E. Research Laboratory it was shown that ordinary double strength window glass transmits no measurable amount of energy radiated from a source at 500 F or lower; that it transmits only 6.0 and 12.3 per cent of the total radiation from surfaces at 700 F and 1000 F, respectively; and that it transmits 65.7 per cent of the radiation . from an arc lamp, 76.3 per cent of the radiation from an incandescent tungsten lamp, and 89.9 per cent of the radiation from the sun. Thus, glass windows in a room constitute heat traps, which allow rather free transmission of radiant energy into the room from the sun to warm objects in it, but do not allow the transmission of re-radiated heat from these same objects. ' Tests have been made which indicated that sunshine through window glass is the most important factor to contend with in the cooling of an office building. At times it was shown to account for as much as 75 per cent of the total cooling necessary. Because of the importance of the sunshine load, cooling systems should be zoned so that the side of the building on which the sun is shining can be controlled separately from the other sides of the building. If buildings are provided with awnings so that the window glass is shielded from sunshine, the amount of cooling required will be reduced and there will also be less difference in the cooling requirements of different sides of the building. The total cooling load for a building exposed to the sun on more than one side is of course less than the sum of the maximum cooling loads in the individual rooms since the maximum solar radiation load on the different sides occurs at different times. In determining the total cooling load for a building if the time when the maximum load occurs is not obvious, the load should be calcu lated for various times of day to determine the times at which the sum of the loads.on the different sides of the building is a maximum. Heat Emission of Occupants The heat and moisture given off by human beings under various states of activity are shown in Figs. 8 to 11 and Table 4 of Chapter 3. It will be observed that the rate of sensible and latent heat emission by human beings varies greatly depending upon state of activity. In many applica tions this component becomes a large percentage of total load. 'Loc. Ot. Note 6. /? 157 1 Heating Ventilating Air Conditioning Guide 1938 Heat Introduced by Outside Air An allowance must be made for the heat and moisture in the outside air introduced for ventilation purposes or entering the building- through, cracks, crevices, doors, and other places where infiltration might occur. The volume of air entering due to infiltration may be estimated from data given in Chapter 6. Information on the amount of outside air required for ventilation will be found in Chapter 3. . In the event the volume of air entering an enclosure due to infiltration exceeds that required for ventilation, the former should be used as a basis for determining the portion of the load contributed by outside air. Where volume of air required for ventilation exceeds that due to infiltration it is assumed that a slight positive pressure will exist within the enclosure with a resulting exfiltration instead of infiltration. In this case the air required for ventilation is used in determining outside air load. The sensible heat gain resulting from the outside air introduced may be determined by the following formula:. - ' . . H, = 0.24 X 60 do Q (to - t) . (4) where ' \. .. . Ha = sensible heat to be removed from outside air entering the building, Btu per hour. ' Q = volume of outside air entering building/ cubic feet per minute. - ; do = density of air, pounds of dry air per cubic foot at temperature <oto = temperature of outside air, degrees Fahrenheit. t = temperature of inside air, degrees Fahrenheit. ,' .The total heat gain resulting from outside air introduced may be deter mined by the following formula: . ' '. . H = 60 do Q (ho -- A) . (5) where . ... ... . .. . H = total heat to be removed from outside air entering the enclosure, Btu per hour. Q = volume of outside air entering enclosure, cubic feet per minute. ' ' ... do = density of air, pounds of dry air per cubic foot of air (at temperature to). . ho = heat .content of mixture of outside dry air and water vapor, Btu per.pound of dry air (at temperature to). . ' h = heat content of mixture of inside dry air and water vapor, Btu per pound of . dry air (at temperature I)- \ The'latent heat gain resulting from outside air introduced may be determined by the following formula: .' where .. ' lt\ = 11 -- Ha ' . ((>) -' Hi = latent heat to be removed, Btu per hour. H = total heat to be removed, Btu per hour.. ... . Ha = sensible heat to be removed, Btu per hour. . . . ... Heat Emission oi Appliances . . .. Heat generating appliances which give off either sensible heat or both sensible and latent heat in an air conditioned enclosure may-be divided " 158 Chapter 8. Cooling Load into three general classes of equipment or devices: J. Electrical appliances. 2. Gas appliances. 3. Steam heating appliances. In the first group may be found such devices as lights, motors, toasters, waffle ii;ons, etc. The capacities of most electrical devices may be determined from the watt capacity indicated-on their name plates. The Btii equivalent of heat generated per hour is determined by multi plying the watt capacity by 3.4 (one watthour is equivalent to 3.413 Btu). The capacities of electric- motors are usually expressed in terms of horsepower instead of watts. If the motor efficiency is known, the watts input may be calculated from the formula: . p . 746 (hp) . .n . . where .. P = motor input, watts. hp = motor load, horsepower. n = motor efficiency (expressed as a decimal). . - (7) . When the motor efficiency is not known the heat equivalent of electrical input can be approximately determined by applying data given in Table 9. Table 9. Heat Generated; by Motors ' . Nameplate Rating Hobsepoweh . . , Heat Gain in Btu per Houb fbb Hobsepowsb- .: Connected Load in Same Room - - Connected Load Ootside of Room-' H to ^ . : . y2 to 3 3 to 20 4250 3700 2950 . 1700 - 1150 - . - '. : . 400. ; In the second group belong such appliances as coffee urns, gas ranges, steam tables, broilers, hot plates, , etc.; For heat generating capacities of such appliances refer to Table 10. ' .' . Considerable judgment must be exercised in the use of data given in Table 10. Consideration must be given to time of day when appliances are used and the heat they contribute to.the space at time of peak load-. Only those appliances in use at the time of the peak load need be con sidered. Consideration must also be given to the way appliances are installed, whether products of combustion are vented to a flue, whether products of combustion escape into the space to be conditioned or whether appliances are hooded allowing part of the heat to. escape through a stack connected with the hood. There are no generally accepted data available on the effects of venting and shielding heating appliances but it is believed that when the appliances are properly hooded with a positive fan exhaust system through the hood that 50 per cent of the heat will be- conveyed up into the hood and the balance of 50 per cent will be dissipated in the space to be conditioned. Where latent as well as sensible heat is given off, it is usually safe to assume that all latent heat will be removed by a properly designed and operated vent or hood. - ; , . 159 Heating Ventilating Air Conditioning Guide 1938 Table 10. Heat Gain from Various Sources Source Btu Peb Hour Sensible Latent Total Electric Heating Equipment Electric Equipment--Heating Water--Stewing. Boiling, etc. --............. ,, . . Electric Toasters or Electric Griddles Coffee Urn--Large, 18 in. Diameter--Single Drum Coffee Urn--Small, 12 in. Diameter--Single Drum....... .. - Electric Ranee--Small Burner Electric Range--Large Burner * ........................... .................................. ..................... Steam Table--Per Square Foot of Top Surface Plate Warmer--Per Cubic Foot of Volume. Baker's Oven--Per Cubic Foot of Volume............................... Frying Griddles--Per Square Foot of Top Surface...... .......................................... Hot Plates--Per Square Foot of Top Surface Permanent Wave Machine in Beauty Parlor--24-25 w Units-................................. 100% 80% 50% 3.4 3413 2546 90% 2000 1200 600 * * 8000 1025 300 850 3200 * * 2050 2050 ' 0% 20% 50% 0 0 10% 2000 1200 600 * * 2000 0 800 0 1300 * * o 0 100% 100% 100% 3.4 3413 100% 4000 2400 3400 7500 1100 850 4500 4600 9000 2050 Gas Burning Equipment Gas Equipment--Dry Heat--No Water Evaporated...... ........................... Gas Equipment--Heating Water--Stewing, Boiling, etc.______________ ___ Stove, Domestic Type--No Water Evaporated--Per Medium Size Burner Gas Heated Oven--Domestic Type .. Stove, Domestic Type--Heating Water--Per Medium Size Burner Residence Gas Range--Giant Burner (About 5M in. Diameter) Residence Gas Range--Medium Burner (About 4 in. Diameter)............ Residence Gas Range--Double Oven (Total Size 18 in. x 18 in. x 22 in. High) Residence Gas Range--Pilot........................... ............. Restaurant Range--4 Burners and Oven Cast-Iron Burner--Low Flame--Per Hole Cast-Iron Burner--High Flame--Per Hole............. '. . . Coffee Urn--Large, 18 in. Diameter--Single Drum...................... . Coffee Urn--Small, 12 in. Diameter--Single Drum Coffee Um--Per Gallon of Rated Capacity......... Egg Boiler--Per Egg Compartment......:............................ Steam Table or Serving Table--Per Square Foot of Top Surface___ _ .. Dish Warmer--Per Square Foot of Shelf Cigar Lighter--Continuous Flame Type ...................................................... __ .. ___ ... Bunsen Type Burner--Large--Natural Gas Bunsen Type Burner--Large--Artificial Gas.......... Bunsen Type Burner--Small--Natural Gas.......................................... ....................... Bunacn Type Burner--Small--Artificial Gas Weisbach Burner--Natural Gas. ' Fish-tail Burner--Natural Gaa Fish-tail Burner--Artificial Gaa Lighting Fixture Outlet--Large. 3 Mantle 480 C.P.--__ '> .. . Lighting Fixture Outlet--Small, 1 Mantle 160 C.P____ _______ _.. One Cubic Foot of Natural Gas Generates One Cubic Foot of Artificial Gas Generates .:.......................................................... One Cubic Foot of Producer Gas Generates........ -...................................................... 90% 67% 50% 9000 12000 5000 * * * * * * * * 5000 3000 600 2500 400 540 2250 2250 * * * * * * * * 4500 2250 900 540 135 10% 100% 33% 100% 50% 1000 10000 6000 18000 5000 10000 * 12000 * - 10000 * 18000 * 250 * ' 100000 * 100 . * 250 * 2500 5000 10000 3000 6000 500 1000 2500 5000 900 1300 60 600 250 2500 250 2500 * 5000 3000 * 3000 * 1800, 3000 * 5000 * 3000 500 5000 250 2500 100 1000 60 600 15 150 Steam Heated Equipment Insulated Surface, Per Square Foot........................... - _____ ________ Steam Table--Per Square Foot of Top Surface ' ` 330 130 80 400 220 110 2000 1200 2500 300 0 0 0 0 0 0 2000 1200 ' 2500 800 330 130 80 400 220 110 4000 2400 5000 1100 Miscellaneous Heat Liberated from Hot Water used direct and on towels per hour--Barber Shops 30 1 30 1 60 100 | 200 1 300 *Per cent sensible and latent heat depends upon use of equipment; dry beat, baking or boiling. 160 Chapter 8. Cooling Load GENERAL From the foregoing discussion it is obvious that the determination of the maximum cooling load is rather complicated by reason of the variable pature of contributing load components. If the time when the maximum load occurs is not obvious the load should be calculated for various times of the day to determine the probable time ait which the sum of the various component loads is a maximum. .. Application of the foregoing data in determining cooling load require ments is illustrated in Example 1. Fig. 3. Plan Diagram of Clothing Store Example 1. Determine cooling load requirements for a clothing store illustrated in Fig. 3 and located in Cleveland, Ohio, Latitude 40 deg. This is a one-story building located on a corner and it faces south and west. Assume building on east and north sides conditioned. Wall construction, 8 in. hollow tile, 4 in. brick veneer, plaster on walls, U = 0.33 (Table 4, Wall 38 B, Chapter 5). Roof construction, 2 in. concrete, Yi in. rigid insulation, metal lath and plaster ceiling, U = 0.26 (Table 11, Wall 2 J, Chapter 5). Floor, maple flooring on yellow pine, no ceiling below, U = 0.34 (Table 8, Wall 1 D, Chapter 5). Partition, wood lath and plaster on both sides of studding, U = 0.34 (Table 6, Wall 77 B, Chapter 5). Show windows, provided with awnings and thin panel partition at rear. Front doors, 2 ft 6 in. x 7 ft (glass panelled), U = 1.13 (Table 13 A, Chapter 5). Side door, 3 ft x 7 ft (solid, 1 % in. thick), U = 0.51 (Table 13 B, Chapter 5). Occupancy, 10 clerks, 40 patrons. Lights, 4200 w. Outside design conditions, dry-bulb 95 F; wet-bulb 75 F. Inside design conditions; dry-bulb 80 F; wet-bulb 67 F. Basement temperature, 85 F. Store room temperature, 88 F. - 161 Heating Ventilating Air Conditioning Guide 1938 Solution: The normal heat transmission through various surfaces shown in load calculations are determined by application of Formula 1. It is quite obvious from the shape and exposure of this store that the maximum sun load will exist on the west wall: Since the west wall has a large glass area with a negligible time lag, the peak load may be expected at 4:00 p.m. at which time, from Table 4, Iq " 182. Iq for south glass at 4:00 p.m. is 2. Because of the small amount of solar, -radiation transmitted through the south glass, the transmission due to temperature difference has also been included.. Assuming time lag in roof and walls to be 2 hours, the corresponding values for I for south and west walls and roof will be those shown in Table 4 for 2:00 p.m. They are respectively 77, 143 and 258. A time lag of 1 hour was assumed for the west door amounting to I = 192. By substituting these values in equations 2 and 3 the solar heat load is determined. . To determine the heat gain from the outside air it is necessary first to determine the volume of the outside air to be introduced. Since the show.windows-are sealed so as not to permit infiltration and since there are only three doors in this store through which infiltration can take place, it is obvious that infiltration of air will be a negligible quan tity. The volume of the store is 21,600 cu ft. Good practice indicates that in a store of this character there should be a minimum of from 1 to 1outside air changes per hour. On a basis of 1^ air changes the volume of outside air to be introduced would be 32,400 cfh. By reference to Chapter 3 it will be noted that the minimum ventilation require ments are 10 cfm per person. On this basis the ventilation requirements would be 30,000 cfh. Since this will produce approximately 1^ outside air changes per hour, 30,000 cfh will be considered in this application. 'v To determine load imposed by occupants it will be found from Table 4, Chapter. 3 that the average person standing at rest will dissipate 225 Btu sensible heat and 206 Btu latent heat per hour. Normal Transmission Load: 1 1 1' - . 1 ................. Surface S Glass S Wall W Wall W Door Roof Floor N Partition Total Dimensions 2(2 ft 6 in. x 7 ft) + 2(10 ft x 6 ft) (30 ft x 12 ft) -155 (60 ft x 12 ft)-321 3 ft x 7 ft 60 ft x 30 ft 26 ft x 54 ft 30 ft x 12 ft Area SQ FT 155 205 399 21 1800 1404 360 V 1.13 0.33 0.33 0.51 0.26 0.34 0.34 Temp. Diff. Deo F 15 15 15 15 15 5 8 Btu per Hour 2,627 1,015 1,975 161 7,020 2,387 - 979. 16.164 Sun Load: Surface S Wall S Glass W-Glass W Door W Wall Roof . Total. Dimensions 3(14 ft x 6 ft)+(8 ft x 6 ft) Area BQ FT 205 155 F 0.078 a 0.7 . I OB * ` 77 2 Shade Btu per Factor Hour 0.28 _ 862 87 300 21 399 1800 . 0.118 0.078, 0.062 0.7 0.7 0.9 182 0.28 192 143 258 15,288 333 3,113 25,914 45,597 Outside Air Heat Gain: Sensible heat, HB = 0.24 X 60 do Q (to -- t) (Formula 4). Q = 50 X 10 = 500 cfm. Density of air at 95 F dry-bulb and 75 F wet-bulb for a barometric.pressure of 29.92 in. is 0.07089 lb per cubic foot (Table 4, Chapter 1). . Dew-point of outdoor air is 66 F (psychrometricchart). .. 162 . . Chapter 8. Cooling Load . . Partial pressure of vapor is 0.64378 in. Hg. (Pressure of saturated vapor at 66 F, Table 6, Chapter 1). . . .. , " ' w = 0.622 (^) - 0.622 (29= 0.0137 lb water vapor per . pound dry air (Formula 5 a; Chapter 1). --------- --------- = 0.986 lb dry air per pound outside air. 1 plus 0.0137 ... /. . . do '= 0.07089 X 0.986 = 0.0699 lb dry air per cubic foot outside air. He = 60 X 500 X 0.0699 X 0.24 (95-80) =, 7549 Btu per hour. Total heat, H = 60 d0 Q iK -- h) (Formula 5). ' ho = 38.46 Btu per pound, dry air at 75 F wet-bulb (Table 6, Chapter 1). . h = 31.51 Btu per pound dry air at 67, F wet-bulb (Table 6, Chapter 1).- . H = 60 X 0.0699 X 500 (38.46 - 31.51) = 14,574 Btu per hour. Latent heat gain from outside air = 14,574 -- 7549 = 7025 Btu per hour. . People Heat Gain: 50 X 225 = 11,250 Btu per hour, sensible heat. 50 X 206 = 10,300 Btu per hour, latent heat. ; Light Heat Gain: 4200 X 3.413 '= 14,335 Btu per hour. Summary: - */ Component of Load '- .- Btu prb Hour - , Sensible. 16,164 45,597' * 7,549 11,250 14,335 ` 94,895 ' Latent ` ` ` 7,025 . 10,300 17,325 Total Load: . 94,895 + 17,325 = 112,220 Btu per hour. PROBLEMS IN PRACTICE 1 The outdoor and indoor temperatures are 90 F and 78 F, respectively. What is the amount of heat transmitted per hour through a 7 ft by 4 ft north window? Ht = 28 X 1.13 (90-78) = 380 Btu per hour. (Equation 1, Chapter 8 and Table 13 A, Chapter 5). '' . ... 2 a. If a restaurant has two 10 gal gas-heated coffee urns, what is the cooling load due to them? ' ' . b. What is the cooling load due to four 1350 w burners on an electric range? a. 2 X 10 X 1000 = 20,000 Btu per hour (Table 10). .. . ft. 4 X 1350 = 5400 w = 5.4 kw. 5.4 X 3413 = 18,430 Btu per hour (Table 10). . . 3 a. What is the maximum heat transmission for a flat roof located in Pitts burgh (latitude 40 deg) exposed to the sun with the outdoor and indoor tern- Heating Ventilating Air Conditioning Guide 1938 i perature 95 F and 80 F, respectively? The roof is of uninsulated 6 in. concrete with its underside exposed, and with a black upper surface. b. What time of day will maximum cooling load due to the roof exist? a. Ht + i/B -- [A U (*o -- /)] + [A Fal\ (Formulas 1 and 2). U for roof = 0.64 (Table 11, Wall 4 A, Chapter 5). F = 0.147 (Fig. 2). a = 0.9 (Table 6). I = 293 (Table 4). Ht + Hr = [1 X 0.64 (95-80)] + [1 X 0.147 X 0.9 X 293] = 48.5 Btu per square foot per hour. . b. Maximum sun intensity occurs at noon (Table 4). Maximum effect in cooling load will occur at 3 p.m. (Table 7). 4 a. What is the maximum rate of heat delivered to a room through a bare window in the west wall of a building located in New Orleans (30 deg latitude)? b. What time of day will it occur? c. What will maximum rate be if window is protected by awning? a. Hq = AgIg (Formula 3). /G = 177 (Table 2). Hq = I X 177 = 177 Btu per square foot per hour. b. At 4 p.m. (Table 2). c. 177 X 0.28 = 49.6 Btu per square foot per hour (Table 8). . . 5 What is the heat gain per cubic foot of outside air introduced, under the following conditions if the barometric pressure is 29.5 in. Hg.? Outdoor temperatures, 90 F dry-bulb and 75 F wet-bulb. Inside temperatures, 78 F dry-bulb and 65 F wet-bulb. Density of air at 90 F dry-bulb, 75 F wet-bulb and 29.5 in Hg. is 0.0705 lb per cubic foot (Table 4, Chapter 1). Dew-point of outdoor air is 68.2 F (psychrometric chart). Pressure of saturated vapor at 68.2 F is 0.6946 in. Hg. (Table 6, Chapter 1). W = 0.622 ^ = 0.622 (29 5^--^0 6946 ) = ^ water vapor per pound dry air (Formula 5a, Chapter 1). 1 plus 0 015 = dry air per pound outside air. . do -- 0.0705 X 0.985 = 0.06944 lb dry air per cubic foot outside air. Heat content outside dry air at 75 F wet-bulb =>8.46 Btu per pound. Heat content inside dry air at 65 F wet-bulb = 29.96 Btu per pound. Total heat, H = 0.06944 (38.46 -- 29.96) = 0.59 Btu per cubic foot. 6 A 7 X 4 ft west window is equipped with an inside aluminum finished Venetian blind which is adjusted to fully cover the window when the sun shines. The net glass area is 75 per cent of the total area of the window. What is the cooling load due to the window at 10 a.m. and 4 p.m.? Temperatures are: 10 a.m., outside 85 F and inside 77 F; 4 p.m., outside 95 F and inside 80 F. Latitude 40 deg. 10 a.m.: Ht -- 28 X 1.13 (85-77) = 253 Btu per hour (Equation 1, and Table 13A, Chapter 5). 4 p.m.: 28 X 0.75 = 21 sq ft net glass area. HG = 21 X 182 X 0.58 = 2217 Btu per hour (Tables 4 and 8). . 164 Chapter 9 FUELS AND COMBUSTION Classification o Coal, Air for Combustion, Draft Required, Combustion of Anthracite, Firing Bituminous Coal, Burning Coke, Hand Firing, Classification and Use of Oil, Classification and Use of Gas THE choice of fuel for heating is a question of economy, cleanliness, fuel availability, operation requirements, and control. The principal fuels to be considered are coal, oil, and gas. CLASSIFICATION OF COALS The complex composition of coal makes it difficult to classify it into clear-cut types. Its chemical composition is some indication but coals having the same chemical analysis may have distinctly different burning characteristics. Users are mainly interested in the available heat per pound of coal, in the handling and storing properties, and in the burning characteristics. A description of the relationship between the qualities of coals and these characteristics requires considerable space; a treatment applicable to heating boilers is given in U. S. Bureau of Mines Bulletin 276. A classification of coals is given in Table 1, and a brief description of the kinds of fuels is given in the following paragraphs, but it should be recognized that there are no distinct lines of demarcation between the kinds, and that they graduate into each other: Anthracite is a clean, dense, hard coal which creates very little dust in handling. It is comparatively hard to ignite but it burns freely when well started. It is non-caking, it burns uniformly and smokelessly with a short name, and it requires little attention to the fuel beds between firings. It is capable of giving a high efficiency in the common types of hand-fired furnaces. A tabulation of the quality of the various anthracite sizes will be found in U. S. Bureau of Mines Report of Investigations No. 3283. Semi-anthracite has a higher volatile content than anthracite, it is not as hard and ignites somewhat more easily: otherwise its properties are similar to those of anthracite. Semi-bituminous coal is soft and friable, and fines and dust are created by handling it. It ignites somewhat slowly and burns with a medium length of flame. Its caking pro perties increase as the volatile matter increases, but the coke formed is relatively weak. Having only half the volatile matter content of the more abundant bituminous coals it can be burned with less production of smoke, and it is sometimes called smokeless coal. _ The term bituminous coal covers a large range of coals and includes many types having distinctly different composition, properties, and burning characteristics. The coals range from the high-grade bituminous coals of the East to the poorer coals of the West. Their caking properties range from coals which completely melt, to those from which the volatUes and tars are distilled without change of form, so that they are classed as non caking or free-burning. Most bituminous coals are strong and non-friable enough to permit of the screened sizes being delivered free from fines. In general, they ignite 165 Heating VentiiiAting Air Conditioning Guide 1938 easily and burn freely; the length of flame varies with different coals, but it is long. Much smoke and soot are possible especially at low rates of burning. , Sub-bituminous coals occur in the western states; they are high in moisture when mined and tend to break up as they dry or when exposed to the weather; they are liable to ignite spontaneously when piled or stored. They ignite easily and quickly and have a medium length flame, are non-caking and free-burning; the lumps tend to break into small pieces if poked; very little smoke and soot are formed. Lignite is of woody structure, very high in moisture as mined, and of low heating value; it is clean to handle. It has a greater tendency than the sub-bituminous coals to disintegrate as it dries, and it also is more liable to spontaneous ignition. Freshly mined lignite, because of its high moisture, ignites slowly. It is non-caking. The char left after the moisture and volatile matter are driven off burns very easily, like charcoal. The lumps tend to break up in the fuel bed and pieces of char falling into the ashpit continue to burn. Very little smoke or soot is formed. .' Coke is produced by the distillation of the volatile matter from coal. The type of coke depends on the coal or mixture of coals used, the temperatures and time of distil lation and, to some extent, on the type of retort or oven; coke is also produced as a residue from the destructive distillation of oil. . Table 1. Classification of Coals by Rank/. Legend: F.C. = Fixed Carbon. V.M. = Volatile Matter. Btu = British thermal units". Hr.A fig Group Limits op Fixed Carbon or Btu Mineral-Matter-Free Bass Requisite Physical Properties I. Anthracite_____ Drv F.C., 98 per cent or more (Dry V.M., 2 per.'cent or less) Dry F.C., 92 per cent or more and less than 98 per cent.(Dry-V.M., 8 per cent or less and more than 2 per cent) Dry F.C., 86 per cent or more and less Non-agglutinating* than 92 per cent (Dry V.M., 14 per cent or less and more than 8 per cent) 'II. Bituminous*__ 1 1 Low volatile bituminous Dry F.C., 77 per cent or more and less. than 86 per cent (Dry V.M., 23 per cent dr less and more than 14 per cent) . .- 2. Medium volatile bituminous coal Dry F.C., 69 per cent or more and less than 77 per cent (Dry V.Mi, 31 per' cent or less and more than 23 per cent)' . '. / . *3. High volatile A bituminous coal Diy F.C., less than 69 per cent:(Dry V.Mm- more than 31per cent);-and moist6. Btu, 14,000* or. more . 4. High volatile B bituminous coal. Moist6 Btu, 13,000 or more and less than 14,000* " 5. High volatile C bituminous coal. Moist Btu, 11,000 or. more and leas ESther agglutinating than 13,000* - \ or non-weathering*' r HI. Sab-bituminouflJ Moist Btu, 11,000 or more and less Both weathering and than 13,000* ' non-agglutinating . than 11,000* ' , - . 1 than9500* * IV- Ldgnitic_______ | - Moist Btu less than .8300 .Unconsolidated- ' *If agglutinating, classify in low-volatile group of the bituminous class.- - - '. ;. 6Moist Btu refers to coal containing its natural bed moisture but not including visible water on the surface of the coal. . ... 'Pending the report of the Subcommittee on Origin and Composition and Methods of Analysis, it is recognized that there may be non-caking varieties in each group of the bituminous class. . *Coals having 69 per cent or more fixed carbon on the dry, mineral-matter-free basis shall be classified according to fixed carbon, regardless of Btu. . . - , .- - - There are three varieties of coal in the High-volatile C bituminous coal group, namely,.Variety 1, agglutinating and non-weathering; Variety 2, agglutinating and weathering;..Variety 3, non-agglutinating and non-weathering. ' *, ./Adapted from A.S.T.M. Standards on Coal and Coke, p. 68. American Society far Testing Materials, Philadelphia/1934. ' .- 166 Chapter 9. Fuels and Combustion High-temperature cokes. Coke as usually available is of the high-temperature type, and contains between 1 and 2 per cent volatile matter. High-temperature cokes are sub divided into beehive coke of which comparatively little is now sold for domestic use, by product coke, which covers the greater part of the coke sold, and gas-house coke. The differences among these three: cokes are relatively small; their denseness and hardness decrease and friability increases in the order named. In general, the lighter and more friable cokes ignite and burn the more easily. Low-temperature cokes are produced at low coking temperatures, and only a portion of the volatile matter is distilled off. Cokes as made by various processes under develop ment have contained from 10 to 15 per cent volatile matter. In general, these cokes ignite and burn more readily than high-temperature cokes. The properties of various low-temperature cokes may differ more than those of the various high-temperature cokes because of the differences in the quantities of volatile matter and because some may be light and others briquetted. The sale of petroleum cokes for domestic furnaces has been small and is generally confined to the Middle West. They vary in the amount of volatile matter they contain, but all have the common property of a very low ash content, which necessitates the use of refractory pieces to protect the grates from being burned. In order to obtain perfect combustion a definite amount of air is re quired for each pound of fuel fired. A deficiency of air supply will'result in combustible products passing to the stack unburned. An excess of air absorbs heat from the products of combustion and results in a greater loss of sensible heat to the stack. Total Air Required. The theoretical amount of air required per pound of fuel for perfect combustion is dependent upon the analysis of.the fuel; Table 2. Pounds of Air per Pound of Fuel as Fired ' Anthracite Core Sshi-Bituminous Bituminous . Lignite - 9.6 11.2 11.2 10.3 . 6.2 however, for estimating purposes the theoretical air required for different grades of fuel may roughly be taken from Table 2. An excess of about 50 per cent over the theoretical amount is considered good practice under usual operating conditions. . The amount of excess air, based upon the laws of combustion, can be. determined by its relation to the percentage of COi (carbon dioxide) in the products of combustion. This relationship is shown by the curves (Fig. 1) for high and low volatile coals and for coke. In hand-fired fur naces with long periods between firings the combustion goes through a cycle in each period and' the quantity of excess air present varies. . Secondary Air. The division of the total into primary and secondary air necessary to produce the same rate of burning and the same excess air depends on a number of factors which include size of fuel, depth of fuel bed, and diameter of firepot. The ratio of the secondary to the primary air increases with decrease in the size of the fuel, pieces, with increase in the depth of the fuel bed, and with increase in the area of the firepot; the ratio also increases with increase in rate of burning. Size of the fuel is a very important factor in fixing the quantity of secondary air required for non-caking coals. With caking coals it is not 167 Heating Ventilating Air Conditioning Guide 1938 EXCESS AIR. PER CENT Fig. 1. Relation Between CO, and Excess Air in Gases of Combustion . so. important because small pieces fuse together and form large lumps. Fortunately a smaller size fuel gives more resistance to air flow through the fuel bed and thus automatically causes a larger draft above the fuel bed, which draws in more secondary air through the same slot openings. In spite of this, a small size fuel requires a larger opening of the door slots; for a certain size for each fuel no slot opening is required, and for larger sizes too much excess air gets through the fuel bed. It is impossible to establish a single rule for the correct slot opening for all types and sizes of fuels and for all rates of burning. Furthermore, the Fig. 2. Relative Amount of Fire Door Slot Opening Required in a Given Furnace to Give Equally Good Combustion for High Temperature ' Coke of Various Sizes When Burned at Various Rates - 168 . Chapter 9. Fuels and Combustion size of slot opening is dependent on whether the ashpit damper is open or closed. It is better to have too much than too little secondary air; the opening is too small if there is a puff of flame when the firing door is opened. Fig.'2, taken from the U. S. Bureau of Mines Report of Investigations No. 2980, shows the relationship of the slot opening, for a domestic fur nace, to the size of coke and the rate of burning; these openings are with the ashpit damper wide open, and would be less if the available draft permits of its being partly closed. The same openings are satisfactory for anthracite. Bituminous coals require a large amount of secondary air during the period subsequent to a firing in order to consume the gases and to reduce the smoke. The smoke produced is a good indicator, and that opening is best which reduces the smoke to a minimum. Too much secondary air will cool the gases below the ignition point, and prove harmful instead of beneficial. The following suggestions will be helpful: 1. In cold weather, with high combustion rates, the secondary air damper should be half open all the time. .' . . . 2. In very mild weather, with a very low combustion rate, the secondary air damper should be closed all the time. ' 3. For temperatures between very mild and very cold, the secondary air damper should be in an intermediate.position. ... . . 4. For ordinary house operation, secondary air is needed after each firing for about one hour. . ', Draft Requirements The draft required to effect a given rate of burning the fuel as measured at the smokehood is,dependent on the following factors: , . .. - ' 1. Kind and size of fuel. " ' 2; Combustion rate per sqiiare foot of grate area per hour. r' 3. Thickness of fuel bed. :. ' ' 4. Type and amount of ash and clinker accumulation. 5. Amount of excess air present' in the gases. ' "' 6. Resistance offered by the boiler passes to the flow of: the gases. 7. Accumulation of soot in the passes.- Insufficient draft will necessitate additional manipulation of the fuel bed and more frequent cleanings.to keep its resistance down. Insufficient draft also restricts the control by adjustment of the dampers. . The quantity of excess air present has a marked effect on the draft required to produce a given rate of burning, and it is often possible to produce a higher rate by increasing the thickness of the fuel bed. Combustion oi Anthracite1 - . An anthracite fire should never be poked, as this serves to bring ash to the surface of the fuel bed where it melts into clinker. ' Egg size is suitable for large firepots (grates 24 in. and over) if the fuel can be fired at least 16 in. deep. The air spaces between the pieces of coal are large, and for best results this coal should be fired deeply; : ISee reports published by Anthracite Industries Laboratory, Primos. Pennsylvania. 169 Heating Ventilating Air Conditioning Guide 1938 Stove size coal is the proper size of anthracite for many boilers and furnaces used for heating buildings. It bums well on grates at least 16 in. in diameter and 12 in. deep. The only instructions needed for burning this type of fuel are that the grate should be shaken daily, the fire should never be poked or disturbed, and the fuel should be fired deeply and uniformly. Chestnut size coal is in demand for firepots up to 20 in. in diameter, with a depth of from 10 to 15 in. Pea size coal is often an economical fuel to burn. It is relatively low in price. When fired carefully, pea coal can be burned on standard grates. It is well to have a small amount of a larger fuel on hand when building new fires, or when filling holes in the fuel bed. Care should be taken to shake the grates only until the first bright coals begin to fall through the grates. The fuel bed, after a new fire has been built, should be increased in thickness by the addition of small charges until it is at least level with the sill of the fire door. This keeps a bed of ignited coal in readiness against the time when a sudden demand for heat shall be made on the heater. A very satisfactory method of firing pea coal consists of drawing the red coals toward the front end and piling fresh fuel toward the back of the fire-box. Pea size coal requires a strong draft and therefore the best results generally will be obtained by keeping the choke damper open, the coldair check closed, and by controlling the fire with the air-inlet damper only. Pea size can also be fired in layers with stove or egg size anthracite and its use in this manner will reduce the fuel costs and attention required. ' Buckwheat size coal for best results requires more attention than pea size coal, and in addition the smaller size of the fuel makes it more difficult to bum on ordinary grates. Greater cafe must be taken in shaking the grates than with pea coal on account of the danger of the fuel falling through the grate. In house heating furnaces the coal should be fired lightly and more frequently than pea coal. When banking a buckwheat coal fire it is advisable after coaling to expose a small spot of hot firfe by putting a poker down through the bed of fresh coal. This will serve to ignite the gas that will be distilled from the fresh coal and prevent an explosion of gas within the firepot, which in some cases depending upon the thickness of the bed of fresh coal is severe enough to blow open the doors and dampers of the furnace.' -A good draft is required and consequently the fire is best controlled by the air-inlet damper only. Where frequent attention can be given and care exercised in manipulation of the grates this fuel can be burned satisfactorily without the aid of any special equipment. In general it will be found more satisfactory with buckwheat coal to maintain a uniform heat output and consequently to keep the system warm all the time, rather than to allow the system to cool off at times and then to attempt to bum the fuel at a high rate while warming up. A uniform low fire will minimize the clinker formation and keep the clinker in an easily broken up condition so that it readily can be shaken through the grate. -. Forced draft and small mesh grates are frequently used for burning buckwheat anthracite. For best results and a higher degree of con venience, domestic stokers, are used: ,. 170 ---- Chapter 9. Fuels and Combustion No. 2 buckwheat anthracite, or rice size, is Used only in domestic stokers. No. 3 buckwheat anthracite, or barley, has no application in domestic heating. Firing Bituminous Coal - Bituminous coal should never be fired over the entire fuel bed at one . time. A portion of the glowing fuel should always be left exposed to ignite the gases leaving the fresh charge. . Air should be admitted over the fire through a special secondary air device, or through a slide in the fire door or by opening the fire door slightly. If the quantity of air admitted is too great the. gases will be cooled below the ignition temperature and will fail to burn. The fireman can judge the quantity of air to admit by noting when the air supplied is just sufficient to make the gases burn rapidly and smokelessly above the fuel bed. The red fuel in the firebox, before firing, excepting only a shallow layer of coke on the grate, should be pushed to one side or forward or back- .ward to form a hollow in which to throw the fresh fuel. Some manu facturers recommend that all red fuel be pushed to the rear of the firebox and that the fresh fuel be fired directly on the grate and allowed to ignite from the top. The object of this is to reduce the early rapid distillation of gases and to reduce the quantity of secondary air required for smoke less combustion. ' It is well to have the bright fuel in the firebox so placed that the gases from the freshly fired fuel, mixed with the air over the fuel bed, pass over the bed of bright fuel on the way to the flues. The bed of bright fuel then supplies the heat to raise the mixture of air and gas to the ignition temperature, thereby causing the gaseous matter to burn and preventing the formation of smoke. The fuel bed should be carried as deep as the size of fuel and the available draft permit, in order to have as much coked fuel as possible for pushing to the rear of the firebox at the time of firing. A deep fuel bed allows the longest firing intervals. If the.coal is of the caking kind the fresh charge will fuse into one solid mass which can be broken up with the stoking bar and leveled from 20 min to one hour after firing, depending on the temperature of the firebox. Care should be exercised when stoking not to bring the bar up to the surface of the fuel as this will tend to bring ash into the high temperature zone at the top of the fire, where it will melt and form clinker. The stoking bar should be kept as near the grate as possible and should be raised only enough to break up the fuel. With fuels requir ing stoking it may not be necessary to shake the grates, as the ash is usually dislodged during stoking. The output obtained from any heater with bituminous coal will usually exceed that obtainable with anthracite, since soft coal burns more rapidly than hard coal and with less draft. Soft coal, however, will require frequent attention to the fuel bed, because it burns unevenly, even though the fuel bed may be level, forming holes in the fire which admit too much air, chilling the gases over the fuel bed and reducing the available draft. 171 Heating Ventilating Air Conditioning Guide 1938 Semi-bituminous coal- is fired as bituminous coal, and because of its caking characteristics jt requires. practically 'the same attention.- . The Pocahontas Operators Association recommends the central cone method of firing, in which the coal is heaped on to the center of the bed forming a cone the top of which should be level with the middle of the .firing door; This allows the larger lumps to. fall to the,sides, and the fines to remain in the center and be coked. The poking should be limited to breaking down the coke without stirring, and to gently rocking the grates. . It is recom mended that the slides in the firing door be kept closed, as the thinner fuel bed around the sides allows enough air to get through.' Burning Coke - - '- ' Coke is a very desirable fuel and usually will give satisfaction as soon as the user learns how to control the fire. Coke ignites and bums very rapidly with less draft than anthracite coal. In order to control the air admitted to the fuel .it is very important that all openings or leaks into the ashpit be closed tightly. A coke fire responds more' rapidly than an anthracite fire to the opening of the dampers. This is an advantage in warming up the system, but it also makes it necessary to watch the dampers more closely in order to prevent the fire from burning too rapidly. A deep fuel bed always should be `maintained when burning coke.. The grates should be shaken only slightly in mild weather and should be shaken only until the first red particles drop from the grates in cold weather. Since coke weighs only about half as much as anthracite per cubic foot only about half as much can be put in the firepot, so it will be necessary .to fire oftener. The best size of coke for general use, for small firepots where the fuel depth is not oyer 20 in., is that which passes over a 1 in. screen and through a in. screen. For large firepots where the fuel caii be fired over 20 in. deep, coke which passes over a 1 in. screen and through a 3 in. screen can be used, but a coke of uniform size is always more satisfactory; Large sizes of coke should be either mixed with fine sizes or broken up Before using. Dustless Coal ' . The practice of treating the more friable coals to allay the dust they create is increasing. The coal is sprayed with a solution of calcium chloride or a mixture of calcium and magnesium chlorides. Both these salts are very' hygroscopic and their moisture under normal atmospheric conditions'keeps the surface of the coal damp, thus reducing the. dust during delivery and in the cellar, and obviating the necessity of sprinkling the coai in the bin. ' " .. . . The ..coal is sometimes .treated at. the mine, but more usually by the iocal distributor just before delivery. The solution is sprayed under high pressure, using from 2 to 4 gal or from 5 to 10.1b of the salt per ton of coal, depending on its friability arijd size. "' - . ... Pulverized Coal ' . ' .' ; ... . ,, " . '. : 1 installations of- pulverized, coal burning plants in heating boilers are of the unit-type, in which thei.pulverized eo.ah is .delivered;into.the furnace immediately after grinding, together with the proper amou.nt,of preheated Chapter 9. Fuels and Combustion air. With this apparatus, where, the necessary furnace volume is ob tainable, high efficiencies can be obtained. A 150-hp boiler has generally been considered the smallest size for which pulverized fuel is feasible. Complications are introduced if an installation with a single boiler has to take care of very light loads, Hand Firing; Hand firing is the oldest and the most widely used method of burning coal for heating purposes. To keep the fuel bed in proper condition where hand firing is used, the following general rules should; be observed: 1. Remove ash from fuel bed by shaking the grates whenever fresh fuel is fired. This removes ash from the fire, enables the air to reach the fuel, and does away with the for mation of clinker which is melted ash. 2. Supply the boiler with a deep bed of fuel. Nothing is gained by attempting to fire a small amount of fuel. A deep bed of fuel secures the most economical results. 3. Remove ash from ashpit at least once daily. Never allow ash to accumulate up to the grates. If the ash prevents the air from passing through, the grate bars will burn out and much clinker trouble will be experienced. . The principal requirements for a hand-firedfurnace are that it shall have enough grate area and correctly proportioned combustion space. The amount of grate area required is dependent upon the' desired combustion . ' rate. '. . The furnace volume is influenced by the kind of coal used. Bituminous coals, on account of their long-flaming characteristic,, require more space in which to burn the gases of combustion completely than do the coals low in volatile matter. For burning high volatile coals provision should be made for mixing the combustible gases thoroughly so that com bustion is complete before the gases come in contact with the relatively cool heating surfaces. An abrupt change in the direction of flow tends to mix the gases of combustion more thoroughly. Anthracite requires practically no combustion space. . CLASSIFICATION OF OILS Uniform oil specifications were prepared in 1929 by the American Oil Burner Association, in cooperation with the American Petroleum Institute, the U. S. Bureau of Standards, the American Society for Testing Materials and other interested organizations. Oil fuels were classified into six groups, as indicated by Table 3. When these specifications were prepared, it was generally accepted that the first three grades were adapted to domestic use, while the last three were suitable only for commercial and industrial burners. . Today domestic installations may use No. 4 oil of the so-called heavy oil group, when and if said oil very closely follows the specifications of No. 3. Up-to-date listing by the Underwriter's Laboratories- should be referred to before! a No. 4 grade of fuel is used which merely meets Commercial Standards CS 12-35. ` Since the specifications as originally drawn provide for maximum limits only for the several grades, this differentiation has not proved stable. Realizing how unsatisfactory it is to have specifications which permit the 173 Heating Ventilating Air Conditioning Guide 1938 Table 3. Commercial Standard Fuel Oil Specifications A. Detailed Requirements for Domestic Fuel OUs'> Grade of Oil Approx. Btu per Gal.* Flash Point Min. Max. No. 1 Domestic Fuel Oil . ? A light distillate oil for use in burners requir ing a high grade fuel. . 139,000 100 F 150 F or legal No. 2 Domestic Fuel Oil A medium distil late oil for use in burners re quiring a high grade fuel.' * 141,000 125 F 190 F or legal No. 3 Domestic Fuel Oil A distillate fuel oil for use in burners .where a low viscosity oil is required. 143,400 150 F 200 F or legal Water and Sediment, Maximum Carbon Residue Maximum 0.05% 0.02% 0.05% 0.05% 0.1% 0.15% Distillation Test Max. Mm. 10% point 420 F Viscosity Maximum End point '. 600 F 10% point 440 F 90% point 620 F End point 600 F 90% point 620 F Saybolt Universal at 100 F 70 seconds Adapted from "Fuel Oils," p, 2, V. S. Department of Commerce. Bureau of Standards. Commercial Standard *Pour CPSSoI1iPn2-tSMB5,aWximasumhmingistpo1n5,. 1935. F. Lower or higher pour points may be specified whenever required by conditions of storage and use. However, these specifications shall not require a pour point less than 0 F undeGroavneyrncmonednittisopnesc. ifications do not give Btu per gallon, but they are noted here for information only. B. Detailed Requirements for Industrial Fuel Oilsd Grade of Oil Approx. Btu per Gal.* Flash Min. Point, Max. . No. 4. Industrial Fuel Oil An oil known to the trade as a light fuel oil for use in burners where a low vis cosity industrial fuel oil is required. 144,500 150 F, See Note* No. 5 Industrial Fuel Oil Same as Federal Specifications Board specification for bunker.oil "B for burners adapted to the use of indus trial fuel oil of medium viscosity. 146,000 150 F No. 6 Industrial Fuel Oil . ' Same as Federal Specifications Board 150,000 specification for bunker oil "C for burners adapted to oil of high viscosity 150 F Water and Sediment, Maximum Ash Maximum 1.0% 0.1% 1.0% ' 0.15% . 2.0% Viscosity, Maximum Saybolt Universal at 100 F. 500 seconds Saybolt Furol - at 122 F 100 seconds Saybolt Furol at 122 F 300 seconds Pour point may be specified whenever requited by conditions of storage and use. However, these specifications shall not require a pour puoiimnt. ltesas tuhwaun 1i5 F* under any -c-o--n--d--i-t-i-o--n--s-. Whenever required, as for example in burners with automatic Ignition, a maximum flash point may - be specified. However, these specifications shall not require a flash point less than 250 F under any con ditions- - -' 174 Chapter 9. Fuels and Combustion substitution of one grade for another, the U. S. Bureau of Standards in cooperation with the American Society for Testing Materials is figuring on a new set of specifications providing for definite limits for each grade. When these specifications are adopted, it is expected that the National Board of Fire Underwriters will retest all burners using oils of the maximum specifications for the grade so that if a burner is approved for a certain grade it will burn any oil meeting the specifications for that particular grade. Several burners adapted to industrial use have recently been listed for automatic operation with No. 5 oil. Usually oils No. 5 or 6 require preheating for proper operation, but where conditions are favorable, No. 5 can be used without the equipment that this entails. . There are two reasons for the trend to lower grades of oil. While the lighter oils contain slightly more heat units per pound, the weight per gallon increases more rapidly than the decrease in heat units per pound, and oil is bought by the gallon. As a consequence, while a No. 1 oil may contain 139,000 Btu per gallon, oil No. 5 may test 146,000 Btu per gallon, or 6 per cent more. Usually there is a differential of 3 to 4 cents between ' the No. 1 and No. 5 oils, so that the economy of buying the heavier fuels is apparent; there remains the economic utilization of the heat content of the heavier oils. - The cost of oil fuel is dependent also upon the amount that can be delivered at one time, and the method of delivery. Common practice has split the tank of the truck delivering oils for domestic use into compart ments of 150 to 500-gal capacity, and these unit dumps are made the basis of price. Where a truck can be connected to a storage-tank fill and quickly discharge its oil by pump, the price obviously can be less than where a smaller quantity must be. drawn off in 5-gal cans and poured. For similar reasons an installation that can be supplied from a tank car on a siding provides for a lower unit fuel cost than one where the oil must be trucked, even in the large trucks holding 2,000 gal or more that are used for distributing the heavier oils. GAS CLASSIFICATION . Gas is broadly classified as being either natural or manufactured. Natural gas is a mechanical mixture of several combustible and inert 1 gases rather than a chemical compound. Manufactured gas as dis tributed is usually a combination of certain proportions of gases produced by two or more processes, and is often designated as city gas. When gas is burned a large amount of water vapor is produced as one of the products of combustion. This ordinarily escapes up the chimney, carrying away with it a certain amount of heat. However, when the heat value of gas is determined in an ordinary, calorimeter, this water vapor is condensed and the latent heat of vaporization that is given up during the condensation is reported as a portion of the heat value of the gas. The heat value so determined is termed the gross or higher heat value and this is what is ordinarily meant when the heat value of gas is specified. The heat that is reclaimed by the condensation of the water vapor amounts to about 10 per cent of the total heat value. It is impractical to utilize the entire higher heat value of the gas in any house-heating Heating VentiixAting Air Conditioning Guide 1938 appliance, because to do so it would be necessary to cool the products of combustion down below their dew point, which is ordinarily in the neighborhood of 130 F.. The actual dew point in the chimney is different from the theoretical value because excess air is admitted not only at the burner but also at the backdraft diverter which lowers the dew point. Natural gas is the richest of the gases and contains from 80 to 95 per cent methane, with small percentages of the other combustible hydrocarbons. In addition, it contains from 0.5 to. 5.0 per cent of COj, and from 1 to 12 or 14 per cent of nitrogen! The heat value varies from 700 to 1500 Btu per cubic foot, the majority of natural gases averaging about 1000 Btu per cubic foot. Table 4 shows typical values for the four main oil fields, although values from any one field vary materially. Table 4 also gives the calorific values of the more common types of manufactured gas. Most states have legislation which controls the distri bution of gas and fixes a minimum limit to its heat content. The gross or higher calorific value usually ranges between 520 and 545 Btu per cubic foot, with an average of 535. A given heat value may be maintained and yet leave considerable latitude in the composition of the gas so-that as distributed the composition is not necessarily the same in different dis- Table 4. Representative Properties of Gaseous Fuels. Based on Gas at 60 F and 30 in. Hg. . Btu per Cu Ft Products op Combustion (tAH Specific Ghavttt. FOB COMBU3- Cubic Feet Ulti- Flams Tem- High (Gross) (Net) . I.UU (Cu Ft) COi HiO Total with Ni *0(5* Dry Basis (deo Fahb) Natural gas-- California Natural gas-- Mid-Conti nental 1200 1087 0.67 967 873 0.57 11.26 1.24 2.24 12.4 12.2 9.17 . 0.97 1.92 10.2 11.7 3610 ' 3580 Natural gas-- .Ohio . Natural gas-- Pennsylvania Retort coal gas Coke oven gas 1130 1232 575 588 1025 1120 510 521 0.65 10.70 1.17 ' -A 0.71 11.70 1.30 0.42 5.00 0.50 0.42 5.19 0.51 2,16 2.29 1.21 1.25 11.8 12.9 5.7 5.9 12.1 12.3 11.2 11.0 3600 3620 3665 3660 Carburetted water gas Blue water gas 536 496 0.65 308 281 0.53 4.37 2.26 0.74 0.75 5.0 17.2 0.46 0.51 2.8 22.3 3815 3800 Anthracite pro ducer gas 134 124 0.85 1.05 0.33 0.19 1.9 19.0 3000 . Bituminous producer gas Oil gas 150 140 0.86 575 510 0.35 1.24 4.91 0.35 0.19 0.47 1.21 2.0 19.0 5.6 10.7 3160 3725 176 Chapter 9. Fuels and Combustion tricts, nor at successive times in the same district. There are limits to the variation allowable, because the specific gravity of the gas depends on its composition, and too great a change in the specific gravity necessitates a change in the adjustment of the burners of small appliances. Table 4 shows that a large proportion of the products of combustion when gas is burned may consist of water vapor, and that the greater the proportion of water vapor, the lower the maximum attainable COt by gas analysis. The table also shows that a low calorific value does not neces sarily mean a low flame temperature since, for example, natural gas has a theoretical flame temperature of 3600 F and blue water gas-of 3800 F, although it has a calorific value less than one third that of natural gas. The quantity of air given in Table 4 is that required for theoretical, combustion, but with a properly designed and installed burner, the excess air can be kept low. The division of the air into primary and secondary is a matter of burner design and the pressure of gas available, and also of the type of flame desired. - PROBLEMS IN PRACTICE . 1 Differentiate between the general characteristics of hard and soft coals. . Hard coals contain fixed carbon in large proportions and in addition more ash is present, especially in the smaller sizes. Soft coals have an increasing percentage of carbon in combination with hydrogen which is volatile and will distill on under high temperature, , producing smoke. 2 Name several important properties of coal from a utilization standpoint. a. Caking tendency, whether none, weak, or strong. b. Quantity of volatile matter. c. Friability. . d. Fusibility of the ash. 3 What are the main data commonly available that fix the qualities of coal, and do these tell the whole story? ' a. Calorific value, Btu per pound. b. Proximate analysis giving percentages of moisture, volatile matter, fixed carbon, ash, and sulphur. " c. Temperature at which the ash softens. d. Screen sizes. Other important qualities not usually given are the friability of the coal, its caking tendency, and the qualities of the volatile matter. The percentage of ash and its fusion temperature do not tell how the ash is distributed or how much of it is less fusible lumps of slate or shale. 4 Are there available complete and sufficient data on gas and oils to fix their burning properties and furnace requirements? . Yes. Because gas and oils are'of simple and uniform composition, data are available to fix their burning properties and furnace requirements, but the ability to control their combustion is somewhat less determinable. ' 5 What effect does moisture in fuels have on their efficiency? With any solid fuel, latent and sensible heat are lost at the stack when moisture is dried out of the fuel in burning, and when its hydrogen is burned. Therefore, such fuels as sub-bituminous coal and lignite, which are high in moisture content, have a low efficiency. However, these efficiencies may be improved if the stack gases are cooled to room tem perature, by heating the feed water, for example. 177 Heating Ventilating Air Conditioning Guide 1938 6 t What are the advantages of a sized fuel for heating furnaces? Because a sized fuel encourages a more uniform flow of air through the bed, the burning' will be more uniform, and the bed will be less liable to develop holes and will require less attention. Uniformity of fuel size is more desirable as the area of the bed becomes smaller; it is less important with fuels that cake, but with sized fuels the caking will be more uniform and the air flow through the bed will be steadier. In addition, ash and pieces of slate are less likely to be segregated and to form lumps of clinker. 7 Does the size of a fuel affect the quantity of air required to burn it at a given rate? ' The total air required to give the same gas analysis at the stack is independent of the size of the fuel burned, but for non-caking fuels the ratio of the air passing through the fuel bed to the total air entering the burner base decreases, for the same thickness of bed, as the. size of the fuel becomes smaller; this decrease is very rapid for sizes less than one inch.' For coals that cake, this ratio will depend on the way the caked bed is broken up and on the size of the resulting pieces. ' 8 Is the volatile matter which is given off when coals are burned of the same nature in all coals? No. The products given off by coals when they are heated differ materially in the ratios by weight of the gases to the oils and tars. No heavy oils or tars are given off by anthra cite, and very small quantities are given off by semi-anthracite. As the volatile matter in the coal increases to as much as 40 per cent of ash-free and moisture-free coal, in creasing amounts of oils and tars are given up. For coals of higher volatile content, the relative quantity of oils and tars decreases, so it is low in the sub-bituminous coals and in lignite. . 9 Is smoke a primary product in the burning of fuels? Visible smoke may include very small particles of carbon, oil, tar, water (condensed steam), and ash. Of these, the oils, tars, and ash are mainly primary products, and the water is partly primary. The carbon, which usually comprises the greater part of the smoke, results from the breaking up by heat of oils, tars, and such gases as methane, so it may be considered a secondary product. 10 9 Is the sulphur in coals detrimental to combustion? . Not so far as is known, but its complete combustion gives only 25 per cent as much heat as is given by the same weight of carbon. Sulphur is undesirable because it causes cor rosion of flues and stacks, and also because its gases pollute the atmosphere, and damage buildings and vegetation. 11 How do deposits of soot on the surfaces of a boiler or heater affect the quantity of fuel burned? There are two effects. The soot acts as an insulating layer over the surface and reduces the heat transmission to the water or air; the Bureau of Mines Report of Investigations No. 3272 shows that the loss of seasonal efficiencyIs not as great as has been believed and should not be over 6 per cent because the greater part of the heat is transmitted through the firepoti The soot clogs the passages and reduces the draft; the loss of efficiency from this action may be much more, and also the lack of draft results in unsatisfactory heating. 178 Chapter 10 CHIMNEYS AND DRAFT CALCULATIONS Natural Draft, Mechanical Draft, Characteristics of Natural Draft Chimneys, Determining Chimney Sizes, General Equa tion, Chimney Construction, Chimneys for Gas Heating THE design and construction of a chimney is so important a part of the heating engineer's work that a general knowledge of draft characterictics and calculations is essential. . Draft, in general, may be defined as the pressure difference between the atmospheric pressure and that at any part of an installation through which the gases flow. Since a pressure difference implies a head, draft is a static force. While no element of motion is inferred, yet motion in the form of circulation of gases throughout an entire boiler plant installation is the direct result of draft. This motion is due to the pressure difference, or unbalanced pressure, which compels the gases to flow. Draft is often classified into two kinds according to whether it is created thermally or artificially, viz, (1) natural or thermal draft, and (2) arti ficial or mechanical draft. ' Natural Draft Natural draft is the difference in pressure produced by the difference in weight between the relatively hot gases inside a natural draft chimney and an equivalent column of the copier outside air, or atmosphere. Natural draft, in other- words, is an. unbalanced pressure produced thermally by a natural draft chimney as the pressure transformer and a temperature difference. The intensity of natural draft depends, for the most part, upon the height of the chimney above the grate bar level and also the temperature difference between the chimney gases and the atmosphere. A typical natural draft system consists essentially of a relatively tall chimney built of steel, brick, or reinforced concrete, operating with the relatively hot gases which have passed through the boilers and accessories and from which all the heat has not been extracted. Hot gases are an essential element in the operation of a natural draft system, although inherently a heat balance loss.. . . A natural draft chimney performs the two-fold service of assisting in the creation of draft by aspiration and also of discharging the gases at an elevation sufficient to prevent them from becoming a nuisance. Natural draft is quite advantageous in installations where the total loss of draft due to resistances is relatively low and also in plants which have practically a constant load and whose.boilers are seldom operated above 179 Heating Ventilating Air Conditioning Guide 1938 their normal rating. Natural draft systems have been, and are still being, employed in the operation of large plants during the periods when the boilers are operated only up to their normal rating. When the rate of operation is increased above the normal rating, some form of mechanical draft is employed as an auxiliary to overcome the increased resistances or draft losses. Natural draft systems are used almost exclusively in the smaller size plants where the amount of gases generated is relatively small and it would be expensive to install and operate a mechanical draft system. . The principal advantages of natural draft systems may be summarized as follows: (1) simplicity, (2) reliability, (3) freedom from mechanical Fig. 1. General Operating Characteristics of Typical Induced Draft.Fan parts, (4) low cost of maintenance, (5) relatively long life, (6) relatively low depreciation, and (7) no power required to operate.. The principal disadvantages are: (1) lack of flexibility, (2) irregularity, (3) affected by surroundings, and (4) affected by temperature changes. , . Mechanical' Draft ' N Artificial.draft, or mechanical draft, as it is more commonly-called, is a difference in pressure produced either directly or indirectly by a forced draft fan, an induced draft fan, or a Venturi chimney as the pressure transformer. The intensity of mechanical draft is dependent for the most part upon the size of the fan and the speed at which it.is operated. The element of temperature does not enter into the creation of mechanical draft and therefore its intensity, unlike natural draft, is independent of the temperature of the gases and the atmosphere. Mechanical draft includes the induced and Venturi types of draft systems in which the pressure difference is the result of a suction, and also the forced draft system in which the pressure difference is.the result of a blowing. Mechanical draft systems tend to produce a vacuum or a. plenum, as the system used in-its production. creates a pressure difference below, or above, atmospheric - 180 Chapter 10. Chimneys and Draft Calculations Fig. 2. Operating Characteristics of Typical Centrifugal Pump - pressure, respectively'. A mechanical draft system may be used either in conjunction with, or as an adjunct to, a natural draft system. ; Draft Control '. ; To obtain the maximum efficiency'of combustion,, a definite minimum supply,of air to the combustion chamber must- be maintained.; To pro-; vide this condition, it is necessary to have some mechanical means, of- draft control or adjustment, because of variable wind velocities, fluctua^ tions in atmospheric temperatures and barometric pressures, and their effect upon draft. ' - -; , . For this purpose there are various mechanical devices which auto matically control the volume of air admitted to the.combustion chamber. Mechanical draft regulators designed to. control or adjust draft, should Fig. 3. Typical Set of Operating Characteristics of a Natural Draft Chimney 181 Heating Ventilating Air Conditioning Guide 1938 not be confused with mechanical draft systems that create draft mechani cally, but which must also be automatically controlled. The use of such a device to provide a more uniform and dependable control of draft than could be maintained by manually operated dampers, will produce better combustion of fuel. This higher efficiency of combus tion together with the reduced heat losses up die chimney by reason of decreased gas velocity, results in fuel economy, with consequent lower costs of plant operation. CHARACTERISTICS OF CHIMNEYS In order to analyze the performance of a natural draft chimney, it may be advantageous to compare its general operating characteristics with those of a centrifugal pump and also of a centrifugally-induced draft fan, there being a similarity among the three. Figs. 1, 2 and 3 show the general operating characteristics of a typical centrifugally-induced draft fan, a typical centrifugal pump, and a typical natural draft chimney,. respectively. The draft-capacity curve of . the chimney corresponds to the head-capacity curve of the pump and also to the dynamic-head capacity curve of the fan. . When the gases in the chimney are stationary, the draft created is termed the theoretical draft. When the gases are flowing, the theoretical intensity is diminished by the draft loss due to friction, the difference between the two being termed the total available draft. The general equation for this net total available draft intensity of a natural draft chimney with a circular section is as follows: where Z)a = 2MHBa (Wo \To _ TQ) 0.00126W'TcfL DlB0Wo (1) Da = available draft, inches of water. H = height of chimney above grate bars, feet. B0 = barometric pressure corresponding to altitude, inches of mercury. W0 = unit weight of a cubic foot of air at 0 F and sea level atmospheric pressure, ; pounds per cubic foot. Wo -- unit weight of a cubic foot of chimney gases at 0 F and sea level atmospheric ! pressure, pounds per cubic foot. Do =`absolute temperature of atmosphere, degrees Fahrenheit. To -- absolute temperature of chimney gases, degrees Fahrenheit. W = amount of gases generated in the combustion chamber of the boiler and passing through the chimney, pounds per second. ; / = coefficient of friction. .' L = length of friction duct of the chimney, feet. D = minimum diameter of chimney, feet. The first term of the right haftd expression of Equation 1 represents the theoretical draft intensity, and the second term, the loss due to friction. Example 1. Determine the available draft of a natural draft chimney 200 ft in height and 10 ft in diameter operating under the following conditions: atmospheric tempera ture, 62 F; chimney gas temperature, 500 F; sea level atmospheric pressure, B0 = 29.92 in. of mercury; atmospheric, and chimney gas density, 0.0863 and 0.09, respectively; coefficient of friction, 0.016; length of friction duct, 200 ft. The chimney discharges 100 lb of gases per second. Chapter 10. Chimneys and Draft Calculations Substituting these values in Equation 1 and.reducing: Da = 2.96 X 200 X 29.92 X (^|p 0.09V 960/ 0.00126 X 100* X 960 X 0.016 X 200 10* X 29.92 X 0.09 = 1.27 - 0.14 = 1.13 in. Fig. 3 shows the variation in the available draft of a typical 200 ft by 10 ft chimney operating under the general conditions noted in Example 1. When the chimney is under static conditions and no gases are flowing, the available draft is equal to 1.27 in. of water, the theoretical intensity. As the amount of gases flowing increases, the available intensity decreases until it becomes zero at a gas flow of 297 lb per second, at which point the draft loss due to friction is equal to the theoretical intensity. The draftcapacity curve, corresponds to the head-capacity curve, of centrifugal . Fig. 4. Relation Between Barometric Pressure and Altitude pump characteristics and the dynamic-head-capacity curve of a fan. The point of maximum draft and zero capacity is called shut-off draft, or point of impending delivery, and corresponds to the point of shut-off head of a centrifugal pump. The point of zero draft and maximum capacity is called the wide open point and corresponds to the wide open point of a centrifugal pump. A set of operating characteristics may be developed for any size chimney operating under any set of conditions by substituting the proper values in Equation 1 and then plotting the results in the manner shown in Fig. 3. . In substituting the values for the various factors in Equation 1, care should be exercised that the selections be as near the actual conditions as is practically possible. The following notes will serve as a guide for these selections: _ 1. The barometric pressure varies inversely as the altitude of the plant above sea level. Fig. 4 gives the barometric pressure corresponding to various elevations as computed from the equation: . . 90 Q9 Ei = 62,737 logio --w-- . (2) where Ei = altitude of plant above sea level, feet. . 183 Heating Ventilating Air Conditioning Guide 1938 In general, the barometric pressure decreases approximately 0.1 in. of. mercury per. 100 ft increase, in elevation. . 2.The unit weight of a cubic foot of chimney gases at O F arid sea level barometric pressure is given by the equation: Wc = 0.131 CO, + 0.095 O, + 0.083 N, (3) In this equation COt, Oj and Nt represent the percentages of the parts by volume of the carbon dioxide, oxygen and nitrogen content, respectively, of the gas analysis. For ordinary operating conditions, the value of Wc may be assumed at 0.09. The density effect on the chimney gases due to superheated water vapor resulting from moisture and hydrogen in the fuel, or due to any air infiltrations in the chimney proper are here disregarded. Though water vapor content is not disclosed by Orsat analysis, its presence tends to reduce the actual weight per cubic foot of chimney gases. ' 3. The atmospheric temperature is the actual observed temperature of the outside air at the time the analysis of the operating chimney is made. The mean atmospheric' temperature in the temperate zone is approximately 62 F. 4. The chimney gas temperature does not vary appreciably from the gas temperature as it leaves the breeching.and enters the chimney. For average operating conditions, the chimney gas temperature will vary between 500 F and 650 F except in the case when economizers and recuperators are used, when the temperature will vary between 300 F and 450 F. If a chimney has been properly constructed, properly lined and has no air infiltration due to open joints, the temperature of the gases throughout the chimney will not differ appreciably from the foregoing figures. In most up-to-date heating plants, the temperature may be read from instruments or ascertained from a pyrometer. The analysis of this section is predicated on the assumption of constant gas temperature and no air infiltration throughout the height of the chimney. 5. The coefficient offriction between the chimney gases and a sooted surface has been taken by many workers in this field as a constant value of 0.016 for the conditions in volved. This value, of course, would be less for a new unlined steel stack than for a brick or brick-lined chimney, but in time the inside surface of all chimneys regardless of the materials of construction becomes covered with a layer of soot, and thus the coef ficient of friction has been taken the same for all types of chimneys and in general constant for all conditions of operation. For reasons of simplicity and convenience to the reader, this constant value of 0.016 has been employed in the development of the various special equations and charts shown in this chapter. However, much to be recommended as an alternate method is the practise of separ ately determining duct friction factors as a function of the flow conditions,- specifically, as a function of the Reynolds number and the relative,duct roughness. The Reynolds criterion is based on the physical properties of the gas, the duct dimensions, and the gas velocity. The gas velocity for a chimney is usually well above the critical velocity. It is likely that this procedure of using a separately determined variable friction factor for-chimney flow will give results that are to be preferred over those based on a set constant. " ' . .. The Reynolds number, a dimensionless ratio, may be stated as follows: ' athere DVp Cr P- (4) D -- chimney diameter, feet. V = velocity of hot gas, feet per second. p = mass density-of the chimney gas per cubic foot. .. pi = viscosity of-, the gas in pounds-second per square foot taken at the gas tem perature. . In another form: 1.27 W = 0.0396 W D\ig . D\l (5) 184 Chapter 10. Chimneys and Draft Calculations where IV = weight of gas passed per second. g = acceleration of gravity. .... . ... .. , ' The value of p for chimney gases is usually taken as that of air or nitrogen, and for the variation of p with temperature, the Sutherland equation may be employed as follows, giving in pounds-second per square foot: . - .. where r273 + n r tc "l1-5 = 1X0 LtTT^cJ Lwj .' Tc -- chimney gas temperature, degrees Centigrade, po = gas viscosity at 0 C. C = constant tor specific gas. Using International Critical Table values, for air po = 35.6 X 10-8; Q = 124; for nitrogen po = 34.5 X 10-8; and C -- 110. Fig. 5. Variation of Friction Factor / with Reynolds Number Values for the viscosity of air and of nitrogen (the principal component of chimney gases) for the differerit temperatures follow, in which the values given in pounds-second per square foot are to be multiplied by 10-8: . .. .. Temp. F Air Nitrogen 300 49.7 47.7 400 54.5 52.2 500 58.5 56.0 600 62.5 59.8 700 66.7 . 63.5 800 70.5 67.0 Example S. To determine the Reynolds number Cr for a flow of 118 lb gas per second up a 12 ft diameter chimney at a temperature of 500 F. The gas may be assumed to have the same viscosity as nitrogen at 500 F. Using Equation 5: W Cr = 0.0396 Dy. 0.0396 X 118 = 698,000 12 X 56.0 X 10-8 The variation of the friction factor / with the Reynolds number is shown in Fig. 5*. Three curves are shown: A, B, and C, where the choice of the friction factor curve depends on the relative surface roughness, and this'for usual chimney construction-may See also Flow of Fluids in Closed Circuits, by R. J. S. Pigott (Mechanical Bnginccrixe, August, 1933). 185 Heating Ventilating Air Conditioning Guide 1938 be selected by size since surface conditions in service are always undeterminant. For sizes up to 3 ft in diameter, Curve C may be used; from 3 to 6 ft. Curve B; and from 6 ft upwards, Curve A. Thus for the previous example with Cr = 698,000 and 12 ft diameter, / would be taken from Curve A as 0.0039. 6. The length of the friction duct is the vertical distance between the bottom of the breeching opening and the top of the chimney. Ordinarily this distance Is approximately equal to the height of the chimney above the grate level. ' Fig. 6. Chimney Performance Chart3 To solve a typical example: Proceed horizontally from a Weight Flow Rate point to intersection with diameter line; from this intersection follow vertically to chimney height line; from this intersection follow horizontally to the right to Available Draft scale. Starting from a point of Available Draft, take steps in reverse order. ,' - 7. Assuming no air infiltration the amount of gases flowing and being discharged is, of course, equal to the amount of gases generated in the combustion chamber of the boiler. The total products of combustion in pounds per second for a grate-fired boiler may be computed from the equation: _ CgGWtp 3600 (6) where Cg = pounds of fuel burned per square foot of grate surface per hour. G = total grate surface of boilers; square feet. Cg X G = total weight of fuel burned per hour. JPtp = total weight of products of combustion per pound of fuel. A similar computation may be made in the case of gas, oil, or stoker-fired fuel. 186 _ Chapter 10. Chimneys and Draft Calculations Fig. 6 is a typical chimney performance chart giving the available draft intensities for various amounts of. gases flowing and sizes of chimney. This chart is based on an atmospheric temperature of 62 F, a chimney gas temperature of 500 F, a unit chimney gas weight of 0.09 lb per cubic foot, sea level atmospheric pressure, a coefficient of friction of 0.016, and a friction duct length equal to the height of the chimney above the grate level. These curves may be used for general operating conditions. For specific operating conditions, a new chart should be constructed from Equation 1. It has been the usual custom, and still is to a lamentably great extent, to select the required size of a natural draft chimney from a table of chimney sizes based only on boiler horsepowers. After the ultimate horsepower of the projected plant had been determined, the chimney size in the table corresponding to this figure was then selected as the proper size required. Generally, no further attempt was made to determine if the height thus selected was sufficient to help create the required draft demanded by the entire installation, or the diameter sufficiently large to enable the chimney quickly, efficiently, and economically to dispose of the gases. Since the operating characteristics of a natural draft chimney are similar in all respects to those of a centrifugal pump, or a centrifugal fan, . it is no more possible to select a proper size chimney from such a table, even with correction factors appended, than it is to select the proper size pump from tables based only on the amount of water to be delivered. DETERMINING CHIMNEY SIZES The required diameter and height of a natural draft chimney are given by the following equations: H= Dr l&ifWcB0V' TCD (7) where VD = 0.288 WTC B0WC V (S) H = required height of chimney above grate bar level, feet. ' D = required minimum diameter of chimney, feet (constant for entire height). V = chimney gas velocity, feet per second. Dr -- total required draft demanded by the entire installation outside of the chimney, inches of water. Equations 7 and 8 give the required size of a natural draft chimney with all of the operating factors taken into consideration. Values for all of the factors with the exception of the chimney gas velocity may be either observed or computed. It is, of course, necessary to assume an arbitrary value for the velocity in order to arrive at some definite size. For any one set of operating conditions there will be as many sizes of chimneys as there are values of reasonable velocities to assume. Of the number of sizes corresponding to the various assumed velocities, there is one size which will be least expensive. Since the cost of a chimney structure, regardless . 187 X Y Heating Ventilating Air Conditioning Guide 1938 of the kind of material used in the construction, varies as the volume of material in the structure, -the cost criterion then may be represented by the approximate equation: .. ' - . Q = TciHD ' (9) where - Q = volume of material, cubic feet. t = average wall thickness, feet. . ' . . ' ' For all practical purposes, the value of irf-may be taken as a constant regardless of the size of the structure. Hence, in general, the volume, and consequently the cost, of a chimney structure may be based on the factor HD as a criterion. Therefore, the value of the chimney gas velocity which will result in the least value of HD for any one set of operating con ditions will produce a structure which will be the most economical to use, because its cost will be least. . The problem at. hand is to. deduce an equation for the chimney gas velocity which will result in a combination of a height and a diameter whose product HD'will'be least.. The solution is obtained by equating, the product of Equations 7 and 8 to HD, differentiating this product with respect to V and equating , the resulting expression to zero. This; pro-' cedure results in the following expression: , . where = economical chimney gas velocity, feet per second. ,1 Equation 10 gives the economical velocity of the chimney gases for' any set of operating conditions, and represents the velocity which will result in a chimney the size of which will, cost less than that of any other size as determined by any other velocity for the same operating con ditions. After the value of the economical velocity has been determined, the corresponding height arid, diameter can then be determined from Equations 7 and 8, respectively, and the economical size will then be attained. Equations 7, 8 and 10 may be simplified considerablys for average operating conditions in ari average size steaih plant by assuming typical conditibrisi.; "' " w . ; -Average; chimney gas temperature, 500 F......................... -Tc = 960 .... Mean atmospheric temperature, 62 F........ ..................... ,:...T0 = 522 Average coefficient of friction, 0.016...... .................................../ = 0.016 . Average chimney, gas' density, 0.09.:_______ ........ ......... ...... Wc = 0.09 . ! Sea level elevation, with: barometer of 29.92.________:-------B0 = 29.92 : \ . Substituting these values in Equations 10, 8 and. 7, respectively;, and reducing, the results are substantially: , .. ye = 13.71F1/5 ' ' "' : ' (n) : ' ' ., d = \:wV6 . . (lax - . : H = 190Dr ' . .! ; (13)' 188 . Chapter 10. Chimneys and Draft Calcuijvtions Fig. 7 gives the economical chimney sizes for various amounts of gases flowing and for required draft intensities as computed from Equations 11, 12 and 131 They are based on the operating factors' used in reducing Equations 7, 8 and 10 to their simpler form. The sizes shown by the curves in the chart should be used for general operating conditions only, or for installations where the required data necessary for an exact deter- Height of Chimney, ft . Fig. 7., Economical Chimney Sizes ^Diameter values also for gas temperatures of 400, 500 and 600 F > iriination are'difficult or impossible to secure. Whenever'it is pbssible to secure accurate data, or' the anticipated operating conditions are fairly well known,-the required size should be deteriniried from Equations 7, 8-and-10. The recommended minimum inside dimensions and heights of chimneys for small and medium size installations are given-in Table 1. ' GENERAL EQUATION ;* The'general draft equation for a steam prodiicirig plant may be; stated as follows: '.' . '. . Dt -- if = Af + hi If hid + he + hBr + hv + ho + hs + Ar . ..:.(14) 189 Heating Ventilating Air Conditioning Guide 1938 where Dt = theoretical draft intensity created by pressure transformer, inches of water. hf = draft loss due to friction in pressure transformer, inches of water. hF -- draft loss through the fuel bed, inches of water. fiB = draft loss through the boiler and setting, inches of water. hBr = draft loss through the breeching, inches of water. hv -- draft loss due to velocity, inches of water. ftBd = draft loss due to bends, inches of water. he = draft loss due to contraction of opening, inches of water. ho = draft loss due to enlargement of opening, inches of water. Ae draft loss through the economizer, inches of water. . Ar draft loss through recuperators, regenerators, or air heaters, inches of water. The left hand member of Equation 14 represents the total amount of available draft created by the pressure transformer, that is, the natural draft chimney, Venturi chimney, or fan, and is equal to the theoretical intensity less the internal losses incidental to operation. The right hand member represents the sum of all of the various losses of draft throughout the entire boiler plant installation outside of the pressure transformer itself. The left hand member expresses the available intensity and is analogous to the head developed by a centrifugal pump in a water works system, while the right hand member expresses the required draft in tensity and is analogous to the total dynamic head in a water works system. For a general circulation of gases Da = Dr where Da = available draft intensity, inches of water. Dt 83 required draft, inches of water. (15) The draft loss through thefuel bed (hp), or the amount of draft required to effect a given or required rate of combustion, varies between wide limits and represents the greater portion of the required draft. In coal-fired installations, the draft loss through the fuel bed is dependent upon the following factors: (1) character and condition of the fuel, clean or dirty; (2) percentage of ash in the fuel; (3) volume of interstices in the fuel bed, coarseness of fuel; (4) thickness of the fuel bed, rate of combustion; (5) type of grate or stoker used; (6) efficiency of combustion. There is a certain intensity of draft with which the best results will be! obtained for every kind of coal and rate of combustion. Fig. 8 gives the intensity of draft, or the vacuum in the combustion chamber required to burn various kinds of coal at various rates of combustion. Expressed in other words, these curves represent the amount of draft required to force the necessary amount of air through the fuel bed in order to effect various rates of combustion. It will be noted that the amount of draft increases as the percentage of volatile matter diminishes, being comparatively low for the lower grades of bituminous coals and highest for the high grades and small sizes of anthracites. Also, when the interstices of the coal are large and the particles are not well broken up, as with bituminous coals, much less draft is required than, when the particles are small and are well 190 Chapter 10. Chimneys and Draft Calculations broken up, as with bituminous slack and the small sizes of anthracites. In general, the draft loss through the fuel bed increases as: (1) the per centage of volatile matter diminishes; (2) the percentage of fixed carbon increases; (3) the thickness of the bed increases; (4) the percentage of ash increases; (5) the volume of the interstices diminishes. ' In making the. preliminary assumptions for the draft loss through the fuel bed, due allowances should be made for a possible future change in the grade of fuel to be burned and also in the rate of combustion. A value . Table 1. Recommended Minimum Chimney Sizes for . Heating Boilers and Furnaces .. Warm Am Furnace Capacity in Sq In. op Leader Pipe SfKAH Boiler Capacitt Sq Ft op Radi ation 790 1000 590 690 900 900 1,100 1,700 1,940 2,130 2,480 3,150 4,300 4,600 5,000 5,570 5,580 6,980 7,270 8,700 9,380 10,150 10,470 Hot Water Heater Capacitt Sq Ft or Radi ation 973 1,140 1,490 1,490. 1,820 2,800 3,200 3,520 4,090 5,200 7,100 7,590 8,250 9,190 9,200 11,500 12,000 14,400 15,500 16,750 17,250 Nokinal Dimen sions or Fire Clat Z/QflNG in Inches Rectangular Flub Actual Inside Dimensions of FireClay lining in Inches Actual Area 8q In. 8^x13 7 xll^ 81 13x13 llMxllM 127 8^x18 6Mxl6M no 13x18 UKxl6K 183 18x18 15Jxl5J4 248 20x20 17Mxl7ji 298 20x24 24x24 17x21 21x21 24 x 24b 357 441 576 24 x 28b 672 28 x 28b 784 30 x 30b 900 28 x 32b . 896 Round Flub Inside Diam eter of tolining Indies Actual Area Sq In. 10 79 12 113 15 177 18 254 20 314 22 380 24 452 27 573 Height in Ft Abotb Grate 35 40 45 50 55 60 65 `This table is taken from the A.S.H.V.E. Code of Minimum Requirements for the Heating and Venti- iauon of Buildings (Edition of 1929). - ^Dimensions are for unlined rectangular flues. should be selected for this loss which will represent not only the highest rate of combustion which will be encountered, but also the grade of coal which has the greatest resistance through the fuel bed and which may be burned at a later date. In powdered-fuel and oil-fired installations, there will be no draft loss through the fuel bed since there is none and, consequently, this factor becomes zero in the general draft equation. All other factors being constant, the height of the chimney in installations of this character will be less than the height in coal-fired installations, and in the rasp of me chanical draft installations the driving units need not be as large since the head against which the fan is to operate is not as great in the former as in the latter. 191 Heating Ventilating Air Conditioning Guide 1938. The draft loss through the boiler and setting (ha) also varies between wide limits and, in general, depends upon the following factors: 1. Type of boiler. 5. Arrangement of baffles. . 2. Size of boiler. 6. Type of grate.. 3. Rate of operation. . 7. Design of brickwork setting. 4. Arrangement of tubes. 8. Excess air admitted. 9. Location of entrance into breeching. .. . Curves showing the draft loss through the boiler are usually based on the load or quantity of gases passing through the boiler, expressed in terms of percentage of normal rate of operation. Owing to the great variety of boilers of different designs and the various schemes of baffling, it is impossible to group together a set of curves for the draft loss through POUNDS OF COAL BURNED PER SQ FT OF GRATE SURFACE PER HOUR Fig. 8. Draft Required at Different Rates of Combustion for Various Kinds of Coal the boiler which may even be used generally. It is therefore necessary to secure this information from the manufacturer of the particular type of. boiler and baffle arrangement under consideration. . . .. When a boiler is installed and in operation, the draft loss depends upon the amount of gases flowing through it. This, in turn, depends upon the proportion of excess air admitted for combustion. Primarily, the amount of excess air is measured by the COt content; the less the amount oi COi, the greater the amount of excess air and hence the greater the draft loss. The loss of draft through the boiler will vary directly as the size of the boiler, and' the length of the gas passages within. The loss also varies as the number of tubes high, but not in a direct ratio inasmuch as the loss due to' the reversal of flow at the ends of the baffles remains constant regardless of the height-of the boiler. The arrangement of .the tubes, whether the gases flow parallel to or at right angles to' the tubes, has an appreciable effect on the loss. The arrangement of the baffles, influences the draft loss greatly, the loss through a boiler with five passes being 192 ' Chapter 10. Chimneys and Draft Calculations greater than the loss through one of three or four passes. A poor design and a- rough condition of the brickwork will increase the loss greatly, whereas a proper design and a smooth condition will keep the loss at a minimum. . The loss through the boiler will be less when the breeching entrance is located at or near the top of the boiler than when it is located at or near the bottom since the gases , have a shorter distance to travel in the former instance. . The draft loss through the breeching (tar) is given by the general equation: :. '. .- where 0.000194W>TcfL A*B0WcCbr ' (16) W = the amount of gases flowing, pounds, per second. Tc = absolute temperature of breeching gases, degrees Fahrenheit. . ' / = coefficient of friction. . .. .. L = length of breeching,, feet. . A = area of breeching, square feet. B0 = atmospheric pressure corresponding to altitude, inches of mercury. . Wc = weight of a cubic foot of breeching gases at 0 F and sea level atmospheric pressure, pounds per cubic foot. Cbr = hydraulic radius of breeching section. '' It has been the general custom to lump off the intensity of the breeching loss at 0.10 in: of water per 100 ft of breeching length regardless of its size or shape or the amount and temperature of the gases flowing through it. This practice is hazardous and has no more foundation in fact than that of determining the friction head in a water works system without taking into consideration the size of the pipe or the amount of water, flowing through it. When the length of the breeching is relatively short, any variation in any one of the factors in the equation will have no appreciable effect on the draft loss. However, when the breeching is relatively long, the draft loss is affected greatly by the various factors, particularly by the size and shape as well as by the weight of gases flowing. . The draft loss due to velocity (hy) is given by the equation 0.000194WTc Av = A`B0WC (17) and represents the amount of draft required to accelerate the gases from zero velocity to the velocity at which the gases are flowing, or- in other words, from a static gas condition of zero flow to the amount of gases flowing throughout the installation. This loss corresponds to the velocity head in water works systems.. .. The draft loss due to bends (Am) is equivalent to the loss due to the velocity head for a 90-deg bend. In changing direction of -flow, the gas velocity decreases to zero with a loss of velocity head and then increases to its proper value at the expense of a loss in pressure head, the net result being a loss in pressure head equal to the. velocity head at . the bend. This loss is given by the equation: ; 0.000194W'Tc Am.= A*B0Wc (18) 193 Heating Ventilating Air Conditioning Guide 1938 The friction at a right-angle bend is sometimes expressed as the equivalent of a straight length of flue of a certain length for a certain diameter, similar to the procedure used in estimating the loss due to bends in piping systems conducting water. Most flues, however, par ticularly breechings, are built square or rectangular in section and no general equation based on the shape of the flue can be conveniently expressed. The draft loss due to sudden contraction of an area (he) is given by the equation: ' .. 0.000194gc^rc hc = a\bqwc (19) where Kc -- coefficient of sudden contraction based on TM, the ratio of the areas of the smaller to the larger section = 0.5 ^ 1 -- ^ A. = area of the smaller section. When the flue or passage through which the gases flow is suddenly contracted, a considerable portion of the static head in the larger section is converted into velocity head and a draft loss of some consequence, par ticularly in a short breeching, takes place. A sudden contraction should always be avoided where possible. At times, however, due to obstruc tions or limited head-room, it is necessary to alter the size of the breeching, but a sudden contraction may be avoided by gradually decreasing the area over a length of several feet. The draft loss due to a sudden enlargement of an area (ho) is given by the equation: 0.000194goTFrc ho = a\bqwc (20) where . As Ka = coefficient of sudden enlargement based on A, the ratio of the areas of the smaller to the larger section When the flue or passage through whicji the gases flow is suddenly enlarged, a portion of the velocity head is converted into static head in the larger section and, like the loss due to sudden contraction, a loss of some consequence, particularly in short breechings, takes place. A sudden enlargement in a breeching may be avoided by gradually increasing the area over a length of several feet. In large masonry chimneys, the area of the flue at the region of the breeching entrance is considerably larger than the area of the breeching at the chimney, and a sudden enlargement exists. . . ,i- . The draft loss through the economizer (h&) should be obtained from the manufacturer but for general purposes it may be computed from the following general equation: . ' 6.6W'nNTc He 10a (21) 194 Chapter 10. Chimneys and Draft Calculations where .. Wa -- pounds of gases flowing per hour per linear foot of pipe in each economizer section. N = number of economizer sections. An economizer in a steam plant affects the draft in two ways, (1) it offers a resistance to the flow of gases, and (2) it lowers the average chimney gas temperature, thereby decreasing the available intensity. In the case of a natural draft installation, both of these factors result in a relative increase in the height of the chimney and, in the case of a large plant, they may add as much as 20 or 30 ft to the height. The decrease in the temperature of the gases after they have passed through the economizer has an extremely important effect on the performance of a natural draft chimney and also upon the performance of a fan. CONSTRUCTION DETAILS For general data on the construction of chimneys reference should be made to the Standard Ordinance, for Chimney Construction of the National Board of Fire Underwriters. Briefly summarized, these provisions are as follows for heating boilers and furnaces: The construction, location, height and area of the chimney to which a heating boiler or warm-air furnace is connected affect the operation of the entire heating system. Most residence chimneys are built of brick and may be either lined or unlined, but in either case the walls must be air-tight and there should be only one smoke opening into the chimney. Cleanout, if provided, must be absolutely air-tight when closed. . The walls of brick chimneys shall be not less than 3% in. thick (width of a standard size brick) and shall be lined with fire-clay flue lining, f ire-clay flue linings shall be manufactured from suitable refractory clay, either natural or compounded, and shall be adapted to withstand high temperatures and the action of flue gases. They shall be of standard commercial thickness, but not less than % in. All fire-clay flue linings shall meet the standard specification of the Eastern Clay Products Association. The flue sections shall be set in special mortar, and shall have the joints struck smooth on the inside. The masonry shall be built around each section of lining as it is placed, and all spaces between masonry and linings shall be completely filled with mortar. No broken flue lining shall be used. Flue lining shall start at least 4 in. below the bottom of smokepipe, intakes of flues, and shall be continued the entire heights of the flues and project at least 4 in. above the chimney top to allow for a 2 in. projection of lining. The wash or splay shall be formed of a rich cement mortar. To improve the draft the wash surface should be concave wherever practical. Flue lining may be omitted in brick chimneys, provided the walls of the chimneys are not less than 8 in. thick, and that the inner course shall be a refractory clay brick. All brickwork shall be laid in spread mortar, with all joints push-filled. Exposed joints both inside and outside shall be struck smooth. No plaster lining shall be permitted: Chimneys shall extend at least 3 ft above flat roofs and 2 ft above the ridges of peak roofs when such flat roofs or peaks are within 30 ft of the chimney. The chimney shall be high enough so that the wind from any direction shall not strike the top of the chimney from an angle above the horizontal. The chimney shall be properly capped with stone, terra cotta, concrete, cast-iron, or other approved material; but no such cap or coping shall decrease the flue area. ' _ There shall be but one connection to the flue to which the boiler or furnace smokepipe is attached. The boiler or furnace smoke-pipe shall be thoroughly grouted into the chimney and shall not project beyond the inner surface of the flue lining. . The size or area of flue lining or of brick flue for warm-air furnaces depends on height of chimney and capacity of heating system. For chimneys not less than 35 ft in height above grate line, the net internal dimensions of lining should be at least 7 x 1in. 195 1 1 ij Heating Ventilating Air Conditioning Guide 1938 for a total leader pipe area up to 790 sq in. Above 790 and up to 1,000 sq in. of leader pipe area the lining should.be at least 11M x 11M in. inside. In case of brick flues not less than 35 ft in height with no linings, the internal dimensions should be at least 8 x 12 in. up to 790 sq in. of leader area, and at least 12 x 12 in. for leader capacities up to . 1,000 sq in. Chimneys under 35 ft in height are unsatisfactory in operation and hence should be avoided. . CHIMNEYS FOR GAS HEATING ; The burning of gas differs from the burning of coal in that the force which supplies the air for combustion of the. gas comes largely from the pressure of the gas in the supply pipe, whereas air is supplied to a bed of burning coal by the force of the chimney draft. If, with a coal-burning boiler, the draft is poor, or if the chimney is stopped, the fire is smothered and the combustion rate reduced. In a gas boiler or furnace such a condition would interfere with the combustion of the gas, but the gas would continue to pass to the burners and the resulting incomplete com bustion would produce a dangerous condition. In order to prevent incom plete combustion from insufficient draft, all gas-fired boilers and furnaces should have a back-draft diverter in the flue connection to the chimney. Table 2. Suggested General Dimensions for Vertical Back-Draft Diverter Chapter 10. Chimneys and. Draft Calculations A study :of a typical back-draft diverter shows that partial or complete chimney stoppage will merely cause some of the products of combustion to be vented out into the boiler, room, but, will not-interfere with, com bustion. In fact, gas-designed appliances must perform safely under such a,condition to be approved by the American Gas Association Laboratory. Other functions of the back-draft diverter are to protect the burner and pilot from the effects of down-drafts, and to neutralize the effects of variable chimney drafts, thus maintaining the appliance efficiency at a substantially constant value.. Converted boilers or furnaces', as well as gas-designed appliances, should be provided with back-draft diverters. Since back-draft diverters have a special function to perform in pro tecting gas burning appliances, it is necessary that they should be built to the proper size as shown in Table 2 for a vertical type and in Table 3 for a horizontal arrangement. Equipment of this kind listed by the American-Gas Association Testing Laboratory must bear the listing symbol A.G.A. . ... . `v. . ' ' .r ... Table 3. Suggested General Dimensions for Horizontal Back-Draft. Diverter - Ptpe . Size A. B c D E F G H I J ELM 3 4 - 5, 6 ,7 8 9 10 11 ; 12 3 4 5 6 7. 8 9 10 11 .12: 3 5.5 4 7.2 5 9.4 6 11.5 -7.. 13.5 8 -15.5 9 17.5 10 19.7 11 22.2 12 24.7 7.0 3.8 0:7 9.5 5.0 1.0 10.8 5.3 1.5 12.0 5.6 1.9 13.9 '.6.4 2.3 15.8 ' 7.1 2.7 17.5 7.7 3.1 18.8 7.9 3.6 20.7 8.4 ' 4.3 22.2. 8.7 5.0 4.4 3.0 6.0 4.0 8.0 5.0 9.8 6.0 11.6 7.0 13.4 ' 8.0 15.2 9.0 17.2 10:0 19:6,- 11.0 22:0 12.0 1.5 2.0 2.3 2.5 2.9 3.2. 3:5 3.8 4.1 4.4 2.5 3.5 4.0 4.5 5.3 6.0 6.7. 7.3 8.0 8.5 0.7 1.0 0.9 0.8 0.9 1.0 1.0 1.0 .1.5 1.7 1.5 2:3 2.0 3.0 2.4 3.52.7 4.0 3.1 4.6 3.5 5:3-.. 4.0 5.8 4.3 6.2 4:6 6.6 5.0 7.0 ' Pipe Size A- B c D 'E F g' . H I. J K L 'M ' 3 .4 5 6 7 8 9 10 . 11 12 3 3 6 1.5 4 4 8 2.0 5' 5 10 2.5 6 6 12 3.0 7 7 14 3.5 8 8 16 4.0 9 9 18 4.5 10 10 20 5.0 11 11 .22- 5.5 12 12 24 6.0 4^8 4.8 4.8 4.8 4.8 4.8 4.8 4.8 4.8. 4.8 3.8 5.0 6.3' 7.5 8,8 10.0 11.3 12.5 13.8 15.0 1.4 1.9 2.4 .2.9 3.4 3.9 4.4 4.9 5.4 5.9 2.5 3.4 4.2 5.0 5.9 6.7 7.5 8.4 9.2 10.0 2.5 3.4 4.2 5.0 5.9 6.7 '7.5, 8.4 9.2 10.0 2.5 3.4 4.2 5.0 5.9 6.7 7.5' 8.4 9.2 10.0 2.1 2.9 3.5 4.3 5.0 5.6 6.4 7.0 7.8. 8.5 0.6 0.8 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 1.8 2.3 2.9 3.54.1 4.7 : 5.3 5.8 6.4 7:0 197 Heating Ventilating Air Conditioning Guide 1938 As is the case with the complete combustion of almost all fuels, the products of combustion for gas are carbon dioxide (CO,) and water vapor with just a trace of sulphur trioxide (SO,). Sulphur usually burns to the trioxide in the presence of an iron oxide catalyst. The volume of water vapor in the flue products is about twice the volume of the carbon dioxide when coke oven or natural gas is burned. Because of the large quantity of water vapor which is formed by the burning of gas, it is quite important that all gas-fired central heating plants be connected to a chimney having a good draft. Lack of chimney draft causes stagnation of the products of combustion in the chimney and results in the condensation of a large amount of the water vapor. A good chimney draft draws air into the chimney through the openings in the back-draft diverter, lowers the dew point of the mixture, and reduces the tendency of the water vapor to condense. . The flue connections from a gas-fired boiler or furnace to the chimney should be of a non-corrosive material. In localities where the price of Table 4. Minimum Round Chimney Diameters for Gas Appliances (Inches) Height ot Chxmmbt Feet 100 200 Gab Consumption in Thousands op Btu fkb Hour 300 400 500 750 1000 1500 2000 20 4.50 5.70 6.60 7.30 8.00 9.40 10.50 12.35 13.85 40 4.25 5.50 6.40 7.10 7.80 9.15 10.25 12.10 13.55 60 4.10 5.35 6.20 6.90 7.60 8.90 10.00 11.85 13.25 80 4.00 5.20 6.00 6.70 7.35 8.65 9.75 11.50 12.85 100 3.90 5.00 5.90 6.50 7.20 8.40 9.40 11.00 12.40 gas requires the use of highly efficient appliances, the material used for the flue connection not only should be resistant to the corrosion of water, but should resist the corrosion of dilute solutions of sulphur trioxide in water. Local practice should be followed in the selection of the most appropriate flue materials. . When condensation in a chimney proves troublesome, it may be necessary to provide a drain to a dry well or sewer. The cause of the excessive condensation should be investigated and remedied if possible. This may be done by raising the flue temperature slightly or increasing the size of the back-draft diverter. The protection of unlined chimneys has been investigated and the results indicate that after the loose material has been removed, the spraying with a water emulsion of asphalt- chromate provides an excellent, protection. A chimney for a gas-fired boiler or furnace should be constructed in accordance with the principles applicable to other boilers. Where the wall forming a smoke flue is made up of less than an 8-in. thickness of brick, concrete, or stone, a burnt fire-clay flue tile lining should be used. Care should be used that the lengths of flue tile meet properly with no openings at the joints. Cement mortar should be used for the entire chimney. ' Table 4 gives the minimum cross-sectional diameters of round chim- . 198 - Chapter 10. Chimneys and Draft Calculations neys (in inches) for various amounts of heat supplied to the appliance, and for various chimney heights. This is in accordance with American Gas Association recommendations. PROBLEMS IN PRACTICE 1 0 What are the principle factors influencing the intensity of natural draft? The intensity of natural draft depends largely upon the height of chimney above the grate bar level and the temperature difference between the chimney gases and the atmosphere. . 2 t What two kinds of draft need be considered? Natural draft caused by temperature differences, and artificial draft caused by me chanical forcing. . 3 What is the effective height of a chimney? The height from the grate level to the top of the chimney is the effective height in pro ducing natural draft. . 4 What dual purpose does a tall chimney fulfill? A tall chimney primarily creates the necessary draft to move the air required for the combustion process and to move the products of combustion, and secondarily it dis charges the gases at a high elevation to prevent them from becoming a nuisance. 5 What is the direct influence of the height on the design of a chimney? The immediate purpose of height is to provide that draft intensity under the conditions of chimney gas temperature such that it will be adequate to overcome all the frictional resistances of the installation, as well as to provide for the actual gas movement. 6 # Of what importance is chimney cross-sectional area in stack design? The area should be as large as is economically feasible in order that the frictional loss for the chimney height should not destroy the effectiveness of the height-created draft in overcoming the necessary frictional resistances of the boiler and its flue connections. 7 Of what importance is the Reynolds number in chimney* design? It permits the selection of a more specific value of the chimney friction factor, rather than a general one, to correspond with conditions of size, nature of the gas, rate of gas flow, and condition of the surface. 8 9 a. Name the principle advantages of natural draft. - b. Name the principle disadvantages of natural draft. ' a. Simplicity, reliability, freedom from mechanical parts, low cost of maintenance, relatively long life, relatively low depreciation, operation with no power requirement. b. Lack of flexibility, irregularity, dependence on surroundings, susceptibility to tem perature changes. 9 0 How is mechanical draft created? By forced draft, by induced-draft fans, or by a Venturi chimney. I Distinguish between theoretical and available draft. Theoretical draft is the difference in pressure inside and outside the base of a chimney when jt is under operating temperatures but when there are no gases flowing. Available draft is less than theoretical draft by the friction loss due to the flow of gases through the chimney. 199 r Heating Ventilating Air Conditioning Guide 1938 11 Explain the term efficiency of a natural draft chimney. ... The efficiency of a chimney is the ratio of thie work it does in moving gases to the theo retical amount of power it generates. . r. 12 How is the available draft used in a heating plant? The available draft at the base of the chimney is used to overcome the loss in pressure through the grate, the fuel bed, the boiler passes, the breeching. 13 9 What are some of the factors that influence the draft loss through the fuel bed? Uniformity and size of coal, the amount of ash mixed,with the fuel on the grate, thickness of fuel bed, rate of combustion, amount of air supply as related to the coal burning rate. 14 How does the volatile matter content affect the draft loss through the fuel bed? i: ; The higher the volatile content and the lower the fixed carbon content, the lower the draft loss. .. 15 # In what cases will there be no fuel bed draft loss? ... . In oil, gas, and powdered fuel firing the fuel is mixed and burned in suspension; con sequently, no measurable resistance is encountered in the combustion zone. 16 # Is it possible to state an average value for the draft loss, through a boiler and its setting? 1/ ` No. The draft loss varies.widely and depends on many factors such as the size and type of gas passageways. The manufacturer is usually able to supply such information. 17 Of what significance is the CO* content of stack gases in establishing draft loss? . .: ' The COj content of the exit gases is a measure of the completeness of the combustion arid the amount of excess air supplied. Low CO* indicates a high excess of air and hence a high draft loss. .. . 18 f What two.effects, does an' economizer have on the draft loss? An economizer offers resistance to the flow of gases over the added surfaces; it lowers the temperature of the gases going to the chimney and therefore decreases the available draft. This decrease often necessitates the addition of forced draft. .. 19 9 What main provisions should be considered in good chimney construction? Chimneys should be air-tight and connected to only one smoke opening. The chimney top should be high enough above surroundings so the wind will not strike it at any angle above the horizontal. Chimney walls should be not less than one brick in width, and they should be lined with fire-clay tile of the.size required for the attached heating unit. Tile lining sizes are stated as outside dimensions; therefore, their effective dimensions are less by the thickness of the wall. . 20 # What is the purpose of a back draft diverter as used on gas burning units? Since the fuel is supplied under pressure independent of draft it is necessary to free the unit from the variable chimney draft and to supply air for combustion in direct propor tion to the supply of fuel gas. The back draft diverter protects the pilot and burners from down drafts. - i .20Q "^ *1 Chapter 11 AUTOMATIC FUEL BURNING EQUIPMENT Classification of Stokers, Combustion Process and Adjustments, Furnace Design, Classification of Oil Burners, Combustion Chamber Design, Classification of Gas-Fired Appliances AUTOMATIC mechanical equipment for the combustion ofsolid, liquid and gaseous fuels is considered in this chapter. MECHANICAL STOKERS A mechanical stoker is a device that feeds a solid fuel into a combustion chamber, provides a supply of air for burning the fuel under automatic control and, in some cases, incorporates a means of removing the ash and refuse of combustion automatically. Coal can be burned more efficiently by a mechanical stoker than by hand firing because the stoker provides a ' uniform rate of fuel feed, better distribution in the fuel bed and positive control of the air supplied for combustion. Stokers may be divided into four types according to their construction, namely, (1) overfeed flat grate, (2) overfeed inclined grate, (3) underfeed side cleaning type, and (4) underfeed rear cleaning type. , Overfeed Flat Grate Stokers This type is represented by the various chain- or traveling-grate stokers. These stokers receive fuel at the front of the grate in a layer of uniform_______ I thickness and move it back horizontally to the rear of the furnace. Air is supplied under the moving grate to carry on combustion at a sufficient rate to complete the burning of the coal near the rear of the furnace. The ash is carried over the back end of the stoker into an ashpit beneath. This type of stoker is suitable for small sizes of anthracite or coke breeze and also for bituminous coals, the characteristics of which make it desirable to burn the fuel without disturbing it. This type of stoker requires an arch over the front of the stoker to maintain ignition of the incoming fuel. Frequently, a rear combustion arch is required to maintain ignition until the fuel is fully consumed. A typical traveling-grate stoker is illustrated in Fig. 1. . Another and distinct type of overfeed flat-grate stoker is. the spreader (Fig. 2) or sprinkler type in which coal is distributed either mechanically or by air over the entire grate surface. This type of stoker has a wide application on small sized fuels and on certain special fuels such as lignites, high-ash coals, and coke breeze. 201 . / f j ! [ i j j = ; ? l i ; ;j | j j [ j i i i I j j I ! | \ Heating Ventilating Air Conditioning Guide 1938 Overfeed Inclined Grate Stokers In general the combustion principle is similar to the flat grate stoker, but this stoker (Fig. 3) is provided with rocking grates set on an incline to advance the fuel during combustion. Also this type is provided with an ash plate where ash is accumulated and from which it is dumped periodi cally. This type of stoker is suitable for all types of coking fuels but . preferably for those of low volatile content. Its grate action has the tendency to keep the fuel bed well broken up thereby allowing for free ^Chapter 11. Automatic Fuel Burning Equipment : the volatile gases are released, are mixed with air, and pass through the fire where they are burned. The ash may be continuously discharged as in the small stoker or may be accumulated on a dump plate and periodi cally discharged. This stoker requires no arch as it automatically pro vides for the combustion of the volatile gases. passage of air. Because of its agitating effect on the fuel it is not so desirable for badly clinkering coals. Furthermore, it should usually be provided with a front arch to care for the volatile gases. Underfeed Side Cleaning Stokers In this type (Fig. 4), the fuel is introduced at the front of the furnace to one or more retorts, is advanced away from the retort as combustion progresses, while finally the ash is disposed of at the sides.- This type of stoker is suitable for all coking coals while in the smaller sizes it is suitable for small sizes of anthracites. In this type of stoker the fuel is delivered to a retort beneath the fire and is raised into the fire. During this process 202 Fig. 4. Underfeed Plunger Type Stoker Underfeed Rear Cleaning Stokers - This type of stoker accomplishes combustion in much the same manner as the side cleaning type, but consists of several retorts placed side by side and filling up the furnace width, while the ash disposal is at the rear. In principle, its operation is the same as the side cleaning underfeed. 203 X Heating VentiIiAting Air Conditioning Guide 1938 Stokers also may be. classified according to their size based upon coal feed rates. The following classification has been made by the United Siates Department of Commerce in cooperation with the Stoker Manu facturers' Association. Class 1. Up to and including 60 lb of coal per hour. Class 2. 60 to 100 lb of coal per hour. Class 3. 100 to 300 lb of coal per hour. Class 4. 300 to 1200 lb of coal per hour. (A fifth class is included covering stokers having a feeding capacity above 1200 lb of coal per hour). Class 1 and Class 2 Stokers, Household ' Since these stokers are used primarily for home heating, it is desirable that their design be simple and attractive in appearance, and that they be quiet and automatic in operation. A common type of stoker in this class consists, essentially of a coal reservoir or hopper, a screw for conveying the fuel from the hopper to the burner head or retort, a fan which supplies the air for combustion, a Chapter 11. - Automatic Fuel Burning Equipment ment of Commerce has issued commercial standards for household anthra cite burners, which may be obtained by application. . Standards of performance for bituminous coal stokers are also being developed by Bituminous Coal Research, Inc. The standards for anthracite stokers are described in the next paragraphs. Operating Requirements for Anthracite Stokers Efficiency. The over-all efficiency of the unit at all points above 50 per cent of maxi-; mum coal feed shall be above 50 per cent when, installed in a round sectional cast-iron boiler having three intermediate sections and 1)4 in. of asbestos insulation or its equiva Fig. 5. Underfeed Screw Stoker, Hopper Type transmission for driving the coal feed worm, and an electric motor or motors for supplying the motive power for both coal feed and air supply as indicated in Fig. 5. The shape of the retort in this class of stokers is usually round although rectangular retorts ^are favored by some manu facturers. In all cases, however, the retort incorporates tuyeres through which the air for combustion is admitted. Some household stokers are provided with an automatic grate-shaking mechanism together with screw conveyors for removing the ash from the ashpit (Fig. 6) and depositing it in an ash receptacle outside the boiler. Certain types can also be provided with a coal conveyor which takes coal from the storage bin and maintains a full hopper at the stoker. In some cases the coal bin functions as the stoker hopper as shown in Fig. 7, and an extended worm is used to convey the fuel to the combustion furnace. Domestic stokers may feed coal to the furnace either intermittently or with a continuous flow regulated automatically to suit conditions. ' . Household stokers are made for all classes of fuel; anthracite, bitu minous and semi-bituminous coals, and coke. The United. States Depart- 204 lent in good condition of repair, operating at 50 per cent or more of the boiler capacity.The efficiency shall be maintained for any continuous period of .4 hours during any test or observation run. ". Ash Loss. Combustible in ash shall not exceed 7.5 per cent of the Btu content of the coal as fired at any rate of coal feed above 50 per cent of maximum. Methods of test" according to Code No. 3 of the A.S.H.V.E.1 are to be followed in all details applicable- to stoker testing. . Clinker. Ash removing systems should at all times be capable of disposing of any clinker which may be formed under any conditions of operation with the coals prescribed. Tax^o^ MBSv'* tor Seam Solid Fuel *** <Code 3). (A.S.H.V.E.. 205 Heating Ventilating Air Conditioning Guide 1938 Combustion Sate. A combustion rate of at least 13 lb per square foot of horizontal projected area of ash ring per hour must be continuously maintained for at least 9 hours with the above conditions of efficiency, ash and clinker. . Flue Gas. Flue gas shall be not below 6 per cent in carbon dioxide with a reasonably tight boiler at any rate of operation above 50 per cent of maximum coal feed. Maximum Rating. The maximum rating, in terms of gross square feet of water or steam radiation which the burner will supply, when intended for installation in the average existing cast-iron boiler, shall be 90 per cent of the maximum steam produced in a round cast-iron boiler in good repair having three intermediate sections and the equivalent of 1H in. of asbestos insulation. However, in no case shall the maximum rating be greater than 29 sq ft of direct steam radiation for each pound of coal fired per hour, and in no case shall ratings be based upon efficiency figures below 50 per cent. The maximum rating as defined in the preceding paragraph shall be based upon com bustion of Pennsylvania anthracite having the following approximate analysis: Volatile matter 3.5 to 9 per cent; ash content not to exceed 15 per cent; sulphur content under 1.5 per cent; ash fusing temperature 2750 F, or above (volatile, ash and sulphur content on dry basis in accordance with A.S.T.M. method D271-33); Btu content 12,000 or above; properly sized as follows: A No. 1 buckwheat should pass through a round mesh screen having He in. holes and over a similar screen having `'/\ 6 in. holes. The undersizing should not exceed 15 per cent and the oversizing should not exceed 10 per cent. A No. 2 buckwheat (rice) should pass through a round mesh screen haying holes He in. >n diameter and over a like screen having holes of H6 in. in diameter. The under sizing should not exceed 15 per cent and the oversizing should not exceed 10 per cent. Coal Storage. It is recommended that the coal bin or closet be constructed so as to be dustproof. Electrical Consumption. The electrical consumption shall not exceed 18 kwh per 2000 lb of coal burned at any rate of coal feed above 50 per cent of the maximum. Operation Upon Other Sizes of Coal. The foregoing specifications have been drafted for operating with the Nos. 1 and 2 buckwheat sizes of anthracite. In the event that other sizes are recommended, ratings shall be based upon the same efficiency and ash loss requirements. * Banking. The burner shall be so constructed or controlled as to maintain a fire during an indefinite banking period. . Acceleration. When the burner resumes operation after a 12 hour banking period, the time required for the stack temperature to reach a normal maximum shall not exceed 60 min. Stoker-Fired Units ' Boilers and air conditioners especially designed for stokers are now becoming available. Present designs feature better coordination between the heat absorber and the stoker. Increased setting height and furnace volume and more heating surface than in conversion installations are usually to be found in these stoker units. Class 3 Stokers, Apartment House, Small Commercial ' This class is used extensively for heating plants in apartments and hotels, and also for small industrial plants such as laundries, bakeries, and. creameries. The majority of stokers used in this field are of the underfeed type. The principal exception is an overfeed type having step action grates in a horizontal plane and so arranged that they are alternately moving and stationary, and are designed to advance the fuel during com bustion to an ash plate at the rear. All of the stokers are provided with a coal hopper outside of the boiler. In the underfeed types, the coal feed from this hopper to the furnace may be accomplished by a continuously revolving screw or by an intermittent 206 Chapter 11. Automatic Fuel Burning Equipment plunger.. The drive for the coal feed may be an electric motor, or a steam or hydraulic cylinder. With an electric motor, the connection between the driver and the coal feed may be through a variable speed gear train which provides two or more speeds for the coal feed; or it may be through a simple gear train and a variable speed driver for the change in speed of the coal feed; or a simple gear train with a coal feed having an adjustment for varying the travel of the feeding device. With a steam or hydraulic cylinder, the power piston is connected directly to the coal feeding plunger. The stokers in this class vary also in their retort design according to the fuels and load conditions. The retort is placed approximately in the middle of the furnace and is provided with tuyere openings at the top on all sides.. In the plunger-feed type the retort extends from the inside of the front wall entirely to the rear wall or to within a short distance of the rear wall. This type of retort has tuyeres on the sides and at the rear. These stokers also differ in the grate surface surrounding the retort. In many of the worm-feed stokers this grate is entirely a dead plate on which the fuel rests while combustion is completed. In the dead-plate type, all of the air for combustion is furnished by the tuyeres at the retort. Because of this, combustion is well advanced over the retort so that it may easily be completed by the air which percolates through the fuel bed. With the dead-plate type of grate the ash is removed through the fire doors and it is therefore desirable that the fuel used shall be one in which the ash is readily reduced to a clinker at the furnace temperature, in order that it may be removed with the least disturbance of the fuel bed. ' In other stokers in this class, the grates outside of the retort are air- admitting and some stokers have shaking grates. These grates permit a large part of the ash to be shaken into the ashpit beneath, while the clinkers are removed through the fire doors. With this type of grate, die main air chamber extends only under the retort while the side grates receive air by natural draft from the ashpit. ' . In still other stokers of this class, the main air chamber extends beyond the retort and is covered with fuel-bearing, air-supplying grates. With this type of grate, the fuel is supplied with air from the main air chamber throughout combustion. Also with this type of grate, dump plates are provided beyond the grates where the ash accumulates and from which it. can be dropped periodically into the ashpit beneath. , Stokers in this class are compactly built in order that they may fit into standard heating boilers and still leave room for sufficient combustion space above the grates. The height of the grate is approximately the same that of the ordinary grates of boilers, so that it is usually possible to install such stokers with but minor changes in the existing equipment. In some districts, there are statutory regulations governing such settings. These stokers vary in furnace dimensions from 30 in. square to approxi mately 66 in. square. The capacity of the stokers is measured by the amount of coal that can be burned per hour. In general, manufacturers recommend that, for continuous operation, the coal burning rate shall not exceed 25 lb of coal per square foot of grate per hour, while for . short peaks this rate may be increased to 30 lb per hour. Although' these stokers were designed to bum bituminous coal, types are available for 207 Heating Ventii*ating Air Conditioning Guide 1938 the semi-bituminous coals such as Pocahontas and New River. They can also be used to burn the small sizes of anthracite but at a somewhat lower rate. Class 4 Stokers, Medium Commerial These stokers are usually of the screw feed type without auxiliary plungers or other means of distributing the coal. Rectangular retorts with sectional tuyeres and dead plates without air ports are employed.. The unit type of construction is almost universally used, the unit incor porating the hopper, the transmission for driving the feed screw, and the fan for supplying air for combustion. Class 4 Stokers, Large Commercial, Small High Pressure Plants Stokers in this group vary widely in details of mechanical design and the several methods of feeding coal previously described may be employed Such methods of applying power to the fuel conveying mechanism as, continuous gear train transmission, ratchet type speed reducer, hydraulic cylinder and steam cylinder are used. Varying methods of ash disposal are found in this class. Large Stokers This class includes stokers with hourly burning rates of over 1200 lb of coal per hour. The prevalent stokers in this field are: o. Overfeed flat grate stokers. . b. Overfeed inclined grate stokers. ' c. Underfeed side cleaning stokers. , d. Underfeed rear cleaning stokers. Overfeed inclined grate stokers are seldom built in sizes of over 500 hp and are not as extensively used as other types of stokers. Underfeed side cleaning stokers are made in sizes up to approximately 500 hp and in this field are extensively used. These stokers are not so varied in design as those in the smaller classes although the principle is much the same. Practically all of them are of the front coal feed type, either power driven or steam driven. Dump plates at the side are manually operated. These stokers are heavily built and designed to operate continuously at high boiler ratings with a minimum amount of attention. Because of the fact that all volatile gases must pass through the fire before reaching the combustion chamber, these stokers will operate smokelessly under ordinary conditions. ' Also because of the fact that these stokers are always provided with forced draft, they are the most desirable type for fluctuating loads or high boiler ratings. In the design of the grates for supporting the fuel between the retort and the ash plates,' the stokers differ in providing for movement of the fuel during combustion. Some stokers are designed with fixed grates of sufficient angle to provide for this movement as.the bed is agitated by the incoming fuel, while others have alternate moving and stationary bars in' this area and provide for, this movement mechanically. In either type, with proper, operation, all refuse-will . be deposited at the dump plate. 208 t ? i Chapter 11. Automatic Fuel Burning Equipment Recent developments in this type of stoker provide for sliding distributor blocks along the bottom of the retorts which give flexibility in providing proper distribution of fuel over the grate area and assist in preventing coke masses when strong coking coals are used. Another difference in these stokers is that some use a single air chamber under the whole grate area thus having the same air pressure under the ignition area as under the rest of the grate, while others have a divided air chamber using the full air pressure under the ignition area and a reduced air pressure under the remainder of the grate. These stokers vary in size from approxi mately 5 sq ft to a maximum of 8j^ sq ft. The most prevalent type of rear cleaning underfeed stoker is the multiple retort design. Occasionally double or triple retort side cleaning underfeeds are made. The multiple retort underfeed stoker is made for the largest sizes of boilers for large industrial plants and central stations. This stoker has reached a very fine stage of development mechanically and in the matter of air supply and control. In some instances zoned air control has been applied both longitudinally and transversely to the grate surface. Ash dumps on smaller sizes are sometimes manually operated. The Combustion Process Due to the marked differences in design and operating characteristics of stokers and the widely differing characteristics of stoker fuels, it is difficult to generalize on the subject of combustion in automatic stokers. In anthracite stokers, which are almost exclusively of the small (Class 1) underfeed type, burning takes place within the stoker retort. The ash and refuse of combustion spills over the edge of the retort into an ashpit or receptacle from which it may be removed either manually or auto matically. Anthracite is usually supplied for stoker firing in No. 1 buckwheat or No. 2 buckwheat size. Those stokers burning coke operate in a similar manner to anthracite stokers. Since the majority of bituminous coal stokers used in heating plants operate on the underfeed principle some general observations-of their operation are given. When the coal is fed from the hopper or bin into the retort it is generally degraded to some extent and some segregation of sizes occurs. Because of these factors there may be some difference in the actions occurring in the various portions of the retort. - The coal moving upward in the retort toward the zone of combustion established by previous kindling of the fire is heated by conduction and radiation, from the zone of combustion. As the temperature of the coal rises it first gives off moisture and occluded gases, which are largely non-combustible. When the temperature increases to around 700 or 800 F, the coal particles become plastic, the degree of plasticity varying with the type of coal. , , ;' A rapid evolution of combustible volatile matter occurs during arid directly after the plastic stage of the coal. The distillation of volatile matter continues above the plastic zone and the coal is coked. The strength and porosity of the coke formed will vary according to the size and characteristics of the coal used. - 209 Heating Ventilating Air Conditioning Guide 1938 As more coal is fed from below the mass of coke continues to grow .forming a coke tree, plug or spar as it is variously designated. After a period of time, dependent upon the strength of the coke formed, pieces of the coke tree break off and fall upon the hearth surrounding the retort or within the retort itself where they are burned. While part of the ash fuses into particles at the surface of the coke as it is released, most of it is freed in unfused flakes or grains. The greater part of this unfused ash remains on the hearth or dead plates although a part may be expelled from the furnace with the gases. The ash layer becomes thicker with time and that near the retort, being exposed to temperatures which are high enough at times, fuses into a clinker. The temperature attained in the fuel bed, the chemical compo sition and homogeneity of the ash, and the time of heating are factors which govern the degree of fusion. - Bituminous coal stokers of the Class 1 type operate on the principle of the removalof ash as clinker and clinker tongs are provided to facilitate this purpose. Typical representations of underfeed bituminous stoker fuel beds- are shown in Figs. 8 and 9. . : The appearance of such fuel-beds is very ragged at times, and large masses-of coke build up, surrounded by blowholes with intense white; flame'indicating the presence of excess air.- There is a natural tendencyfor users-to disturb the fuel bed and make it conform to the conventional representation or- ideal fuel bed.: Such attention should'not-be required, as usually the fuel bed tends to correct its own faults as the cycles of plasticity, coke, free formation and ash fusion recur. ^ - There are a number of factors which materially affect the rate and type; of combustion'obtained in stoker usage, the most important of thesebeing: -the type anddesign of stoker, the type arid characteristics of the. fuel, the method of stoker installation and the method of stoker operation. 210 Chapter 11. Automatic Fuel Burning Equipment Furnace Design The burning of the fuel on the grate or in the retort will be influenced directly by the stoker design. The burning of the volatile gases above, the fuel bed is a matter of furnace design. Proper care should be taken to provide furnaces sufficiently liberal in volume and with the grates or retorts at a sufficient distance from the heating surface to permit proper combustion of the gases. Smoke and low efficiency will result if the furnace is too small to permit proper mixing of the gases and completion of combustion. ' Table 1. * Recommended Setting. Heights for Heating Boilers Equipped with Mechanical Stokers2 Fibebox Boxlsbs ` Actual Loadb A B 2500 18" 42" 5000 18" 48" 7500 20" 54" A - Distance from bottom of Water Leg to floor. 10000 20" 60" 12500 15000 20000 25000 30000 22" 22" 24" 24" 24" 66" 72" 78" 84" 84" B= Distance from Crown Sheet to bottom of Water Leg. Compact Welded Boilebs Actual Loadb A B 2500 18" 30" 5000 18" 33" 7500 20" 36" A - Distance from bottom of Water Leg to floor. 10000 20" 42" 12500 15000 20000 25000 30000 22" . 22" 24" 24" 24" 45" 48" - 54" 60" 60' B = Distance from Crown Sheet to bottom of Water Leg! H. R. T. Boilebs . Hp - 50. 75 . .100 125 150 175 200 225 A. 5'-0" 5'-6" 6/-0'r 6'-6T. 7'-0" . 7'-0" 7t6" 8'rO" - A Distance from bottom of shell to floor. ' Hp = Installed horsepower. 250 ; 275 8';6" . 9'-0" " 300 9'-0" In the case of the Firebox or Compact Welded type boilers the desired setting height can be obtained by combining A and B dimensions. The load ratings shown for this class of boilers are actual developed loads in square feet of equivalent cast-iron steam radiation and are not manufacturers' ratings. -' " The setting heights given for H. R. T. boilers may be used for developed loads up to 50 per cent above normal rating. ' . '. -- . .............. . . . , ` "From Data prepared by the Mid-west Stoker Association. ...... .. . ^Expressed as steam radiation, 1 sq ft = 240 Btu. ` '. ' ' . _ The standards that have been rriost universally adopted for the. propor tioning of furnaces for bituminous coal stokers are those of the Midwest Stoker Association and the Steel Heating Boiler Institute. See Chapter 13. Table 1 gives recommerided setting heightsior: heating boilersequipped with mechanical stokers using bituminous coal. Furnace volume is not an important item in anthracite stoker instal lations.; ..Due care should be exercised for both anthracite and:bitutninous stokers. to: prevent intense heat application on the -metal surfaces -of The combustion chamber. The installation of a baffle orjadjustment.in setting height of the stoker.may be desirable in some cases. -- -. .-.-.5.7 2tt Heating Ventilating Air Conditioning Guide 1938 The prime essentials of good furnace design are: correct proportions, moderate combustion rate, adequate furnace volume and sufficient flame clearance. If these factors are properly compensated for and provision is made for the proper mixing of the gases bituminous coal stokers will operate smokelessly. In those stokers which are operated intermittently, however, some smoke may be produced during the off periods. Combustion Adjustments Satisfactory stoker performance may be secured by regulating the coal feed and the air supply so as to maintain, as nearly as possible, an ideal balance between the load demand and the heat liberated by the fuel. When the coal is consumed at about the same rate as that which it is fed this balance exists and uniform fuel bed conditions will be found. Under such conditions no manual attention to the fuel bed should be required other than the removal of clinker in those stokers which operate on this principle of ash removal. Since complete combustion is not obtained in stoker furnaces receiving only the air theoretically required, it is necessary, even under the best of conditions, to supply from 30 to 50 per cent excess air to obtain desired combustion results. Due to the variable characteristics of solid fuels in burning, consideration must be given to a number of factors which affect the maintenance of the combustion conditions wanted. - The specified rate of coal feed of a stoker may vary due to changes in the bulk density of the coal dependent upon: (a) the size of coal, (b) dis tribution of size in the coal, (c) segregation of coal in the stoker hopper, and (d) friability of the coal. ; The following factors may affect the rate of air supply: (a) changes in fuel bed conditions and resistance, (6) changes in furnace draft due to a variety of causes, i.e., changes in chimney draft because of weather changes, seasonal changes, back drafts, failure or inadequacy of auto matic draft regulator, use of chimney for other purposes, possible stoppage of the chimney and changes in draft resistance of boiler due to partial stoppage of the flues, and (c) changes in air inlet adjustments to the fan. ' Many domestic' bituminous stokers now incorporate some method of automatic control which compensates for changes in fuel bed resistance. Since a secondary source of air due to leakage is present in most installa tions, the use of an automatic draft regulator to maintain the furnace draft at about 0.05 in. of water is desirable. This is quite important with intermittently operated stokers. Some fuel is burned by natural draft in the off periods, when fuel is not being fed, and it is essential that the burning in these periods be controlled. -With excessive draft, due either to fan pressure or chimney pull, an increase in the discharge of soot and fly ash from the combustion chamber will result. Measurement of the Efficiency oi Combustion . . . ' As efficient combustion is based upon a certain percentage of excess air; it is possible to determine the results by analysis of the gases formed by the combustion process. An Orsat apparatus can be used to determine the percentage (by volume) of the carbon dioxide (COt), oxygen (Os) and 212 Chapter 11. Automatic Fuel Burning Equipment carbon monoxide (CO) in the flue gases. Due to variations in the fuel bed and rate of burning of stoker-fired solid fuels it is not sufficient to analyze a grab sample. A continuous gas sample drawn at a constant rate through out an operating period of reasonably long duration should be used. A C02 reading of 12.5 to 14 per cent indicates that the excess air supplied is in the range of 30 to 50 per cent. The presence of CO indicates a loss due to improper mixing of the air and the gases of combustion. As an increase in excess air maintained during on periods will decrease the tendency toward smoke in the off periods of intermittently operated bituminous coal stokers, care should be taken that the delivery of air by the fan is great enough to avoid smoke. Controls The industry developed by stokers in Classes 1, 2, 3 and 4 has been due as much to the application of proper controls as to the stoker itself. This is especially true of Class 1 stokers because of their application to resi dential heating, a field wherein the majority of owners and users are not familiar with control problems or stoker operation. The usual controls applied are as follows: 'a. Thermostats (plain and.clock). .. b. Limit Controls (steam, vapor, vacuum, hot water, or air). c. Stack Temperature or Time Controls (for actuating fires periodically). d. Relay (for low voltage controls). e. Safety or Overload Cutout (for protection against overload); /. Low Water Cutout (steam, vapor and vacuum). DOMESTIC OIL BURNERS An oil burner is a mechanical device for producing heat automatically and safely from liquid fuels. This heat is produced in the furnace or firepot of hot water or steam boilers or warm air furnaces and is absorbed by the boiler, and thus made available for distribution to the house through the heating system. With oil, as with any kind of fuel, efficient heat production requires that all combustible matter in the fuel shall be completely consumed and that it shall be done with a minimum of excess air. The combustion of oil is a rather rapid chemical reaction. Excess air provides an over supply of oxygen so that all of the oil, composed of carbon anl hydrogen, will be completely oxidized and thus produce all the heat possible. The use of unreasonable quantities of air in excess of theoretical combustion require ments results in lowered efficiencies due to increased stack losses. Such losses, if not accompanied by unburned products of combustion (saturated and unsaturated hydrocarbons, hydrogen, etc.), may be offset somewhat by increasing the secondary heating surfaces of the . heat absorbing medium, boiler or furnace. . :. Oil is . a highly concentrated fuel composed mainly of hydrogen and carbon. In its liquid form oil cannot burn. It must be converted into a gas or vapor, by some means. If the excess air is to be kept within efficient limits it means that air must be supplied in carefully regulated Heating Ventilating Air Conditioning Guide 1938 quantities. The air and oil vapor must be vigorously mixed to get a rapid and complete chemical reaction. The better the mixing, the less excess air that will be needed. The combustion must take place in a space that maintains the temperatures high so the reaction will not be stopped before completion. When equipped with a means of igniting the oil and safety devices to guard against mishaps, the oil burner possesses All. of the elements to be efficient and automatic. . The number of combinations of the characteristic elements of domestic oil burners is rather large and accounts for the variety of burners found in actual practice. Domestic oil burners may be classified as follows: 1. AIR SUPPLY FOR COMBUSTiON a. Atmospheric--by natural chimney draft. b. Mechanical--electric-motor-driven fan or blower. c. Combination of (a) and (6)--primary air supply by fan or blower and secondary ' air supply by natural chimney draft. 2. METHOD OF OIL PREPARATION a. Vaporizing--oil distills on hot surface or in hot cracking chamber. b. Atomizing--oil broken up into minute globules. (1) Centrifugal--by means of rotating cup or disc. (2) Pressure--by means of forcing oil under pressure through a small nozzle or orifice. (3) Air or steam--by high velocity air or steam jet in a special type of nozzle. . (4) Combination air and pressure--by air entrained with oil under pressure and forced through a nozzle. =. . . c. Combination of (a) and (b). 3. TYPE OF FLAME . a. Luminous--a relatively bright flame. An orange-colored flame is usually best ' if no smoke is present. ' . .. .. * b.'Non-luminous--Bunsen-type flame (..; blue flame). - ` . 4. METHODS OF IGNITION a. Electric. .. ` : : ; f. ; (1) Spark--by ; transformer producing high-voltage sparks. Usually . shielded to avoid radio interference. May take, place continuously . .. while the burner is operating or just at the beginning of.operation. . . .(2) Resistance--by means of hot wires or plates. . ... b. Cos. , '* ' . ' .. ' . (1). Continuous--pilot light of constant size. . . ; : ... (2) Expanding--size of pilot light expanded temporarily at the beginning . .. ; of burner operation. . . ;...... c. Combination--electric sparks light,the gas and the gas flame ignites the oil; d. Manual--by manually-operated gas torch for continuously operating burners. 8. MANNER OF OPERATION . ; . a. On and off--burner operates only a portion of the time (intermittent). ; . . b. High arid kno--burner operates continuously but varies from a high to a low V' : flame. ' .. . ' c. Graduated--burner operates continuously but flame is graduated according to needs by regulating both air and oil supply. ` 214 \ Chapter 11. Automatic Fuel Burning Equipment A trade classification of oil burners consists of the following general types: (a) gun or pressure atomizing, (i>) rotary and (c) pot or vaporizing. The gun type, illustrated in Fig. 10 is characterized by an air tube, usually horizontal, with oil supply pipe centrally located in the tube and arranged so that a spray of atomized oil is introduced and mixed in the combustion chamber with the air stream emerging from the air tube. A variety of patented shapes are employed at the end of the air tube to influence the direction and speed of the air and thus the effectiveness of the mixing process. . Fig. 11. Center Flame Vertical : Rotary Burner ' ' Fig.-12. Wall Flame.Vertical . Rotary Burner . y The most distinguishing feature of vertical'rotary burners is the Principle of flame application. These burners are of two general types; the center flame and wall flame? In the former type, (Fig. 11) the oil is atomized by being thrown from the rim.of a revolving disc or cup.and the flame burns in suspension with a chariacteristic yellow color.. Combustion is supported by means of a bowl-shaped chamber or hearth. The. wall flame burner (Fig. 12) differs in that combustion takes place in a ring of 2IS . Heating Ventilating Air Conditioning Guide 1938 refractory material, which is placed around the hearth. These types of burners are further characterized by their installation within the ashpit of the boiler or furnace. . The pot type burner (Fig. 13) can be identified by the presence of a metal structure, called a pot or retort, in which combustion takes place. When gun type (pressure atomizing) or horizontal rotary burners are used the combustion chamber is usually constructed of firebrick or other suitable refractory material, and is part of the installation procedure. The oil burners are operated by a small electric motor which pumps the oil and some or all of the air required. The smallest sizes can generally burn not much less than 1 gal of oil per hour. The grade of oil burned ranges from No. 1 to No. 4. No. 4 oil is the heaviest and most viscous of the various grades mentioned. An oil burner satisfactory for No. 4 oil can burn any of the lighter grades easily but an oil burner recommended for No. 2 oil should never be supplied with the heavier grades. It has been found that while the heavier grades of oil have a smaller heat value per Chapter 11. Automatic Fuel Burning Equipment duction usually controlling the selection of fuel. Some of the largest office buildings have been using oil for many years. Many department stores have found that floor space in basements and sub-basements can be used to better advantage for merchandising wares, and credit the heat pro ducing department with this saving. . Wherever possible, the boiler plant should be so arranged that either oil or solid fuel can be used at will, permitting the management to take advantage of changes in fuel costs if any occur. Each case should be considered solely in the light of local conditions and prices. Burners for commercial heating may be either large models of types used in domestic heating, or special types developed to meet the condi tions imposed by the boilers involved. Generally speaking, such burners are of the mechanical or pressure atomizing types, the former using rotating cups producing a horizontal torch-like flame. (Fig. 14). As much pound, they have, due to greater density, a larger heat value per gallon. The relative economy of the various grades must be based upon price and the amount of excess air required for clean and efficient combustion. Boiler-Burner Units . Boilers and air conditioners especially designed for oil burners are available to the purchaser of this type of equipment. They are used for replacements as well as for new installations. This type of equipment usually has more heating surface than the older coai-burning designs. Flue proportions and gas travel have been changed with beneficial results. All problems of combustion chamber design, capacities, efficiencies, etc., have been solved. The selection of the proper size of unit should be a simple process. . -. . COMMERCIAL OIL BURNERS Liquid fuels are used for heating apartment buildings, hotels, public and office buildings, schools, churches, hospitals, department stores, as well as industrial plants of all kinds. Contrary to domestic heating, con venience seldom is a dominating factor, the actual net cost of heat pro- 216 as 350 gal of oil per hour can be burned in these units, and frequently they are arranged in multiple on the boiler face, from two to five burners to each boiler. . The larger installations are nearly always started with a hand torch, and are manually controlled, but the use of automatic control is increasing, and completely automatic burners are now available to burn the two heaviest grades of oil. Nearly all of the smaller installations, in schools, churches, apartment houses and the like, are fully automatic. Because of the viscosity of the heavier oils, it is customary to heat them before transferring by truck tank. It also has been common practice to preheat the oil between the storage tank and the burner, as an aid to movement of the oil as well as to atomization. This heating is accomplished by heat-transfer coils, using water or steam from the heating boiler, and heating the oil to within 30 deg of its flash point. . . Unlike the domestic burner, units for large commercial applications frequently consist of atomizing nozzles or cups mounted on the boiler front with the necessary air regulators, the pumps, for handling the oil 217 Heating Ventilating Air Conditioning Guide .1938 and the blowers for air supply being mounted in sets adjacent to the boilers. In such cases, one pump set can serve several burner units, and common prudence dictates the installation of spare or reserve pump sets. Pre-heaters and other essential auxiliary equipment also should be in stalled in duplicate. Boiler Settings As the volume of space available for combustion is the determining factor in oil consumption, it is general practice to remove grates and extend the combustion chamber downward to include or-even exceed the ashpit volume; in new installations the boiler should be raised to make added volume available. Approximately 1 cu ft of combustion volume should be provided for every developed boiler horsepower, and in this volume from 1.5 to 2 lb of oil can properly be burned. This cor responds to a maximum liberation of about 38,000 Btu per cubic foot per hour. There are indications that at times much higher fuel rates may be satisfactory. This in turn suggests that the value of 38,000 Btu per cubic foot per hour might be adjusted according to good engineering judgment. For best results, care should be taken to keep the gas velocity below 40 ft per second. Where checkerwork of brick is used to provide secondary air, good practice calls for about 1 sq in. of opening for each pound of oil fired per hour. Such checkerwork is best adapted to flat flames, or to conical flames that can be spread over the floor of the combustion chamber. The proper bricking of a large or even medium sized boiler for oil firing is important and frequently it is advisable to consult an authority on this subject. The essential in combustion chamber design is to provide against flame impingement upon either metallic or fire brick surfaces. Manufacturers of oil burners usually have available detailed plans for adapting their burners to various types of boilers, and such information should be utilized. The Combustion Process Efficient combustion, as previously indicated, must produce a clean flame and must use relatively small excess of air, i.e., between 25 and 50. per cent. This can be done only by vaporizing the.oil quickly, completely, and mixing it vigorously with air in a combustion chamber hot enough to support the combustion. A vaporizing burner prepares the oil, for combustion, by transforming the liquid fuel to the gaseousi state through the application of heat. This is accomplished before the oil vapor mixes with air to any extent and if the air and oil vapor temperatures are high and the fire pot hot, a clear blue flame is produced. There may- be a deficiency of air as shown by the presence of carbon monoxide (CO) or an excessive supply of air, depending upon burner adjustment, without altering the clean, blue appearance of the flame. An atomizing burner i.e., gun and rotary types is so named because the oil is mechanically separated into very fine particles so that the surface exposure of the liquid to the radiant heat of the combustion chamber is vastly increased and vaporization proceeds quickly. The result of such practice is the ability to burn more and heavier oil within a given com bustion space or furnace volume. Since the air enters the fire pot with the liquid fuel particles, it follows that mixing, vaporization and burning are 218 Chapter 11. Automatic Fuel Burning Equipment all occurring at once in the same space. This produces a luminous instead of a blue or non-luminous flame. In this case a deficient amount of air is indicated by a dull red or dark orange flame with smoky flame tips. An`excessive supply of air may produce a brilliant white flame in some cases or, in others, a short ragged flame with incandescent sparks flashing through the combustion space. While extreme cases may be easily detected, it is generally not possible to distinguish, by the eye alone, the finer adjustment which competent installation requires. . Certain tests indicate that there is no difference in.economy between a blue flame and a luminous flame if the position, shape and the per cent of excess air of both flames are about the same. ' ; ' ' ' . Furnace or Combustion Chamber Design The furnace or combustion chamber may be defined as that part of a boiler or conditioner in which combustion is established. With burners requiring a refractory combustion chamber the size and shape should be in accordance with the manufacturer's instructions. It is important that the chamber shall be as nearly air tight as is possible, except when the particular burner requires a secondary supply of air for combustion. It is evident that the atomizing burner is dependent upon the surround ing heated refractory or fire brick surfaces to vaporize the oil and support combustion. While the importance of the combustion chamber is obvious, its design has been troublesome. Unsatisfactory combustion.may be due to inadequate atomization and mixing. A combustion chamber can only compensate for these things to a limited extent. If liquid fuel continually reaches- some part'of the fire brick surface, a carbon deposit will result. Fundamentally, the combustion chamber should enclose a space having a shape. similar to the. flame but large enough to avoid flame contact. The nearest approach in practice is to have the bottom of the combustion chamber flat but far enough below the nozzle to avoid flame contact, the sides tapering from the air tube at the same angle as the nozzle spray and the back wall-rounded.- A plan view of the combustion chamber thus resembles in shape the outline of the.flame. In this, way as much firebrick as possible is close to the flame so it may be kept quite hot. This insures quick vaporization, rapid combustion and better mixing -by eliminating dead dr inactive-dpaces-in the combustion chamber. An overhanging arch at the back, of the fire pot is sometimes used to increase the flame travel and give more time for mixing and burning, and sometimes;to pre vent:. the gases from going too directly into the. boiler flues. When good atomization and vigorous.mixing are achieved by the burner; combustion chamber, design becomes a less critical matter. Where secondary , air. js used, combustion chamber design is quite.important. | With some of the vertical rotary burners- considerable care must be exercised in definitely following, the manufacturers instructions, when installing the hearth as in this class successful performance depends upon this factor. Combustion Adjustments . . , : - -- . j Where adjustments of oil- and air have been made which give efficient combustion, the-problem of maintaining the adjustments constant be comes an important one. Particularly is this true when he change causes the per cent-of excess air to decrease below allowable limits of the 219 Heating Ventilating Air Conditioning Guide 1938 burner. A decrease in air supply while the oil delivery remains constant or an increase in oil delivery while the air supply remains constant will make the mixture of oil and air too rich for clean combustion. The more efficient the adjustment {i.e., 25 per cent excess air) the more critical it will be of variations. The oil and air supply rates must remain constant. The following factors may influence the oil delivery rate: (a) changes in oil viscosity due to temperature change or variations in grade of oil delivered, (6) erosion of atomizing nozzle, (c) fluctuations in by-pass relief pressures and (d) possible variations in methods 26 (3) and 26 (4) listed in the previous classification table. Note that any change due to partial stoppage of oil delivery will increase the proportion of excess air. This will result in less heat, reduced economy and possibly a complete inter ruption of service but usually no soot will form. The following factors may influence the air supply: (a) changes in combustion draft due to a variety of causes {i.e., changes in chimney draft because of weather changes, seasonal changes, back drafts, failure or inadequacy of automatic draft regulator, use of chimney for other purposes, possible stoppage of the chimney and changes in draft resis tance of boiler due to partial stoppage of the flues), and (6) changes in air inlet adjustments to the fan. It is recognized that a secondary source of air due to leakage in the boiler setting is present in many installations and it is highly desirable that this leakage be reduced to a minimum. Obviously the amount of air leakage will be determined by the draft in the combustion chamber. It is important that this draft should be reduced as low as is consistent with the proper disposal of the gases of combustion. When using mechani cal draft burners, with average conditions, the combustion chamber draft should not be allowed to exceed 0.02-0.05 in. water. An automatic draft regulator is very helpful in maintaining such values. Measurement of the Efficiency of Combustion Efficient combustion being based upon a clean flame and certain proportions of oil and air employed, it is possible to determine the results. by analyzing the gases formed by the combustion process. An Orsat apparatus is a device which measures the volume of carbon dioxide (COj), oxygen (Oj) and carbon monoxide (CO) in the fluegases. Except in the case of a non-luminous flame it is usually sufficient to analyze only for carbon dioxide (COj). A showing of 10 to' 12 per cent indicates the best adjustment if the flame is clean. Most of the good installations at the present time show from 8 to 10 per cent COj. Taking into account the potential hazard of oil or air fluctuations with low excess air. (high COj) a setting to give 10 per cent COj constitutes a reasonable standard for most oil burners. This is particularly true of non-luminous flame burners which will not function properly with less than 10 per cent CO-i- Controls . . .... Oil burner controls may be divided into two parts: (a) devices to regulate burner operation so the desired house heating result may be obtained and (6) devices for the safety and protection of the boiler and burner. For control devices generally consult Chapter 37. The room thermostat has recently been improved to provide more frequent, burner 220 Chapter 11. Automatic Fuel Burning Equipment operation and greater uniformity of room temperature. Class (6) controls comprises a device to shut off the burner if the oil fails to ignite or if the flame should cease due to lack of oil; a device actuated by steam boiler pressure to shut off the burner when the pressure reaches some pre determined value; a device on the boiler to shut off the burner if the water level acts too low for safety or one which automatically feeds additional water to the boiler; a device on warm air furnaces to shut off the burner if the air temperature gets too high; a valve in the oil supply line which automatically closes in the event of fire in or near the cellar; and a device to keep the temperature of the boiler water within certain limits when it is being used to heat domestic hot water. These devices are all tested and approved by the Underwriters' Laboratory of Chicago, 111., before they are offered to the purchaser. The selection of class (6) devices is made by the oil burner manufacturer. : Fuel Oil Gages . To insure a constant supply of fuel oil and to check deliveries and consumption it is essential to have accurate means of readily determining the quantity of oil in the storage tank. For this purpose various types of indicating or recording gages are used, the simplest forms being the glass level gage, and a float-and-dial arrangement having a graduated dial face indicating the proportion of the tank containing liquid. Other more accurate and dependable devices are designed to operate by hydraulic action or by hydrostatic impulse. These instruments may be attached to the tank, giving a direct reading of the liquid contents; or the instrument itself may be located at a convenient point remote from the tank and connected with the tank by pipe or tubing. The quantity readings may be in gallons of liquid, height of liquid level in feet and inches, or in other desired units of measurement. .. GAS-FIRED APPLIANCES The increased use of gas for house heating purposes has resulted in the production of such a large number of different" types of gas heating systems and appliances that today there is probably a greater variety of them than'there is for any other kind of fuel. Gas-fired heating systems may be classified as follows: - . .1. Gas-Designed Heating Systems. ' A. Central Heating Plants. 1. Steam, hot water, and vapor boilers. 2. Warm air furnaces. . . .. B. Unit Heating Systems. ... 1. Warm air floor furnaces. 2. Industrial unit heaters. : 3. Space heaters. . . . 4. Garage heaters. . . . .. . . , .: .' `. II. Conversion Heating Systems. A. Central Heating Plants. 1. Steam,, hot water and vapor boilers. 2. Warm air basement furnaces. . : . . .. ' . ' . .: :. 221 Heating Ventilating Air Conditioning Guide 1938 These systems are supplied with, either automatic or manual .control. Central heating plants, for example, whether gas designed or conversion systems, may be equipped with room temperature control, push-button control, or manual control. . Gas-Fired Boilers . '. . Information on gas-fired boilers will be found in Chapter 13. Either snap action or throttling control is available for gas boiler operation. This is especially advantageous in straight steam systems because steam pressures can be maintained at desired points, while at the same time complete cut-off of gas is possible when the thermostat calls for it: Gas-Fired Warm Air Furnaces Warm air furnaces are variously constructed of cast iron, sheet metal and combinations of the two materials. If sheet metal is used, it must be of such a character that it will have the maximum resistance to the corrosive effect of the products of combustion. With some , varieties of manufactured gases, this effect is quite pronounced. Warm air furnaces are obtainable in sizes from those sufficient, to heat the largest residence down to sizes applicable to a single room. The practice ,of installing a number of separate furnaces to heat individual rooms is peculiar to mild climates. Small furnaces, frequently controlled by electrical valves, actuated by push-buttons in the room above, are often installed to heat rooms where heat may be desired for an hour or so each day. These! furnaces are used also for heating groups of rooms in larger residences.' In a system of this type each furnace should supply a group of rooms in which the heating requirements for each room in the group are similar as ' far as the period of heating and temperature to be maintained are con cerned. . ... .. , : The same fundamental principle of design that is followed in the con struction of boilers, that is, breaking'the hot gas into fine streams so that all particles are brought as close as possible to the heating surface, is equally applicable to the design of warm air furnaces. y' ; Codes for proportioning warm air heating plants, such as that, formulateki by the National Warni Aik Heating and Air Conditioning'Association, are equally applicable to gas furnaces and coal furnaces. Recirculation should always be practiced with gas-fired warm air furnaces.: It not only aids in heating, but is essential to economy. Where fans are used in con nection with warm air furnaces for residence heating, it ib.weffto have the control of the fan and of the gas so.coordinated that there wilt; be .sufficient delay between the turning on of the gas and the starting ;of the fan to prevent blasts of cold air being blown into the heated rooms. An additional thermostat in the air duct easily may be arranged to accomplish this. Floor Furnaces ... Warm air floor furnaces are well adapted for heating first floors, or where heat is required in only one or two rooms. A number may be used to provide heat for the entire building where all rpoms are on the ground floor, thus giving the heating system flexibility, as any number of rooms may be heated without heating the others. With the usual type the register is installed in the floor, the heating element and gas.piping being 222 Chapter 11. Automatic Fuel Burning Equipment ' suspended below. Air is taken downward between the two sheets of the double casing and discharged upward over the heating surfaces and into the room. The appliance is controlled from the room to be heated by means of a control lever located near the edge of the register. The handle of the control is removable as a precaution against accidental turning on or off of the gas to the furnace. Space Heaters Space heaters are generally used for auxiliary heating, but may be, and are in many cases, installed for furnishing heat to entire buildings. With the exception of wall heaters, they are portable, and can be easily removed and stored during the summer season. Although they should be connected with solid piping it is sometimes desirable to connect them with flexible gas tubing in which case a gas shut-off on the heater is not permitted, and only A.G.A. approved tubing should be used. , Parlor furnaces or circulators are usually constructed to resemble a cabinet radio. They heat the room entirely by convection, i.e., the cold air of the room is drawn in near the base and passes up inside the jacket around a drum or heating section, and out of the heater at or near the top. These heaters cause a continuous circulation of the air in the room during the time they are jn Operation. The burner or burners are located in the base at the bottom of. an enclosed combustion chamber. 'The products of combustion pass up around baffles within the heating element or drum, and out the flue at the back near the top. They are well adapted not only for residence room heating but also for stores and offices. Radiant heaters make admirable auxiliary heating appliances to be used during ;the occasional cool days at the beginning and end of the heating season when heat is desired in some particular room for an hour or two. The radiant heater gives off a considerable portion of its heat in the form of radiant energy emitted by an incandescent refractory that is heated by a Bunsen flame. They are made in numerous shapes and designs and in sizes ranging from two to fourteen or more radiants. Some have sheetiron bodies finished in enamel or brass while others have cast-iron or brass frames with heavy fire-clay bodies. An atmospheric burner is supported near the center of the base, usually by set screws at each end. Others have a group of small atmospheric burners supported on a manifold attached to the base. Most radiant heaters are supported on legs and are portable; however, there are also types which are encased in a jacket which fits into the wall with a grilled front, similar to the ordinary wall register. Others are encased in frames which fit into fireplaces. 1 ',. Gas-fired steam and hot water radiators are popular types of room heating appliances. They provide a form of heating apparatus for intermittently heated spaces such as stores, small churches and some types of offices and apartments.' They are made in a large variety of shapes andsizes and are similar in .appearance to the ordinary steam or hot water radiator con nected to a basement boiler. A separate combustion chamber is provided in the base of each radiator and is usually fitted with a one-piece burner. They may be secured in either the vented or unvented-types, and with steam pressure, thermostatic or room temperature controls. Warm air radiators are similar in appearance to the steam or hot water radiators. They are usually constructed of pressed steel or sheet metal 223 Heating Ventilating Air Conditioning Guide 1938 hollow sections. The hot products of combustion circulate through the sections and are discharged out a flue or into the room, depending upon whether the radiator is of the vented or unvented type. Garage heaters are usually similar in construction to the cabinet circulator space heaters, except that safety screens are provided over all openings into the combustion chamber to prevent any possibility of explosion from gasoline fumes or other gases which might be ignited by an open flame. They are usually provided with automatic room tem perature controls and are well suited for heating either residence or commercial garages. Conversion Burners .. Residence heating with gas through the use of conversion burners in stalled in coal-designed boilers and furnaces represents a common type of gas-fired house heating system. In many conversion burners radiants or refractories are employed to convert some of the energy in the gas to radiant heat. Others are of the blast type, operating without refractories. Many conversion units are equipped with sheet metal secondary air ducts which are inserted through the ashpit door. The duct is equipped with automatic air controls which open when the burners are operating and close when the gas supply is turned off. This prevents a large part of the circulation of cold air through the combustion space of the ap pliance when not in operation. By means of this duct the air necessary for proper combustion is supplied directly to the burner, thereby making it possible to reduce the amount of excess air passing through the com bustion chamber. Conversion units are made in many sizes both round and rectangular to fit different types and makes of boilers and furnaces. They may be secured with manual, push-button, or room temperature control. . The Combustion Process . . .. r . Because of the varying composition of gases used for domestic heating it. is difficult. to generalize on the subject of gas burner combustion. Refer to the section on Gas Classification, in Chapter 9. . .'. , Combustion Adjustments - ,' ' . Little difficulty should be experienced in maintaining efficient com bustion conditions when burning gas. The fuel supply is normally held to close limits of variation in pressure and calorific value and, therefore, the rate of heat supply is nominally constant. Since the force.necessary to introduce the fuel into the combustion chamber is an inherent factor of the fuel, no draft by the chimney is required for this purpose. The use of a draft diverter insures the maintenance of constant low draft condition in the combustion chamber with a resultant stability of air supply. A draft diverter is also helpful in controlling the amount of excess air and pre venting back drafts which might extinguish the flame. Measurement of the Efficiency of Combustion It is possible to determine the. results of combustion by analyzing the gases of combustion with an Orsht apparatus. It is desirable to determine 224 ' Chapter 11. Automatic Fuel Burning Equipment the percentage of carbon dioxide (C02), oxygen (02) and carbon monoxide (CO) in the flue gases. While ultimate C0% values of 10 to 12 per cent may ' be obtained from the combustion of gases commonly used for domestic heating, a combustion adjustment which will show from 8 to 10 per cent (70s represents a practical value. Under normal conditions no CO will be produced by a gas-fired boiler or furnace. Limitations as to output rating by the A .G.A. are based upon operation with not more than 0.04 per cent CO in the products of combustion. This is too small an amount to be determined by the ordinary' flue gas analyzer. Controls Gas burner controls may be divided into two parts: (a) devices to regulate burner operation so that the desired house heating results may be obtained and (b) devices for the safety of the boiler and burner. Control devices are treated in detail in Chapter 37. A room thermostat may be used as a control of house heating effect. These may be obtained in a number of types. Some central heating plants are equipped with push button or manual control. Class (b) controls include a device to shut off the burner if the gas fails to ignite, a device actuated by boiler pressure, water temperature, or furnace bonnet temperature to shut off the burner when the pressure or temperature becomes excessive, a device on the boiler to shut off the burner if the water level falls below safe limits or one which automatically feeds additional water to the boiler, and a device for controlling the gas pressure within desired limits. The main gas valve may be either of the snap action or throttling type. Sizing Gas-Fired Heating Plants While gas-burning equipment can be and usually is so installed as to be completely automatic, maintaining the temperature of rooms at a pre determined and set figure, there are in use installations which are manually controlled. Experience has shown that, in order to effectively overcome the starting load and losses in piping, a manually-controlled gas boiler should have an output as much as 100 per cent greater than the equiva lent standard cast-iron column radiation which it is expected to serve.- Boilers under thermostatic control, however, are not subject to such severe pick-up or starting loads. Consequently, it is possible to use a much lower selection, or safety factor. A gas-fired boiler under thermo static control is sensitive to variations in room temperatures so that in most cases a factor of 20 per cent is sufficient for pick-up load. The factor to be allowed for loss of heat from piping, however, must vary somewhat, the proportionate amount of piping installed being con siderably greater for small installations than for large ones. Consequently a selection factor for thermostatically controlled boilers must be variable. Liberal selection factors to be added to the installed steam radiation under thermostatic control are given in Fig. 3 of Chapter 13. Appliances used for heating with gas should bear the approval seal of the American Gas Association Testing Laboratory. Installations should be made in accordance with the recommendations shown in the. publi cations of that association. ' . 225 Heating Ventilating Air Conditioning Guide 1938 Ratings for Gas Appliances Since a gas appliance has a heat-generating capacity that can be pre dicted accurately to within 1 or 2 per cent, and since this capacity is not affected by such things as condition of fuel bed and soot accumulation, makers of these appliances have an opportunity to rate their product in exact terms. Consequently all makers give their product an hourly Btu output rating. This is the amount of heat that is available at the outlet of a boiler in the form of steam or hot water, or at the bonnet of the furnace in the form of warm air. The output rating is in turn based upon the Btu input rating which has been approved by the American Gas Asso ciation Testing Laboratory and upon an average efficiency which has been assigned by that association. In the case of boilers, the rating can be put in terms of square feet of equivalent direct radiation by dividing it by 240 for steam, and 150 for water. This gives what is called the A merican Gas Association rating, and is the manner in which all appliances approved by the American Gas Association Laboratory are rated. To use these ratings it is only necessary to increase the calculated heat loss or the equivalent direct radiation load by an appropriate amount for starting and piping, and to select the boiler or furnace with the proper rating. The rating given by the American Gas Association Laboratory is not only a conservative rating when considered from the standpoint' of capacity and efficiency, but is also a safe rating when considered from the standpoint of physical safety to the owner or caretaker. The rating that is placed upon an appliance is limited by the amount of gas that can be burned without the production of harmful amounts of carbon monoxide. This same limitation applies to all classes of gas-consuming heating appliances that are tested and approved by the Laboratory. Gas boilers are available with ratings up to 14,000 sq ft of steam, while furnaces with ratings up to about 500,000 Btu per hour are available. (See Chapter 20.) REFERENCES Stoker Information, Bulletin No. 5, Committee of-Ten, 307 N. Michigan Ave., Chicago, 111. Domestic Burners for Pennsylvania Anthracite, Commercial Standard CS48-34 U. S. Department of Commerce. . Performance Expectancy of Domestic Underfeed Stokers for Anthracite, by Allen J. Johnson (Transactions, A.I.M.E., Coal Division, Vol. 119, 1936). - . The Relation of the Size of Bituminous Coals to Their Performance on Small. Under feed Stokers--The Relation of the Size in the Hopper to That Burned.in the Retort, by R. A. Sherman and E. R. Kaiser, Technical Report No. 1, Bituminous Coal Research, Inc., (December, 1935) Pt. I. ... The Relation of the Size of Bituminous Coals to Their Performance on Small Under feed Stokers--Burning Tests on Four Typical Coals, by R. A. Sherman, E. R. Kaiser and, H. R. Limbacher, Technical Report No. 1, Bituminous Coal Research, Inc. (July, 1937) Pt. II. ' Stoker Coals, Anonymous, Bulletin of Chesapeake and-Ohio Railway Co., 1935: Study of Performance Characteristics of Oil Burners and Low Pressure Heating Boilers, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 517). ' i . A Study of Intermittent Operation of Oil Burners, by L. E. Seeley and J. H. Powers (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 317). ;' 226 Chapter 11.- Automatic Fuel Burning Equipment Air Supply and Its Effect on Performance of Oil Burners and Heating Boilers, by L. E. Seeley, J. H. Powers and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 75). : Study of Fuel Burning Rates and Power Requirements of Oil Burners in Relation to Excess Air, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 319). Oil Burning in Residences, by D. W. Nelson (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 355). Domestic Oil Burners, by A. H. Senner (Mechanical Engineering, November, 1936). A Study of Oil-Fired Heating Boilers, by R. C. Cross and W. R. Lyman (Heating and Ventilating, October, 1931). Value of Oil Burner Installation Surveys, by R. C. Cross and W. R. Lyman (Heating and Ventilating, January, 1931). . House'Heating, Industrial Gas Series, American Gas Association. Approval Requirements of Central House Heating Gas Appliances, American Gas Association. A Method for Determining Fuel Burning Rates in Heating. Boilers Fired by Auto matic Devices, by R. C. Cross (Heating and Ventilating, January, 1932). Heat Losses and Efficiencies of Fuels in Residential Heating, by R. A. Sherman and R. C. Cross (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, January, 1937, p. 53). Efficiencies and Costs of Various Fuels in Domestic Heating, by R. A. Sherman and R. C. Cross, Technical Report No. 3, Bituminous Coal Research, Inc., (December, 1936). Automatic Heating Equipment, American Architect Reference Data, No. 7, September, PROBLEMS IN PRACTICE 1 List some factors which might account for, higher efficiencies with stoker, firing than with hand firing. a. The uniform rate of coal feed, b. Better distribution in the fuel bed, and c. Positive control of the air supplied for combustion. . 2 9 Classify stokers as to. construction and operation. ' .' .- a.. Overfeed flat grate, b. Overfeed inclined grate, c. Underfeed side cleaning type, and d. Underfeed rear cleaning type. 3 9 What classification may be made of stokers as to their use? , Class 1. For residences (Capacity up to 60 lb of coal per hour). Class 2. For apartment houses and small commercial heating plants (Capacity 60 to 100 lb of coal per hour). . Class 3. For medium sized commercial heating plants (Capacity 100 to 300 lb of coal per hour). , Class 4. For large commercial plants and small high pressure steam plants (Capacity 300 to 1200 lb of coal per hour). 4 9 What main parts are found in an underfeed residential stoker? A hopper is supplied to hold coal which is fed by a screw or plunger into a retort provided with air openings called tuyeres. A blower supplies air under pressure for combustion, and a gear case provides for changes in coal feeding rates. 5 What is a dead-plate? A dead-plate is a flat surface without air supply openings upon which the fuel rests while combustion of the fixed carbon is completed. Generally the ash is removed from the dead-plate. " 227 Heating Ventilating Air Conditioning Guide 1938 6 What features of furnace design are essential for the proper burning of the volatile coal gases above the fuel bed? Adequate provisions should be made so that the furnace volume is sufficiently liberal and that the grates are a sufficient distance from the heating surfaces to permit the proper combustion of gases. 7 9 What methods of oil atomization are used? a. Throwing the oil from a rotating cup or disc, b. Forcing the oil under high pressure through a nozzle, c. Propelling the oil with a high velocity jet of air or steam, and d. Forcing an oil and air mixture through a nozzle. 8 What is the purpose of atomization? -. Atomization is used to increase the surface area of the oil in order to* facilitate putting it into a vaporous state so it may bum. 9 0 Is the furnace of much importance in oil burning? In most cases it is very important. It is the function of the oil burner to supply the air and fuel in correct proportions; the furnace must provide heated space for proper mixing and combustion. '. 10 0 Which flame is considered better, the luminous or the non-luminous? Laboratory tests show that they are equally efficient in the usual installation. .. 11 0 How should oil burner adjustments be made? Adjustments should be made by an experienced man who uses a gas analysis apparatus to determine the COt content. 12 0 What CO, content should be attained in oil burning? Ten per cent CO, is considered good practice, for it indicates the supplying of 50 per cent excess air. .. 13 0 What maximum heat release is considered good practice in oil burning? A heat release of 38,000 Btu per cubic foot .per hour is considered to be the maximum for average large installations. This figure has been greatly exceeded in some cases. The design of the combustion chamber, as to impingement of flame and as to proper mixing at high temperatures, has much to do with the attainable heat release. ^ ; 14 0 Name five types of gas-fired space heaters. . Parlor furnaces or circulators. , Radiant heaters. . c. Gas-fired steam or hot water radiators. d. Warm air radiators. . e. Garage heaters. ^ : ..; . . 15 0 How are gas heating units rated? Gas-fired units are rated on the basis of output in Btu per hour. .. 16 0 What safety consideration is noted in establishing the ratings of gas-fired units? . . The rating is limited by the amount of gas that can be burned without the liberation of harmful amounts of carbon monoxide. . 228 Chapter 12 HEAT AND FUEL UTILIZATION Toted Heat Loss Requirements, Utilization Factors, DegreeDay Methods, Base Temperature Determinations, Steam Consumption of Buildings, Fuel Consumption, Maximum . Demands, Load Factors r I 'nn. nouny neat loss w J. losses (Hf) and the infiltration losses (Ilf) of the rooms or spaces to be heated. The total equivalent heating surface required is equal to H 240 Sqft In estimating the fuel consumption of a building of more than .one room divided by walls or partitions, it is not correct to use the calculated heat loss of the building without making the proper allowances for the fact that the heating load at any time does not involve the sum of the infiltration losses of all the heated spaces of the building but only part of ' the infiltration losses. This is explained in Chapter 6. It is sufficiently accurate in most cases to consider only half of the total infiltration losses of a building having interior walls and partitions. The value of H in Equation 1 would, under these conditions, be equal to H` ' He -f ~. In some cases, where the building has no interior walls or partitions, the infiltration losses are calculated by using only half of: the total crack. In this case the entire infiltration loss should be considered. The heat required to warm the cold building and contents is a factor to be considered.. Under certain conditions the cooling of the structure and contents will, to some extent, compensate for the heat required to rewarm the building. For example, if the building is under thermostatic control and the day and night temperatures are, 70 F and 50 F respectively, there will be a period during which no heat will be added while the building is cooling to 50 F, and the saving resulting therefrom will correspond' to the additional heat required to bring the building and contents back to the daytime temperature. ESTIMATING FUEL CONSUMPTION There are two methods in use for estimating heat or fuel consumption. One method is theoretical, based on a calculated heat loss and assuming absolute constant temperatures for very definite hours each day through out the entire heating season. It does not take into account factors which are difficult to evaluate such as opening of windows, abnormal heating of the building, sun effect, poor heating systems, etc. 229 Heating Ventilating Air Conditioning Guide 1938 The second method is based on steam consumption data which have been taken from a group of buildings in operation, and the results com puted on a degree-day basis. While this method may not be as theo retically correct as the first mentioned method, it is of more value for practical use. Calculations of heat consumption made by the second method will invariably be higher than calculations made by the first method. Theoretical Estimation Method To predict the amount of fuel likely to be consumed in heating a building during a normal heating season, it is necessary to know.the total heat requirements of the building and the utilization factor of the fuel. The accuracy of the estimate will depend on the ability to select these values and on the care taken in making allowances for other variable factors. ' Heat requirements are given by the following general formula: M_ fa - fa . (i) : Steam requirements are determined by dividing the above by 1000, thus: '' . . '` 5 = g - fa) N (fa - fa) 1000 (2) \. Fuel requirements may be determined by the following formula: M F = C XE . (3) inhere ' . t =. inside temperature, degrees Fahrenheit. . , <d = inside design temperature, degrees Fahrenheit. ' fa average outside temperature, degrees Fahrenheit (Table 2, Chapter 7). ' .. fa outside design temperature, degrees Fahrenheit. . , H = calculated heat loss of building based on outside temperature (fa), Btu per hour, N = number of heating hours per season; 5088 from October 1 to May ll. . M = heat loss, Btu per season. '' .' 5 = steam required to.supply M Btu of heat loss. : . F = quantity of fuel required per.heating season. . .. . C = calorific value of one unit of fuel, the unit being the same as that on which F is based. E = efficiency of utilization of the fuel, per cent. ' Example 1. A small factory building located in Philadelphia is to be heated to 60 F between the hours of 7 a.m. and 7 p.m., and to SO F during the remaining hours. The calculated hourly heat loss based on a design temperature of --6 F is'500,000 Btu. ' If coal having a calorific value of 12,500 Btu is fired and the overall heating efficiency is assumed to be 60 per-cent, how many pounds of steam would be required for a normal heating season? . "7 ------ 1 '' ' This is the period for which / (Table 2. Chapter 7) is calculated. If the hearing season is different than this period, the corrected values may be.substituted for N and ia . 230 Chapter 12. Heat and Fuel Utilization Solution. Since there are no partitions in the building, the entire heat loss is con sidered. From Table 2, Chapter 7, the average outside temperature (fa) during the heating season is 42.7 F; N for the period for which fa is taken (October 1 to May 1) is 5088; 'H = 500,000; fa = --6 F; t = 50 F and 60 F; fa -- 60 F; = 60 per cent average for heating season; C = 12,500. The average daily temperature for the 24 hours is: 50 X 12 + 60 X 12 _ Substituting in Equation 1: M = 500,000 X (55 - 42.7) X 5088 60 - (-6) 474,100,000 5 = 474,100 lb of steam. , F = o 60^X^12^500 ~ 63,200 lb of coal = 31.5 tons. Practical or Degree-Day Method The amount of heat required by a building depends upon the outdoor temperature, if other variables are eliminated. Theoretically it is pro portional to the difference between the outdoor and indoor temperatures. Some years ago the American Gas Association! determined from experi ment in the heating of residences that the gas consumption varied directly as the difference between 65 F and the outside temperature. In other words, on a day when the temperature was 20 deg below 65 F, twice as much gas was consumed as on a day when the temperature was 10 deg below 65 F. The degree day is defined in Chapter 45. Degree-days for various cities in the United States and Canada are given in Table 1. Establishing the Base Inside Temperature. Recently the National District Heating Association has studied the metered steam consumption of 163 buildings5 in 22 different cities and has published data substanti ating the fact that the 65 F base originally chosen by the gas industry is approximately correct. The steam consumption of each building by months was divided by the number of days in each month, thus giving the average daily steam con sumption by months. The average steam consumption was then plotted against the average monthly temperature, as shown in Fig. 1, and the temperature at which a line drawn through the points crossed the base line indicated the temperature corresponding to zero steam consumption, or the base temperature. The composite results from 163 buildings calculated in this manner are shown in Table 2. The resultant average of 66.0 F is close to the A.G.A. figure of 65 F. It will be noted that the base temperature calculated for hotels, apart ments and residences is consistently higher than those for such buildings as garages, auto sales buildings, and manufacturing buildings. This, of course, would be expected in view of the higher inside, temperatures carried in the former group; in fact, an even greater difference would be *^ee industrial Gas .Series, House Heating {third edition) published by the American Gas Association. These buildings are all served with steam from a district heating company. 231 Heating Ventilating Air Conditioning Guide 1938 Table 1. Degree-Days for Cities in the United States and Canada3 Stats Crrr Jan. Feb. Mar. Apr. Mat Sept. Oct. Nov. Dec. Total Ala. 589 577 260 69 318 595 428 311 152 186 394 1153 969 896 654 636b 292d 577 840 1128 459 325 257 87 252 465 Ark Little Rock............ 719 582 353 78 47 381 651 Calif 326 266 239 159 90 123 301 San Francisco........ 465 356 354 294 458b 502c 146 261 428 Col.............. Colorado Springs.. 1085 993 884 612 459b 162 502 789 1067 Denver. ................. 1079 918 799 534 267 72 428 759 1017 Conn........... New Haven............ 1110 1011 899 543 223 39 360 693 1017 D. C. Fla. Ca 285 207 56 682 558 388 132 75 267 96 396 639 409 316 167 201 397 1098 848 651 435 235 108 434 738 1011 111. . . 1262 1095 909 Springfield.............. 1180 1008 760 Ind.............. 949 854 640 1128 969 756 Iowa........... Des Moines............ 1392 1173 890 Sioux City.............. 1434 1386 967 1116 890 688 1221 980 741 Ky 974 867 648 939 801 589 La. 332 230 58 Me............. 1380 1232 1110 Portland.................. 1321 1168 1017 Md_______ Baltimore.________ 955 843 700 Mass.-- . . Boston..................... 1150 1042 908 Springfield.-........... .-- 1253 1134 976 Marquette............ 1501 1360 1249 Minn___ Duluth 1727 1473 1277 Minneapolis. ... 1609 1400 1095 520 384 195 Mn 1201 987 750 1060 854 657 Mont_____ Billings.................... 1316 1120 955 Havre...........______ 1624 1450 1168 549 248 365 56 276 384 58 429 118 489 164 342 46 339 342 25 264 30 33 786 843b 566c 642 368 120 348 22 570 245 48 ..... ....... 573 226 42 804 682b 268d 810 722b 2984 570 235 93 321 15 276 534 376b 189 630 513 270 353 756 1113 282 681 1038 155 528 862 298 687 1017 357 798 1216 415 870 1265 276 672 1004 270 699 1051 245 612 903 186 552 849 102 301 543 843 1228 443 780 1153 223 567 875 363 693 1026 400 777 1113 567 960 1301 620 1062 1491 481 963 1405 252 471 285 605 1038 205 597 936 524 909 1192 620 1041 1383 1355 1125 868 Nev.._......... Reno-- .................... 1041 823 753 N. H______ Concord................... 1349 1240 1011 NJ 992 903 806 1014 942 735 N. M..... .. Santa Fe................. 1110 902 775 N. Y.......__ Albany.................... 1286 1142 980 Buffalo.................... 1 1240 1156 1032 1061 960 837 Utica................... 1242 1181 991 N. C.. 722 630 446 555 468 322 N. Dak.___ Bismarck._________ 414 84. 534 456b 144 669 351b 168 519 220 402 81 543 3016 120 549 493 72 675 347 75 486 155 587 244 187 183 108 ___ a. "Heating and Ventilating Degree*Day Handbook. ^Including June. "Including July and August, d Including August. . 328 780 1174 452 714 974 484 846 1234 254 588 893 242 588 930 459 780 1073. 446 774 1147 418 774 1104 276 618 955 426 787 1140 130 429 694 19 303 527- -- 2408 1471 7145 1845 2665 2811 1504 3264 6553 5873 5895 4626 890 2891 1490 4558 4924 6315 5370 4164 5297 6373 7023 5034 5301 4616 4180 1023 8531 7012 4533 6045 6464 6494 8692 9480 7851 1822 5202 4585 7115 8699 6231 6128 5891 6852 5175 4934 6063 6889 6821 5348 6785 3234 2302 8498 232 Chapter 12. Heat and Fuel Utilization Table 1. Degree-Days for Cities in the United States and Canada3 (Continued) State . Cnr Jan. Feb. Mar. Apr. Mat Sept. Oct. `Nov. Dec. Total Cincinnati.. __ 1076 910 747 378 73 700 1180 1075 950 564 270 ~TT ^66 7T? Columbus________ 1113 980 703 420 87 Okla______ Oklahoma City.._J. 865 742 465 162 Oreg---------- Portland__________ Salem _8_06 _644 558 402 335b 105 313 690 1017 105 459 815 332 558 728 Pa________ Philadelphia...... .... 1001 895 756 402 68 242 588 903 Pittsburgh 1054 944 787 423 78 313 669 967 R. I_______ Providence. ____ 1116 1069 890 558 251 63 348 693 1026 S. C_______ Charleston________ 487 372 242 36 207 425 Spartanburg-........ 725 688 431 147 121 429 716 S. Dak....... Sioux Falls... ..... Tenn.._!___ Memphis Nashville 744 599 384 96 812 747 476 180 --62 "402 663 136 483 744 5323 3613. 4468 4629 4855 5235 6014 1769 3257 7fi83 2950 3578 Dallas...... ................ Houston 366 277 65 San Antonio 381 274 74 Utah______ Logan. 1260 1072 893 Salt Lake City...... 1110 885 722 Vt___ 1535 1294 10KQ zz 525 376 114 453 234 18 276b 111 .. 2455 114 335 1157 126 347 1202 468 819 1218 ` 6735 388 723 1020 5553 Va____ __ Fredericksburg! 887 Norfolk___________ 738 - Richmond............... 825 Wash--___ Seattle.--............ --. 775 Spokane.__________ 1171 W. Va.____ Morgantown 1026 Parkersburg.......... 820 583 650 520 702 552 653 623 952 778 944 713 303 246 240 465 487b 276c 504 366 192 414 .223 .549 878 4243 99 ` 1<K 483 7fy* .. ^725 403 570 716 4968 514 819 1057 6353 294 648 977 5016 Wis______ _ 1 Wyo--. Fond du Lac 1507 1321 1046 Green Bay 1538 1358 1125 LaCrosse................. 1535 1265 1032 Milwaukee 1383 1328 1023 Cheyenne 1215 1075 995 603 276 uT *493 "92I 1328 600 322 132 505 921 1322 528 183 96 462 909 1280 648 389b 84 449 846 1222 720 569 240 605 900 1143 7612 7823 7290 7372 7462 Province . - Cm Jan. Feb. Mar. Apr. Mat Sept. Oct. Nov. Dec. Total b. c. ; 5777 Vancouver.____j___ -- 5976 Alb_________ Sask. . Kamloops..________ Medicine Hat_____ -- -- -- -- -- -- -- Ou'Appelle .. ------- 6724 8152 ------ - 11,261 Man..;.. Ont. . Port Arthur_______ Toronto..... -- 11,166 -- -- -- 10,803 7732 Que------------- Montreal 1615 1409 1219 720 309" I90" ~372 961 1422 8417 N. R N. S...____ P. E. I......... Ouehec Fredericton________ Yarmouth.. ------ -- -- ------- Charlottetown_____ -- -- -- .:----- -- -- --- -- 8628 9099 7694 8485 "Heating and Ventilating Degree*Day Handbook, ^including June. "Including July and August. 233 Heating Ventilating Air Conditioning Guide 1938 Table 2. Base Temperature for the Degree-Day3 , Temperature F Cob* 1 Trra of Building i........................ . No. of Buildings responds to Zero Analyzed .. Steam Consumption .. Office......... .".J. 1V ____________ ______ __ .. ____.... Office and Bank___ 1 Banfr ! ...... .:... ' ___ ____ ' ` '' - Office and Telephone Exchange......... .. ...... ,.i. Office and Stores.:. '. ______________ ` Stores.__ ____ ______ :....................................... Department Stores............................................................. Hotels _ : . __ ________________ _______ . Apartments. ........ ....................................................... Residences. ____ _; Clubs. . .,....................... ........................... .1____ .. _ Lodges._......'. ; . ......_........... TheatresTM !......_________ ___ 1J Churches. ______ :............................................................ Garage. ....._________________ ...._____________________ Auto Sales and Service--______________ _______ ' Newspaper and Printing........ ............... . J__________ Warehouse and Loft________ ______ '............ ; Office and Loft.' ________ ___ 1........................ Manufacturing--_____ ______:........... ................ ..... ............ .. - `' ' . '. : 60........ ". 4.............. 3 .. ' 2* 6 11 '. 12 . .' :r 14 ' 8 4 5 3 2 2' 4 3 3 2 8 66.2 65.8 66.2 65.5 67.4 84.0 64.3 66.5 68.8 ' 66V9" 65.5 64.9 67.6 65.8 64.8 61.2 67.7 67.7 65.2 65.4 , `. ' . . Average for 163 Buildings...... .. 66.0 F ( "Report of Commercial Relations Committee, 1952 Proceedings, National District Heating Association. / .Table 3. Steam Consumption for Various Classes of Buildings4 . {Heating Season Only) 1 , Building Classification Steam Consumption No. or Pounds pee Degbbb-Dat--$5 F Bab4 Buildings . Listed Per M Cu Ft Per M Sq Ft Per M Bta of Heated of Radiatore per Hr of Space Surface Heat Loesb Apartments........................ .............. ............................ 16 Hotels; .................................. --.................................... 10 12 Printing____ . ,,1................................................ 7 Clubs and Lodges. ................................................ 10 \ Retail Stores.. . . . ............ ................................ 18 Theatres... ... .. .............................................. 6 Loft and Mfg. . . _________ _ ______ _ 16 Batiks..... ........... ...................I............................................ " 7 Auto Sates and Service.--......................................... .8 6 14 6 Offices (Total). ____ --....... ____ --...;. 35 Offices; (Heating only).................................... .... 35 1.78 1.46 1.32. 1.25 0.96 0.90 0.90 0.89 0.88 0.83 0.58 0.57 0.42 1.09 0.975 97.5 80.6 64.2 105.5 77.0 80.6 75.0~ 72.3 .45.2 62.2 49.4 60.7 72.3 70.0 65.4 0.359 0.371 0.268 . 0.498 0.283 0.238 0.283 0.256 Includes steam for heating domestic water for heating season only. bHeat loss calculated for maximum design condition (in most cases 70 F inside, zero outside). Equivalent steam radiator surface. . ' .' dThe figures are a numerical--not a weighted--average for the several buildings in each class. Based on zero consumption at 55 F. 234 Tf 1 JI ^ : ' i i t !| 3 .1 j i i j j Chapter 12. Heat and,Fuel Utilization expected. .For ari.average figure, the A.G.A. base of 65 F may'therefore.be safely used, and if greater refinement is desired, the figure for the type of building under consideration can be taken from Table 2. - . . Table 34 gives, the steam consumption per degree-day, expressed in three different ways, for 196 buildings in 14 different classifications. These buildings are divided among. 21 different cities in the United States. The steam used for heating the domestic water is included, in these figures, but in the case of office buildings, the steam for heating only is also shown. The'data are placed on a comparable basis by expressing the steam consumption in terms of pounds per degree-day per thousand square feet of equivalent installed radiator surface, per thousand cubic feet of heated space, and per thousand Btu of calculated heat loss. ..............Fig. 1. Method of Determining Base Temperature for -. ' Degree-Day Calculations'; ; 1' ' . The choice of these units of comparison require some explanation. The use of heated space in preference to the gross cubage used by architects is obviously_more accurate for this purpose. The architect's cubage includes the outer walls and certain percentages of attic and basement space which are usually unheated. . The net heatpd.space is usually about 80 per cent of the gross cubage and can be. calculated from the latter if. it cannot be measured. The cubical content is somewhat inaccurate as a basis of.comparison due to differences in types of construction, exposure, and.ratio of exposed area.-to cubical contents. / ' -' ......... The use of radiator surface as the basis, of comparison has two ob-. jections. One is that the amount of radiator surface in a building is often either excessive or. deficient, and figures for steam consumption based on it are therefore likely to be in error. Another reason is that it is difficult to convert fan. coil surface into equivalent direct radiator surface with accuracy. On the whole, the use of radiator surface as the basis of coin- parison is the least satisfactory of the three.methods. . -' , . 'The Heat Requirements of Buildings, by J. H. Walker and g'. H. Tuttle (A.S.H.V.E..Transactions, Vol. 41, 1935. p. 171). . '. . .......................... ' `Report of Commercial Relations Committee; 1952 Proceedings', National- District Heating Association^ 235 Heating Ventilating Air Conditioning Guide 1938 It should be noted that the-figures in Table d are for the heating season only and include steam for heating dome&tifc water. / vfo Example 1 solved by the degree-^day method ahd using;values-taken from Table 3 would show a higher steam consumption. r . 3-oe Example S. Factor .for steam consumption for a manufacturing building per M.^tu per hour heatloss per degreeday. = 0.283; total number of degree-days per year (Table 1) = 4855; heat loss = 500,000 Btu per hour. Solution.. 0.283 X 4855 X -500 = 686,982 lb of steam per year. This calculation results in an estimate 45 per cent higher than the previous/calculation and one which would be more nearly correctffor actual practice. . , Chapter 12. Heat and Fuel Utilization unit, the consumption should be assumed as from .10 to 20 per cent greater. One reason for this difference in steam consumption is that district steam is a metered service, and building managers are therefore more conscious of their heating costs, which generally results in better maintained heating systems. Also, the district steam service is usually installed with ther mostatic control which reduces overheating to a minimum. .... Fig. 2 shows the amount of coal or oil that may be estimated when the steam consumption is known. Assuming the steam consumption that CU FT OF GAS PER DEGREE DAY PER UNIT Fig. 2. Curve for Estimating Fuel Consumption for Various Known Steam Consumption3 This curve is based on heating efficiencies of 60 to 70 per cent for coal and oil, respectively, a calorific value of coal of 13,000 Btu per pound, a calorific value of oil of 140,000 Btu per gallon. In case the heat loss figure is not known this method of estimating heat or steam consumption can also be applied if the net heated space figure is available. ' " ~ j ; :! ' CALQULATION OF FUEL CONSUMPTION , After the heat and stewin'consumption of the building have been calcu lated, the corresponding'/fuel ^requirements may also be, estimated by assuming the correct boilet and furnace efficiencies. If the building is to be supplied with steam from a district heating company, the steam con sumptions as calculated-by the two Methods are generally assumed to be correct. However, if the.steam is to be supplied from an individual boiler 236 Fig. 3. Chart Giving Gas Requirements per Degree-Day for Various Calorific Values of Gas and for Different Heating Systems3 i This chart Is based on an inside temperature of 70 Fiand an outside temperature of zero. If the radia tion is installed on the basis of any other temperature difference, multiply the result obtained from this chart by 70, and divide by the actual temperature difference. From Industrial Gas Series House Heating {third edition) published by the American Gas Association. ' "- was calculated in Example 2, 686,982 lb, the corresponding coal -con sumption, from the curve, is 44 tons and the. oil consumption 6000 gal. Fig. 3 indicates the average gas consumption per degree-day for various heat contents. White the fuel consumption in individual cases may vary-somewhat from the curve values, these average values are sufficiently accurate for estimating purposes and give satisfactoiy results. The value generally used in the' manufactured gas" industry for resi dences is 0.21 cu ft per degree-dqy.per .square foot of equivalent steam radiation (240 Btu) based ori. the theoretical requirements. A correction for warmer climates is necessary and/it is .customary to gradually increase, the relative fuel consumption below 30Q0 degrpe-days to about 20 per cent: . more at 1000 degree-days.' ............ 237 Heating Ventilating Air Conditioning; Guide 1938 GROSS OUTPUT - HUNDRED FEET STEAM RADIATION r--j--|ii--i--i--i--i--i--i--i--i--i--i--l--i--i--i--i--i--l--l--i--I--I--I--1--' i""r O5 10 15 .20 25 50 GROSS OUTPUT- HUNORED FEET WATER RAOIATION . Fig. 4. Coal Fuel Burning Rate Chart. Chapter 12. Heat and Fuel Utilization For hot water or warm air heat the fuel consumption is about 0.19 cu ft per degree-day per square foot of equivalent steam radiation, that is,.per 240 Btu per hour. The actual requirements likewise* relatively increase with hot water or warm air systems as the number of degree-days decreases below 3000. For larger installations, that is 1000 sq ft of theoretical radiation and above, there is an increase in efficiency, and a consequent decrease in the fuel consumption per degree-day per square; foot of heating surface. ': The approximate quantities of steam required in New York City per square foot of heating surface for various classes of buildings are given in Chapter 42. The preceding discussion on fuel consumption has dealt with the heating requirements of the building irrespective of any air that may be i-----1-* ---- 1-- i - t----- 1 i-----1-----1-----1-----1-----r i-----1-----1 0 . 2 4.6 8 10 . . 12 14 * GROSS OUTPUT - HUNDREO FEET STEAM RAOIATION r~ 16 i--7--j--i--|--i--I----i--i--rn--r--1--i--i--i--i--l--l--l--i--i--J--l--i--r .0 5 K>' IS 20 25 . GROSS OUTPUT-HUNDRED FEET WATER RADIATION i i. i 18 20 . Fig. 5. Oil Fuel Burning Rate Chart. . This chart is based upon No. 3 oil having a heat content of 143,400 Btn per gallon. If other grades of olfare used multiply the value obtained from this chart by the following factors: No. 1 oil (139,000 Btu per gallon) 1.032; No. 2 oil (141,000 Btu per gallon) 1.017; No. 4 oil (144,500 Btu per gallon) 0.992; No. - 6 oil (146,000 Btu per gallon) 0.982; and No. 6 oil (150,000 Btu per gallon) 0.956' '- 238 GROSS OUTPUT - HUNDREO FEET STEAM RAOIATION i--t----i--i--------i--i--'--i--1--i--i--i--i--i--i--i--i--i--i---->--i--i--i--i--m--i--i------ 0_. 5 10 e 20 25 30 . GROSS OUTPUT-HUNDRED FEET WATER RAOIATION Fig. 6. Gas Fuel Burning Rate Chart. . introduced for ventilation purposes other than the normal infiltration Of outside air. The heat required for warming air brought into the building for ventilation may be estimated from data given in Chapters 3 and 21. Rate of Fuel Burning - If the estimated maximum load or gross output is determined as out lined in Chapter 13, the fuel burning rates for coal, oil, or gas may be determined from the charts illustrated in Figs. 4, 5 .and 6. For a given efficiency, the rate of fuel burning is directly proportional to-the gross output, and therefore, these charts can be extended by moving the decimal point the same number of digits in both vertical and horizontal scale. All.charts are based upon values of one square foot steam radiation equivalent to 240 Btu per hour and one square foot hot water radiation equivalent to' 150 Btu. per hour. In using these charts, .consideration 239 Heating Ventilating Air Conditioning Guide 1938 must be given to the overall efficiency of the boiler or firing device. This factor is largely dependent upon good judgment and is a measure of the degree of efficiency to be expected from a particular installation.. : The correct fuel burning rate can be determined directly from the several charts for oil or gas burning installations, as these customarily operate on a strictly intermittent basis. These fuel burning devices usually introduce the fuel at a single fixed rate during the on periods and this rate should be sufficient to carry the gross or maximum design load. In the case of coal stokers, which are usually capable of variable- raths of firing, it is desirable to operate at as low a rate as weather conditions will permit, but the maximum firing rate of the stoker should be sufficient to carry the gross load. This rate may be determined by the same method as used for oil or gas. . In the case of warm air heating installations the heat loss of the building expressed in Btu per hour can be determined by use of the Standard Codes6 of the National Warm Air Heating and Air Conditioning Asso ciation. If the design heat loss of the building is divided by the proper factor, the required gross output may be obtained from the proper charts shown in Figs. 4,. 5 and 6. Example 3. The estimated net load (including domestic hot water supply) as calcu lated for a residence is 1500 sq ft of hot water radiation. Determine the firing rates for various fuels assuming an overall efficiency of 70 per cent; using coal with a calorific value of 12,500 Btu per pound; No. 3 fuel oil and natural gas having a gross heating value of 1000 Btu per cubic foot. ' . ; . : Solution. Referring to Fig; 3, 'Chapter 13, a piping and pick-up factor for a net load of 1500 sq ft is found to be 43 per cent or the gross output is equivalent to 1500 X 1.43 = 2145 sq ft hot water radiation. ; Using the chart in Figs. 4,. 5 and 6 project vertically from the gross output value on the.proper horizontal scale to the intersection of the 70 per cent efficiency line. From the intersection of this line, proceed horizontally to the proper vertical scale where a direct . value of the required fuel burning rate is given. These values are rates of burning while firing device is in operation and are not indicative of hourly fuel consumption. By use of the respective charts the firing rates for the various fuels will be found to be: coal 36.8 lb per hour, oil 3.2 gal per hour, and gas 460 cu ft per hour. Table 4. Building Load Factors and Demands op Some Detroit Buildings3 Building Classification Clubs and Lodges............................................................ Hotels........ Printing........... Offices.................................................................................. Apartments Retail Stores ` Auto Sales and Service. __________________ _______ Banks.. . . Churches........ ............. ........... ;....................................... Department Stores . Theatres...... Load Factor 6.318 0.316 0.287 0.263 . 0.255 0.238 0.223 0.203 0.158 0.138 0.126 Lb or Demand per Hr per Sq Ft or Equivalent Installed Radiator Surface 0.184 0.207 0.217 0.209 0.225 0.182 0.248 0.158 0.152 0.145 0.151 ` Loc. Cit. Note 5. ' Standard Code Regulating the Installation of Gravity Warm Air Heating Systems in Residences (9th edition) and the Technical Code for the Design and Installation of Mechanical Warm Air Heating Systems, may be obtained from the National Warm Air Heating and Air Conditioning Association, 50 W. Broad St., Columbus, Ohio. 240 Chapter 12. Heat and Fuel Utilization MAXIMUM DEMANDS AND LOAD FACTORS In one form of district heating rates, a portion of the charge is based upon the maximum demand of the building. The maximum demand may be measured in several different ways. It may be taken as the instan taneous peak or as the rate of use during any specified interval. One method is to take the average of the three highest hours during the winter. These figures are available for a number of buildings in Detroit, as shown in Table 4. . These maximum demands were measured! by an attachment on the condensation meter and therefore represent the amounts of condensation' passed through the meter in the highest hours, rather than the true rate at which steam is supplied. There might be slight differences in these two quantities due to time lag and to storage of condensate in the system, but wherever this has been investigated it has been found to be negligible. The load factor of a building is the' ratio of the average load tq the maximum load and is an index of the utilization habits. . Thus,, in Table 4' the . theatres, operating for, short hours, have a load factor of 0.126 as- compared with the figure of 0.318 for clubs and lodges. ; \1 PROBLEMS IN PRACTICE 1 What will be the cost per year of heating a building with gas, assuming that the calculated hourly heat loss is 92,000 Btu based on 0 F, which, includes 26,000 Btu for infiltration? The design temperatures are 0 F and 72 F. The normal heating season is 210 days, and the average outside temperature during the heating season is 36.4 F. The heating efficiency will be 75 per cent. The heating plant will be. thermostatically controlled, and a temperature of '55 F. will be maintained,from 11 p.m. to 7 a.m. Assume that the price of gas is . 7 cents per 100,000 Btu of fuel consumption, and disregard the loss of, heat through open windows and doors. .. . ............. The average hourly temperature is : - ta = (?2 X 16) +^(5 X 8) _ 66 3 p . : The maximum hourly heat loss will be H = 92,000 - non . " = 79,000 Btu. M = 79,000 (66.3 - 36.4) X 24 X 210 ------i00[000 X 0.75 X (72 - 0):~ = 2204 6 hundred thousand Btu; 2204.6 X 0.07 = $154.34 = cost per year of heating the buiiding. 2 What factors, should be taken' into consideration when determining' the efficiency at which a. fuel will be burned? Manufacturers' catalogs usually, give equipment efficiencies obtained under test con-, ditions. These values do' not allow for poor attendance, defects in installation, or poor' draft.. Such efficiencies' do not consider heat radiatedfrom the outside of-the equipment/ but in many cases this heat is utilized. 241 Heating Ventilating Air Conditioning Guide 1938 3 If 20 tons of coal having a calorific value of 13,000 Btu per pound are burned in a warm air furnace and produce 286,000,000 Btu at the bonnet, what is the efficiency of the furnace? Number of Btu at bonnet________________________=___e_f_f_ic_iency. ' Number of tons X calorific value X number of pounds in one ton 286,000,000 X 100 = 55 per cent. 20 X 13,000 X 2000 4 4 Make a rough approximation of the gas required to heat a building located in Chicago, 111., assuming that the calculated heating surface requirements are 1000 sq ft of hot water radiation based on design temperatures of 0 F and 70 F. Chicago has 800-Btu mixed gas, and 6315 degree-days. Using Fig. 3, the fuel consumption for a design temperature of 0 F with 800-Btu gas is found to be 0.08 cu ft of gas per degree-day per square foot of hot water radiation. 0.08 X 6315 X 1000 = 505,200 cu ft. '> 54 A certain building has a maximum heat loss of 250,000 Btu per hour in --15 F weather. How many tons of fuel will be required to maintain a temperature of 70 F during a 260-day heating season in which the average temperature is 39 F? The heating value of the fuel is 13,200 Btu per pound and the efficiency of com bustion is 60 per cent. :. 250,000 (70 - 39) 260 X 24 (70 + 15) 13,200 X 0.60 X 2000 ' ' 6 Which item may be determined more closely, the heating value of a fuel or the efficiency of its combustion? : . The. heating .values of oil, gas, and solid fuels are closely determinable, whereas the efficiency of burning depends on the particular equipment chosen and the skill used in handling it. . 7 4 In nn office building, the thermostats are set to maintain 70 F from 7 a.m. to 5 p.m. and 50 F during the rest of the time. When the outside temperature is 30 F, how much saving might be expected because the temperatures are lowered? Under the above conditions the building becomes 50 F by 11 p.m. and warms up to 70 F by 8 a.m. ' . ' A temperature of 70 F is maintained during 9 hours, and one of 50 F during 8 hours; the temperature would average about 60 F during the 7 hours required for cooling down and warming up. The average is 60.4 for the 24 hours. (The average temperature calcu lated would have been 68.3 F, had the warming and cooling periods been neglected.) The saving is ^75 X 100 = X 100 = 24 per cent. 8 How does the heat capacity of a structure influence the saving made by carrying lower temperatures during.the night? . The heat storage capacity of the walls prevents rapid dropingof temperatures at night time and delays the warming up process in the morning. In an extreme case, the building would not reach the lowered temperature by the time the higher temperature is called for in the morning. But under any conditions, the saving made by lowering the tem perature can be correctly estimated by using the average temperature observed over the 24-hour period as a factor, as in Question 7. . 4 What are some of the miscellaneous factors that may cause actual fuel consumption to vary from the theoretical fuel requirements as calculated by the use of heat losses, temperature difference, and fuel burning efficiency? . The opening of windows; abnormally high or low inside temperatures;,other .sources of heat, such as.machinery or lights; sun effect; high occupancy; mid unusual winds. , 242 Chapter. 13 HEATING BOILERS . Cast-Iron Boilers,1.; Steel Boilers,. Special Heating Boilers, . :' Gas-Fired Boilers, Hot Water Supply Boilers, Furnace Design, Heating Surface, Testing and Rating Codes, Output Effic iency. Selection of Boilers, Connections and Fittings,.Erection,' Operation and Maintenance, Boiler Insulation STEAM and hot water boilers for low pressure heating work are built in a wide variety of types, many of which are illustrated in the Catalog Data Section, and are classified as (1) cast-iron sectional, (2) steel fire tube, (3) steel water tube, and (4) special. 1 ... ,. ; . CAST-IRON BOILERS........................... .......... Cast-iron boilers may be of rohnd pattern with circular grate and hori zontal pancake sections joined by push nipples and tie rods, or of rec tangular pattern with vertical sections; -The latter type may be either of outside header construction where each section is independent of the other and the water and steam connections are made externally, through these headers, or assembled with push nipples and tie rods, in which'case the water and steam connections are internal. Cast-iron boilers usually are shipped knocked down to facilitate hand ling at the place of installation where assembly is made. One of the chief advantages of cast-iron boilers is that the separate sections can be taken into or out of basements and other places more or less inaccessible after the building is constructed. This feature is of importance in making repairs to or replacing a damaged or worn-out boiler and should be given consideration in the original selection. -Sufficient space should be pro vided ip the boiler room for assembling the boiler and for disassembling it conveniently if repairs are needed. With the outside header type of boiler a damaged section in the middle of the boiler can be removed without disturbing the other sections so side clearance should be provided. Capacities of cast-iron boilers range from that required for- small residences up to about 18,000 sq ft of steam radiation. For larger loads, cast-iron boilers must be installed in multiple, or a steel boiler, must be used.. In most cases cast-iron boilers are limited to working pressures, of 15 lb for steam and 30 lb for water. Special types are built for hot water supply which will withstand higher, local water pressures. STEEL BOILERS - Two general classifications may be applied to steel boilers: first, with regard to the relative position of water and hot gases,distinguished^ fixe tube or water tube; second, with regard to arrangement of furnace and 243 Heating Ventilating Air Conditioning Guide 1938 flues, as (1) horizontal return tubular (HRT) boilers, (2) portable (selfcontained) firebox boilers with either water or fire tubes, and (3) water tube boilers of the power type. Fire tube boilers are constructed so that the water available to produce steam is contained in comparatively large bodies distributed outside of the boiler tubes, the hot gases passing within the tubes. In water lube boilers, the water is circulated within the boiler tubes, heat being applied ex ternally to them. . The-HR T boiler is the oldest type and consists of a horizontal cylin drical shell with fire tubes, enclosed in brickwork to form the furnace and Table 1. Practical Combustion Rates for Small Coal-Fired Heating Boilers Operating on Natural Draft of from 14 in. to in. Water3 , . Kind op Coal No. 1 Buckwheat Anthracite Anthracite Pea Anthracite Nut and Larger Bituminous * Sq Ft Grate Up to 4 5 to 9 10 to 14 15 to 19 20 to 25 Up to 9 10` to 19 20 to 25 . Up to 4 5 to 9 10 to 14 15 to 19 20 to 25 Up to 4 5 to 14 15 and above Lb op Coal per Sq Ft - Grate per Hour ' 3 4 m 5 5 6 8 9 . 10 11 13 9.5 12 15.5 aSteel boilers usually have higher combustion rates for grate areas exceeding 15 sq ft than those indicated in this table. ' combustion chamber. All heating surfaces and the interior of the boiler are accessible for both cleaning and inspection. Horizontal return tubular boilers, especially the larger sizes, should be^uspended from structural columns and beams independent of the brick setting. Small HRT boilers sometimes are supported by brackets resting on the brick setting. Portablefirebox boilers are the more generally used type of steel heating boilers, their outstanding characteristic being the water-jacketed firebox which eliminates virtually all brickwork. They are shipped in one piece from the factory and'come to the job ready for immediate hook-up to jpiping. They may be of welded or riveted construction and have either water or fire tubes. Manufacturers' catalogs usually list heating surface as well as grate area. The elimination of brickwork also makes this type the most compact of steel boilers as well as the lowest in first cost. Water tube boilers. For large heating loads water tube boilers are quite frequently used. They usually require more head room than other types of. boilers but require considerably less floor space and make possible a . 244 Chapter 13. .Heating Boilers much higher, rate of evaporation per square foot of heating surface, with proper setting, baffling and draft. Water`tube boilers, used for heating purposes are either completely supported, insplattd and, encased in steel, or else brick set, supported on structural steel columns and have the brick setting encased in an insulated steel housingjto prevent air infiltration and to minimize heat losses. For large heating loads at a,high rate of evapora tion,"such boilers should be operated at pressures above 15 lb per square inch with a pressure-reducing valve on the.connection to the heating main. SPECIAL HEATING BOILERS A special, type, of boiler, known as the magazine feed boiler, has been developed for the burning of small sizes of anthracite and coke. These are built of both cast-iron and steel, and have a large fuel carrying capacity which results in longer firing petiods than would be the case with the standard types using buckwheat sizes ofcoal. Special attention must be given to insure adequate draft and proper chimney sizes and connections. Oil-burner boiler units, in which a special boiler has been designed with a furnace shaped to meet the general requirements qf oil burners or are specially adapted to one particular burner have been developed by a number of manufacturers. These usually are. compact units with the burner and all controls enclosed within an insulated steel jacket.' Ample furnace, volume is provided for efficient combustion, and the heating surfaces are proportioned for effective heat transfer. Consequently, higher efficiencies are obtainable than with the ordinary coal fired boiler converted to oil firing. , GAS-FIRED BOILERS . Gas boilers have assumed a well-defined individuality. The usual boiler is sectional in construction with a number of independent burners placed beneath the sections. In most boilers each section has its own burner. In all cases the sections are placed quite closely together, much closer than would be possible when burning a soot-forming fuel. The effort of the designer is always to break the hot gas up into thin streams, so that all particles, of the heat-carrying gases can come as close as possible to the heat-absorbing surfaces. Because there is no fuel bed resistance and because the gas company supplies the motive power to draw in the air necessary for combustion (in the form of the initial gas pressure), draft losses through gas boilers are low. See Chapter 11. HOT WATER SUPPLY BOILERS Boilers for hot water supply are classified as direct, if. the water heated passes through the boiler, and as indirect, if the water heated does not come in contact with the water or steam, in the boiler. . Direct heaters are built to operate at the pressures found in city supply mains and are tested at pressures from 200 to 300 lb per square inch. The life of direct heaters depends almost entirely on the scale-making properties of the water supplied. If; water temperatures are maintained below 140 F the life of . .the heater will be much longer than- if higher temperatures are used, owing to decreased scale formation and minimized corrosion, below 140 iF. Direct water heaters in some cases-are designed to burn refuse.and garbage. .> 245 Heating Ventilating Air Conditioning Guide 1938 Indirect heaters generally consist of steam boilers in connection-with heat exchangers of the coil or tube types which transmit the heat from the steam to the water. This type of installation has the following advantages: 1. The boiler operates at low pressure. 21 The boiler is protected from scale and corrosion. 3. The scale is formed in the heat exchanger in which the parts to which the scale is attached can be cleaned or replaced. The accumulation of scale does not affect efficiency although it will affect the capacity of the heat exchanger. _4. Discoloration of water may be prevented if the water supply comes in contact with only non-ferrous metal. . : . ' Where a steam heating system is. installed, the domestic hot water usually is obtained from an indirect heater placed below the water line of the boiler. '. " '` : ' " FURNACE DESIGN V' . Good efficiency and. proper boiler performance.'are dependent on cor rect furnace design embodying sufficient' volume for; burning the par ticular fuel at hand, which requires thorough mixing of air and gaseS ;at a high temperature with a velocity low enough to permit complete conri bpsdon of aif the Volatiles/ On account of the small amount of volatiles 'contained in coke/'anthracite, and semi-bituminous coal, these fuels;caij be` btirnecl efficiently with less furnace volume-than is requiredTor; bU tuminquspq'at, the combustion space being proportioned adcording to .the amount of-volatifes present:' - : Combustion should take place before the gases are cooled by the boiler heating surface, and the volume of the furnace must be sufficient for this purpose. The'furnace temperature must be maintained sufficiently High to produce complete combustion,,thus resulting in a higher COt content and . the . absence of CO.' Hydrocarbon. gases ignite at temperatures varying from 1000 to 1500 F. ' . .. . r. -> -The question of furnace proportions, particularly in regard to mechani cal -stoker installations, has been given some consideration by-various manufacturers' associations. Arbitrary values have been recommended for minimum dimensions. A customary rule-of-thumb method of figuring furnace volumes is to allow 1- cu ft Of space for a maximum heat release of 50,000 Btu per hour. This value is equivalent to allowing approxi mately 1 cu ft for each developed horsepower, and-it is approved by most smoke prevention organizations. The setting height will vary with the type of stoker. In an overfeed stoker, for instance, all the volatiles'must be burned in the combustion chamber and, therefore, a greater distance should be allowed than for an underfeed stoker where a considerable portion of the gas is burned while passing through the incandescent fuel bed. The design of the boiler also may affect the setting height, since in certain types the gas enters the tubes immediately after leaving the combustion chamber, while in others it passes over a bridge wall and toward the rear, thus giving a better opportunity for. combustion by obtaining a longer travel before entering the tubes. .... ... To secure suitable furnace, volume, especially;for mechanical stokers or oil burners, it often is necessary either to pit the stoker or oil burner, or . 246 . Chapter 13. Heating Boilers where water line conditions and.headroom permit, to raise the boiler on a brick foundation setting.,. . : . Smokeless combustion of the more volatile bituminous coals is furthered by the use of mechanical stokers. (See Chapter 11.) Smokeless com bustion in hand-fired boilers burning high volatile solid fuel is aided (1) by the use of double grates with down-draft through the upper grate, (2) by the use of a curtain section through which preheated auxiliary air is introduced over the fire toward the rear of the boiler, and (3) by the intro duction of preheated air through passages at the front of the boiler. All three methods depend largely on mixing secondary air with the partially burned volatiles and causing this mixture to pass over an incandescent fuel bed, thus tending to secure more complete combustion than is pos sible in boilers without such.provision. - HEATING SURFACE : Boiler heating surface is that portion of the surface of the heat transfer apparatus in contact with the fluid being heated on one side and the gas or refractory being cooled on the other side. Heating surface on. which the fire shines is known as direct or radiant surface and that in Contact with hot gases only, as indirect or convection surface. The amount of heating surface, its distribution. and the temperatures on either side thereof influence the capacity of any boiler.' ' Direct heating surface is more valuable than indirect per square foot because it is subjected to a higher temperature and also, in the case of solid fuel, because it is in position to receive the full radiant energy of the . fuel bed. The heat transfer capacity of a radiant heating surface may be as high as 6 to 8 times that of an indirect surface. This is one of the reasons why the water legs of some boilers have been extended, especially in the case of stoker firing where the extra amount of combustion chamber secured by an extension of the water legs is important. For the same reason, care should' be exercised in building a refractory Combustion chamber in an -oil-burning boiler so as not to screen any more of this valuable surface with refractories than is necessary for good combustion. The effectiveness of the heating surface depends on its cleanliness, its location"in the boiler, and the shape of the gas passages. Investigations1 by the U. S. Bureau of Mines show that: . 1. A boiler in which the heating surface is arranged to give long gas passages of small cross-section will be more efficient than a boiler in which the gas passages are short and of larger cross-section. ." 2. The efficiency of a water tube boiler increases as the free area between individual tubes decreases and as the length of the gas pass increases. ,: 3. By inserting baffles so that the heating surface is arranged in series with respect, to the gas flow, the boiler efficiency will be increased. ' The area of the gas passages must not be so small as to cause excessive resistance to the flow, of gases where natural draft is employed. Heat Transfer . Rates .. ^~r- Practical rates of heat transfer in heating boilers will average abput ' 3300 Btu per sq ft per hour for hand-fired boilers and 4000 Btu; per sq- ft 16ee U. S. Bureau of Miner Bulletin No. IS/ Tbe Transmission of Heat into Steam Boilers. .. - Heating Ventilating Air Conditioning Guide 1938 per hour for mechanically fired boilers when operating at design load. When operating at maximum loads these values will run between 5000 and 6000 Btu per sq ft per hour.' Boilers operating under favorable conditions at the above heat transfer rates will give exit gas temperatures that are considered consistent with good practice. r ' TESTING AND RATING CODES 1 The Society has adopted three solid fuel testing codes, a solid fuel rating code and an oil fuel testing code. A.S.H.V.E. Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers--Codes 1 and 2--(Revision of June 1929)*, are intended to provide a method for conducting and reporting tests to:determine heat efficiency and performance' characteristics. A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers--Code No. 3--(Edition of 1929)* is intended for use with A.S.H.V.E. Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers*4. The object of this test code is to specify the tests to be conducted and. to provide a method for conducting and reporting tests to determine the efficiencies arid performance of the boiler. The A.S.H.V.E. Standard Code for Testing Steam Heating Boilers Burning Oil. Fuel5 is intended, to provide a standard method for con ducting and reporting tests to'determine the heating efficiency and per formance characteristics when' oil fuel is used, with steam heating, boilers. Steel :Heating Boilers Ratings ' The Steel Heating Boiler Institute has adopted a method for the ,rating of low pressure boilers based on theif physical characteristics arid expressed in square feet of steam or water radiation or in Btu per hourias given in Table 2. The following requirements are included in this Code: : 1. One square foot of steam, radiation is to be considered equal to the emission of 240 Btu per hour and'one square, foot of water radiation is to be considered equal to emission of 150 Btu per hour. 1 < - 2. The rating of a boiler expressed in square feet of steam radiation in which solid fuel hand fired is used is based on the amount equal to 14 times the heating surface of the boiler in square feet. . , . .. . . .. ' 3. The rating of a boiler expressed in square feet of steam radiation in which solid fuel mechanically fired, or in which oil or gas is burned. is based on the amount equal to 17 times the heating surface of the boiler in square feet. ' 4. Heating surface is to be expressed in square feet and include those surfaces in the boiler which are exposed to the products of combustion on one side and water on the other. In measuring surfaces, the outer, tube areas are to be considered! When a boiler has the water leg height increased the heating surface noted in the published ratings are not to be increased. .. 5. A.grate area is to be considered as an area of the grate surface expressed in square feet and measured in the plane of the top surface of the grate; For double grate boilers the grate.surface is to be considered as the area of the upper grate plus one-quarter of the area of the lowet grate. . 6. The grate area of a boiler for rating as determined in No. 2 is to be not less than that determined by the following formulae: . For boilers with ratings 1800 sq ft to 4000 sq ft of steam radiation:' Gratp Art.a = ../Catalogue Rating (in square feet steam radiation) -- .200 ". ni M ' 25.5 .., ' Fordefinitions of designload and maximum load see pages'251 and 252. See A.S.H.V.E. Transactions, Vol. 35, 1929, p. 12. Also Chapter 45. 4See A.S.H.V.E. Transactions, VoL 36, 1930, p. 35. Also Chapter 45. See A.S.H.V.E. Transactions, >Vol.'37, 1931, p. 23; - Also Chapters. ' 248 - Chapter 13.' Heating Boilers Table 2. Standard Steel Heating Boiler Ratings Hand Fired Capacity Rating Mechanically Fired Capacity Rating Steam Water Radiation Radiation Sq Ft Sq Ft Btu per Hr Heating Grate Steam Water Surface Area Radiation Radiation Sq Ft Sq Ft Sq Ft Sq Ft 1,800 2,200 2,600 3,000 3,500 4,0004,500 5,000 6,000 7,000 8,500 10,000 12,500 15,000 17,500 20,000 25,000 30,000 35,000 2,880 3,520 4,160 4,800 5,600 6,400 > 7,200 8,000 9,600 11,200 13,600 16,000 20,000 24,000 28,000 32,000 40,000 48,000. 56,000 432,000 129 7.9 2,190 ' 3,500 528,000 158 8.9 2,680 4,280 624,000 186. 9.7 3,160 5,050 720,000 215 , 10.5 3,650 5,840 840,000 250 11.4 4,250 6,800 960,000 286 12.2 4,860 7,770 1,080,000 322 13.4 5,470 8,750 1,200,000 358 14.5 6,080 9,720 1,440,000 429 16.4 7,290 11,660 1,680,000 500 18.1 8,500 13,600 2,040,000 60S 20.5 10,330 16,520 2,400,000, 715 22.5 12,150 19,440 3,000,000 .. . 893 25.6 .15,180. 24,280 3,600,000. 1,072 28.41 18,220 29,150 4,200,000 1,250 30.9 21,250 34,000 4,800,000 1,429 33.2 24,290 38,860 6,000,000 1,786 37.4 30,360 48,570 7,200,000 2,143 41.2 36,430 58,280 8,400,000 2,500 44.7 42,500 68,000 Btu per Hr 1 -525,600 ; 643,200 758,400 876,000 1,020,000 1,166,400 1,312,800 1,459,200 1,749,600 2,040,000 2,479,200 2,916,000 3,643,200 4,372,800 5,100,000 5,829,600 7,286,400 8,743,200 10,200,000 Furnace Volume Bituminous Coal Cu Ft 15.7 19.2 22.6 26.1 30.4 34.8 39.1 43.5 52.1 60.8 73.8 86.8 108.5 130.2 151.8 173.5 216.9 260.3 303.6 . - ^Adopted by the Steel Healing Boiler Institute in cooperation with the Bureau ofStandards, United States Department of Commerce Simplified Practice Recommendation R 157-35. For boilers with ratings 4000 sq ft of steam radiation and larger: Crate Art>a = /Catalogue Rating (in square feet steam radiation) -- 1500 col Jl 16.8 .r 7. The volume for furnaces in which solid fuel is burned is to be considered as the cubical content of the space between the bottom of the fuel bed and the first plane of entry into or between the tubes. Volume of furnaces in which pulverized liquid fuel or gaseous fuel is burned are to be considered as the cubical content of the space between the hearth and the first plane of entry into or between the tubes. No minimum furnace volume is to be specified for mechanical fired boilers burning anthracite. 8. The furnace volume for a boiler, with a fating as determined in No. 3 in which oil, gas or bituminous coal stoker fired is burned is not to be less than one cubic foot for every 140 sq ft of steam rating. ; 9. The average height of furnace for the rating determined in No. 3 in which bitu minous coal, stoker fired is burned is not to be less than that determined graphically in Fig. 1 or mathematically by the following formula: . - SA : <3> where - H average furnace height, inches as determined by the following formula; , ' 1r1r - 1A2F - W12LF . R = stoker fired boiler rating, square foot steam radiation:- ' A = plan area of firebox, square feet measured'attfieTiottom of the fuel bed. F = furnace volume, cubic feet. Heating Ventilating Air Conditioning Guide 1938 W = average width of furnace, measured at the bottom of the fuel bed, feet. L = length of furnace, feet. If the furnace is longer than the fuel bed or contains a bridge wall, the total length of the furnace may be used except that this length is not to exceed W. . BOILER OUTPUT Boiler output as defined in A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers (Code No. 3) is the quantity of heat available at the boiler nozzle with the boiler normally insulated. It should be based on actual tests conducted in accordance with this code. This output is usually stated in Btu and in square feet of equivalent heat ing surface (radiation). According to the A.S.H.V.E. Standard Code for Fig. 1. Furnace Heights foe Stoker Fired Boilers and Bituminous Coal Rated in Square Feet Steam Radiation . - .. ' *\ Rating Steam Heating, Solid Fuel, Hand-Fired Boilers, the performance data should be given in tabular or curve form on the following items for at least five outputs ranging from maximum down to 35 per cent of maxi mum: (1) fuel available, (2) combustion-rate, (3) efficiency, (4) draft tension, (5) flue gas temperature. The only definite restriction placed on setting the maximum output is that priming shall not exceed 2 per cent. These curves provide complete data regarding the performance of the boiler under test conditions. Certain other pertinent information, such as grate area, heating surface and chimney dimensions is desirable also in forming an opinion of how the boiier will perform in actual service. The output of large heating boilers is frequently stated in terms of boiler horsepower instead of in Btu per hour or square feet of equivalent radiation. . ' ... 250 Chapter 13. Heating Boilers Boiler Horsepower: The evaporation of 34.5 lb of water per hour from and at 212 F which is equivalent to a heat output of 970.2 X 34.5 = 33,471.9 Btu per hour. . . .. ,. . Equivalent Evaporation: The amount of water a boiler -would evaporate, in pounds per hour, if it received feed water at 212 F.and vaporized it at this same temperature and at atmospheric pressure.' ; It is usually considered that 10 sq ft of boiler heating surface will pro^- duce a rated boiler horsepower. A rated boiler horsepower in turn can carry a design load of from TOO to 140 sq ft of equivalent radiation. Itis apparent, therefore, that 1 sq ft of boiler heating surface can carry a design load of from 10 to 14 sq ft of equivalent radiation, or somewhat more if the boiler is forced above rating. The application of these values is discussed under the heading Selection of Boilers. BOILER EFFICIENCY . . The term efficiency as. used, for guarantees .of ..boiler performance .is usually construed as follows: .' , 1. Solid Fuels. The efficiency of the boiler alone is the ratio .of-the heat absorbed by .. the water and steam in the boiler per pound of combustible burned on- the grate to the . calorific-value of 1 lb of combustible as fired. The combined efficiency of boiler, furnace and grate is the ratio of the heat absorbed by the water and steam in the boiler, per pound of ftielas fired to the calorific value of 1 lb of fuel as fired. ' - - -'2.' Liquid Fuels.' The combined efficiency: of. boiler,- furnace and burner is the ratio of the heat absorbed by the water and steam iri: the boiler per pound of fuel to the calorific value,of 1 lb of fuel. ........ .. . , ' .. ' . Solid- fuel boilers usually show an efficiency of 50: to 75 per cent when , operated under favorable conditions at their rated capacities. Infor mation bn the combined efficiencies of, boiler, furnace and burner has resulted from research conducted at Yale University in cooperation with the A.S.H.V.E. Research Laboratory -and the American Oil Burner Association*.. . SELECTION OF BOILERS Estimated Design. Load: The load, stated in Btu per hour or equiva lent direct radiation, as estimated by the purchaser for the conditions of inside and outside temperature for which the aniount of installed radiation was determined is the sum of the heat emission of the radiation to be actually installed plus the allowance for the heat loss of the connecting piping plus the heat requirement for any apparatus requiring heat con nected with the system (A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers--Edition of April, 1932). The estimated design load is the sum of the following three items7: _. 1. The estimated heat emission in Btu per hour of the connected radiation (direct, indirect or central fan) to be installed. . .- -. - , :, . 2. The estimated maximum heat in Btu per hour required to supply water heaters or other apparatus to be connected to the boiler. . .. - 8Study of the Characteristics of Oil Burners and Heating Boilers, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E.Transactions, Vol. 37,1931, p. 517), A Study of Intermittent Operation of Oil Burners, by L. E. Seeley and J. H. Powers (A.S.H.V.E. Transactions, VoLJJ8>J32, p. 317). .,. 'A.S.H.V.E.' Code of Minimum Requirements for the Heating and Ventilation of Buildings (Edition of 1929). * ,. 251 Heating Ventilating Air Conditioning Guide 1938 3. The estimated heat emission in Btu per hour of the piping connecting the radiation and other apparatus to the boiler. Estimated Maximum Load: Construed to mean the load stated in Btu per hour or the equivalent direct radiation that has been estimated by the purchaser to be the greatest or maximum load that the hoiler will be called upon to carry. (A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers--Edition of April, 1932.) The estimated maximum load is given by: . 4. The estimated increase in the normal load in Btu per hour due to starting up cold radiation. This percentage of increase is to be based on the sum of Items 1, 2. and: 3 and the heating-up factors given in Table 3. . . : Table 3. Warming-up Allowances for Low Pressure Steam and Hot Water Heating Boilers3! bi c______________________ Design Load (Representing Summation or Items 1,2, and 3,4 Percentage Capacity to Add for Warming Up . Btu per Hour , Equivalent Square Feet of Radiation*! Up to 100,000 100,000 to 200,000 200,000 to 600,000 600,000 to 1,200,000 1,200,000 to i,800,000 . Above 1,800,000 Up to 420 420 to 840 840 to 2500 !; 2500 to 5000 5000 to 7500 Above 7500 ' 65 60 55 50 45 40 This table is taken from the A.S.H.V.E. Code of Minimum Requirements for the Heating and Venti lation of Buildings, except that the second column has been added for convenience in interpreting the design load in terms of equivalent square feet of radiation. . `- bSee also Time Analysis in Starting Heating Apparatus, by Ralph C. Taggert (A.S.H.V.E. Transac tions. Vol. 19,1913, p. 292); Report of A.S.H.V.E. Continuing Committee on Codes for Testing and Rating Steam Heating Solid Fuel Boilers (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 35); Selecting the Right Size Heating Boiler, by Sabfn Crocker (Heating, Piping and Air Conditioning, March, 1932). . This table refers to hand-fired, solid fuel boilers. A factor of 20 per cent over design load is adequate when automatically-fired fuels are used (see Fig. 3). . ' - d240 Btu per square foot. . Other things to be considered are: 5. Efficiency with hard or soft coal, gas, or oil firing, as the case may be. 6. Grate area with hand-fired coal, or fuel burning rate with stokers, oil, or gas. 7. Combustion space in the furnace. __ 8. Type of heat liberation, whether continuous or intermittent, or a combination of both. . 9. Miscellaneous items consisting of draft available, character of attendance, pos sibility of future extension, possibility of breakdown and headroom in the boiler room. Radiation Load ; The connected radiation (Item 1) is determined by calculating the heat losses in accordance with data given in Chapters 5, 6 and 7, and dividing by 240 to change to square feet of equivalent radiation as explained in Chapter 14. For hot water, the emission commonly used is 150 Btu per square foot, but the actual emission depends on-the temperature of the medium in the heating units and of the surrounding air. (See Chapter 14.) Although it is customary to use the actual connected load in equivalent square feet of radiation for selecting the size of boiler, this connected load usually represents a reserve in heating capacity to provide for infiltration in the various spaces of the building to be heated, which reserve, however, - ' *Loc. Cit. Note 7. ' 252 '' Chapter 13. Heating Boilers is not in use at all places at the same time, or in any one place at all times. Fpr a further discussion of this subject see Chapter 6. Hot Water Supply Load . When the hot water supply (Item 2) is heated by the building heating boiler, this load must be taken into consideration in sizing the boiler. The 1000 900 600 700 900 900 400 300 FUEL CAPACITY.LB. ' FUEL AVAILABLE, LB. FUEL DEPTH,IN. ' *51 414 10 ASH SULPHUR MOISTURE BTU PER LB. 9.67 g.66 3.00 13,655 Fig. 2. Typical Performance Curves for a 36-in. Cast-Iron Sectional Steam Heating Boiler, Based on the A.S.H.V.E. Code for Rating Steam . Heating Solid Fuel Hand-Fired Boilers allowance to be made will depend on the amount of water heated and its temperature rise. A good approximation is to add 4 sq ft of equivalent radiation for each gallon of water heated per hour through a temperature range of 100 F. For more specific information, see Chapter 43. Piping Tax (Item 3) ' It is common practice to add a flat percentage allowance to the equivalent connected radiation to provide for the heat loss; from bare and covered pipe in the: supply and return lines. The use of a flat allowance of 25,per cent for steam systems and 35 per cent for hot water systems is preferable to ignoring entirely the load due to heat loss from the supply 253 Heating Ventilating Air Conditioning Guide 1938 and return' lines, but better practice, especially when there is much bare pipe, is to compute the emission from both bare and covered pipe surface in accordance with data in Chapter 39. A chart is shown in Fig. 3 indicat ing percentage allowances for piping and warming-up which are applic able to automatically-fired heating plants using steam radiation. With direct radiation served by bare supply and return piping the percentages may be higher than those stated, while in the case of unit heaters where the output is concentrated in a few locations, the piping tax may be 10 per cent or less. ' Warming-Up' Allowance The warming-up.allowance represents the load due to heating the boiler and contents to operating temperature and.heating, up cold radiation and piping. (See Item 4.) The factors to be used for determining the allowance to be made should be selected from Table 3 and should be applied to the estimated design load as determined by Items 1, 2 and 3. While in every case the estimated maximum load will exceed the design load if adequate heating response is to be achieved, there is however, no object in over-estimating the allowances, as the only effect would; be to reduce the time of warming-up by .a few minutes. Otherwise, it might result in firing the boiler unduly and increasing the cost of operation. Performance-Curves for Boiler Selection : : -- In the selection of a boiler to meet the estimated load, the A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuef Hand-Fired Boilers recommends the use of performance curves based on actual tests con ducted in accordance with the A.S.H.V.E. Performance Test Code for Steani Heating Solid Fuel Boilers (Code No. 3), similar to the typical curves shown in Fig. 2. It should be understood that performance data apply to test conditions and that a reasonable allowance should be made for decreased output resulting frqm soot deposit,' poor fuel or inefficient attention.' ~ . : - . . . ' : .. - , 254 Chapter 13. Heating Boilers Selection Based on Heating Surface and Grate Area Where performance curves are not available, a good general rule for conventionally-designed boilers is to provide 1 sq ft of boiler heating surface for each 14 sq ft of equivalent radiation (240 Btu per square foot) represented by the design load consisting of connected radiation, piping tax and domestic water heating load. As stated in the section on Boiler Output, this is equivalent to allowing 10 sq ft of boiler heating surface per boiler horsepower. In this case it is assumed that the maximum load including the warming-up allowance will be provided for by operating the boiler in excess of the design load, that is, in excess of the 100 per cent rating on a boiler-horsepower basis. . Due to the wide variation encountered in manufacturers' ratings for boilers of approximately the same capacity, it is advisable to check the grate area required for heating boilers burning solid fuel by means of the following formula: G = CX FXE where . G = grate area, square feet. H -- required total heat output of the boiler, Btu per hour (see Selection of Boilers, p. 251). - C = combustion rate in pounds of dry coal per square foot of grate area per hour, depending on the kind of fuel and size of boiler as given in Table 1. F = calorific value of fuel, Btu per pound. E = efficiency of boiler, usually taken as 0.60. Example 1. Determine the grate area for a required heat output of the boiler of 500,000 Btu per hour, a combustion rate of 6 lb per hour, a calorific value of 13,000 Btu per pound, and an efficiency of 60 per cent. 500,000 G= 6 X 13,000 X 0.60 10.7 sq ft The boiler selected should have a grate area not less than that deter mined by Formula 4. With small boilers where it is desired to provide sufficient coal capacity for approximately an eight-hour firing period plus a 20 per. cent reserve for igniting a new charge, more grate area may be required depending upon the depth of the fuel pot. ' Selection of Steel Heating Boilers Boiler ratings previously described under the Steel Heating Boiler Institute's Boiler Rating Code are intended to correspond with the esti mated design load based on the sum of items 1, 2 and 3 outlined on pages 252 and 253. Insulated residence type boilers for oil or gas may carry a net load expressed in square feet of steam radiation of not more than 17 times the square feet of heating surface in the boiler, provided the boiler manufacturer guarantees the boiler to be capable of operating at a maximum output of not less than 150 per cent of net.load rating with over all efficiency of not less than 75 per cent with at least two different makes of each type of standard cbmmercial burner recommended by the boiler manufacturer. If the' heat loss from the piping system, exceeds 20 per cent of the installed radiation, the excess is to be considered as a part of the net load. ' ; 1 ' '' . ' ' ' '' ' : i\ Heating Ventilating Air Conditioning Guide 1938 When the estimated heat emission of the piping (connecting radiation, and other apparatus to the boiler) is not known the net load to be con sidered for the boiler may be determined from Table 4. Selection of ,Gas-Fired Boilers Gas-heating appliances should be selected in accordance with the percentage allowances'given in Fig. 3. These factors are for thermo statically-controlled systems; in case manual operation is desired, a warming-up allowance of 100 per cent is recommended by the A.G.A. A gas boiler selected by the use of the A.G.Ai factors will be the minimum Table 4. Boiler Ratings Based on Net Load* Hand Fired Ratings Mxchanicallt Fired Ratings . '- ' Steam Radiation Sq Ft 1,800 2,200 2,600 3,000 3;500 4,000 4,500 5,000 6,000 7,000 8,500 10,000 12,500 15,000 17,500 20,000 25,000 30,000 35,000 . Net Loadb Steam Radiation Sq Ft i- 1,389 1,702 2,020 2,335 2,732' 3,135 3,540 3,945 4,770 5,608 . 6,885 8,197 . 10,417 ' 12,500 14,584 . 16,667 20,834 25,000 29,167 Steam Radiation 8q Ft i Net Load** Steam Radiation Sq Ft 2,190 2,680 3,160 3,650 4,250 4,860 5,470 6,080 7,290 . 8,500 ' 10,330 12,150 15,180 18,220 21,250 24,290 30,360 36,430 42,500 ^ . . .. 1,695 2,089 2,461 2,853 3,335 3,830 4,330 4,834 5,850 6,885 8,490 10,125 .12,650 15,183.; 17,708 20,242 25,300 30,359 35,417 . . ' ^Adopted by the Steel Healing Boiler Institute in cooperation with the Bureau of Standards, United States department of Commerce Simplified Practice Recommendation R 167SS.- . V .; * hThe net ioad is made up by the sum of the estimated design load, items 1 and 2 (pages 252 and 253)'. AJJ- net loads are expressed in 70 F. For hand filed boiler ratings less than 1800 eq ft ofsteam or 2880 sq ft of . water and mechanically fired boiler ratings of 2190 sq ft of steam or 3500'sq ft of water, apply the factor 1.3 to the net load to determine the boiler size. For water boilers use the equivalent net load for steam boilers of similar physical size. .^ . size boiler which'can carry the load. From a fuel economy standpoint, it may be advisable to select a somewhat larger boiler;and then, throttle the gas and air adjustments as required. This will tend to give a low stack temperature with high efficiency and at the same time provide reserve capacity in case the load is under-estimated or more is added in the future.- Conversions; ' The conversion of a coal or oil boiler to gas burning is simpler than the reverse since little.furnace volume need, be provided for- the proper com bustion of gas. When a solid fuel boiler of 500 sq ft (or less) capacity is converted to gas burning, the necessary gas heat units should be approxi mately double the connected load. The presumption for a . conversionjob is that the boiler is installed and probably will not be made larger; 256 Chapter 13. Heating Boilers therefore, it is a matter of setting a gas-burning rate to obtain best results with the available surface. Assuming a combustion efficiency of 75 per cent for a conversion installation the boiler output would be 2 X 0.75 = 1.5 times the connected load, which allows 50 per cent for piping tax and pickup. In converting large boilers, the determination of the re quired Btu input should not be done by an arbitrary figure or factor but should be based on a detailed consideration of the requirements and characteristics of the connected load. t An efficient conversion installation depends upon the proper size of flue connection. Often the original smoke breeching between the boiler and chimney is too large for gas firing, and in this case, flue orifices can be used. They are discs provided with an opening of the size for the gas input used in this boiler. The size should be based on 1 sq in. of flue area for each 7500 hourly Btu input. ' If dampers are found in the breeching they should be locked in position so'that they will not interfere with the normal operation of the gas burners at maximum flow. In the case of large boiler conversions, automatic damper regulators proportion the position of the flue dampers to the amount of gas flowing and may be substituted for existing dampers. Generally in residence conversions automatic dampers are not of the proportioning type but close the flue during the off periods of the gas burners. Automatic shutoff dampers - should be located between the backdraft diverter and the chimney flue. Automatic dampers are usually designed to operate with electric, contact mechanism, but frequently an arrangement is utilized which functions with mechanical fluid or gas pressure. `^ Physical Limitations . , As it will usually be found that several boilers will meet the speci fications, the final selection of the boiler may be influenced by other con siderations, some of which are; - 1. Dimensions of boiler. .. 2. Durability under service. 3. Convenience in firing and cleaning. 4. Adaptability to changes in fuel and kind of attention. ' . 5. Height of water line. In large installations, the use of several smaller boiler units instead of one larger one will obtain greater flexibility and economy by permitting the operation, at the best efficiency, of;the required number of units according to the heat requirements. Space Limitations ' Boiler rooms should, if possible, be situated at a central point with respect to the building and should be designed for a maximum of natural light. The space in front of the boilers should be^ sufficient for firing, stoking, ash removal and cleaning or renewal of flues, and should be at least 3 ft greater than the length of the boiler firebox. ' A space of at least 3 ft should be allowed on at least one side of every boiler for convenience of erection and for accessibility to the various . 257 Heating Ventilating Air Conditioning Guide 1938 dampers, cleanouts and trimmings. The space at the rear of the boiler should be ample for the chimney connection and for cleanouts. With large boilers die rear clearance should be at least 3 ft in width. The boiler room height should be sufficient for the location of boiler accessories and for proper installation of piping. In general the ceiling height for small steam boilers should be at least 3 ft above the normal boiler water line. With vapor heating, especially, the height above the boiler water line is of vital importance. When steel boilers are used, space should be provided for the removal and replacement of tubes. '. - CONNECTIONS AND FITTINGS The velocity of flow through the outlets of low pressure steam heating boilers should not exceed 15 to 25 fps if fluctuation of the water line and undue,entrainment of moisture are to be avoided. Steam or water outlet connections preferably should be the full size of the manufacturers' tapping and should extend vertically to the maximum height available above the boiler. For gravity circulating steam heating systems, it isrecommended that a Hartford Loop, described in Chapter 16, be utilized in making the return connection. . Particular attention should be given to fitting connections to secure con formity with the A.S.MJi. Boiler Construction Code for Low Pressure . Heating Boilers. Attention is called in particular to pressure gage piping, water gage connections and safety valve capacity. Steam gages should be fitted with a water seal and a shut-off consisting of a cock with either a tee or lever handle which is parallel to the pipe when the cock is open. Steam gage connections should be of copper or brass when smaller than 1 in. I.P.S? if the gage is more than 5 ft from the boiler connection, and also in any case where the connection is less than y2 in. I.P.S. Each steam or vapor boiler should have at least one water gage glass and two or more gage cocks located within the range of the visible length of the &lass. The water gage fittings or gage cocks may be direct connected to the boiler, if so located by the manufacturer, or may be mounted on a separate water column. No connections, except for combustion regu lators, drains or steam gages, should be placed on the pipes connecting the water column and the boiler. If the water column or gage glass is con nected to the boiler by pipe and fittings, a cross, tee or equivalent, in which a cleanout plug or a drain valve and piping may be attached,- should be' placed in the water connection at every right-angle turn to facilitate cleaning. The water line in steam boilers should be carried at the level specified by the boiler manufacturer. * Safety valves should be capable of discharging all the steam that can be generated by the boiler without allowing the pressure to rise more than 5 lb above the maximum allowable working pressure of the boiler. This should be borne in mind particularly in the case of. boilers equipped with mechanical stokers or oil burners where the amount of grate area, has little significance as to the steam generating capacity of the boiler. .* 258 M-S.Af.E. Code, Identification of Piping Systems. 258 Chapter 13. Heating Boilers Where a return header is used on a cast-iron sectional boiler to distribute the returns to both rear tappings, it is advisable to provide full size plugged tees instead of elbows where the branch connections enter the return tappings. This facilitates cleaning sludge from the bottom of the boiler sections through the large plugged openings. An equivalent clean out plug should be provided in the case of a single return connection. Blow-off or drain connections should be made near the boiler and so arranged that the entire system may be drained of water by. opening the drain cock. In the case of two or more boilers separate blow-off connec tions must be provided for each boiler on the boiler side of the stop valve on the main return connection. Water service connections must be provided for both steam and water boilers, for refilling and for the addition of make-up water to boilers. This connection is usually of galvanized steel pipe, and is made to the return main near the boiler or boilers. For further data on pipe connections for steam and hot water heating systems, see Chapters 16 and 17 and theA.S.M.E. Boiler Construction Code for Low Pressure Heating Boilers. . .. Smoke Breeching and Chimney Connections. The breeching or smoke pipe from the boiler outlet to the chimney should be air-tight and as short and direct as possible, preference being given to long radius and 45-deg instead of 90-deg bends.' The breeching entering a brick chimney should not project beyond the .flue lining and where practicable it should be grouted from the inside of the chimney. A thimble or sleeve grout usually is provided where the breeching enters a brick chimney. - Where a battery of boilers is connected into a breeching each boiler should be provided with a tight damper. The breeching for a battery of boilers should hot be reduced in size as it goes to the more remote boilers. Good connections made to a good chimney will usually result in a rapid response by the boilers to demands for heat. . . ERECTION. OPERATION, AND MAINTENANCE The directions of the boiler manufacturer always should be read before tiie assembly or installation of .any boiler is started, even though the contractor may be familiar with the boiler. All joints requiring, boiler putty or cement which cannot be reached after assembly is complete must be finished as the assembly progresses. The following precautions should be taken in all installations to prevent damage to the boiler: - . , 1: There should be provided proper and convenient drainage connections for use if the boiler is not in operation during freezing weather. 2. Strains on the boiler due to movement of piping during expansion should be prevented by suitable anchoring of piping and by proper provision for pipe expansion and contraction. . . 3. Direct impingement of too intense local heat upon any part of the boiler surface, as with oil burners, should be avoided by protecting the surface with firebrick or other refractory material. . ' 4. Condensation must flow back to the boiler as rapidly and uniformly as possible. Return connections should prevent the water from backing out of the boiler. . 5. Automatic boiler feeders and low water, cut-off devices which shut off the source 259 Heating Ventilating Air Conditioning Guide 1938 of heat if the water in the boiler falls below a safe level are recommended for boilers mechanically fired. . Boiler Troubles A complaint regarding boiler operation generally will be found to be due to one of the following: 1. The boiler fails to deliver enough heat. The cause of this condition may be: (a) poor draft; (A) poor fuel; (c) inferior attention or firing; (d) boiler too small; () improper piping; (f) improper arrangement of sections; (g) heating surfaces covered with soot; and (A) insufficient radiation installed. 2. The water line is unsteady. The cause of this condition may be: (o) grease and dirt in boiler; (A) water column, connected to a very active section and, therefore, not showing actual water level in boiler; and (c) boiler operating at excessive output. 3. Water disappears from gage glass. This may be caused by: (a) priming due to grease and dirt in boiler; (A) too great pressure difference between supply and return piping preventing return of condensation; (c) valve closed in return line; (d) connection of bottom of water column into a very active-section or thin waterway; and (e) improper connections between boilers in battery permitting boiler with excess pressure to push returning condensation into boiler with lower pressure. 4. Water is carried over into steam main. This may be caused by: (a) grease and dirt in boiler; (A) insufficient steam dome or too small steam liberating area; (c) outlet con nections of too small area; (d) excessive rate of output; and (e) water level carried higher than specified. ' ' 5. Boiler is slow in response to operation of dampers. This may be due to; {a) poor draft resulting from air leaks into chimney or breeching; (A) inferior fuel; (e) inferior attention; (d) accumulation of clinker on grate; and (e) boiler too small for the load. 6. Boiler requires too frequent cleaning of flues. This may be due to: (a) poor draft; (A) smoky combustion; (c) too low a rate of combustion; and (d) too much excess air in firebox causing chilling of gases. . 7. Boiler smokes through fire door. This may be due to: (a) defective draft in chimney or incorrect setting of dampers; (A) air leaks into boiler or breeching; (e) gas outlet from firebox plugged with fuel; (d) dirty or clogged flues; and (e) improper reduction in breeching size. . Cleaning Steam Boilers All boilers are provided with flue clean-out openings through which the heating surface can be reached by means of brushes or scrapers. Flues of solid fuel boilers should be cleaned often to keep the surfaces free of soot or ash. Gas boiler flues and burners should be cleaned at least Once a year. Oil burning boiler flues should be examined periodically to deter mine when cleaning, is necessary. \ The grease used to lubricate the cutting tools during erection of new piping systems serves as a carrier for sand and dirt, with the result.that a scum of fine particles and grease accumulates on the surface of the water in all new boilers, while heavier particles may settle to the bottom of the boiler and form sludge. These impurities have a tendency to cause foaming, preventing the generation of steam and causing an unsteady water line. '. This unavoidable accumulation of oil and grease should be removed by blowing off the boiler as follows: If.not already provided, install.a surface blow connection of at least 1 id. nominal pipe size with outlet extended to within 18 in. of the floor or to sewer, inserting a valve in line close to boiler. Bring the water line to center of outlet, raise steam pres sure and while fire is burning briskly open valve in blow-off line. When 260 Chapter 13.- Heating Boilers . pressure recedes close valve and repeat process, adding water at intervals to maintain proper level. As a final operation bring the pressure in the boiler to about 10 lb, close blow-off, draw the fire or stop burner,- and open drain valve. After boiler has cooled partly, fill and flush out several times before filling it to proper water level for normal service. The use of soda, or any alkali, vinegar or any acid is not recommended for cleaning heating boilers because of the difficulty of complete removal and the possibility of subsequent injury, after the cleaning process has been completed. Insoluble compounds have been developed which iare effective, but special instructions on the proper cleaning compound and directions for its use in a boiler, as given by the boiler manufacturer, should be carefully followed. : It is common practice when starting new installations to discharge heating returns to the sewer during;the first week of operation. This prevents the passage of grease, dirt or other foreign matter into the boiler and consequently may avoid the necessity of cleaning the boiler. During the time the returns are being passed to the sewer, the feed valve should be cracked sufficiently to maintain the propSr water level in the boiler. . Care of Idle Heating Boilers . Heating boilers are often seriously damaged during summer months due chiefly to corrosion resulting from the combination of sulphur from ' the fuel with the moisture in the cellar air. At the end of the heating season the following precautions should be taken: ' . 1.. All heating surfaces should be cleaned thoroughly of soot, ash and residue, and the ' .heating surfaces of steel boilers should be given a Coating of lubricating oil.on the fire side. ' ' . `` 2. All machined surfaces should be coated with oil or grease. 3. Connections to the chimney should be cleaned and in case of small boilers the pipe should be placed in a dry place after cleaning. . 4. If there is much moisture in the. boiler room, it is-desirable to drain the boiler to prevent atmospheric condensation on the heating surfaces of the boiler when they are below.the dew-point temperature. Due to the hazard of some one inadvertently building a fire in a dry boiler, however, it is safer to keep the boiler filled with water. A hot water system usually is left filled to the expansion tank. 5. The grates and ashpit should be cleaned: 6. Clean and repack the gage glass if necessary. . , 7. Remove any rust or other deposit from exposed surfaces by scraping with a wire brush or sandpaper. After boiler is thoroughly cleaned, apply a coat of preservative paint where required to external parts normally painted. " 8. Inspect all accessoriCs'of the boiler carefully to see that they are in good Working order. In this connection, oil all door hinges, damper bearings and regulator1 parts. ' _______ _ BOILER INSULATION ' . Insulation for cast-iron boilers is of .two general types: (1) plastic material or blocks wired on, cemented and covered with canvas or duck; and.(2) blocks, sheets or plastic material covered with a metal.jacket furnished by the boiler manufacturer. Self-contained steel firebox boilers usually are insulated with blocks, cement and canvas, or rock wool blankets ; .HRT boilers are brick set and do not require, insulation beyond that provided in the setting. It is essential that the insulation on a boiler 261 Heating Ventilating Air Conditioning Guide 1938 and adjacent piping be of non-combustible material.as even slow-burning insulation constitutes a dangerous fire hazard in case of low water in the boiler. , . PROBLEMS IN PRACTICE . 1 What basic requirements of boiler design are to be accomplished with a combination boiler and oil burner unit? . Combination units vary widely but in general, the basic requirements of design depends upon a combustion chamber of proper design and arranged for the flame shape with adequate heating surface for the complete combustion of the fuel. ' 2 # What is the normal rating range of each type of boiler? a. Cast-iron boilers are rated at from 200 to 18,000 sq ft EDR. b. Steel boilers are rated at from 300 to 50,000 sq ft EDR. . . 3 9 What factors contribute to economical fuel operation in low pressure boilers burning coal or oil? ..... ., a. Proper furnace volume for complete combustion. . . .: b. Arrangement of heating surfaces in series to create a turbulent and scrubbing contact of gases against the convective surfaces. .. c. Rapid internal water circulation which will remove steam bubbles from the water side of heating surfaces and allow other steam bubbles to be formed. ' Rapid disen gagement of steam bubbles increases the steam generating efficiency of each unit area of heating surface, and thereby lowers flue gas temperatures. . 4 What equipment is usually directly attached to a low pressure heating boiler? ... .... For coal burning steam boilers: water column, water gage, tri-cocks, steam gage, lever pop safety valve, boiler damper regulator. ', For coal burning hot water boilers: damper regulator,- altitude gage, thermometer, relief valve. . . .. For oil burning boilers, the damper regulators are omitted and the following additional equipment is usually attached: automatic water feeder, low water cutout, a pressure control, and a water temperature control. These are generally furnished by the oil burner manufacturer and do not come with the boiler. 5 What 'general precautions 'regarding the boiler should be faken to make sure a proposed heating installation will work properly? .' a. Select the right size and type of boiler. 1 b. Be sure the combustion space is proper for the type of fuel burned. c. .;Allow sufficient space around the boiler for cleaning. ' . d. Secure proper height and area.of chimney and connecting breeching. . e. Clean the boiler thoroughly and provide surface blowoff connections and bottom . blowoff connections for periodic cleaning after operation is begun. /. See that the boiler heating surface is cleaned at regular periods. -. g. Check flue gas temperatures and make a flue gas analysis at least once a month. h. Secure information and advice from boiler manufacturer. 5 What is the average heat transmission rate in heating boilers in Btu per sq ft of heating surface per hour? 3500 for coal burning boilers; 4200 for oil burning boilers. 262 Chapter 14 . '. RADIATORS AND GRAVITY CONVECTORS ' Heat Emission of Radiators and Convectors, Types of Radi- .. ators. Output of Radiators, Heating Effect, Heating Up the " Radiator and Convector, Enclosed Radiators, Convectors, Selection, Code Tests, Gravity-Indirect Heating Systems THE accepted terms for heating units are: (1) radiators, for direct surface heating units, either exposed, enclosed, or shielded; which emit a large percentage of their heat by radiation: and (2) convectors, for heating units haying a large percentage of extended fin surface and which emit heat principally by convection. Convectors are dependent' upon enclosures to provide the circulation by gravity of large volumes of air. HEAT EMISSION OF RADIATORS AND CONVECTORS All heating units emit heat by radiation and convection. The resultant heat from these processes depends upon whether or not the heating unit is exposed or enclosed and upon the contour and surface characteristics of the material in the units. An exposed radiator emits less than half of its heat by radiation, the amount depending upon the size and number of sections. When the radiator is enclosed or shielded, radiation is further reduced. The balance of the emission is by conduction to the air in contact with the heating surface, and the resulting circulation of the air warms by convection. A convector emits practically all of its heat by conduction to the air - surrounding it and this heated air is in turn transmitted by convection to the rooms or spaces to be warmed, the heat emitted by radiation being negligible. _ TYPES OF RADIATORS . Present day radiators may be classified as. tubular, wall, or window types, and are generally made of cast iron. Catalogs showing the many . designs and patterns available now include a junior size which is more compact than the standard unit. Pipe Coils . .- ' Pipe coils are assemblies of standard pipe or tubing (1 in. to 2 in.) which are used as radiators. In older practice these coils were commonly used in factory buildings, but now wall type radiators are most frequently used for this service. When coils are used, the miter type assembly is to be 263 Heating Ventilating Air Conditioning Guide 1938 preferred as it best cares for expansion in the pipe. Cast manifolds or headers, known as branch tees, are available for this construction. OUTPUT OF RADIATORS The output of a radiator can be measured only by the heat it emits. The old standard of comparison used to be square feet of actual surface, but since the advance in radiator design and proportions, the surface area alone is not a true index of output. (The engineering unit of output is the Mb or 1000 Btu.) However, during the'period Of transition from the old to the new, radiators may be referred to in terms of equivalent square feet. For steam service this is based on an emission of 240 Btu per hour per square foot. Table 1. Variation in Dimensions and Catalog Ratings of 10-Section Tubular Radiators ;No. of Tubes.. ' .3 Width of Radiator_________________ Inches ' 4.6-5.1 Length per Section____ .Inches . 2.5 4 " 6.0-7.0 2.5 5 8.0-8.9 2.5 67 9.1-10.4 ; 11.4-12.8 2.5. 2.5-3.0 Height wits Legs--Inches Heat Emission-- Equivalent Square Feet . 13-14 16-18 20-21 .22-23 25-26 30-32 36-38 15.0-17.5 20.0-21.3 20.0-26.7 25.0-30:9 30.0-36.7 20.0-22.5 25 - 25.0-27.5 33.3-35.0 40.0-42.5 28.5 2,5.0-31.2 30.0-33.9 32.5-39.8 40.0-48.6 50.0-56.5 20 30 35 37.5-40.0 1 50 . .- 60 25 0-32 5 30 0-38 3 36.7-45.0 40.0-45.2 50.0-53.5 63.3-62.5 70.0-75.4 Output of Tubular Radiators . -Table 1 illustrates the difficulty in tabulating tubular radiator outputs since there is so much variation in design between the products of the different manufacturers. Only on the four-tube and six-tube sizes is. there any practical agreement;.in output value. The heat emission values appear as square feet butare entirely'empirical, being based on the heat emission of the radiator and not on the measured surface. . Output of Wall Radiators ` An average value of 300/Btuper actual square foot of surface area per hour has been found for wall radiators one section- high placed with their bars vertical. Several recent tests1 show that this value will be reduced from 5 to 10 per cent if the radiator is placed near the ceiling with the bars horizontal and in an air temperature exceeding 70 F. When radiators are placed near the ceiling, there is usually so noticeable a difference in temperature between the floor leyel and .the ceiling that it becomes dif ficult to heat the living zone of-a room satisfactorily. University of Illinois. Engineering Experiment Station Bulletin No. 223, p. 30. 264 Chapter 14. Radiators and Gravity Convectors Output of Pipe Coils The heat emission of pipe coils placed vertically on a wall with the pipes horizontal is given in Table 2. This has been developed from avail able data and does not represent definite results of tests. For such coils the heat emission varies as the height of the coil. The heat emission of each pipe of ceiling coils, placed horizontally, is about 126 Btu, 156 Btu, and 175 Btu per linear foot of pipe, respectively, for 1-in., lj^-in., and lj^-in. coils. Table 2. Heat Emission of Pipe Coils Placed Vertically on a Wall (Pipes Horizontal) Containing Steam at 215 F and Surrounded with Air at 70 F Btu per linear foot of coil per hour (not linear feet of pipe) firen op Pipe Single row............................................................ 'p .... . Four.------------ :---------------------- ---------- ------ -...... Six.............-- ---------------- -------------- -................ Eight..................... .................. ................................ Ten.. __--..................-...................................... Twelve. --............................................. -........... 1 In. 132 252 440 567 651 732 812 IK ! 162 312 545 702 796 907 1005 IK l. 185 348 616 793 907 1020 1135 Effect of .Paint The prime coat of paint on a radiator has little effect on the heat output, but the finishing coat of paint does influence the radiation emission. Since this is a surface effect, there is no noticeable change in the convection loss. Thus, the larger the proportion of direct radiating surface, the greater will be the effect of painting on the radiation. Available tests are on oldstyle column type radiators which gave results shown in Table 3. Table 3. Effect of Painting 32-in. Three Column, Six-Section Cast-Iron Radiator3 Radiator No. 1 2 3 4 ,,. Finish ' Bare iron, foundry finish.............-- One coat of aluminum bronze.------Gray paint`dipped; _______________ One coat dull black Pecora paint__ Area Sq Ft 27 27 27 27 Coefficient of Heat Trans. Btu Relative Heating Value Per Cent 1.77 1.60 1.78 1.76 100.5 90.8 101.1 100.0 Comparative Tests of Radiator Finishes, by W. H. Severns (A.S.H.V.E. Transactions, Vol. 33, 1927, p. 41). Effect of Superheated Steam Available research data indicate that there is probably a decrease in heat transfer rate for a radiator or gravity convector with superheated steam in comparison with saturated steam at the same temperature. The decrease is probably small for low temperatures of superheats-and additional tests are necessary with varying degrees of superheat to establish accurate comparisons for all types of radiators and convectors'. *Test8 of Radiators with Superheated Steam, by R. C. Carpenter (A.S.H.V.E. Transactions. Vol. 7, 1901, p. 206). . 265 Heating Ventilating Air Conditioning Guide 1938 HEATING EFFECT For several years the heating effect of radiators has been considered by engineers in order to use it for the rating of radiators and in the design of heating systems. Heating effect is the useful output of a radiator, in the comfort zone of a room, as related to the total input of the radiator3. ^CoJd room temp in deg F -22 i 5.52 lb Test R-E2, 5-tube rad -22 z -2.7 s 5.62 lb Test R-E61. 3-tube rad a 5.42 lb Test R-E1Q. 1-tube panel rad -2.9 530 lb Test R-2c, (Bui 223) wall rad 0 12 3 .5 6 7 8 Net lb of steam condensed per hour 23 4 56 HEIGHT ABOVE FLOOR IN FEET Fig. 1. Room Temperature Gradients and Steam Condensing Rates for Four Types of Cast-Iron Radiators with a.Common Temperature at the 60-In. Level Note that the steam condensations are practically the same for all four radiators when the same air temperature of 69 F is maintained at the 60-in. level. 'Ccfid room temp in deg F 6.68 lb Test R-E56,5-tube rad. 6.48 15 Test R-E20. 3-tube rad. 6.12 (b Test R-C58,1-tube panel rad. 55.0 (b Test R-2c, (Bui. 223) wall rad.. 0 1 2 3.4 5 6 7 8 Net lb of steam condensed per hour HEIGHT ABOVE FLOOR IN FEET Fig. 2. Room Temperature Gradients and Steam Condensing Rates for Four Types of Cast-Iron Radiators with a Common Temperature at the 30-In. Level Note that the steam condensations are different for all four radiators when the same air temperature of 68 F is maintained at the SO-in. level. . The results of tests conducted at the University of Illinois are shown in Figs. 1 and 24.* For the four types of radiators shown, the following con clusions are given: '. The Heating Effect of Radiators, by Dr. Charles Brabbet (A.S.H.V.E. Transactions, Vol. 33. 1927, p. 33). The Application of the Eupatheoscope for Measuring the Performance of Direct Radiators and Con vectors in Terms of Equivalent Temperature, by A. C. Willard, A. P. Kratz and M. K. Fahnestock (A.S.H. V.E. Transactions, Vol. 39. 1933, p. 303). 4Steam Condensation an Inverse Index of Heating Effect, by A. P. Kratz and M. K. Fahnestock (A.S. H.V.E. Transactions, Vol. 37, 1931, p. 475). - 266 Chapter 14. Radiators and Gravity Convectors 1. The heating effect of a radiator cannot be judged solely by the amount of steam condensed within the radiator. 2. Smaller floor-to-ceiling temperature differentials can be maintained with long, low, thin, direct radiators, than is possible with high, direct radiators. 3. The larger portion of the floor-to-ceiling temperature differential in a room of average ceiling height heated with direct radiators occurs between the floor and the breathing level. 4. The comfort level (approximately 2 ft-6 in. above floor) is below the breathing line level (approximately 5 ft-0 in. above floor), and temperatures taken at the breathing line may not be indicative of the actual heating effect of a radiator in the room. The comfort-indicating temperature should be taken below the breathing line.level. 5. High column radiators placed at the sides of window openings do not produce as comfortable heating effects as long, low, direct radiators placed beneath window openings8. HEATING UP THE RADIATOR AND CONVECTOR The maximum condensation occurs in a heating unit when the steam is first turned on6. Fig. 3 shows a typical curve for the condensation rate in pounds per hour for the time elapsing after steam is turned into a castiron radiator. The data are from tests on old style column type radiators. TIME ELAPSED AFTER STEAM TURNED INTO RADIATOR. MINUTES Fig. 3.` Chart Showing the Steam Demand Rate for Heating-Up a Cast-Iron Radiator with.Free Air Venting and Ample Steam Supply In practice-the rate of steanrsupply to the heating-unit whrle-heatirig up is frequently retarded by controlled elimination of air through air vsdves or traps. Automatic control valves may also retard the supply of steam. ENCLOSED RADIATORS The general effect of an enclosure placed about a direct radiator is to ' restrict the air flow, diminish the radiation and, when properly designed, improve the heating effect. Recent investigations7 indicate that in the design of the enclosure three things should be considered: - . ^Effect of Two Types of Cast-Iron Steam Radiators in Room Heating, by A. C. Willard and M. K. Fahnestock {Heating, Piping and Air Conditioning, March, 1930, p. 185). ;r "The Cooling and Heating Rates of a Room with Different Types of Steam Radiators and Convectors, by A. P. Kratz, M. K. Fahnestock and E. L. Broderick (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, April, 1937, p. 251). . 'University of Illinois, Engineering Experiment Station Bulletin Nos. 192 and 223, and Investigation of Heating Rooms with Direct Steam Radiators Equipped with Enclosures and Shields, by A. C. Willard, A. P. Kratz, M. K. Fahnestock and S. Konzo (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 77). * 267 Heating Ventilating Air Conditioning Guide 1938 1. There should be better distribution of the heat below the breathing.line level to produce greater heating comfort and lowered ceiling temperatures.. 2. The lessened steam consumption may not materially change the radiator heating performance. . 3. The enclosed radiator may inadequately heat the space. A comparison between a bare or exposed radiator (A) and the same radiator with a well-designed enclosure (B), with a poorly-designed enclosure (C), and with a cloth cover (D) will illustrate the relative heating effects; In Fig. 4 the curve (B) reveals that the enclosed radiator used less steam than the exposed radiator, but.gave a satisfactory .heating performance. A well-designed shield placed over a radiator gives about the sftme heating effect. Curve (C) shows the unsatisfactory effects produced by improperly designed enclosures. Curve (D) shows that the ; Chapter 14. Radiators and Gravity Convectors room by convection thereby resulting in a form of gravity convector, generally better results are obtained with specially designed units which permit a free circulation of a larger volume of air at moderate tempera tures. Since air stratifies according to temperature, moderate delivery temperatures at the outlet of the enclosure reduce the temperature dif ferential between the floor and ceiling and accordingly accomplish the desired heating effect in the living zone. Fig. 5 shows a typical built-in convector. . The heating element con sisting of a large percentage of fin surface, is usually shallow in depth and effect of a cloth cover extending downward 6 in. from the top of the radiator was to make the performance unsatisfactory and inadequate. Practically all commercial enclosures and shields for use on- direct radiators are equipped with water pans for the purpose of adding moisture to . the air in the room. Tests8 show that an average evaporative rate of about 0.235 lb per square foot of water surface per hour may .be obtained from such pans, when the radiator is steam hot and the relative humidity in the room is between 25 and 40 per cent. This source of supply of moisture alone is not adequate to maintain a relative humidity above 25 per cent on a zero day. ,. . ' CONVECTORS OR CONCEALED HEATERS Although any standard radiator may be concealed in a cabinet dr other enclosure so that the greater percentage of heat is conveyed to the University of Illinois, Engineering Experiment Station Bulletin No. 230, p. 20. 268 Fig. 5. . Typical. Concealed Convector Using Specially Designed Heating Unit placed low in the enclosure in order to produce maximum chimney effect in the enclosure. The}air enters the enclosure near the floor line just below the heating element, is moderately heated in passing through the core and delivered to the rodm through an opening near the top of en closure. Since the air can only enter the enclosure at the floor line,, the cooler air in the room which always lies at this level, is constantly being withdrawn and replaced by the warmer air.' This air movement accom plishes the desired'reduction in temperature differentials'and assures maximum comfort in the living zone. . The Convector Manufacturers, Association has adopted the A.S.H.V.E. Standard9 in the formulation of it's ratings and has compiled a tentative A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radiation (Steam), (A.S.H.V.E. Transactions. Vol. 37. 1931. p. 367); (Hot Water). (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 237). ' . ' . . 269 Heating Ventilating Air Conditioning Guide 1938 standard of heating effect allowances for various enclosure heights to be included in the ratings by its members. ' All published ratings bearing the title C.M.C. Ratings (Convector Manu facturers Certified Ratings') indicate that the convectors have been tested in accordance with the A.S.H.V.E. Code by an impartial and disinterested laboratory and that the ratings have been approved by the Standardiza tion Committee of the Convector Manufacturers Association. Concealed heaters or convectors are generally sold as completely built-in units. The enclosing cabinet should ..be designed with suitable air inlet and outlet grilles to give the heating element its best performance. Tables of capacities are catalogued for various lengths, depths and heights, and combinations are available in several styles for installations, such as the wall-hung type, free-standing floor type, recess type set flush with wall or offset, and the completely concealed type. Most of these types may be arranged with a top outlet grille in a plane parallel with the floor, although the front outlet is practically standard. In cases where enclosures are to be used but are not furnished by the heater manufacturer, it is important that the proportions of the cabinet arid the grilles be so designed that they will not impair the performance of the assembled convector. It is impor tant that the enclosure or housing for the convector fit as snugly as pos sible so that the air to be heated must pass through the convector and cannot be by-passed in the enclosure. . The output of a convector, for any given length and depth-, is a variable of the height. - Published ratings are generally given in terms of equiva lent square feet, corrected for heating effect. However, an extended surface heating unit is entirely different structurally and physically from a direct radiator and, since it has no area measurement corresponding to the heating surface of a radiator, many engineers believe that the per formance of convectors should be stated in Btu's. ' For steam convectors, as for radiators, 240 Btu per hour may be taken as an equivalent square foot of radiation. .. . ... . RADIATOR AND CONVECTOR SELECTION Since the capacity of a radiator varies as the 1.3 power and a convector10 as the 1.5 power of .the temperature difference between the.inside of radiator and surrounding air it is obvious that for other than 70 F room temperatures the heat emission will be other than 240 Btu per square foot of rating. Therefore in selecting the size of radiator or convector to be used it is necessary to correct for this difference. Table 4 shows factors by which radiation requirements, as determined by dividing heat load by 240, shall be multiplied to obtain proper radiator or corivector sizes from < published rating tables for room temperatures ranging between 50 and 80 F as well as for steam or water temperatures from 150 to 300 F. For other room and heating medium temperatures the factor is determined by the following formulae: . For radiators: ________ .. ,, /215 - 70V-3. C*~\ <, -I") . . .. '"Factors Affecting the Heat Output of Convectors, by A. P. Kratz, M. K. Fahnestock, and E. L. Brod erick (A.S.H.V.E. Transactions, Vol. 40. 1934. p. 443). 1 , '. 270 . Chapter 14. Radiators and Gravity Convectors For convectors: where ,, /215 - 65\i-s Cs " V U-k ) Cs - correction factor. Is = steam temperature, degrees Fahrenheit. If = room temperature, degrees Fahrenheit. !i = average inlet air temperature, degrees Fahrenheit. Table 4. Correction Factors for Direct Cast-Iron Radiators and Convector Heaters3 Steam Phbss. Approx. Gage Abe. Steam or Water Temp. Factors por Direct Cast-Iron Radiators Room Temperature F Factors por Convectors Inlet Air Temperature F Vacuum Lb per F In. Hg Sq In. 80 75 70 65 60 55 50 80 75 70 65 60 55 50 22.4 20.3 17.7 14.6 10.9 6.5 LbperSqln. 1 .6 15 '27. 52 3.7 4.7 6.0 7.5 9.3 11.5 .15.6 21 30 42 67 150 2.58 2.36 2.17 2.00 1.86 1.73 1.62 3.14 2.83 2.57 2.35 2.15 1.98 1.84 160 2.17 2.00 1.86 1.73 1.62 1.52 1.44 2.57 2.35 2.15 1.98 1.84 1.71 1.S9 170 1.86 1.73 1.62 1.52 1.44 1.35 1.28 2.15 1.98 1.84 1.71 1.59 1.49 1.40 180 1.62 1.52 1.44 1.35 1.28 1.21 1.15 1.84 1.71 1.59 1.49 1.40 1.32 1.24 190 1.44 1.35 1.28 1.21 1.15 1.10 1.05 1.59 1.49 L40 1.32 1.24 1.17 1.11 200 1.28 1.21 1.15- 1.10 1.05 1.00 0.96 1.40 1.32 1.24 1.17 1.11 1.05 1.00 215 1.10 1.05 1.00 0.96 0.92 0.88 0.85 1.17 1.11 1.05 1.00 0.95 0.91 0.87 230 0.96 0.92 0.88 0.85 0.81 0.78 0.76 1.00 0.95 0.91 0.87 0.83 0.79 0.76 250 0.81 0.78 0.76 0.73 0.70 0.68 0.66 0.83 0.79 0.76 0.73 0.70 0.68 0 65 270 0.70 068 0.66 0.64 0.62 0.60 6.58 0.70 0.68 0.65 0.63 0.60 0.58 0.56 300 0.58 0.57 0.5S 0.53 0.52 0.51 0.49 0.56 0.54 0.53 0.51 0.49 0.48 0.47 To determine the heater size for a given space, divide the heat loss in Btu per hour by 240 and multiply the result by the proper factor from the above table. ' To determine the heating capacity of a heater at other than standard conditions, divide the heating capacity at standard conditions by the proper factor from the above table. CODE TEST FOR RADIATORS AND CONVECTORS As previously indicated, the output of radiators and convectors is still designated by the terms of older practice, but this is gradually giving place to an engineering method of designating heat emission. The A.S.H.V.E. has adopted the following standards: Code for Testing Radiators (1927); Codes for Testing and Rating Concealed Gravity Type Radiation (Steam, 1932, and Hot Water, 1933). For steam services the actual condensation weight is taken without any allowance for heating effect; for hot water services the weight of circulated water is used without allowance for heating effect. In all cases the total heat transmission varies as the 1.3 power for radiators11 and the 1.5 power for convectors12 of the temperature difference between that inside the.radiator and the air in the room, and is expressed in Btu or Mb per hour. Standard test conditions specify either a steain pressure of 1 lb gage (215 F), or hot water at 170 F and a room temperature of 70 F for radi ators,or an inlet air temperature of 65 F for convectors. The heating .capacity of a steam radiator or steam convector is determined as follows: ____________ Hi = WJttt (1) uLoc. Cit. Note 9. wLoc. Cit. Notes 9 and 10. 271 Heating Ventilating Air Conditioning Guide 1938 where ,,. Ht = Btu per hour under test conditions. Ws = condensation in pounds per hour. ' hfg = latent heat in Btu per pound. Ht may be converted to standard conditions of code ratings by using - the proper correction factor from the following formulae: j For radiators: ' C. /'21S - 70V-3 \T,-T,J / 145 V V-T, - Tr) (2) For convectors: .. Cs /215 - 65\l-5 / 150\ \ Ts - T\ ) \TS-Ti) (3) The output under standard conditions will be: -. . Hs = Cs fft - where .- Cs = correction factor. Ts = steam temperature during test, degrees Fahrenheit. 7'r = room temperature during test, degrees Fahrenheit. 7'i = inlet air temperature during test, degrees Fahrenheit. Hs = heat emission rating under standard conditions, Btu per hour. . (4) ''[ .: Similarly, for hot water convectors, the output under test conditions may be determined as follows: ' ... .. //- FK (0, - 0,) 36^ . - -. (5) where ................... H = Btu per hour under test conditions: . W = pounds of water handled during test. 0i .= average temperature of inlet water, degrees Fahrenheit. 0t = average temperature of outlet water, degrees Fahrenheit. t = duration of test, seconds. ... : : : To. convert test results to standard conditions, the following correction factor is used: . .. . / 170 - 65 \ls /N 105 : A1-5 C = ( 9. +.0, l.=| 01 + 0. ) V 2 -" 7 V " 7 (6) It.has been shown that when the exponent .1.5 is used-the range of error is less than 3 per cent13 for convectors. . .; , GRAVITY-INDIRECT HEATING SYSTEMS14 The heating units for this system are usually of the extended surface type for steam or hot water, arid are installed about as shown in Fig"6. The temperature and volume of the air leaving the register must be great wLoc. Cit.- Note 10. - ,4For further information on this subject see A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings (edition of 1929) and Mechanical Equipment of Buildings, by Harding and Willard. Vol. 1. second edition, 1929. ... . 272 Chapter 14. Radiators and Gravity Convectors enough so that in cooling to room temperature the heat available will just equal the heat loss during the same time. In cases where ventilation is a requirement, the air volume needed may become so large that the entering air temperature will be but slightly above the room temperature. To establish and maintain a constant heat flow, provision must be made for removing the air in the room, after it has cooled to the desired room tem perature, by a system of vent flues or ducts. As the air flow is maintained Fig. 6. Gravity-Indirect Heating System3 See.Mechanical Equipment of Buildings, by Harding and Willard. Vol. I. second edition, 1929. by natural draft and this.gravity head is very slight, it is necessary to make all ducts as short as possible, especially the runs from the heating units to the base of the vertical warm air flues. Gravity-indirect arrange ments, such as illustrated in Fig. 6, are not to be generally recommended for hot water systems unless the water temperature can be maintained at a reasonably high temperature and rapid circulation of the water can be had. PROBLEMS IN PRACTICE 1 What is the effect on the heat output of a wall radiator when installed on .the ceiling of a room? -' Because the temperature differential is increased between the floor level and the ceiling when a wall radiator is placed near the ceiling, the heat output may be decreased from 5 to 10 per cent.- Under such circumstances it becomes difficult to heat the living zone of a room satisfactorily. . .. - 273. r --' Heating Ventilating Air Conditioning Guide 1938 2 f What are the principal differences between a radiator and a convector? A radiator, is commonly thought of as a commercial heating unit having a maximum amount of direct heating surface, whereas a convector is a heating device in which the extended or secondary surface may be several times that of the prime surface and which is specially designed to utilize to the fullest extent the convection principal of heating. The radiator ordinarily has vertical tubular chambers for the heating medium but most convectors have horizontal tubular chambers to which fins are attached so as to form vertical flues for the passage of air. While radiators are either exposed, enclosed, or shielded, convectors are concealed by means of a tight-fitting enclosure. Radiators are commonly made of cast iron but convectors may be made of a combination of metals, such as copper and brass, or copper and aluminum, as well as entirely of cast iron. 3 9 How did the term heating effect come into use? It has been found that a room requiring a radiator of a certain determined capacity could under certain conditions be properly heated, with less temperature gradient be tween floor and ceiling and with less steam condensation, by the same radiator or by one of a different design having the same commercially rated capacity. This resulted in the use of the term heating effect to apply to the useful heat output of a radiator, in the com fort zone of a room, as related to the total input to the radiator. 4 Is it necessary to make any allowance for the performance of-a convector because it is enclosed? .. - No. The commercial ratings of convectors have been determined by testing the con vectors in proper, enclosures with grilles in place just as they should be installed for ordinary service. ' - j* , 5 9 On what basis are the capacities of convectors published? . Published ratings of convectors are expressed in equivalent square feet of direct cast iron radiation. Some manufacturers have increased their ratings by as much as 30 per cent to allow for a supposed improved heating effect. Tests indicate that the credit to be given heating effect' is, in all cases, probably less than 10. per cent, and in many cases ' negligible. ' 6 How are fins of convectors attached to the tubes or prime, surface? Tubes or a solid core may .be-forced ithrough .piercings in the. fins under pressure, or the tubes may be expanded into the holes through the fins. In addition a metallic bonding agent is sometimes used to insure permanent contact. . 7 What is the procedure in selecting a convector when the required amount of radiation is known?- * - ' ' 1 First the limiting factor or factors of the enclosure must be determined so the available size of the wall recess can be found. Manufacturers' catalogs show capacities of con vectors of each standard length and depth with varying enclosure heights. From these capacity tables, the proper convector of the required capacity can be selected for the available wall recess. If all three dimensions of the wall recess are insufficient to accom modate a convector of the required capacity, the available height and length can be maintained, but greater depth can be obtained by using a partially recessed enclosure. 8 Given a room to be heated to 80 F with outside temperature at'O F, assume the heat loss under these conditions to be 10,000 Btu per hour. ' Deter mine the size of the steam radiator to be installed. A square foot of radiation is equivalent to a heat emission of 240 Btu per hour under standard conditions of steam at one -pound gage pressure (215 F) and surrounding air at 70 F. With surrounding air at SO F, the heat emission from a radiator will be less. Under these conditions, the heat emission will not be 240 Btu per square foot of catalog rating per hour, but 240 Cs. . Cs ( Is - ti Y:* \215 - 70/ /215 - 80 Y*` \215 - 70 / 0.912, and 240 C8 = 240-X'0.912 = 218.5 Btu. Therefore, the size of the radiator to be selected shall have a catalog rating of 10,000 divided by 218.5 or 45.8 sq ft. : 274 A * j ' . . ' , ' ! i 1 j . - Chapter 15 STEAM HEATING SYSTEMS Gravity and Mechanical Return, Gravity One-Pipe Air-Vent System, Gravity Two-Pipe Air-Vent System, One-Pipe Vapor System, Two-Pipe Vapor System, Atmospheric System, Vacuum System, Sub-Atmospheric System, Orifice System, Zone Control, Auxiliary Conditioning Unit, Condensation Return Pumps, Vacuum Pumps, Traps THE essential features of the common type of steam heating systems are described in this chapter. They may be classified according to the . piping arrangement, the accessories used, the method of returning the con densate to the boiler, the method of expelling air from the system, or the type of control employed. Information concerning the design and layout of steam heating systems will be found in Chapter 16. GRAVITY AND MECHANICAL RETURN In gravity systems the condensate is returned to the boiler by gravity due to the static head of water in the return mains. The elevation of the boiler water line must consequently be sufficiently below the lowest heating units and steam main and dry return mains to permit the return of condensate by gravity. The water line difference1 must be sufficient to overcome the maximum pressure drop in the system and, when radiator and drip traps are used as in two-pipe vapor systems, the operating pressure of the boiler. The condensing return of'the radiation will increase the required water line difference and is especially important where the radiation is a type having a high condensing rate. This applies only to closed circuit systems, where the condensation is returned to the boiler. If the condensation is wasted, no water line difference is required, but other conditions are introduced which warrant the use of an appro-. priate mechanical system in preference to wasting the condensate. ' ` In mechanical systems the condensate flows to a.receiver and is then forced into the boiler against the boiler pressure. The lowest parts of the supply side of the system must be kept sufficiently above the waiter line .of the receiver to insure adequate drainageof water from the system, but the relative elevation of the boiler water line is unimportant in such cases . `The voter line difference is the distance between the water line of the boiler and,the level of the water in the dry or wet return main. (See Fig: 4.) . * ...............J-` 275 s' Heating Ventilating Air Conditioning Guide 1938 except that the head on the pump or trap discharge becomes greater as the height of the boiler water line above the trap or pump increases. There are three general types of mechanical returns in common use, namely, (1) the mechanical return trap, (2) the condensation return pump, and (3) the vacuum return pump. Further information on pumps and traps will be presented later in this chapter. . GRAVITY ONE-PIPE AIR-VENT SYSTEM In the gravity one-pipe air-vent system each radiator has but a single connection through which steam must enter and condensation must return in the opposite direction. Each radiator has an individual air valve. .. . - Up-Feed Gravity One-Pipe Air-Vent System IT This system is the most common of . all methods of steam heating, especially for small size installations, due largely to its low cost of instal Chapter IS. Steam Heating Systems are branched off the main or mains to feed the radiators, the steam passing up the riser and the condensation flowing down it. The steam and con densation flow in opposite directions in the riser but after the condensa tion enters the steam main it flows in the same direction as the steam and is disposed of through the drip connection at the end of the main. In buildings of several stories, it is customary to drip the heel of each riser separately, whereas in one- or two-story buildings this is not necessary. Both types of branches and risers are shown in Fig. 1. Rapid elimination of air and condensation from the steam piping is essential to the successful operation of this system. It is therefore desirable that the venting and dripping of the steam main in long runs be made at several intermediate points where the steam main may again be brought to a higher elevation. It is desirable to install the air-vent valves on the steam main about a foot ahead of the drips, as is indicated in Fig. 1 to prevent possible damage to the mechanism of the air-vent valve by water, in case the valves are installed directly above the drips. Horizontal branches to radiators and risers should be pitched at least Yi in^ in 10 ft downward toward the riser or vertical pipe, and the hori- lation .and its simplicity. Where the size of the system is moderate or large, k cannot be assumed that these systems will be lower in cost than two-pipe systems using steam traps. In some instances it has been found that the cost of one-pipe systems under these conditions is greater owing to the higher cost of labor and materials due to the larger pipe sizes; As will be seen from Fig. 1, the steam piping rises to a point as high as possible at the boiler and pitches downward from this location until.the far end of the main or mains is reached. At the far ends drips are taken off at the low. points of the steam mains, are water-sealed below the boiler water line, and then brought back to the boiler in a wet return. Single pipe risers 276 Fig. 2. Typical Steam Runout where Risers are not Dripped Fig. 3. Typical Steam Runout where Risers are Dripped zontal branches from the steam main should be graded at least this amount toward the main, except where the heel of the riser is dripped, in which case the branch should pitch down toward the riser drip (Figs. 2 and 3). The return line, if wet, may be run without pitch or may be pitched in either direction, but if it is necessary to carry the return main overhead for any distance before dropping, the return should slope down ward with the flow. It is desirable to install the wet return pipe with a pitch so that the system may be drained to prevent freezing in case the building remains unoccupied for a considerable length of time. . ' The radiator valves may be of the angle-globe or gate type. They! should not be of the straight-globe type because the damming effect'of the raised valve seat interferes with the flow of .condensation through the valve. Graduated valves cannot be used, as the steam valves on: this system must be fully open or closed to prevent the radiator's filling with water. Air valves may be manual or automatic, with or without a check to' prevent the re-entrance of expelled air. Usually the automatic type is installed. An objection to one-pipe steam systems is that the heat is all on or all off, with no intermediate position possible. However, intelligent 277 . Heating Ventilating Air Conditioning Guide 1938 use of the on-and-off method of manual control gives reasonably satis factory results. Improved systems and devices are now available which make it possible to obtain a modulating effect from one-pipe gravity heating systems. - It is important that the lowest points of the steam mains and heating units be kept sufficiently above the water line of the boiler to prevent Boiler steam pressure Steam pressure at end of main ^-Water line of boiler -- Level /(Vet return E'Risewater Bne difference Fig. 4. Difference in Steam Pressure on Water in Boiler and at End of Steam Main flooding. . Usually 18 in. is sufficient but construction limitations fre quently make shorter distances necessary. The distance may be checked in the following manner : . . . - . Referring to Fig. 4 it will be seen that the water in the wet return is really in an in verted siphon, or U-shaped'container, with the boiler steam pressureon the top of'the water at one end and the steam main pressure on the top of the water at the other end. The difference between these two pressures is the pressure drop in the system, i.e., the mction of the steam in passing from the briiler to the far end of the main and<the pressure reduction in consequence of the condensation occurring in the system. The water in the far end will rise sufficiently to overcome this difference in order to balance the pres-sures, and it will rise enough farther to produce a flow through the return into the boiler 278 ' Chapter IS. Steam Heating Systems (usually about 3 in. unless the pipes are small or full of sediment), and it will rise still farther if a check valve is installed in the return so as to obtain sufficient head to lift the tongue of the check (usually 4 in. will be necessary). If a one-pipe steam system is designed, for example, for a total pressure drop of Ye lb, and utilizes an Underwriters' Loop1 instead of a check valve on the return, the rise in the water level at the far end of the return due to the difference in steam pressure would be of 28 in., or 3Y in. Adding 3 in. to this for the flow through the return main and 6 in. as a factor of safety gives 12in. as the distance the bottom of the lowest part of the steam main and all heating units must be above the boiler water line. The same system, however, installed and sized for a total pressure drop of Y lb, and with a check in the return, would require Y of 28 in., or 14 in., for the difference in steam pressure, 3 in. for the flow through the return, 4 in. to operate the check, and 6 in. for a factor of safety, making a total of 27 in. as the required distance. Higher pressure drops would increase the distance accordingly. Down-Feed Gravity One-Pipe Air-Vent System In the overhead down-feed gravity one-pipe air-vent system there is no change over the up-feed system in the radiators, the radiator valves, the air valves, or the radiator runouts as far back as the risers. Beyond this Fig. 6. Steam Runouts Dripping Main Fig. 7. Steam Runouts with Main Dripped at End Only point there are basic differences. The steam is taken from the boiler and carried to the top of the building as near the boiler as possible (Fig: 5). . If the run to the main riser is long, or if the riser extends several stories in order to reach the top, the bottom of the riser should be dripped into the wet return. The horizontal main is taken off the top of the riser and grades down from the riser toward all of the drops, each drop taking its share of the main condensation (Fig..6), or all of the drops except the last may be taken from the top of the main (Fig. 7), the last drop being from the bottom and serving as a drain for the entire main. As the overhead main does not carry any condensation from the radiators it is immaterial which method is used. The air vent shown on the main just before the last drop (Fig. 5) may be placed at this point or it may be located at the bottom of the drop under the last radiator connection and sufficiently above the-water line of the boiler to prevent flooding. GRAVITY TWO-PIPE AIR-VENT SYSTEM The.gravity two-pipe system is now considered obsolete although many of these systems are still in use in older buildings. Separate supply and return mains and connections are required for each heating unit; air valves are installed on the heating units and mains; hand valves .are installed on the returns. ' *See discussion of piping details in Chapter 16: 279 Heating Ventilating Air Conditioning Guide 1938 Up-Feed Gravity Two-Pipe System This system (Fig. 8) has a steam and a return connection to each radiator.. The radiator valves for steam, return, and air are the same as those described for the gravity one-pipe air-vent system. The steam main is run and pitched in the same manner as in the one-pipe system, but the returns from each radiator are connected into a separate return line system which has its risers carried down and joined to a wet return line under the boiler water line level. Where the return has to be kept high to function as a dry return, it is advisable to connect the return risers to the dry return main through water seals about 36 in. deep,, as Chapter 15. Steam Heating Systems the gravity one-pipe steam system; in fact, one-pipe gravity installations may readily be changed to one-pipe vapor systems by making, a few simple alterations.. The steam radiator valve is a plug cock which when opened gives a free and unobstructed passageway for water. The auto matic air valve is of special design to permit the ready release of air from the radiator and to prevent the return of the air after it is expelled. The air valves on the main are a quick relief type, and the whole system is designed to operate on a few ounces of pressure. . TWO-PIPE VAPOR SYSTEM Two-pipe vapor systems may be classified as (1) closed systems con sisting of those which have a device to prevent the return of air after it is once expelled from the system, and which can operate at sub-atmospheric pressures for a period of four to eight hours depending upon the tightness of the system and rate of firing, and (2) open systems consisting of those shown in Fig. 9, to prevent steam from one riser entering another and closing the air valves on the nearest radiators. . Down-Feed Gravity Two-Pipe System \ The steam main in the down-feed system is carried to the top of the building, and the piping of the steam side is arranged practically as in the down-feed one-pipe gravity system. The drips at the bottoms of the steam drops and the runouts to the radiators are similar to those shown in Fig. 8 for the up-feed gravity two-pipe system. On the return side of the system, the piping is arranged in exactly the same manner as the up-feed gravity two-pipe system. ONE-PIPE VAPOR SYSTEM A vapor system is one which operates under pressures at or near atmospheric and which returns the condensation to the boiler by gravity. The piping arrangement of a one-pipe vapor system is similar to that of 280 /Floor /7T7777T77777T77777&777777777777777777T77T Fig. 9. Method of Connecting Two-Pipe - Gravity Returns to Dry Return Main which have the return line constantly open to the atmosphere without a check or other device to prevent the return of air, and which operate at a few ounces above atmospheric pressure. The open systems have the disadvantage of not holding heat when the rate of steam generation is diminishing. Under the first classification the essentials are packless graduated valves on the radiators, thermostatic return traps on the returns, and traps on all drips unless they are water sealed. Such a system, illustrated in Fig. 10, should be equipped with an automatic return trap to prevent the water from backing out of the boiler. In this up-feed arrangement the supply piping is carried to a high point directly at the boiler and is graded down toward the end or ends of the supply main, each supply main being dripped at the end into the wet return or carried back to a point near the boiler where it drops down below the boiler water line and becomes a wet return. From this main, runouts are branched off to feed . risers or radiators above, these being graded back toward the steam main if they are not dripped at the bottom of the riser, or toward the riser if the riser heel is dripped. Both conditions are illustrated in Figs. 2 and 3. Return risers are connected to each radiator on its return end through 281 Heating Ventilating Air Conditioning Guide 1938 thermostatic traps. Their bottoms are connected to the return main through runouts which slope toward the main. The return main itself is sloped back toward the boiler if it is carried overhead; if run wet, the slope may be neglected, although it is desirable to slope the pipe so that the system may be drained. An air vent is installed at the point at which the return main drops below the water line. In the simplest cases this vent consists of a %-in. pipe with a check valve opening outward, but certain systems employ special patented forms of vent valves, designed to allow the air readily to pass out of the system and to prevent its return. A check valve is inserted in the return main at.a point near the boiler and a vertical pipe is run up into the bottom of the return trap, which usually is located with the bottom about 18 in. above the boiler water line. Some traps are constructed so that they will operate when they are installed Chapter 15. Steam Heating Systems the main (Fig. 7) and to drip the end of the main through the last riser, as illustrated in the down-feed one-pipe system detail shown in Fig. 6. If this is done, the pipe drop at the end or ends of "the mains should be enlarged one pipe size- to provide capacity for this concentration of the main drip. The steam drops are carried down through the building with suitable reductions as the various radiator connections are taken off until the lowest radiator runout is reached. If the drop is only two or three stories high, the portion feeding the bottom radiator should be increased one pipe; size to provide for draining the 'riser, and if the drop is over three stories high it is well to increase the portion feeding the two lowest radi ators one or two pipe sizes, especially if the two lowest radiators are small Air vent and check Fig. 10. Typical Up-Feed Vapor System with Automatic Return Trap3 "Proper piping connections are essential with special appliances for pressure equalizing and air elimination. with their bottom as close as 8 in. above the boiler water line. On the other side of this connection a second check valve is installed in the main return just before it enters the boiler (Fig. 11). Down-Feed Two-Pipe Vapor System . In the down-feed two-pipe vapor system the steam is carried to the top of the building, the top of the vertical riser constituting the high point of the system, and the horizontal supply main is sloped down from this location' to the far ends of each branch. The branches are taken-off the main from the bottom or at a 45-deg angle downward, with the runouts sloped toward the drops (Fig. 6). Thus each branch from the main forms a drip and no accumulation of water is carried down any one drop. Another method of running the steam main, which is not considered as satisfactory but'which is practical, is to take the branches off the top of 282 ' Fig. 11. Typical' Connections for Automatic Return Trap - and the normal size of drop required is 1 in. or less. The bottom of the steiam drops should terminate with a dirt pocket above which a drip trap connection is located, as shown in Fig. 12. The returns on a down-feed vapor system are the same as on an up-feed system except that every steam drop must have a drip at the bottom connected either into the return through a trap or into a separate water-sealed drip line below the boiler water line, as illustrated in Fig. 10, in which case the thermostatic traps may be omitted. The runouts to the radiators and the radiator connections of the down-feed system are the same as those of the up-feed system already described. ' ATMOSPHERIC SYSTEM The. distinguishing features of the atmospheric system are gravity 283 SaSBWSBW1.'1;--- ->" -- '- ' '" ---------- --------------------- ----- ---------------- - ' ' Heating Ventilating Air Conditioning Guide 1938 return to the boiler or to waste, graduated or ordinary radiator valves, no automatic air valves on the radiators, thermostatic traps on the radiator returns, and the venting of all air from the system by means of pipes open to the atmosphere. The returns are open to the atmosphere at all times, usually by extending the return risers to the top of the building where they are either connected together in groups and carried through the roof or extended through the roof individually. Atmospheric systems, either up-feed or down-feed, are often used where the condensation is not returned to the boiler, as in heating systems supplied by high pressure steam through pressure-reducing valves at locations far from the boilers, The returns may be delivered back to the boiler, if desired, by condensa- . tion return pumps which are vented to the atmosphere. The return lines' in such systems are simply gravity waste lines in which the condensation "' flows entirely by gravity and is not aided by any pressure difference Bottom of steam drop Graduated valve Drip trap Dirt pocket- tt) ,/Floor V////Z////Z ^Connected to dry return (where connected to wet return, drip trap may be omitted) Fig. 12. Detail of Drip Connections at Bottom of Down-Feed Steam Drop Atmospheric systems contemplate maintaining a practically constant pressure in the steam pipe and atmospheric pressure in the return pipe. When graduated.steam valves are provided,'they enable the occupant of a room to vary the flow area to'the radiator so as to obtain a greater or. lesser heating effect. . ,. The steam side may be run as that for either up-feed or down-feed two-pipe vapor systems, as the conditions require;-and the radiator con nections are the same as for vapor systems in that they .have graduated valves on the radiator supply ends and thermostatic traps on the radiator return ends. All drips from the supply main and the steam side of the system must pass through thermostatic drip traps before entering the return system where only atmospheric pressure exists. -Fig. 13 illustrates a typical scheme of piping used on atmospheric systems. Such systems do not maintain heat in the radiators under declining fires. As the steam supply diminishes, air from the atmosphere re-enters through the open vent pipe retarding the inflow, of steam and cooling the radiator. 284 Chapter IS. Steam Heating Systems VACUUM SYSTEM In the vacuum system, a vacuum is maintained in the return line practically at all times but no vacuum is carried on the steam side, and the usual accessories include graduated valves on the radiator supply and thermostatic traps on the radiator return. The air is expelled from the system by a vacuum pump and all drips must pass through thermostatic traps before connecting to the return side of the system. These systems are often fed from high pressure steam mains through pressure-reducing valves but they may be fed direct from a low-pressure steam heating boiler as shown in Fig. 14, in which a typical up-feed vacuum system is illustrated. The supply main slopes down in the direction of flow; the runouts pitch down toward the riser if the riser is dripped (Fig. 3) or up toward the riser if the riser is not dripped (Fig. 2); both conditions are indicated in Fig. 14. The matter of dripping the risers depends largely on the height of the riser and the judgment of the designer. Ordinarily risers less than three stories high are not dripped and those more than four stories high are dripped, but there is no set rule for this. When risers are dripped the runouts from the steam main may be taken from the bottom if desired and each runout then serves as a .drip for the main. The risers are carried up to the highest radiator connection and are connected to the radiator through runouts sloping back toward the riser. The radiators usually have graduated valves on the supply end, although this is. not absolutely necessary. Angle-globe valves and gate valves may / be used where graduated manual control is not desirable. The return valves must be of the thermostatic type which will pass air and water but which will close against the passage of steam. The return risers are connected in the basement into a common return line,, which slopes downward toward the vacuum pump. The vacuum pump discharges the air from the system and pumps the water back to the boiler, or other receiver, which may be a feed-water tank or a hot well. It is essential on these systems that no connection from the supply side to the return side be made at any point except through a trap. While the best practice demands a return flowing to the vacuum pump in an uninterrupted downward slope, in some cases limitations make it necessary to drop the return below the level of the vacuum pump inlet before the pump can be reached. -In such event one of the advantages of the vacuum system is that the return can be raised by the suction of the vacuum pump to a considerable height, depending on the amount of vacuum maintained, by means of a lift fitting inserted in the return. Best practice dictates that the lift should be limited to a single lift con nection at the entrance to the vacuum pump and preferably that an accumulator tank or receiver with float control be used at the low point of the return main at the entrance to the vacuum pump. When the .''lift is considerable, several lift fittings should be used in steps (Fig. 15), more successful operation being obtained by this method than when the lift is made in one step. If the lift occurs close to the vacuum pump, a special arrangement is used as shown in Fig. 16. It is desirable that means be provided for draining manually the low point of the lift fittings to eliminate from the return piping all water in danger of freezing in case 285 Heating Ventilating Air Conditioning Guide 1938 Chapter IS. Steam Heating Systems the system is shut down for a considerable length of time. Lifts for draining condensate from ends of or rises in steam mains should be avoided to secure the greatest economy of operation and noiselessness. Down-Feed Vacuum System The piping arrangement for the down-feed vacuum system is similar on the supply side to the down-feed vapor system in that it has similar runouts, radiator valves, drips on the bottom of the steam drops, and enlargement of the drops for the lower radiator connections. The returnside of the system is exactly the same as the up-feed system except that a Proper piping connections are essential with special appliances for pressure equalizing and air elimination 286 Fig. 15. Method of Making Lifts on Vacuum Systems when Distance is Over 5 ft Lift at Vacuum Pump __ ah--is-ECCENTRIC SEDUCING COUPLING. Fig. 17. Method of Changing Size of Steam Main when Runouts are Taken from Top the steam riser drips at the bottom are connected into the return line through thermostatic traps. It is preferable to take the runouts for the risers from the bottom or at a 45-deg angle down from the steam main (Fig. 6) so that they may serve as steam main drips. When this is done it is practical to run the steam main level if a runout is located at every change in pipe size, or if eccentric fittings are used (Fig. 17). A slight pitch in the steam main, however, should be used when possible. An overhead vacuum down-feed system is shown diagrammatically in Fig. 18. SUB-ATMOSPHERIC SYSTEMS Sub-atmospheric systems are similar to vacuum systems, but in con trast provide temperature control by variation of the heat output from the radiators both by varying the pressure at which steam is circulated in the radiation and the amount of steam. The steam supply is cpntinuous at varying rates. A vacuum pump capable of operating at high partial 287 Heating Ventilating Air Conditioning Guide 1938 vacua is preferable since the higher the vacuum the greater is the accuracy in the distribution of steam through the system, particularly in mild weather. A pump capable of producing up to 25 in. of vacuum on, the system is used in such cases. A controller is placed on the pump so that the vacuum or absolute pressure carried in the returns can be maintained at a certain amount below that existing in the line to insure circulation. The traps are designed to operate in high vacuum. It is apparent that this system differs from the ordinary vacuum system by having a vacuum on both sides of the system, instead of only on the return side, in order, to secure control of the heat emission from the radiators and thus to control \ the temperature in the building. These systems permit the heat output from the steam mains and risers to be diminished as the weather becomes milder, thus giving control to this portion of a heating system. The decrease in condensation in the piping as the temperature of the steam is reduced under a vacuum is a measure of the saving in heat loss from piping resulting from steam circulation at sub-atmospheric pressures as compared with circulation at sub-atmospheric pressure. The system can beV operated in the same manner as the ordinary vacuum system when desired. In the vacuum system, steam pressure above that of the atmosphere exists in the supply mains and radiators practically at all times. In the sub-atmospheric system, steam pressure exists in the steam main and radiators only during the most severe weather, while under average winter temperatures the steam is under a partial vacuum which in mild 288 Chapter 15. Steam Heating Systems weather may reach as high as 25 in. after which further reduction in heat output is obtained by partially filling the radiation with steam. This vacuum is partially self-induced by the condensation of the steam in: the system due to the supply of steam being furnished through the control which admits it, and it being proportioned to balance the existing heat loss. To convert an ordinary vacuum return line system to a sub- atmospheric system, a control valve is inserted on the steam main near the boiler or the boiler is automatically controlled. The steam supply to each radiator is provided with a flow proportioning device, such as an orifice, a high-vacuum pump is substituted for the ordinary type and is supplied with a pressure-difference control, and traps are placed on the radiators and drips which will operate satisfactorily at any pressure from 5 .1b gage to 26 in. of vacuum. . .: The control valve is either a special pressure-reducing valve which may be controlled, manually, or a control valve or combustion equipment which may be operated thermostatically from points' selected in the building. The vacuum pump regulator is simply a diaphragm so ar ranged that, when the vacuum in the return line is insufficient to hold the desired difference in pressure between the steam and return sides of the system, the vacuum pump is automatically started and the vacuum increased to the necessary amount. The actual pressure difference main tained between the two sides of the system is only enough to secure adequate circulation and is often about 2 in. of mercury. This fixed pressure difference between the supply and return sides of the system results in practically constant circulation under all pressure conditions. In order to distribute the steam equally when, the system is being warmed up and also to reduce. the amount of steam delivered to the radiators on mild days, .orifice plates are used in the graduated radiator control valves. A definite, nearly constant, relation exists between the supply and return pressure differential at various points throughout the system which promotes proportionate steam distribution between the various radiators. The heat emitted from the radiators in mild weather and under conditions of high vacuum is not only reduced in proportion to the difference in the steam temperature between that for 2 lb gage and for 25 in. of vacuum but it is reduced still further by a reduction in the amount of steam which can pass through the orifice when the steam is expanded due to the vacuum. This fenders possible the control of heat emission from the radiators to a point not indicated entirely by the difference in steam temperatures, but far beyond it. .. Sub-atmospheric operation has advantages even. where individual thermostatic radiator control is installed. By operating the system with steam temperatures in parallel with the outside temperature require ments, a large part of the load is removed from the temperature control system, it makes fewer operations and the radiator follows an even tem perature without fluctuating from extreme hot to extreme cold. The high-vacuum pumps on this system are equipped with receivers having float control.so that the pump can be placed on a receiver-returnpump basis at night if desired so no high vacuum will be carried. One radical difference between this system and the ordinary vacuum system is that no lifts can be made in the return line, except at the vacuum pump. 289 Heating Ventilating Air Conditioning Guide 1938 The returns must grade downward constantly and uninterruptedly from the radiator return outlet to the inlet on the high-vacuum pump receiver. No attempt should be made to heat service water on this system unless the steam line for water heating is taken off the boiler header back of the heating system control valve, and then only when 2 lb or more will be carried on the boiler at all times. Sub-atmospheric systems are pro prietary. , ORIFICE SYSTEM Orifice systems of steam heating may have piping arrangements identical with vacuum systems but some of these systems omit both the radiator thermostatic traps and the vacuum pump in cases where the returns are wasted to a sewer or delivered to some type of receiver in which no back pressure exists. The principle on which they operate is embodied in the well-known fact that an orifice will deliver varying velocities when the ratio of the absolute pressures on the two sides of the orifice exceeds 58 per cent. If the absolute pressure on the outlet side is less than 58 per cent of the absolute pressure on the inlet side no further increase in velocity will be obtained. As a result, if an orifice is so designed in size as to exactly fill a radiator with steam at 2-lb gage on one side and %-lb gage on the other, the abso lute pressure relation is 14.7 + 0.25 . 14.7+2.0 =90percent Should the steam pressure be dropped to J^-lb gage, the pressure on each side of the orifice would be balanced and no steam flow would take place/ From this it will be seen that if an orifice of a given diameter will fill a given radiator with steam when there is a given pressure on the main, it is simply a question of dropping this main pressure provided the supply pipe pressures be controlled sufficiently closely, so as to fill any desired portion of the radiator down to the point where the main pressure equals the back pressure in the radiator, at which time no steam will be supplied at all. If orifices throughout a system are designed on a similar basis, all radiators will heat proportionately to the steam pressure within the limits for which the orifices are designed. Some systems use orifices not only in radiator inlets but also at different points on the main, thus balancing the system to a greater extent. For example, the system may be designed for a particularly long run involving an initial pressure of 3-lb gage on the main and 2 lb at the end of the main, but each branch from the main may have an orifice for reducing the pressure at it to 2-lb gage. This is particularly useful for branches near the boiler where the drop in the main has not yet been produced. Orifice systems using a vacuum pump operate successfully with the ordinary low vacuum type of pump producing 8 to 10 in. of vacuum. They are controlled by various means to regulate the steam pressure. One method is by a thermostat located on the roof to govern the steam pressure by a combination of outside and inside temperature^; another, useful on systems without traps and vacuum pumps, controls the steam pressure manually from temperature indication stations in the building, 290 Chapter IS. Steam Heating Systems or automatically by a thermostatically-controlled pressure reduction valve or draft regulator on the boiler; with oil or gas firing, the on-and-off control or a boiler pressure control may be used. ZONE CONTROL Certain portions of a building may require more heat at times than others but if the whole building is on one general control, such as would occur with a single piping system with an on-and-off control or with the sub-atmospheric or the orifice systems, it would be necessary to supply sufficient heat to accommodate the coldest portion of the building even though some sections would be overheated. By separation of a building into zones each with its own piping system, each zone of the building may be controlled separately. The sides of the building with different exposures should be considered first, because of the varying effects of the wind and sun. With the pre vailing winter winds from the northwest, a simple zoning would place the north and west sides of the building on one system and the south and east sides on another. If the building is large enough to justify the expendi ture, a better arrangement would be to place all north walls on one zone, all west walls on a second, all east walls on a third, and all south walls on a fourth. . In case of high buildings, the lowest 8 or 10 stories may be well protected from wind by surrounding buildings, the next 10 stories may have moderate exposure, and above this there may be an unobstructed exposure to gales. On still days the heat demands vertically will vary little, but on windy days there will be a marked difference in the heat requirements for the different horizontal sections. In addition, the chimney effect caused by the difference in density between the warm air on the inside of a building and the colder air on the outside will give an air movement which will require zoning to correct. Where such conditions are encountered, the building should be divided horizontally as well as vertically. An arrangement of this character would give 12 zones: namely, north, east, south, and west lower zones; similar middle zones; and similar top zones. Each zone should constitute an individual and separate system of piping with its own supply steam valve (controlled by thermostats in its respec tive zone) and with its own return or vacuum pump, if one is used. Certain interior areas, such as basements, light well walls and-other locations where sun and wind do not affect the conditions, should be placed in still another zone if the most economical results are to be secured. Zoning has advantages even where individual thermostatic radiator control is installed whether this be of pneumatic, electric, or the selfcontained radiator valve type. By operating each zone to supply heat in parallel with its outside temperature and wind fluctuations, a large part of the load is taken off the thermostatic controls; they operate less frequently and the radiators follow a more even temperature instead of fluctuating from extreme hot to extreme cold. Sub-atmospheric, orifice, and zone control systems, generally are proprietary. Sub-atmospheric systems may be zoned to care for ex posure, occupancy and stack effect. 291 Heating Ventilating Air Conditioning Guide 1938 AUXILIARY CONDITIONING UNIT In connection with a residential steam or hot water system using radiator or convector heating a unit as shown in Fig. 19, is available to supplement the old or new system. The unit is arranged in a sheet metal enclosure with a filter, circulating fan, means for adding moisture to the air, heating or tempering coil and generally provisions.are made for the addition of. a cooling coil in case summer air circulation is desired. The unit is frequently located on the ceiling of the basement and is connected with one or more supply and return air ducts in the various rooms. In some cases, provisions are made for the introduction of a portion of the outside air to the system and dampers are included tosadjust the desired air quantities. " The heating coil of the unit may be connected to a steam or hot water boiler system and is adaptable for operation with a one-pipe, two-pipe or vacuum system. The cooling coil may be connected to a source of Chapter IS. Steam Heating Systems the vented receiver. As the receiver is filled, the float mechanism operates either a pilot or an across-the-line switch to start the pump, and upon emptying the tank disconnects the power and stops it. The pump may be used to deliver the condensate direct to the boiler, to a feedwater heater or to raise the water to any higher elevation or pressure than that of the return line. A useful application, for instance, is to use a small condensation unit to handle a remote section of radiation that otherwise would be difficult to grade to the main return. The receiver capacities of these automatic units should be sized so as not to cause too great a fluctuation of the boiler water line if fed directly refrigeration, or in some cases city water is circulated through the coil when 58 F or lower temperature water is available. - : The amount of moisture released is adjustable depending upon the degree of humidifica tion desired. The complete unit may be adapted to various automatic control arrangements to satisfy the comfort demands of the occupants. .V . - CONDENSATION RETURN PUMPS Whenever the conditions of a heating system are such that the returns from the radiation can not gravitate freely to the boiler, they must be returned by some mechanical means such as a condensation pump or .a return trap. . . ... . The most generally accepted condensation pump unit for low pressure heating systems consists of a motor driven centrifugal pump with receiver and automatic float control. Other types in use .include; rotary,, screw and reciprocating pumps with steam-turbine or motor drive, and direct acting steam reciprocating pumps. . Fig. 20 illustrates a typical installation of a. motor driven automatic condensation unit. It will be noted that the returns flow by gravity to 292 to the boiler and at the same time not so small as to cause too frequent operation of the unit. The usual unit provides storage capacity between stops in the receiver of approximately 1.5 times the amount of condensate returned per minute and the pump generally has a delivery rate of 3 to 4 times the normal flow. ' VACUUM HEATING PUMPS On vacuum or sub-atmospheric systems where the returns are under a vacuum, it is necessary.to use a vacuum pump to discharge the air and non-condensable gases to atmosphere and to return the condensate to the boiler. Direct acting steam driven reciprocating vacuum pumps are sometimes used where high pressure steam is available or where the exhaust steam from the pump can be utilized, but in general these have been replaced by the automatic motor driven return line vacuum heating 293 / Heating Ventilating Air Conditioning Guide 1938 pump especially developed for this service. The usual unit consists of a compact assembly of air and water removal units driven by one motor and furnished complete with receiver, separating tank and full auto matic controls mounted as an integrated unit on one base. Practically all of such return line vacuum heating pumps make use of the returned condensate to operate either as a liquid piston or as a jet to withdraw the air, and in many cases the condensate, from the return line. Such hydraulic evacuating devices may be classified as: a. Water ring centrifugal displacement pumps. b. Water piston pumps. ' c. Stationary water ejector pumps. d. Rotary water ejector pumps. The evacuating element is generally combined with a centrifugal water impeller for the delivery of the condensate to the boiler or feed water heater. . The assembled units may be further grouped under two general classifications: . a. Those which perform the function of air separation under atmospheric pressure. b. Those which perform the function of air separation under a partial vacuum. Pumps coming under the first classification remove both the air and condensate from the returns by means of the hydraulic evacuator and deliver both to a separating tank under atmospheric pressure. From this tank the air and non-condensible vapors are vented to atmosphere while the condensate is removed and delivered to the boiler by means of the built-in boiler feed pump impeller. In the second classification, the air and condensate are first separated under vacuum by means of the receiver which is directly connected to the returns. The hydraulic evacuator withdraws only the air and non condensible vapors from the top of the receiver and delivers them to atmosphere. The built-in condensate pump impeller removes the con densate from the bottom of the receiver and delivers it direct to the boiler or feedwater heater:, Under special conditions such as returning the condensate to a high pressure boiler or the furnishing of large air removal units for high vacuum systems, it is customary to supply separate motor driven air and water pumps. Steam turbine drive is also frequently used where high pressure steam is available. There are also special steam turbine driven units which are operated by passing the steam to be used in heating the building through the turbine with only a 2 to 3 lb drop across the turbine required for its operation. . For rating purposes* vacuum pumps are classified as low vacuum, and high vacuum. Low vacuum pumps are those rated for maintaining 5J4 in mercury vacuum on the system, and high vacuum pumps are those rated to maintain vacuums above 5% in. . The vacuum that may be maintained on a system depends upon the H.V.E. Transactions, VoL40, Ratin Return Line Low Vacuum Heating Pumps. (A.S: 294 Chapter IS. Steam Heating Systems relationship of the operating air capacity of the hydraulic evacuator at the vacuum and temperature of the returns to the air leakage rate into the system. It is particularly essential on high vacuum installations that the system be tight and that steam be prevented from entering the return lines through leaky traps, high pressure drips, etc. Vacuum Pump Controls In the ordinary vacuum system the vacuum pump is controlled by a vacuum regulator which cuts in when the vacuum drops to the lowest point desired and which cuts out when the vacuum has been increased to the highest point. This is done largely to eliminate the constant starting and stopping of the vacuum pump which would occur if the vacuum were maintained constant. In addition to this control, a float control is included which will automatically start the pump whenever sufficient condensation accumulates in the receiver, regardless of the vacuum in the system. A selector switch is usually provided to allow operation at night as a condensation pump only, also to give continuous operation if desired. There are several variations to the above control, especially as concerns the control of the vacuum maintained on the system. This may be accomplished by some form of coordinating control which maintains the vacuum of the return system in a pre-determined definite or varying relationship to the system supply pressure. Piston Displacement Vacuum Pumps Piston displacement return vacuum heating pumps may be either power or steam driven. They should be provided with mechanical lubricators and their piston speed in feet per minute should not exceed 20 times the square root of the number of inches in their stroke. They are usually supplied with an air separating tank, open to atmosphere, placed on the discharge side of the pump and at an elevation sufficiently high to allow gravity flow of the condensate to the boiler. If the boiler pressure is too high for such gravity feed then an additional steam pump for feeding the boiler is desirable. The extra pump is sometimes avoided by using a closed separating tank with a float controlled vent. In both arrangements, the air taken from the system must be discharged against the full discharge pressure of the vacuum pump. In the case of high or medium pressure boilers, it is better to use the atmospheric separator and the second pump. In figuring the required displacement for such pumps, a value of from 6 to 10 times the volumetric flow of condensation is used for average vacuums and systems. However, as in the case of return line vacuum heating pumps, the displacement is largely dependent upon the tightness of the system, the efficiency of the traps and the vacuum that is desired to be maintained. TRAPS Traps are used for draining the condensate from radiators, steam piping systems, kitchen equipment, laundry equipment, hospital equip ment, drying equipment and. many other kinds of apparatus. The usual functions of a trap are to allow the passage of condensate and to prevent the 295 Heating VentHiATING Air-Conditioning Guide 1938 passage of steam. In addition to these functions, traps are frequently: required to allow the passage of air as well as condensate. Traps are also required to allow the passage of air and to prevent the passage of either water or steam, or both. . . ; In addition, traps are used for returning condensate either by gravity, by steam pressure, or by both, to a boiler or other point of disposal, and for lifting condensate from a lower to a higher elevation, or for handling condensate from a lower to a higher pressure. The fundamental principle upon which the operation of practically all traps depends is that the pressure within the trap at the time of discharge shall be equal to, or slightly in excess of, the pressure against which the trap must discharge, including the friction head, velocity head and static head on the discharge side of the trap. If the static head is in favor of the trap discharge it is a minus quantity and may be deducted from the other factors of the discharge head. Traps may be classified as to function as separating and return or lifting traps. Traps may be classified according to the principle of operation as (1) float, (2) bucket, (3) thermostatic, (4) tilting, or (5) float and thermostatic traps. . .. Float Traps. A discharge valve is operated by the rise and fall of a float due to the change of water level in the trap. When the trap is empty the float is in its lowest, position, and the discharge valve is closed. A gage glass indicates the height of water in the chamber. Unless float traps are well made and proportioned there is danger of considerable steam leakage through the discharge valve due to unequal expansion of the valve and seat and the sticking of moving parts. The discharge from a float trap is usually con tinuous since the height of the float, and consequently the area of the outlet, is propor tional to the amount of water present. Float and thermostatic traps have both a thermostatic element to release air and a float element to release the water. Bucket Traps. Bucket traps are of two types, the upright and inverted, and although they are both of the open float construction, their operating principle is entirely different.. In the upright bucket trap, the water of condensation enters the trap and fills the space, between the bucket and the walls of the trap. This causes the bucket to float and forces the valve against its seat, the valve and its stem usually being fastened to the bucket. When the water rises above the edges of the bucket it flows into it and causes it to sink, thereby withdrawing the valve from its seat. This permits the steam pressure acting on the surface of the water in the bucket to force the water to a discharge opening. When the bucket is emptied it rises and closes the valve and another cycle begins. The discharge from this type of trap is intermittent. . \ ' In the inverted bucket trap, steam floats the inverted submerged bucket and closes the valve. Water entering the trap fills the bucket which sinks and through compound leverage opens the valve, and the trap discharges. It is impossible to install a water gage glass on an inverted bucket trap, but if visual inspection is necessary, a gage glass can be placed on the line leading to the trap. No air relief cocks can be used, but this is unnecessary, as the elimination of air is automatically taken care of by air passing through the vent in the top of the inverted bucket regardless of temperature. Thermostatic Traps. Thermostatic traps are of two types, those in which the discharge valve is operated by the relative expansion of metals, and those in which the action of. a volatile liquid is utilized for this purpose. Thermostatic traps of large capacity for draining blast coils or very large radiators are called blast traps. Tilting Traps. With this type of trap, water, enters a bowl and rises until its weight overbalances that of a counter-weight, and the bowl sinks to the bottom. As the bowl sinks, a valve is opened thus admitting live steam pressure on the surface of the water and the trap then discharges. After the water is discharged, the counter-weight sinks and raises the bowl, which, in turn closes the valve and the cycle begins again. Tilting1 296 Chapter IS. Steam Heating Systems traDS are necessarily intermittent in operation. They are not ordinarily equipped with glass water gages, as the action of the trap shows when it is filling or emptying. The air relief of tilting traps is taken care of by the valves of the trap. Thermostatic traps are generally used for draining radiators and heaters, except for very large capacities where bucket, float or blast-type thermostatic traps are used. Thermostatic traps for this service usually pass both condensate and air and in the case of float and upright bucket traps the air is usually relieved through an auxiliary thermostatic trap in a by-pass around the main trap. Sometimes this auxiliary air trap is an integral part of the trap. Such traps are termed float and thermostatic traps. __ Blast-type thermostatic traps are sometimes used on vacuum heating systems for connecting old one- or two-pipe gravity systems in parallel with vacuum return line systems, in which case the blast-type thermo static traps should not be provided with auxiliary air by-pass, as the Fig. 21. Method of Discharging High-Pressure Apparatus into Low-Pressure Heating Mains and Vacuum Return Mains through a Low-Pressure Trap action of this will allow the vacuum to draw air into the old system through its air valves, especially when the steam is wholly or partially cut off. The air from the returns of such old systems should be relieved just ahead of the traps by means of quick-venting automatic air valves, preferably of the non-return type, especially if the other air valves on the old system are non-return valves. Return traps used for discharging to a higher or a lower pressure are provided with two or three valves operated by the action of the trap. In the case of the two-valve return traps, one valve closes a steam inlet and the other valve opens a vent outlet while the trap is filling, and as soon as the trap dumps, the first valve opens the steam inlet and the second valve closes the vent outlet, while the trap discharges. In this type of trap there must be a swinging check-valve on each side of the trap, in addition to the usual by-pass, to prevent the pressure in the trap, while discharging, from backing up through the inlet and the pressure in the discharge line from backing up into the trap while it is filling. This 297 Heating Ventilating Air Conditioning Guide 1938 type of trap will blow steam out through the vent while filling, if the pressure on the inlet side is sufficient, and should not be used, therefore, with such pressures unless the vent is properly piped back into the return to a feed water heater, a condenser or a perforated pipe in the bottom of the receiver to which the trap discharges in such a way as to prevent the escape of the steam that comes in with the condensate and passes through the vent. In the three-valve traps of this type there is an extra 298 Chapter 15. Steam Heating Systems valve for closing the discharge while the trap is filling with condensate. High pressure traps should not discharge directly into a vacuum return because of the vapor formed by the re-evaporation of a part of' the hot condensation. Fig. 21 shows a method which may be used for disposing of the greater part of the vapor of re-evaporation. An expansion chamber often is installed between the high- and low-pressure traps. - Automatic Return Traps In the general heating plant, where thermostatic traps are installed on the heating units, it becomes necessary to provide a means for returning the water of condensation to the boiler, if a condensation or vacuum pump is not used. When the return main can be kept sufficiently high above the boiler water line for all operating conditions, the water of condensation will flow back by gravity, and no mechanical device is required. But actually this does not work out in practice. It follows, therefore, that a direct return trap is needed for the handling of the condensation even though it may not be called into action except under some operating condition where the pressure differential exceeds the static head provided. The installation of a direct return trap assures safety for such systems, and guarantees the operation, of the plant under varying conditions. Automatic return traps, sometimes called alternating receivers, may be of the counter-balanced, tilting type, or spring actuated. These consist of a small receiver with an internal float, and when the condensate will not flow into the boiler under pressure, it will feed into the receiver of the trap, and in so doing, raise or tilt the float or mechanism which actuates a steam valve automatically. This admits steam to the. receiver, at boiler pressure, and the equalizing of the pressures which follows allows,the water to flow into the boiler. Fig. 22 shows a direct return tilting trap and receiver properly connected for automatically feeding a boiler from a system of returns delivering the condensate to the receiver. ' PROBLEMS IN PRACTICE 1 What is meant by water line difference in a gravity steam heating system? The water line difference is the distance between the level of the water in the dry or wet return and the boiler water line. This difference is equivalent to the pressure required to overcome the maximum drop in the system and the operating pressure of the boiler. 2 How many types of common mechanical returns are there and what are they? -" '' /. . . Three: (1) the mechanical return trap, (2) the condensation return pump, and (3) the vacuum pump. %. `3 In the ordinary vacuum system of steam heating, where does the vacuum usually exist? .. On the return side of the system only, between the radiator trap and the vacuum, pump. If the radiator supply valve is closed off, the vacuum may extend back through the radiator as far as the supply valve; if an inadequate supply of steam is. furnished to the system, some vacuum may be developed in the steam main, but neither, of these can be termed normal operation. ~ 299 Heating Ventilating Air Conditioning Guide 1938 4 What is the distinction between the open and the closed vapor systems? The open vapor system has the return line always open to the atmosphere, while the closed vapor system has an automatic device on the air vent so that air once expelled from the system through the vent cannot re-enter via this route. 5 On a vacuum system, what device must be placed on all drips before they enter the vacuum return line? A thermostatic drip trap or occasionally, where large volumes of condensation are to be handled, a float trap, or combination float and thermostatic trap. 6 # How does-the sub-atmospheric system differ m operation from the ordinary vacuum system? , - The ordinary vacuum system has pressure in the steam line, and a vacuum produced by the vacuum pump in the return line, usually varying between 5 and 10 in. of mercury. The sub-atmospheric system may have either a vacuum or pressure on the steam and return lines according to the weather conditions, but a constant difference in pressure is maintained between the lines regardless of what vacuum may be carried. The vacuum, which is generally produced jointly by condensation and the exhausting action of the pump, in the system .under conditions of throttled steam supply, will run much higher than in the ordinary vacuum system, and as high as 25 in. of mercury in the radiators. 7 i What is generally understood by zoning in building steam heating systems? Zoning is a term applied to the placing of certain sections of a building on a single temperature control instead of having either individual room control or a single tempera ture control governing the whole building. Zones may be horizontal, such as a single story, a basement, dr an attic, or vertical such as the north side, or the west side. 8 Why does the water line in the far end of a wet return in a gravity steam system rise higher than the water line in the boiler? The friction of the steam flowing through the steam main from the boiler to. the far end of the system and the pressure reduction resulting from the condensing action of the radi ators causes a drop in steam pressure at the point where the wet return is connected; consequently, the steam pressure on top of the water in the wet return is less than the steam pressure on top of the water in the boiler, so the water in the end of the wet return rises until a balanced condition is'set up. 9 On gravity one-pipe systems as indicated in Fig. 1 and Fig. 3, why is the drip on the steam runout connected to wet return? Because if it were connected to dry return, the pressure drops to two different points would not necessarily be the same and the system would short circuit. 10 What is the function of the automatic return trap? . To insure the return of condensate to the boiler when the operating condition is such that the boiler pressure exceeds the static head on the returns. 11 What advantage is there to an air valve with a check to prevent the re entrance of expelled air? A system equipped with such valves builds up a vacuum and holds the heat longer. With proper controls on the boiler, lower radiator temperatures can be maintained in mild weather, giving better plant efficiency. . 12 What are the essentials of a two-pipe closed vapor system? Packless graduated valves on radiators; thermostatic return traps on return and drips;an automatic return trap to prevent water from backing out of the boiler. 13 i Why must the automatic return trap on two-pipe vapor systems be about 18 in. above the boiler water line? That height is necessary to overcome water line difference owing to pressure drop and friction in pipe and fittings. 300 Chapter 16 PIPING FOR STEAM HEATING SYSTEMS Flow of Steam in Pipes, Pipe Sizes, Tables for Pipe Sizing, One-Pipe Gravity Air Vent Systems, Two-Pipe Gravity Air Vent Systems, Two-Pipe Vapor Systems, Vacuum Systems, Atmospheric Systems, Sub-Atmospheric Systems, Orifice Systems, High Pressure Steam, Expansion in Steam and Return Lines, Piping Connections and Details, Boiler Con nections, Hartford Return Connection THE design of a steam heating system should be considered under four headings, namely, (1) the details of the heating units, (2) the arrange ment of the general piping scheme, (3) the details of connections, and (4) the sizing of the lines. Items 1 and .2 are covered in Chapters 14 and 15, respectively, while this chapter considers the two latter items. The functions of piping are to supply the heating units with steam and to remove the condensation. In some systems both the air and con densation are.removed from the heating units by the return piping, To accomplish this effectively, the distribution of the steam should be efficient and equitable, without noise, and the returns should be as short as possible. When air is handled its escape should be facilitated to the utmost since an air-bound system will not heat properly. Condensation . takes place in a steam system not only in the heating units, but through out the piping system as well, and the returns also condense any steam or vapor that may be contained. At the same time part of the condensation may flash back into steam when the vacuum or pressure in the return is considerably below the steam pressure. It is essential that steam piping systems not only distribute steam at full load but also at partial loads, as the average winter demand is less than half of the demand in most severe outside temperatures. Further more, in heating up rapidly the load on the steam main may exceed the maximum operating load even in extreme weather, due to the necessity of raising the temperature of the metal in the system to the steam tem perature. This may require more heat them'would be emitted from the system itself after it once is thoroughly heated. STEAM FLOW The rate of flow of dry steam or steam with a small amount of water flowing in the same direction is in accordance with the general laws of gas flow and is a function of the length and diameter of the pipe, the density of the steam, and the pressure drop through the pipe. This relationship of flow of dry steam or steam with a small amount of water has been 301 Heating Ventilating Air Conditioning Guide 1938 established by Babcock in formula 1. P = 0.0000000367 ( 1 + or (1) (2) where P = loss in pressure, pounds per square inch. d -- inside diameter of pipe, inches. L = length of pipe, feet. D -- weight of 1 cii ft of steam. W = weight of steam flowing per hour, pounds. Example 1. How much steam will flow per hour through 100 ft of 2-in. pipe if the initial pressure is 1.3 lb per square inch and the pressure drop is 1 oz? Solution. P = ^ = 0.0625 lb; d = 2.067 in. (Table 1, Chapter 18); L = 100 ft; D = 0.04038 lb (Table 8, Chapter 1). Substituting these values in Formula 2; 0.0625 X 0..00440033S8 X 2.067s VW = 5220 V 2.067 I 100 = 97.2 lb per hour. Formula 2 does not allow for entrained water in low-pressure steam, condensation in pipe, and roughness in commercial pipe as found in practice. The latent heat of steam (hts) at atmospheric pressure (Table 8, Chapter 1) is 970.2 Btu per pound. Inasmuch as the heat emission of an equivalent square foot of heating surface (radiation) is 240 Btu, 1 lb of 970.2 steam at this pressure will supply or 4.04 sq ft of equivalent heating 240 surface. This figure is usually taken as 4 even. In Example 1, the weight of steam flowing per hour would therefore supply 4 X 97.2 or 388.8 sq ft of equivalent heating surface. PIPE SIZES . The determination of pipe sizes for steam heating depends on the following principal factors: . 1. The initial pressure and the total pressure drhp which may be allowed between the source of supply and the end of the return system. 2. The maximum velocity of steam allowable for quiet and dependable operation of the system; 3. The equivalent length of the run from the boiler or source of steam supply to the farthest heating unit. . 4. Unusual conditions in the building to be heated. ' Initial Pressure and Pressure Drop Theoretically there are several factors to be considered, such as initial pressure and pressure required at the end of the line, but it is most im portant that (1) the total pressure drop does not exceed the initial pressure of the system; (2) the pressure drop is not so great as to cause excessive velocities'; (3) there is a constant initial pressure, except on systems specially designed for varying initial pressures, such as the sub-atmos 302 Chapter 16. Piping for Steam Heating Systems pheric which normally operate under controlled partial vacua, the orifice, and the vapor systems which at times operate under such partial vacua as may be obtained due to the condition of the fire; (4) there is sufficient difference in level, for gravity return systems, between the lowest point on the steam main, the heating units, and the dry return, when considered in relation to the boiler water line. All systems should be designed for a low initial pressure and a reason ably small pressure drop for two reasons: first, the present tendency in steam heating unmistakably points toward a constant lowering of pres sures even to those below atmospheric; second, a system designed in this manner will operate under higher pressures without difficulty. When a system designed for a relatively high initial pressure and a relatively high pressure drop is operated at a lower pressure, it is likely to be noisy and have poor circulation., . The total pressure drop should never exceed one-half of the initial pressure when condensate is flowing in the same direction as the steam. Where the condensate must flow counter to the steam, the governing factor is the velocity permissible without interfering with the condensate flow. Laboratory experiments limit this to the capacities given in Tables 1 and 2 for vertical risers and in Table 3 for horizontal pipes at varying grades. ... Maximum Velocity and Reaming -- The capacity of a steam pipe in any part of a steam system depends upon the quantity of condensation present, the direction in which- the condensate is flowing, and the pressure drop in the pipe. Where the quantity of condensate is limited and is flowing in the same direction as the steam, only the pressure drop need be considered. When the con densate must flow against the steam, even in limited quantity, the ve locity of the steam must not exceed limits above which the disturbance between the steam and the counter-flowing water may produce object ionable sounds, such as water hammer,'or may result in the retention of water in certain parts of the system until the steam flow is reduced sufficiently to permit the water to pass. The velocity at which such disturbances take place is a function of (1) the pipe size, whether the pipe runs horizontally or vertically, (2) the pitch of the pipe if it runs hori zontally, (3) the quantity of condensate flowing against the steam, and (4) freedom of the piping from water pockets which under certain con ditions act as a restriction in pipe size. Three factors of uncertainty always exist in determining the capacity of any steam pipe. The first is variation in manufacture, which appar ently cannot be avoided and which caused an actual difference of 20 per cent in the capacity of a 1-in. pipe in experiments carried on at the A.S.H.V.E. Research Laboratory (Table 4). The second is the reaming of the ends of the pipe after cutting, which, experiments indicate, might reduce the capacity of a 1-in. pipe as much as 28.7 per cent (Table 5). The third is the uniformity in grading the pipe line. All of the capacity tables given in this chapter include a factor of safety. However, the pipe on which Table 4 is based showed no particular defects or constrictions on the inside, and the factor of safety referred to does not cover abnormal defects or constrictions nor does it cover pipe not properly reamed. 303 Heating Ventilating Air Conditioning Guide 1938 Table 1. Maximum Allowable Capacities of Up-Feed Risers for One-Pipe Low Pressure Steam Based on A. 5. H. V. E. Research Laboratory Tests Pcpb Sob Inches A i m 2 2Y2 3 m 4 Velocity Feet Per Second Pressure Drop Ounces per 100 Ft B 14.1 17.6 20.0 23.0 26.0 29;0 31.0 32.0 C 0.68 0.66 0.66 0.57 0.54 0.48 0.44 0.39 Sq Ft Radiation D . 45 98 152 288 464 799 1144 1520 Capacity Btu per Hour E 10.961 23,765 36,860 69,840 112,520 193,600 277,000 368,000 Lb Steam per Hour F 11.3 24.5 38.0 72.0 116.0 199.8 286.0 380.0 INSTRUCTIONS FOR USING TABLE 1 1. Capacities given in Table 1 should never be exceeded on one-pipe risers. 2. Capacities are based on K-lb condensation per square foot equivalent radiation and actual diameter of standard pipe. 3. All pipe should be well reamed and free from constrictions. Fittings should be up to size. (See Tables 4 and 5). - Table 2. Maximum Allowable Capacities of Up-Feed Risers for Two-Pipe Low Pressure Steam , Based on A. S. H. V. E. Research Laboratory Tests* 1 * 3 Pipe Size Inches Velocity Feet per Second Pressure Drop Ounces fee 100 Ft . A 1 m 2 m 3 m 4 B 2 23 27 30 35 1 38 41 42 43 C -- 1.78 1.57 1.48 1.33 1.16 0-95 0.81 0.71 Sq Ft Radiation D 40 74 151 228 438 678 1129 1548 2042 Capacity Btu per Hour E9550 17,900 36,500 55,200 106,100 164,100 273,500 375,500 495,000 Lb Steam per Hour . F 10.0 18.45 37.65 57.0 109.5 .169.4 282.2 387.0 510.5 INSTRUCTIONS FOR USING TABLE 2 1. The capacities given in this table should never be exceeded on two-pipe risers. . 2. Capacities are based on K-Ib condensation per square foot equivalent radiation and actual diameter of standard pipe. . 3. All pipe should be well reamed and free from constrictions. Fittings should be up to size. (See Tables 4 and 5.) ' 304 Chapter 16. Piping for Steam Heating Systems Table 3. Comparative Capacity of Steam Lines at Various Pitches for Steam and Condensate Flowing in Opposite Directions5* Pitch of Pipe in Inches per 10 Ft Pitch op Pipe a rn. Inches SqFt Rad. Based Btu e9 M IN. SqFt Rad. Based on 240 Btu 9) cd 1 IN. SqFt Rad. Based on 240 Btu IM IN. SqFt Rad. Based on 240 Btu 2 in. 3 m. 4 IN. Sq Ft SqFt SqFt Rad. Rad. i Rad. Based Based Based on 240 on 240 1 on 240 Btu Btu Btu 5 m. SqFt Rad. Based on 240 Btu i % 25.0 12 30.3 14 37.3 18 40.4 19 42.5 20 46.1 21 47.5 22 49.3 23 t 45.8 12 52.6 15 63.0 17 70.0 20 7S.2 22 83.0 23 87.9 25 90.2 26 IH IX 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165.0 28 172.6 29 178.2 31 142.6 18 159.0 21 181.0 23 196.5 25 209.3 27 224.0 28 234.8 30 242.6 31 2 236.0 19 263.5 20 299.5 23 325.5 25 346.5 27 371.5 28 388.4 29 401.1 30 aData from American Society of Heating and Ventilating Engineers Research Laboratory. Equivalent Length of Run All tables for the flow of steam in pipes, based on pressure drop, must allow for the friction offered by the pipe as well as for the additional resistance of the fittings and valves. These resistances generally are stated in terms of straight pipe; in other words, a certain fitting will produce a drop in pressure equivalent to so many feet of straight run of the same size of pipe. Table 6 gives the number of feet of straight pipe usually allowed for the more common types of fittings and valves. In all pipe sizing tables in this chapter the length of run refers to the equivalent length of run as distinguished from the actual length of pipe in feet. The length of run is not usually known at the outset; hence it is necessary to assume some pipe size at the start. Such an assumption frequently is considerably in error and a more common and practical method is to assume the length of run and to check this assumption after the pipes are sized. For this purpose.the length of run usually is taken as double the actual length of pipe. Table 4. Per Cent Difference in Capacity for Carrying Steam and Condensate Due to Variation of Pipe Size and Smoothness* Maximum Condensation, Lb per Hour Size of pipe.......... ............................... :___ Minimum Maximum Per cent variation Min. 14.00 15.20 8.6 1 In. 24.89 30.08 20.8 . 1M In. 45.42 52:08 14.7 l^In. 70.50 82.00 16.3 aData from American Society of Heating and Ventilating Engineers Research Laboratory. Table 5. Effect of Reaming Entrance to One-Inch One-Pipe Risers* Reamed entrances Squared entrances Three wheel cnfter Sinele wheel cutter Maximum Capacity o? Riser 24.7 lb per hour 23.9 lb per hour 22.2 lb per hour 19.2 lb per hour 17.6 lb per hour Per Cent Decrease 0.0 3.2 10.1 22.2 28.7 Data from American Society of Heating and Ventilating Engineers Research Laboratory. 305 Heating Ventilating Air Conditioning Guide 1938 Table 6. Length in Feet of Pipe to be Added to Actual Length of Run-- Owing to Fittings--to Obtain Equivalent Length Size of Pipe Inches St'd. Elbow Side Outlet Tee Gate Valve Globe Valve Angle Valve Length in Feet to be Added to Run 2 2H 3 m 4 5 6 7 89 10 12 14 5 7 10 12 14 . 18 22 26 31 35 39 47 53 16 20 26 31 35 44 50 55 63 69 76 90 105 2 18 9 3 25 12 3 33 16 4 39 19 5 45 22 7 57 28 9 70 32 10 82 37 12 94 42 13 105 . 47 15 118 52 18 140 63 20 160 72 Example of length in feet of pipe to be added to actual length of run. . nfAsuseo lchsth. - m.-o. h.......m.Jfc -t------------------ ! BaumLEHT UH6TH - 193-0' til TABLES FOR PIPE SIZING1 Factors determining the size of a steam pipe and its allowable limit of capacity are as follows: .. 1. Pipe condensate flowing with steam. - 2. Pipe condensate flowing against steam. 3. Pipe and radiator condensate flowing with steam. 4. Pipe and radiator condensate flowing against steam. It is apparent that (3) and (4) are practically limited to one-pipe systems while (1) and (2) cover all other systems. . Tables 7 and 8, worked out for determining pipe sizes, have their col umns lettered continuously, Columns A through L being in Table 7, and M through EE in Table 8. In the following text, reference made to columns will be by letter. The tables are based on the actual inside diameters of the pipe and the condensation of. ]/i lb (4 oz) of steam per square foot of equivalent direct radiation (abbreviated EDR) per hour. The drops indicated are drops in pressure per 100 ft of equivalent length of run. The pipe is.assumed to be well reamed without unusual or notice able defects. `Pipe size tables in this chapter have been compiled in simplified and condensed form for the convenience of the user; at the same time all of the information contained in previous editions of The Guide has been retained. Values of pressure drops, formerly expressed in ounces, are now expressed in fractions of a pound. *As steam system design has materially changed in recent years so that 240 Btu no longer expresses the heat of condensation from a square foot of radiator surface per hour, and as present day heating units have different characteristics from older forms of radiation, it is the purpose of The Guide to gradually eliminate the empirical expression square foot of equivalent direct radiation. EDR, and to substitute a logical unit based on the Btu.. The new terms to express the equivalent of 1000 Btu (Mb), and 1000 Btu per.hour (Mbh), have been approved by .the A.S.H.V.E. . .' 306 Chapter 16. Piping for Steam Heating Systems Table 7 may be used for sizing piping for steam heating systems by determining the allowable or desired pressure drop per 100 equivalent feet of run and reading from the column for that particular pressure drop. This applies to all steam mains on both one-pipe and two-pipe systems, vapor systems, and vacuum systems. Columns B to G, inclusive, are used where the steam and condensation flow in the same direction, while Columns H and / are for cases where the steam and condensation flow in opposite directions, as in risers and runouts that are not dripped. Columns J, K, and L are for one-pipe systems and cover riser, radiator valve, and vertical connection sizes, and radiator and runout sizes, all of which are based on the critical velocities of the steam to permit the counter, flow of condensation without noise. . Sizing of return piping may be done with the aid of Table 8 where pipe capacities for wet, dry, and vacuum return lines are shown for the pressure drops pier 100 ft corresponding to the drops in Table 7. It is customary to use the same pressure drop on both the steam and return sides of a system. Table 7. Steam Pipe Capacities Capacity Expressed in Square Feet of Equivalent Direct Radiation (Reference to this table will be by column letter A through L) This table is based on pipe size data developed through the research investiga tions of the American Society of Heating and Ventilating Engineers. Pipe - Size ;IN. A CAPACITIES OF STEAM MAINS AND RISERS Direction of Condensation Flow in Pipe Lute With the Steam in One-Pipe and Two-Pipe Systems J/s lb or HO. Drop `/i** lb or HOt Drop. `/u lb 10* Drop. Hlb 20. Drop Hlb 4 0s Drop Hlb 80s Drop Against the Steam Two-Pipe Only Vertical Hon- sontal BCD B F a /o Special. Capacities fob Onb-Pepe Systems Only Supply Rums UpFeed Radiator Radiator and and - Riser Run- nections Jb K La X 30 l 39 46 56 79 Til 30 157 5fr 26 IX 87 100 122 173 245 346 122 58 m .134 155 190 269 380 538 190 95 2 273 315 386 546 771 1,091 386 195 2X 449 518 635 898 1,270 1,797 635 395 3 822 948 1,163 1,645 2,326 3,289 1,129 700 3X 1,228 1,419 1,737 2,457 3,474 4i913 1,548 1,150 4 1,738 2,011 2,457 3,475 4,914 6,950 2,042 1,700 5 3,214 3,712 4,546 6,429 9,092 12,858 3,150 6 5,276 6,094 7,462 10,553 14,924 21,105 8 10,983 12,682 15,533 21,967 31,066 43,934 10 20,043 23,144 28,345 40,085 56,689 80,171 12 32,168 37,145 45,492 64,336 90,985 128,672 16 60,506 69,671 84,849 121,012 169,698 242,024 -- -- 25 45 98 152 288 464 799 1,144 1,520 -- 20 20 55 55 81 81 165 165 260 475 745 1,110 2,180 ---- A0 Horizontal Mains and Down-Feed Risers UpFeed Risers Mains and Un Updripped Feed Run -Risers outs Radiator Con- nections Run outs ' Not Dripped Note.--All drops shown are in pounds per 100 ft of equivalent run--based on pipe properly reamed. Do not use Column H for drops of 1/24 or 1/32 lb; substitute Column C or Column B as required. bDo not use Column J for drop of 1/32 lb except on sizes 3 in. and over; below 3 in. substitute Column B. On radiator runouts over 8 ft long increase one pipe size over that shown in Table 7. Copyright i American Society of Heating and Ventilating Engineers j Not to be.Reprinted With* 9 (. Heating, Piping and Air Conditioning Contractor* National Association ) out Special Permission 307 Heating Ventilating Air Conditioning Guide 1938 ^N-aOtO^OONiOfOooOoOoOo 8 ftO- OOOOQOOOOO 0rOt'O''t0OO(>VOJ0OO0 "VOOOOOOOO Si J*O'0'O'0O v-iOH't^-(NCMO(S'OO o n o to aooooo On tO O 8888888888 NNC'ONNOONO iOOHnOt^0OOOnQOioCC< NON'O^1N0'O0OHOCOSrOHOOOi0 - `O0'*0CN'rt`t^O0'i0Tj< ______-_i _c_o_*_0_0_0_~uh^cioT OOOO ON to Os o <- ^ ON to v-t fO OOOOO On to On O O i-i ^ On to O 308 AM ERICAN SOCIETT OF H E A TIN G AND V E N TILA TIN G ENGINEERS 1 XT-- ... u _ .. .n ^o ., , , Beating, Piping and A ir Conditioning Coniraeton National Atsociaiion) ^*o t t o R e p r in te d W it h o u t S p e c ia l P e r m is s io n 16.Chapter Piping for Steam Heating Systems Example 8. What pressure drop should be used for the steam piping of a system if the measured length of the longest run is 500 ft and the initial pressure is not to be over 2-lb gage? Solution. It will be assumed, if the measured length of the longest run is 500 ft, that when the allowance for fittings is added the equivalent length of run will not exceed 1 000 ft. Then, with the pressure drop not over one half of the initial pressure, the drop could be 1 lb or less. With a pressure drop of 1 lb and a length of run of 1,000 ft, the drop per 100 ft would be Ho lb. while if the total drop were Yi lb, the drop per 100 ft would be Ko lb. In the first instance the pipe could be sized according to Column D for H6 lb per 100 ft, and in the second case, the pipe could be sized according to Column C for Ye lb. On completion of the sizing, the drop could be checked by talung the longest line and actually calculating the equivalent length of run from the pipe sizes determined. If the calculated drop is less than that assumed, the pipe size is all right; if it is more, it is robable that there are an unusual number of fittings involved, and either the lines must Ce straightened or the column for the next lower drop must be used and the lines resized. Ordinarily resizing will be unnecessary. ONE-PIPE GRAVITY AIR-VENT SYSTEMS One-pipe gravity air-vent systems in which the equivalent length of run does not exceed 200 ft should be sized as follows: 1. For the steam main and dripped runouts to risers where the steam and condensate flow in the same direction, use M6"ib drop (Column D). - 2. Where the riser runouts are not dripped and the steam and condensation flow in opposite directions, and also in the radiator runouts where the same condition occurs, use Column L. 3. For up-feed steam risers carrying condensation back from the radiators, use Column J. 4. For down-feed systems the main risers of which do not carry any radiator con densation, use Column H. ,. , 5. For the radiator valve size and the stub connection, use Column K. 6. For the dry return main, use Column U. 7. For the wet return main use Column T. On systems exceeding an equivalent length of 200 ft, it is suggested that the total drop be not over 34 lb. The return piping sizes should correspond with the drop used on the steam side of the system. Thus, where }$4-lb drop is being used, the steam main and dripped runouts would be sized from Column C; radiator runouts and undripped riser runouts from Column L; up-feed risers from Column J; the main riser on a down-feed system from Column C (it will be noted that if Column H is used the drop would exceed the limit of H4 lb); the dry return from Column R; and the wet return from Column Q. With a J^-lb drop the sizing would be the same as for Yi lb except that the steam main and dripped runouts would be sized from Column B, the main riser on a down-feed system from Column B, the dry return from Column 0, and the wet return from Column N. Example 8. Size the one-pipe gravity steam system shown in Fig. 1 assuming that this is all there is to the system or that the riser and run shown involve the longest run on the system. Solution. The total length of run actually shown is 215 ft. If the equivalent length of run is taken at double this, it will amount to 430 ft, and with a total drop of H lb the drop per 100 ft will be slightly less than H 6 lb. It would be well in this case to use H4 lb, and. this would result in the theoretical sizes indicated in Table 9. These theo- Heating Ventilating Air Conditioning Guide 1938 retical sizes, however, should be modified by not using a wet return less than 2 in. while the main supply, g-h, if from the uptake of a boiler, should be made the full size of the main, or 3 in. Also the portion of the main k-m should be made 2 in. if the wet return is made 2 in. Notes on Gravity One-Pipe Air-Vent Systems 1. Pitch of mains should not be less than 34 in. in 10 ft. 2. Pitch of horizontal runouts to risers and radiators should not be less than 34 in. in 10 ft. Where this pitch cannot be obtained runouts over 8 ft in length should be one size larger than called for in the table. . 3. In general, it is not desirable to have a main less than 2 in. The diameter of the far end of the supply main should not be less than half its diameter at its largest part. 4. Supply mains, branches to risers, or risers, should be.dripped where necessary. Table 9. Pipe Sizes fob One-Pipe Up-feed System Shown in Fig. 1 Past or Ststkm . Section or Pipe Branches to radiators.. Branches to radiators.. Riser-.................... ......... Riser.. ,,. .. Riser________ :________ Riser.________________ Riser Branch to.riser . . ; Supply main,,............... Branch to supply main Dry return main Wet return main- ..... Wet return main~........ Wet return main.......... a to b . b to c c to d d to e e to/ / tog g to h h to j f to k kiorn mton n to p Radiation Supplied (Sq Ft) Theoretical Pipe size (Inches) Practical Pipe mm (Inches) 100 2 2 50 134 134 200 2 2 300 234 234 400 234 234 500 3 3 600 3 3 600 334 334 600 3 3 600 234 3 600 134 2 600 1 2 600 1 2 600 1 2 r=i ^u nn - % 3rd. Ft. tBwi 2nd. A CEL^tJIEIia Fig. 1. Riser, Supply Main and Return Main of One-Pipe System . TWO-PIPE GRAVITY AIR-VENT SYSTEMS .\ . . The method employed in determining pipe sizes for two-pipe gravity air-vent systems is similar to that described for one-pipe systems except that the steam mains never carry radiator condensation. The drop allowable per 100 ft of equivalent run. is obtained by taking the equiva lent length' to the farthest radiator as double the actual distance, and then dividing the allowable or desired total drop by the number of hundreds of feet in the equivalent length. Thus in a system measuring 400 ft from the boiler to the farthest radiator, the approximate equivalent length of run would be 800 ft. With a total drop of ]/% lb the drop per ,100 ft would be or 3fe lb; therefore, Column D would be used for all steam mains where the condensation and steam flow in the same direc tion; If a total drop of lb is desired, the drop per 100 ft would be J42 lb 310 . Chapter 16. Piping for Steam Heating Systems and Column B would be used. If the total drop were to be 1 lb, the drop per 100 ft would be Y% lb and Column E would be used. For mains and riser runouts that are not dripped, and for radiator runouts where in all three cases the condensation and steam flow in opposite directions, Column I should be used, while for the steam risers Column H should be used unless the drop per 100 ft is 34-t lb or 3^2 lb, when Columns B or C should be substituted so as not to exceed the drop permitted. On an overhead down-feed system the main steam riser should be sized by reference to Column H, but the down-feed steam risers sup plying the radiators should be sized by the appropriate Columns B through C, since the condensation flows downward with the steam through them. The riser runouts, if pitched down toward the riser as they should be, are sized the same as the steam mains, and the radiator runouts are made the same as in an up-feed system. . In either up-feed or down-feed systems the returns are sized in the same manner and on the same pressure drop basis as the steam main; the return mains are taken from Columns O, R, U, X, or AA according to the drop used for the steam main; and the risers are sized by reading the lower part of Table 8 under the column used for the mains. The hori zontal runouts from the riser to the radiator are not usually increased on the return lines although there is nothing incorrect in this practice. The same notes apply that are given for one-pipe gravity systems. TWO-PIPE VAPOR SYSTEMS While many manufacturers of patented vapor heating accessories have their own schedules for pipe sizing, an inspection of these sizing tables indicates that in general as small a drop as possible is recommended. The reasons for this are: (1) to have the condensation return to the boiler by gravity, (2) to obtain a more uniform distribution of steam throughout the system, especially when it is desirable to carry a moderate or low fire, and (3) because with large variation in pressure the value of gradu ated valves on radiators is destroyed. .. For small vapor systems where the equivalent length of run does not exceed 200 ft, it is recommended that the main and any runouts to risers that may be dripped should be sized from Column D, while riser runouts not dripped and radiator runouts should employ Column I. The up-feed steam risers should be taken from Column H. On the returns, the risers should be sized from -Column U (lower portion) and the mains from Column U (upper portion). It should again be noted that the pressure drop in the steam side of the system is kept the same as on the return side except where the flow in the riser is concerned. : On a down-feed system the main vertical riser should be sized from Column H, but the down-feed risers can be taken from Column D al though it so happens that the values in Columns D and H correspond. This will not hold true in larger systems. ' .. . For vapor systems over 200 ft of equivalent length, the drop should not exceed Y lb to Y lb, if possible. Thus, for a 400 ft equivalent run the drop per 100 ft should be not over Y lb divided by 4, .or 342 lb. In this case the steam mains would be sized from Column B; the radiator and 311 T Heating Ventilating Air Conditioning Guide 1938 undripped riser runouts from Column I; the risers from Column B, because Column H gives a drop in excess of lb. On a down-feed system, Column B would have to be used for both the main riser and the smaller risers feeding the radiators in order not to increase the drop over J^2 lb. The return risers would be sized from the lower portion of Column 0 and the dry return main from the upper portion of the same column, while any wet returns would be sized from Column N. The same pressure drop is applied on both the steam and the return sides of the system. Notes on Vapor Systems 1. Pitch of mains should not be less than % in. in 10 ft. . 2. Pitch of horizontal runouts to risers and radiators should not be less than x/2 in. in 10 ft. Where this pitch cannot be obtained runouts over 8 ft in length should be one size larger than called for in the table. 3. In general it is not desirable to have a supply main smaller than 2 in., and when the supply main is 3 in. or over at the boiler or pressure reducing valve it should not be less than 2J^ in. at the far end. 4. When necessary, supply main, supply risers, or branches to supply risers should be dripped separately into a wet return. The drip for a vapor system may be connected into the dry return through a thermostatic drip trap. VACUUM SYSTEMS Vacuum systems are usually employed in large installations and have total drops varying from to lb- Systems where the maximum equivalent length does not exceed 200 ft preferably employ the smaller pressure drop while systems over 200 ft equivalent length of run more frequently go to the higher drop, owing to the relatively greater saving in pipe sizes. For example, a system with 1200 ft longest equivalent length of run would employ a drop per 100 ft of Yi lb divided by 12, or M4 lb. In this case the steam main would be sized from Column C, and the risers also from Column C (Column H could be used as far as critical velocity is concerned but the drop would exceed the limit of lb). Riser runouts, if dripped, would use Column C but if undripped would use Column I; radiator runouts, Column I; return risers, lower part of Column S; return runouts to radiators, one pipe size larger than the radiator trap connections. Notes on Vacuum Systems 1. It is not generally considered good practice to exceed j-jj-lb drop per 100 ft of ` equivalent run nor to exceed 1 lb total pressure drop in any system. 2. Pitch of mains should not be less than l/i in. in TO ft. _ 3. Pitch of horizontal runouts to risers and radiators should not be less than }/2 in. in 10 ft. Where this pitch cannot be obtained runouts over 8 ft in length should be one size larger than called for in the table. 4. In general it is not considered desirable to have a supply main smaller than 2 in. When the supply main is 3 in. or over, at the boiler or pressure reducing valve, it should not be less than 2}- in. at the far end. 5. When necessary, the supply main, supply riser, or branch to a supply riser should be dripped separately through a trap into the vacuum return. A connection should not be made between the steam and return sides of a vacuum system without interposing a trap to prevent the steam from entering the return line. 6. Lifts should be avoided if possible, but when they cannot be eliminated they should be made in the manner described in Chapter 15 under Up-Feed Vacuum Systems. 312 i 'j 1 J Chapter 16. Piping for Steam Heating Systems ATMOSPHERIC SYSTEMS The sizing of the supply and return piping on atmospheric systems is practically identical with the sizing used for vacuum systems and the same notes apply, except that no lift can be made in the return line. SUB-ATMOSPHERIC SYSTEMS Any properly pitched, correctly sized vacuum system without a^lift except at the vacuum pump may be used as a sub-atmospheric system when the proper equipment is substituted for the ordinary vacuum pump, traps, and controls. On new systems manufacturers usually recommend a drop on the steam line of between Y/i and x/i lb for the total run, and suggest adding 25 ft to the total equivalent length of run to insure that the steam gets through to the last radiator. The same notes apply to these systems as for vacuum systems, except that no lifts can be made in the returns. ORIFICE SYSTEMS The orifice systems can be operated with any piping system suitable for vacuum operation, according to experienced designers. Because these systems vary considerably in detail, it is advisable to consult the manu facturer of the particular system contemplated for recommendations. The same notes apply to these systems as to vacuum systems, except that lifts cannot be made in the returns of orifice systems if a vacuum pump is used. HIGH PRESSURE STEAM When steam heating systems are supplied with steam from a high pressure plant, one or more pressure-reducing valves are used to bring the pressure down to that required by the heating system. It has been con sidered good practice to make the pressure reductions in steps not to exceed 50 lb in each case. For example, in reducing from 100-lb gage to 2-lb gage, two pressure reducing valves would-be used, the first reducing the pressure from 100-lb gage to 50 lb and the second reducing the pressure from 50-lb gage to 2-lb gage. Valves are available that will reduce 100 lb in one step, and it is questionable whether two valves are now required for initial pressures of 150 lb or less. The pressure-reducing valve, or pressure-regulator as it is sometimes termed, has ratings which vary 200 to 400 per cent. Some of these ratings are based on arbitrary steam velocities through the valve of 5,000 to 10,000 fpm and it is assumed that the valve when wide open has the same capacity as the pipe on the inlet opening of the valve. At times it is considered desirable to keep the steam velocity in the high pressure section of the piping and the low pressure section constant. The velocity through the valve port is obviously a function of the pressure drop across the valve. It is well known that steam flowing through an orifice increases its velocity until the pressure on the outlet side is reduced to 58 per cent of the absolute pressure on the inlet side, and that with further reduction of pressure on the outlet side little change in velocity will be obtained. As practically all pressure-reducing valves used for steam heating work 313 Heating Ventilating Air Conditioning Guide 1938 lower the steam pressure to less than 58 per cent of the inlet pressures, only the maximum velocity through such valves need be considered. If it is assumed that the valve, when fully open, has an area equal to that of the inlet pipe size, that the steam is flowing into a pressure less than 58 per cent of the initial pressure, that the orifice efficiency is approx imately 70 per cent, and that 20 per cent more is allowed for a factor of safety, then the pressure reducing valves will have the working capacities shown in Table 10. If the valve, when fully open, does not give an orifice area equal to that of the pipe on the inlet side, then the capacities will be proportional to the percentage of opening secured, taking the pipe area as 100 per cent. More frequently, difficulty is encountered from the use of pressure reducing valves which are too large in size instead of being Table 10. Capacities of Pressure-Reducing Valves (100-lb Gags Down to any Pressure--52 lb or Less) Inlet Nominal Pipe Diameter (Inches) x X 1 IX iX 2 m 3 3X 4 5 6 Pounds Steam peb Hour at 100-Lb Gaos 866 1,576 2,459 4,263 5,808 9,564 13,623 21,041 28,213 36,285 56,971 82,336 Equivalent Direct Radiation Sq Ft at yi Lb.. . 3,464 6,304 9,836 17,052 23,232 38,256 54,492 84,104 112,852 145,140 227,884 329,344 Equivalent Direct Radiation Sq Ft at Vi Lb 2,598 4,728 7,377 12,689 17,424 28,692 40,869 63,123 84,039 108,855 170,913 247,008 Formula: where A XV X 3600 X .50 144 X 3.88 pounds per hour passed by orifice. A = area of inlet pipe, square inches. V = velocity of steam through orifice (approximately 870 fps). 50 = 70 per cent efficiency of orifice less 20 per cent for factor of safety. 144 = square inches in 1 sq ft. 3600 = seconds in one 'hour. 3.88 = cubic feet per pound at 100-Ib gage. too small. Where valves are large in size, fhe valve tends to work close to the seat, causing it to cut out in a relatively short time, as well as being noisy in operation. Most exact regulation of pressure on steam heating systems is secured from diaphragm-operated valves controlled by a pilot line from the low pressure pipe, taken off the low pressure main at least 15 ft from the reducing valve. The reducing valves operating on the proportionalreduction principle will give a variation of steam pressure on the low pressure side if the initial pressure varies between considerable limits. The so-called dead-end valve is used for reduced pressures where the line has not sufficient condensing capacity at all times to condense the leakage that might occur with the ordinary valve. Single-disc valves do not give as close regulation sis double-disc valves, but the single disc is preferable where dead-end valves are necessary, such as on short runs to thermo 314 Chapter 16. Piping for Steam Heating Systems statically controlled hot water heaters, central fan heating units and unit heaters. The correct installation (Fig. 2) of a pressure-reducing valve includes a pressure-reducing valve with a gate valve on each side, a by-pass con trolled by a globe valve, a pressure gage on the low pressure side, and a safety valve on the low pressure main at some point, usually within a reasonable distance of the pressure-reducing valve. Pressure-reducing valves should have expanded outlets for sizes greater than 2 in. Where the steam main is of still larger diameter than the expanded outlet, and in cases where straight valves are used, an increaser is placed close against the outlet of the valve to reduce the velocity immediately after passing through the valve. Strainers are recommended on the inlets of all pressure-reducing valves. A pressure gage may be located on the highpressure line near the valve if desired. Owing to the large variation in steam demand on the average heating system, it is generally advisable to use two pressure-reducing valves con- Less trouble from expansion leaks will occur when the bypass valve is on the same center line as the pressure reducing valve Bypass (same size as high pressure supply line)' lobe valve High pressure steam Drip Pressure reducing valve Valve Fig. 2. Typical Pressure-Reducing Valve Installation nected in parallel. One valve should be large enough for the maximum load and the other should have a diameter approximately half that of the first. The smaller valve can be used most of the time, for it will give much better regulation than the larger one on light or normal loads. Control Valves . Gate valves are recommended in all cases where service demands that the valve be either entirely open or entirely closed, but they should never be used for throttling. Angle globe valves and straight globe valves should be used for throttling, as done on by-passes around pressure reducing valves or on by-passes around traps. EXPANSION IN STEAM AND RETURN LINES Because all steam and return lines expand and contract with changes in temperature, provision should be made for such movement.. The expansion in steam supply pipes is normally taken at 1 % to 1H in. per 100 ft and in return lines at one-half or two-thirds of this amount. It may be calculated accurately if the temperature rise and fall can be determined with reasonable certainty (Chapter 18). The temperature at the time of erection often has a greater expansion effect on piping than the temperature in the building after it has been put into service. . . 315 Heating Ventilating Air Conditioning Guide 1938 Expansion may be taken care of by any, or all, of three different methods, namely, (1) the spring in the pipe including offsets and expan sion bends, (2) the turning of the pipe on its threads and swing joints, and (3) the use of expansion joints. By the first scheme, which is the most popular method where space permits, the pipe is offset, or broken, around rooms or corners, and is hung so that the spring in the pipe at right angles to the expansion movement is sufficient to absorb the expansion. If conditions do not lend themselves to this treatment, regular expansion bends of the U or offset type may be used. In tight places such as pipe tunnels the expansion joint is pre ferable. See additional material on pipe expansion bends in Chapter 18. On riser runouts and radiator runouts the swing joint is used almost without exception. On high vertical risers the pipes may be reversed every five to ten stories; that is, the supply is carried over to the adjacent return riser location and the return riser is run over to the former supply riser location, thus making horizontal offsets in each line. Corrugated copper expansion joints also are used on risers but must be made acces sible in case future replacement becomes necessary. PIPING CONNECTIONS AND DETAILS Piping connections may be classified into two groups: first, those suitable for any system of steam heating; second, those devised for certain systems which cannot be satisfactorily applied to any other type. There are also various details that apply to piping on the steam side which cannot be used on the returns. An installation that is designed and sized, correctly and installed with care may be rendered defective by the use of improper connections, such as runouts that do not allow for expansion, thermostatic traps unprotected from scale, pressure-reducing valves without strainers, and lack of drips at required points. Supply BOILER CONNECTIONS . Boiler headers and connections have the largest sizes of pipe used in a system. Cast-iron, horizontal-type, low pressure heating boilers usually have several tapped outlets in the top, the manufacturers recommending their use in order to reduce the velocity of the steam in the vertical up takes from the boiler and to permit entrained water to return to the boiler instead of being carried over into the steam main where it must be cared for by dripping. Steel heating boilers usually are equipped with only one steam outlet but many engineers believe that better results are obtained by specifying that such boilers have two. The second outlet, usually located 3 or 4 ft back of the regular one, reduces the velocity 50 per cent in the steam uptake. Fig. 3 shows a type of boiler connection that was used for many years and one with which some boilers are now piped. The uptakes are carried as high as possible, turned horizontally and run out to the side of the boiler and then are connected together into the main boiler runout which drops into the top of the boiler header through a boiler stop valve. No drips are provided on this type of runout except a very small one which is sometimes installed on the boiler side of the stop valve. Fig. 4 shows a 316 Chapter 16. Piping for Steam Heating Systems type of boiler connection which is regarded as superior to that shown in Fig. 3 and which is the type illustrated in the system diagrams in Chapter 15. This type is similar to that shown in Fig. 3 except that the horizontal branches from the uptakes are connected into the main boiler runout, and the steam is carried toward the rear of the boiler. The branch to the building or boiler header is taken off behind the last horizontal boiler con nection. At the rear end of this main runout, a large size drip, or balance pipe, is dropped down into the boiler return, or into the top of the Hart ford Loop, which is described in a following paragraph. As a result, any water carried over from the boiler follows the direction of steam flow toward the rear and is discharged into the rear drip, or balance pipe, without being carried over into the system. Return Cast-iron boilers are generally provided with return tappings on both sides, but steel boilers often are equipped with only one return tapping. A boiler with side return tappings will usually have a more effective cir culation if both tappings are used. Check valves generally should not be used on the return connection to steam heating boilers from one and two pipe gravity systems because they are not always dependable inasmuch as a small piece of scale or dirt lodged on the seat will hold the tongue open and make the check useless. These valves also offer a certain, amount of resistance to the returns coming back to the boiler, and in gravity systems will raise the water line in 'the far end of the wet return several inches. However, if check valves are omitted and the steam pressure is raised with the boiler steam valve closed, the water in the boiler will be blown out into the return system with the accompanying danger of boiler damage. These objections are largely overcome with the Hartford return connection. Sec method of calculating height above water line for gravity one-pipe systems in Chapter 15 317 Heating Ventilating Air Conditioning Guide 1938 Hartford Return Connection In order to prevent the boiler from losing its water under any circum stances, the use of the Hartford Connection, or the Underwriters Loop, is recommended. Fig. 5 shows this connection for a two-boiler installation. For a single boiler installation the connection is made as is indicated for one boiler. The essential features of construction of a Hartford Loop connection are: (1) A direct connection (made without valves) between the steam side of 16.Chapter Piping for Steam Heating Systems boiler and the horizontal main or runout is compensated for by the use of reducing ells (Figs. 3 and 4). The following example illustrates the sizing of the boiler connections shown in Fig. 6. Example U- Determine the size of boiler steam header and connections (Fig. 6) if there are three boilers, two to carry 50 per cent of the load each, and the third to be used as a spare. The steam mains are based on J^-Ib drop per 100 sq ft of equivalent direct the boiler and the return side of the boiler, and (2) a close nipple con nection about 2 in. below the normal boiler water , line from the return main to the boiler steam and return balance connection. Sizing Boiler Connections % ' Little authentic information is available on the sizing of boiler runouts and steam headers. Although many engineers prefer an enlarged steam header to serve as additional steam storage space, there ordinarily is no sudden demand for steam in a steam heating system except during the heating-up period, at which time a large steam header is a disadvantage rather than an advantage. The boiler header may be sized by first com puting the maximum load that must be carried by any portion of the header under any conceivable method of operation, and then applying the same schedule of pipe sizing to the header as is used on the steam mains for the building. . The horizontal runouts from the boiler, or boilers, may be sized by calculating the heaviest load that will be placed on the boiler at any time, and sizing the runout on the same basis as the building mains. The difference in size between the vertical uptakes from the 318 Solution: Size of Boiler Header When Operating oh Boilers Nos. 1 and 2 Nos. 2 and 3 Nos. 3 and 1 Max. Load *A 6000 6000 6000 6000 Load on Various Portions of Header B 0 6000 0 6000 c 2000 8000 2000 8000 D 4000 2000 2000 4000 B 3000 3000 3000 3000 f 3000 3000 3000 3000 Maxdiuu Load 6000 8000 6000 8000 8000 sq ft @ H lb per 100 ft = 6 in. main. (See Table 7.) The three runouts Size of Boiler Runouts G\, Gi, Gt = o = 2667 sq ft each @ lb per 100 ft 4 in. pip-e. Hi, Hi, Hi = 2667 sq ft each @ Jfj lb per 100 ft = 4 in. pipe4 (See Table 7). Ji, Ji, Jt = 5333 sq ft each @ lb per 100 ft = 5 in. pipe4 (See Table 7). Kti Ki, Kt -- 8000 sq ft each @ lb per 100 ft = 6 in. pipe4 (See Table 7). The uptakes from the boiler probably would be 6 in. pipe with a 6 in. X 4 in. reducing ell at top. . . . *Natc.--As Ki, Ku Ki all carry 8000 sq.ft and arc 6 in. pipe, the whole runout including Ji, /l and 7, and Hi, Hi and Hi and the leads from the boiler headers to the main steam header .would also be, made 6 in. pipe. '' '` 319 Heating Ventilating Air Conditioning Guide 1938 . Return connections to boilers in gravity systems are made the same size as the return main itself. Where the return is split and connected to two tappings on the same boiler, both connections are made the full size of the return line. Where two or more boilers are in use, the return to each may be sized to carry the full amount of return for the maximum load which that boiler will be required to carry. Where two boilers are used, one of them being a spare, the full size of the return main would be carried to each boiler, but if three boilers are installed, with one spare, the return line to each boiler would require only half of the capacity of the entire system, or, if the boiler capacity were more than one-half the entire system load, the return would be sized on the basis of the maximum boiler capacity. As the return piping around the boiler is usually small and short, it should not be sized to the minimum. Riser s'joint .. .i Radiator lii.nimilimn i m "Runout below floor PLAN Fig. 7. One-Pipe Radiator Connections With returns pumped from a vacuum or receiver return pump, the size of the line may be calculated from the water-rate on the pump, discharge when it is operating, and the line sized for a very small pressure drop, the size being obtained from the Chart for Pressure Drop for Various Rates of Flow of Water, Fig. 3, Chapter 43. The relative boiler loads should be considered, as in the case of gravity return connections. Radiator Connections Radiator connections are important on account of the number of repetitions, which occur in every heating installation. They must be properly pitched and they must be arranged to allow not only for move ment in the riser but, in frame buildings, for the shrinkage of the building. In a three story building this sometimes amounts to 1 in. or more. The simplest connection is that for the one-pipe system where only one radia tor connection is necessary; Where the radiator runouts are located on the ceiling of under the floor, sufficient space usually is available to make . 320 Chapter 16. Piping for Steam Heating Systems Eccantne bushing Fig. 8. Connections to Steam-Type Radiator for Two-Pipe System Fig. 9. Top and Bottom Opposite End Radiator Connections Fig. 10. Top and Bottom Radiator Connections a good swing joint with plenty of pitch, but where the runouts must come above the floor the vertical space is small and the runouts can project out into the room only a short distance. Fig. 7 illustrates two satisfactory methods of making runouts on a one-pipe gravity air vent system of either the up-feed or down-feed type, the runout below the floor being indicated in full lines and the runout above the floor in dotted lines. Sometimes it is necessary to set a radiator on pedestals, or to use high legs, in order to obtain sufficient vertical distance to accommodate abovethe-floor runouts. Particular attention must be given to the riser expan sion as it will raise the runout and thereby reduce the pitch. Similar connections for a two-pipe system of the gravity air vent type are illustrated in Fig. 8 for the old steam type radiator. If the water type is used, the supply tapping is at the top instead of at the bottom, the runouts otherwise remaining as shown in Fig. 8. A satisfactory type of radiator connection for atmospheric, vapor, vacuum, sub-atmos pheric, and orifice systems of both the up-feed and down-feed types is shown in Fig. 9. While short radiators, not exceeding 8 to 10 sections, may be supplied and returned from the same end as indicated in Fig. 10, the top-andbottom-opposite-end method is to be preferred in all cases where it can be used. On down-feed systems of the atmospheric, vapor, vacuum, subatmospheric, and orifice types, the bottom of the supply riser must be dripped into the return somewhat as illustrated in Fig. 11. On up-feed systems of the vapor and atmospheric types, where radiators in the basement are located below the level of the steam main, the drop to the radiator is dripped into the wet return and an air line is used to vent the return radiator connection into an overhead return line, as illustrated in Fig. 12. When the radiator stands on the floor below the main, the drip Fig. 11. Top and Bottom Opposite End Radiator Connections Fig. 12. Connections to Radiator Hung on Wall 321 Fig. 13. Connecting Drop Riser Direct to Radiator Heating Ventilating Air Conditioning Guide 1938 on the steam branch down to the radiator may be omitted if an overhead valve, as shown in Fig. 13, is used. This method is also suitable for vacuum, sub-atmospheric, and orifice systems. Convector Connections Convectors often are installed without control valves, a damper being used to shut off the flow of air to retard the heat transfer from the con vector even though it is still supplied with steam. The piping connec tions for a convector with the inlet and outlet at the same end are shown in Fig. 14. There is no valve on the steam side but there is a thermostatic trap on the return. The damper for control is shown immediately above the convector. This piping is suitable for atmospheric, vapor, vacuum, Chapter 16. Piping for Steam Heating Systems return were on a vacuum, atmospheric, sub-atmospheric or orifice system, the treatment would be identical. On all heating units it is important to use a nipple the full size of the outlet and to reduce the pipe size to the normal return size required, by the use of a reducing ell, as indicated in Fig. 21. Pipe Coil Connections Pipe coils, unless coupled in a correct manner, often give trouble from short circuiting and poor circulation. The method of connecting shown in Fig. 22 is suitable for atmospheric, vapor, vacuum, sub-atmospheric, and orifice systems. Fig. 14. Convector Con nections Same End . Fig. 15. Horizontal Fin-Type Heating Unit Fig. 16. Heating Unit Valves Behind Grille Fig. 17. Heating Unit . Fig. 18. Fin-Type Heat- with Valves in ing Unit in Cabinet Basement . Fig. 19. Piping Connec tions to Indirect Radiators . -\ ' sub-atmospheric, and orifice systems of the up-feed type. A similar unit with connections on opposite ends and suitable for the same systems is shown in Fig. 15. This unit has no damper but requires a valve on the steam connection for control. When valves must be located so as to be accessible from the supply air grille, the arrangement usually takes the form indicated in Fig. 16. A convector located in the basement and supplying air to a room on the floor above may be piped as pictured in Fig. 17 for all systems except gravity one-pipe or two-pipe systems. Convectors with damper control, installed in cabinets or under window sills, usually are connected as shown in Fig. 18. Vapor systems with heating units in the basement where the returns are dry would be treated as in Fig. 19. Similar heating units where a wet return is available would be connected as shown in Fig. 20. If the dry 322 Indirect Air Heater Connections : Heating units for central fan systems have simple connections on the steam side. The steam main is carried into the fan room and has a single branch tapped off for each row of heating units. Each of these main branches is split into as many connections as need be made to each row, governed by the number of stacks and the width of the stacks. Each stack must have at least one steam connection, and wide stacks are more evenly heated with two steam connections, one at each-end.. 323 Heating Ventilating Air Conditioning Guide 1938 The piping shown in Fig. 23 is for small stacks and has the steam con nected at only one end. On the return side all of the returns are collected together through check valves and are passed through blast-traps, which are connected to the vacuum return or to an atmospheric return. The air from the stacks, in the case illustrated, passes up into a small air line and through a thermostatic trap into a line connecting into the return beyond the blast trap. Where the stacks contain some thirteen or more sections, an auxiliary air tapping is made to the lower portion of one of the middle sections, in the manner illustrated in Fig. 24, to prevent air collecting at this point. Thermostatic control as applied to such heating units in modern practice Fig. 23. Supply and Return Con nections for Heating Units of Central Fan Systems 324 Fig. 24. Typical Connections to Central Fan System Heating Units Exceeding 12 Sections Chapter 16. Piping for Steam Heating Systems consists of a thermostatic valve located in each main branch from the steam line so that each valve will open or close a complete row of stacks across the entire face of the heating unit. In such cases the outlet con nections from each stack should be provided with a check valve. . The stack closest to the outside air intake usually is not equipped with a thermostatic valve. A gate valve on the steam pipe to the first coil is operated manually to supply steam continuously in freezing weather. Good practice demands that the returns be connected in parallel with the steam supplies, with a separate steam trap for each bank of coils having a separately valved steam supply. This arrangement is illustrated in Fig. 23, for blast traps having external thermostatic by-passes and integral thermostatic by-passes, respectively. fk w^Stea ^ N' \\i- jftL.-- Automatic i UvnR air vert valve fsDirt pocket I^ ifL* 111 w Fig. 25. Unit Heater Connected to One-Pipe Air-Vent System A method of connecting a unit heater to a one-pipe air-vent steam heating system is illustrated in Fig. 25. PIPE SIZING FOR INDIRECT HEATING UNITS Pipe connections and mains for indirect heating units are sized in a manner similar to radiators, but the equivalent direct radiation must be ascertained for each row of heating unit stacks and then must be divided into the number of stacks constituting that row and into the number of connections to each stack: ^ where vt>r = <2 X 60 X i - te) = Q X (ft -- M 55.2 X 240 220.8 (3) EDR -- equivalent direct radiation, square feet. Q = volume of air, cubic feet per minute. Ie = the temperature of the air entering the row of heating units under con sideration, degrees Fahrenheit. ' ti -- the temperature of the air leaving the row of heating units under considera tion, degrees Fahrenheit. 60 = the number of minutes in one hour. 55.2 = the number of cubic feet of air heated 1 F by 1 Btu. 240 = the number of Btu in 1 sq ft of EDR, 325 Heating Ventilating Air Conditioning Guide 1938 Example 5. Assume that the heating units shown in Fig. 26 are handling 50,000 cfm of air and that the rise in the first row is from 0 to 40 F, in the second row from 40 to 65 F, and in the third row from 65 to 80 F. Wbat is the load in EDR on each supply and return connection? . Chapter 16. Piping for Steam Heating Systems The pipe sizes would then be based on the length of the run and the pressure drop desired, as in the case of radiators. It generally is considered desirable to place the in direct heating units on a separate system and not on supply or return lines connected to the general heating system. DRIPPING Any steam main in any type of steam heating system may be dropped to a lower level without dripping if the pitch is downward with the steam flow. Any steam main in any heating system can be elevated if dripped (Fig. 27). Steam mains also may be run over obstructions without a change in level if a small pipe is carried below the obstruction to care for l Fig. 26. Typical Piping for Atmospheric and Vacuum Systems with Thermostatic Control (Central Fan System) Solution. For row 1, D _ 50,000 x (40 - 0) r. R ~ ---------- 2208----------- = 9058 Sq ft` For' row 2, ,, 50,000 X (65 - 40) `, R = --!------a2e2h0h.8------------ = 5661 sq ft. For row 3, D _ 50,000 X (80 - 65) ,,,,,,,, R--------------- 2208----------- = 3397 " ft' Each row of heating units consists of four stacks and each stack has two connections .so that the load on each stack and each connection'of the stack is as follows: . Row i 2. 3 . Total Load (EDR) 9058 . 5661 3397 Stack Load* . (EDR) 2265 1415 . 849 Connection Load**. (EDR) 2265 or 1132 1415 or 708 849 or 425 One quarter of total row load. - bOne half of stack load if two steam connections are made: otherwise, same as stack load. 326 Fig. 27. Dripping Main Where It Rises to Higher Level Fig. 28. Looping Main Around Beam Fig. 29. Looping Dry Return Main Around Opening Acceptable (netted Preferred method Fig. 30. Methods' of Taking Branch from Main To find length C-muttiply A by constant tor angle B Fig. 31. Constants for Determining Length Offset Pipe om ,, pocket , _ tT--Wet return Fig. 32. Dirt Pocket Connection the condensation (Fig. 28). Return mains may be carried past doorways or other obstructions by using the scheme illustrated in Fig. 29; in vacuum systems it is well to have a gate valve in the air line. . Branches from steam mains in one-pipe gravity steam systems should use the preferred connection shown in Fig. 30, but where radiator condensa tion does not flow back into the main the acceptable method shown in the same figure may be used. This acceptable method has the advantage.of giving a perfect swing joint when connected to the vertical riser or radia tor connection, whereas the preferred connection does not give this swing without distorting the angle of the pipe. Runouts from the steam main are usually made about 5 ft long to provide flexibility for movement in the main. . Offsets in steam and return piping should preferably be made with 327 Heating Ventilating Air Conditioning Guide 1938 90-deg ells but occasionally fittings of other angles are used, and in such cases the length of the diagonal offset will be found as shown in Fig. 31. Dirt pockets, desirable on all systems employing thermostatic traps, should be so located as to protect the traps from scale and muck which will interfere with their operation. Dirt pockets are usually made 8 in. to 12 in. deep and serve as receivers for foreign matter which otherwise would be carried into the trap. They are constructed as shown in Fig. 32. On vapor systems where the end of the steam main is dripped down into the wet return, the air venting at the end of the main is accomplished by an air vent passing through a thermostatic trap into the dry return line as shown in Fig. 33. On vacuum systems the ends of the steam mains are dripped and vented into the return through drip traps opening into the return line. The same method may be used in atmospheric systems. A float type trap is preferable to a thermostatic trap for dripping steam mains and large risers. If thermostatic traps are used a cooling leg Fig. 33. Dripping End of Main into Wet Return Fig. 34. Dripping End of Main into Dry Return Fig. 35. Dripping Heel of Riser into Dry Return (Fig. 34) should always be provided. The cooling leg is for cooling the condensation sufficiently before it reaches the trap so the trap will not be held shut by too high a temperature. On down-feed systems of atmos pheric, vapor, and vacuum types, the bottom of the steam risers are dripped in the manner shown in Fig. 35. On large systems it is desirable to install a gate valve in the cooling leg ahead of the trap. : PROBLEMS IN PRACTICE ; IS What factors determine the size of steam piping and the allowable limit of capacity? . Factors which determine the size of steam piping are the desired initial pressure and the allowable drop in pressure which is permissable to maintain a pressure in the farthest , radiator. The length of run in sizing piping is important and it is generally considered j as the distance along the piping from the source of steam supply to the farthest radiator, with allowances for resistance of elbows and valves expressed in terms of equivalent length. . . 2 When the size of pipe is still undetermined, what arbitrary percentage is ' - usually added to the actual length to obtain the equivalent length? ; Usually 100 per cent; in other words, the actual length is doubled to allow for the added ; drop produced by the valves, tees, elbows, and other fittings. j 328 I Chapter 16. Piping for Steam Heating Systems 3 What are the major factors to be considered in determining the flow of steam in pipes? a. The initial steam pressure available and the total pressure drop allowable between the ' source of steam supply and the end of the return system. The pressure drop should never exceed one half of the initial pressure. b. The maximum steam velocity allowable. When condensate is flowing against the ' steam, the velocity must not be so great as to produce water hammer, or hold up water in parts of the system until the steam flow is reduced sufficiently to permit the water to pass. The velocity at which disturbances take place depends upon: 1. Size of pipe. . 2. Whether pipe is vertical or horizontal. 3. Pitch or grade of pipe. 4. Quantity of water flowing against steam. . c. The equivalent length of run from the source of steam supply to the farthest heating unit, with allowance for friction in pipe fittings and valves. 4 Name three fundamental considerations in designing the piping system for steam heating. .. a. Provision for the distribution of suitable quantities of steam to the various heating units. b. Provision for the return.of condensate from the radiators and piping to the boiler. c. Provision of means for expelling air from the radiators and piping. , j 1 : ` 5 Why is the proper reaming of the ends of pipe necessary? The capacities of pipes depend upon the free area available for flow. In cutting the pipe this area may be restricted by a burr, which may decrease the capacity of a pipe more than 25 per cent in the smaller pipe sizes. 6 a. What are the major factors to be considered when selecting a pressure reducing valve?, . b. How should such valve be installed? a. The initial pressure of the steam must be considered along with the desired reduced pressure. The connected load to be supplied must be known in square feet of equiva lent direct radiation or in pounds of steam per hour. For operation with a continuous load, a semi-balanced or double-seated valve operated by a diaphragm gives good results. Where the load is intermittent, as in process work or with thermostatically controlled blast heaters, a so-called dead end or single-seated valve should be used. b. The pressure reducing valve should be installed in a horizontal line with a gate valve on each side, and with a by-pass operated by a valve. The pressure balancing pipe from the diaphragm chamber should be connected into the top or side of the low pressure main not less than 15 ft from the reducing valve. ' . ' ; i i j 7 What is the usual expansion allowance and how it is compensated for in heating system supply risers? ' The expansion of low pressure steam piping is normally taken as 1M to 1H in. per 100 ft of pipe. With a five story building a double swing connection between the riser and the ________ main will suffice. In buildings between 5 and 10 stories high the riser should be anchored <=~--- near its center and have double swing connections to the main. For taller buildings expansion loops or riser offsets are used which are capable of handling a length of riser reaching 5 stories in either direction from the joint. The risers are anchored at each alternate 5 stories. All radiators must have double swing connections, and those con- . nected above where the riser is anchored must be given greater pitch to insure their having proper grade when the riser is heated. ' | | ' 329 Heating Ventilating Air Conditioning Guide 1938 8 Why should all boiler steam supply tappings be used full size? - In order to operate at low steam velocities so the water in suspension can separate from the steam and remain in the boiler. 9 # What is the Underwriters Loop or the Hartford Connection? : An arrangement of piping on the returns to low pressure boilers wherein the return line is raised up nearly to the water line of the boiler and is then dropped back and con nected to the boiler return inlet; the high point is connected by a balanced pipe to the steam runout from the boiler on the boiler side of all stop valves. With this loop no check valve is required on gravity systems, and water cannot be backed out of the boiler and into the return at a point lower thap the invert of the pipe at the top of the loop. 10 # What are the important factors in making radiator connections? Connections to radiators should be made as direct as possible, of proper size, with ample pitch of piping and allowance for expansion. ' . : . . ;: ' . i`/ . 11 Why should careful attention be given to proper dripping and drainage of steam piping? ' . The steam mains and risers must be quickly drained of condensate and where necessary" vented of air in order to obtain a sufficient supply of steam to the radiators. Proper, drainage is also necessary to insure a noiseless heating system. . 12 t What is the limit of pressure drop usually recommended in a vacuum system? . Not over ^ lb (2 oz) per 100 ft of equivalent run, and not over 1 lb total drop. 13 # When steam and condensation are flowing in the same direction, what is the maximum total' pressure drop which should be used? . The maximum total pressure drop should not exceed one half of the initial steam pressure.* 14 t What does a proper installation of a pressure reducing valve include? A strainer in front of the pressure reducing valve; a gate valve in front of the strainer; a gate valve after the reducing valve; a by-pass around the two gate valves, strainer, and pressure reducing valve; and a globe valve in the by-pass. Sometimes a safety valve on the low pressure side and pressure gages on both sides are installed. The high pressure line should be dripped just before the high pressure steam enters the pressure reducing valve assembly. 15 Will a pressure reducing valve which is reducing the steam pressure from 100 lb gage to 50 lb gage pass more or less steam than the same valve when reducing the steam pressure from 100 lb gage to 5 lb gage? ' The valve will pass practically the same volume of steam in each case as the velocity of steam flowing through an orifice shows ho material increase after the reduced absolute pressure has fallen to 58 per cent of the initial absolute pressure. Because of its greater - density, the weight of steam passed will be greater in the case of the reduction to 50 lb gage. Chapter 17 HOT WATER HEATING SYSTEMS AND PIPING One- and Two-Pipe Systems, Mechanical Circulation, Cir culators, Iron Pipe and Copper Tube Sizes, Gravity Circula tion, Expansion Tanks, Relief Valves, Installation Details THE various forms of hot water heating may be fundamentally classi fied according to. motive force, namely, forced circulation or gravity flow. Forced circulation is accomplished by the use of centrifugal or propeller type pumps which are especially designed for this particular type of application. Gravity flow is maintained' by the difference in weight of the water in the flow and return mains. These systems may be further classified as to high or low operating water temperatures. Higher water temperatures permit a reduction in radiator size. A large temperature differential between the flow and return results in smaller pipe sizes as also does the use of forced circulation. Light wall copper tubing has recently been introduced to supplement the customary black iron piping which has been used for these systems in the past. Low temperature water(150 to 180 F) is generally that which provides a heat emission per square foot of radiation of from 150 to 165 Btu while a high temperature water (200 to 220 F) will deliver from 200 to 240 Btu. The use of high temperature water in a heating system is desirable as the maximum outside temperature for which the system is designed will occur for a relatively short time during the average season. The increased use of automatic heating equipment with more accurate controls, makes it possible to use higher temperatures and smaller heating units without sacrificing good design. . . - ! . . The unit, a square foot of equivalent direct radiation, EDR, has been used for many years for rating purposes in both steam and hot water systems, but its use, especially in hot water systems, has always resulted in compli cations and confusion. It is the plan of The Guide to eventually eliminate this empirical expression and to substitute a logical unit based on the Btu. The Mb, the equivalent of 1000 Btu and the Mbh, the equivalent of 1000 Btu per hour, which have been approved by the A.S.H.V.E. are used in this chapter on hot water systems to replace the square foot of radiation formerly used. u. . : 331 Heating Ventilating Air Conditioning Guide 1938 In designing a piping arrangement for a hot water heating system, it is necessary to observe the fundamental rule that the total friction head in any circuit must not exceed the pressure head available for circulating the water. It is necessary to size the pipe in any circuit, so that the friction loss produced by the movement of a sufficient volume of water to handle the heating load will not be greater than the available head. In designing a hot water heating system, it is necessary to determine: 1. The heat losses of the rooms or spaces to be heated. (See Chapter 7.) 2. The size and type of boiler. (See Chapter 13.) , 3. The location, type, and size of heating units. (See Chapter 14.) 4. The method of piping. 5. The type and size of circulating pump (if forced circulation). 6. Suitable pipe sizes. 7. The type and size of expansion tank. ONE- AND TWO-PIPE SYSTEMS . Piping systems may be divided into two general types, namely, onepipe and two-pipe systems. These fundamental piping layouts may differentiate between up-flow, down-flow and zoned systems. Also the type of riser and radiator connection may vary considerably. Zoning is important in modern design and it is accomplished by dividing the system into a number of circuits and controlling each circuit individually. In a two-pipe system the piping is arranged so that the water flows through only one radiator during a circuit through the system, so that all radiators are supplied with water at practically the same temperature as that in-the boiler. In some one-pipe systems, the water flows through more than one radiator during its circuit. In that case, the first radiator receives the hottest water; the second radiator, somewhat cooler water; the third one, still cooler; and so on. As the temperature of the water supplied to a radiator is lowered, the size of the radiator must be increased and, con sequently, the total heating surface for a one-pipe system must be greater than for a two-pipe system for the same requirements. As the velocity is increased in a one-pipe system, the drop in temperature is decreased, so that water at a higher average temperature is delivered to the radiators. This means that the radiators at the end of the main can be sized on the same basis as the radiators at the beginning of the main. If the system is correctly designed, the resulting error is less than the variation in calcu lating the heating load for the enclosure. . By making use of improved devices now available, one-pipe forced circulation systems may be calculated by the same procedure described later for two-pipe systems. Operation may be obtained as satisfactory as with a two-pipe system. Two-pipe systems may be divided into two classes, direct return sys tems (Fig. 1), and reversed return systems (Fig. 2). In a direct return system the water returns to the heater by a direct route after it has passed through its radiator and, as a result, the paths through the three radiators shown in Fig. 1 are of unequal lengths, the path through the first radiator being the shortest and that through the third radiator,' the 332 ' Chapter 17. Hot Water Heating Systems and Piping longest. In a reversed return system, the water returns to the heater by an indirect route after it has passed through the radiators, so that the paths leading through the three radiators shown in Fig. 2 are practi cally of equal length. . The reversed return system has an advantage over the direct return system in that it is more likely to function satisfactorily even though the pipe system is not accurately designed. For example, if in Fig. 2 all pipes are of one size, each of the three radiators will receive approximately the same quantity of hot water because the three paths are practically of equal length, whereas in Fig. 1, if all pipes are of the same size, Radiator 1 will receive more water than the others because the path through it is shorter than those through the other radiators. As a result, Radiator 1 will be filled with water a,t a higher average temperature than the re maining two radiators, and will therefore dissipate more heat. To pre vent this unequal distribution of heat it is necessary to throttle the paths through Radiators 1 and 2 so that the friction heads of the three paths are equal when each radiator receives its proper quantity of water. The two-pipe direct return system, with its inherent lack of balance, is the least satisfactory type of piping possible, yet is the most widely used. Fig. 1. A Direct Return System Fig. 2. A Reversed Return System The modem applications of automatic heating require a system to be very nearly in balance so that uniform distribution of heat will be obtained. Two-pipe systems must be balanced first by calculation and then by test after the. plant is in operation. Unbalanced conditions in a forced circulation system are more detrimental to satisfactory operation than in the system circulated by gravity. The selection of orifices for correcting the unbalance must be more accurate. Due to the variations in water delivery from pipes, the accuracy of calculations is decreased, so that more reliance must be placed on actual test work. This is always costly and seldom completely satisfactory. A comparison of Fig. 1 and Fig. 2 may suggest that a reversed return system requires considerably longer mains than a direct return system. This is not always the case, as will be noted from the reversed return system of Fig. 3. MECHANICAL CIRCULATION AND CIRCULATORS The designer of a forced circulation system generally makes use of the pumps commercially available. Pumps of this type will have character istics which govern the water velocity selected for the heating system. However, available pumps generally have a sufficient range of capacities 333 -Heating Ventilating Air Conditioning Guide 1938 to promote the selection of an economical velocity. If a system is designed to handle a load of 96 Mbh with a 20 F drop allowable in the system, a circulating pump will be required, handling about 10 gpm and at a head pressure high enough to allow a satisfactory friction drop in the system. Frequently water velocities are selected which produce objectionable noises in the system. A velocity of over 4 fps is apt to cause noise in the smaller pipes and tubes. Velocities higher than this value will cause no objectionable trouble in industrial applications. Note that the numbers on the radiators indicate thousands of Btu per hour (Mbh) and not square feet. Low head centrifugal pumps especially designed for hot water sys tems are used to provide the necessary head pressure for forced circulation and to improve the operation of an improperly designed or installed gravity system. These pumps are designated by the nominal pipe size of their connection, but the selection of the pump should be governed by the capacity curves and not. by the nominal pipe size. These pumps operate with little noise and low power consumption, both of which are features of prime importance to the satisfactory operation of a forced 334 Chapter 17. Hot Water Heating Systems and Piping circulation system. They are designed for installation directly into the heating main and require no other support. The common practice is'to install them in the return line but where desirable there is no objection to their location in the supply line". Gate valves should be installed in either side of the pump so that it can be removed without draining a system. A by-pass is not necessary as the friction drop through the pump is not sufficient to prevent gravity recirculation if the pump should become inoperative. ., . Propeller type pumps are also available for hot water service, generally being built into a fitting and are made in all of the commercial pipe sizes commonly used in heating. They are installed in the same manner as a centrifugal pump. . .. Forced circulation lends itself to automatic control and the arrangement of the circuit depends entirely on the design of the system. The control may consist of a thermostat controlling both the automatic firing device and the circulator with the same type of limit control, as a safety switch. This type of control can be satisfactory, provided the radiation is properly selected and accurately located in the building. A circuit using flow control valves to regulate the gravity flow of the water when the pump is not running allows the temperature to be maintained closer to the i desired setting. Under- these circumstances, the circulator motor is controlled by a room thermostat while the automatic firing device is controlled by a'limit switch with a safety device in series. . For exceptionally large installations, such as central heating plants . circulating pumps of the centrifugal single stage type having an average operating efficiency of 70 per cent against heads up to 125 ft are sometimes used. In some cases it is advisable to install pumps in duplicate to provide for contingencies and to insure continuous operation. In such cases, each pump should be made equal to the maximum capacity required. PIPE SIZES The pressure heads available in forced circulation systems are much greater than those in gravity circulation systems, consequently, higher velocities may be used in designing the system, with the result that smaller pipes may be selected and the first cost of the installation reduced. As the pipes of a heating system are reduced in size, the necessary increase in the velocity of the water increases both the cost of operation and the initial cost of the circulating equipment. The increased velocity of. a forced circulation system offers a number of advantages, such as a much shorter heating-up period and a more flexible control of hot water circu lation. This improved performance merits the small increase in operating cost necessary to mechanically circulate the -system. The velocity required should be determined by calculation for the particular system under consideration. . . Since the velocities in forced circulation systems are higher than those in gravity circulation systems, and since the friction heads in a heating system vary almost as the squares of the velocities, a given error in the , calculation or assumption of a velocity is less important in a forced circu lation system than in a gravity circulation system and, consequently, it 335 F riction H ead in M ilinches per Root o p ' Pipe toooq Heating Ventilating Air Conditioning Guide 1938 loo . 300 1000 Meat conveyed per Hour in iooo B.T. U. 5000 10000 Fig. 4.' Friction Heads in Black Iron Pipes for a 20 F Temperature 'Difference of the Water in the Flow and Return Lines Chapter 17. Hot Water Heating Systems and Piping is easier to design a satisfactory forced circulation system than a satis factory gravity circulation system. FORCED CIRCULATION In designing a forced circulation system, black iron pipe sizes may be selected from either Fig. 4 or Table 1, both of which are based on a 20 F temperature difference between the flow and return lines. For other temperature drops, the pipe capacities may be changed to correspond to the desired differentials. Research data are lacking for determining the capacities of copper tube sizes. In the absence of complete test data at the present time, capacities are given in Table 2 for type L copper tube sizes which are based on a recently developed hydraulic formula1. The friction heads of boiler, radiator valve and tee may be expressed in terms of friction head in one elbow according to the values given in Table 3 for iron pipe, and Table 4 for copper tubing. The following examples will illustrate the procedure to be followed in designing forced circulation systems. Example 1. From the plan of Fig. 3 note that the longest circuit consists of 151 ft of iron pipe; 1 boiler; 1 radiator; 1 radiator valve; 1 stop cock; 10 ells and 3 tees; and the shortest circuit consists of 127 ft of pipe; 4 tees; 1 boiler; 1 radiator; 1 radiator valve; 1 stop cock; and 6 ells. Design the piping for this system. Solution. The friction in the various fittings can be expressed in terms of the friction ina 90-deg elbow from the values given in Table 3. The longest circuit consists of 151 ft of pipe and 44 elbow equivalents. The short circuit consists of 127 ft of pipe and 39 elbow equivalents. The friction head in one elbow is approximately equal to the friction produced by the same sized pipe 25 diameters in length. Assume that the average pipe size for this system is 1 in. The equivalent length of the longest circuit will be 151 ft plus 100 ft or 251 ft of pipe. The equivalent length of the short circuit will be 217 ft. Having determined the equivalent length of the circuits, the next step is to assume the rate at which the water is to be circulated in the system. The water may flow through the system so that it will cool any reasonable number of degrees. For the most economi cal average system a 20 F drop seems to be a satisfactory rate. This entails a slower water flow from the pumping equipment with a reasonable relationship between pipe size and flow. Assume 20 F drop for this system. One gallon of water per minute with a density of 7.99 at 215 F will deliver approximately 9600 Btu per hour with a 20 F drop. The total radiation load is 98 Mbh, therefore the pump must deliver 10.2 gpm or 4900 lb of water per hour. Knowing that the rate of flow is 10.2 gpm, the next step is to determine from the characteristics of available pumps, which one will produce a satisfactory velocity in the system. Assume that 4 pumps are available for this load which will produce 10.2 gpm at pressure heads of 2, 5,10 and 18 ft. At these heads the pumps would produce a velocity high enough to make available a friction head per foot of pipe of 96, 240, .480 and 860 milinches per foot respectively. If 95 milinches per foot were used, the gravity head at 215 F average temperature in the mains would be 26 per cent of the total head and should be considered in sizing the system. At 240 milinches per foot the gravity effect is 10 per cent and as this is lower than the delivery variation from the pipe used, it can be neglected. At 480 and 860 milinches the gravity effect is still a- smaller percentage of the total, but at these losses in the average system the cost of pumping will more than offset the advantage gained in pipe sizes. Therefore, pipe size this system at 240 mil- inches per foot which is equivalent to a total loss of 60,000 milinches for the 250 ft equivalent length of pipe. , ' .`Hydraulic Service Characteristics of Small Metallic Pipes, by G. M. Fair, M. C. Whipple and C. Y. Hsiao (Journal of the New England Water Works Association, Vol. XLIV, No. 4, 1930). 337 > Heating Ventilating Air Conditioning Guide 1938 Table 1. Capacities for Black Iron Pipe A = Carrying capacities inMbh B = Velocity in inches per second Hbad Loss. Ft Milinch .Friction Loss Per Foot of Pipe 720 480 360 300 240 ISO 160 144 120 96 90 80 70 60 Equivalent Length of Pipe in Feet (Longest Circuit) 2 3 3M 4 4K 5 5M 6 6M 7 7K 8 8M 9 9X 10 iok 11 11H . .12 Nominal Pipe Size, . In. 33 50 66 80 100 133 150 167 200 250 270 300 340 400 42 62 84 100 125 167 188 208 250 312 333 375 428 500 50 75 100 120 150 200 225 250 300 375 -400 450 510 600 59 87 117 140 175 233 263 291 350 437 463 525 593 700 67 100 133 160 200 266 300 333 400 500 533 600 685 800 75 112 149 180 225 300 338 374 450 562 593 675 758 900 83 125 167 200 250 333 375 416 500 625 666 750 860 1000 92 137 183 220 275 366 413 457 550 6S7 713 825 923 1100 100 150 200 240 300 400 450 500 600 750 800 900 1030 1200 108 162 217 260 325 433 488 540 650 812 843 975 1088 1300 116 175 233 280 350 465 525 580 700 875 933 1050 1200 1400 124 187 249 300 375 500 563 623 750 937 973 1125 1252 1500 133 200 266 320 400 533 600 666 800 1000 1070 1200 1370 1600 142 212 283 340 425 566 638 706 850 1062 1103 1275 1417 1700 150 225 300 360 450 600 675 750 900 1125 1200 1350 1540 1800 159 237 317 380 475 633 713 789 950 1187 1233 1425 1577 1900 167 250 333 400 500 666 750 833 1000 1250 1333 1500 1715 2000 175 262 349 420 525 700 788 872 1050 1312 1363 1575 1737 2100 183 275 366 440 550 733 825 916 1100 1375 1466 1650 1885 2200 192 287 383 460 575 766 863 955 1150 1437 1533 1725 1897 2300 200 300 400 480 600 800 900 1000 1200 1500 1600 1800 2030 2400 Capacity of Pipes Mbh With a 20 F* Drop ' A' KB 20 16 14 13 11 10 9 9 8 7 7 6 6 27 88 19 17 15 IS 18 11 10 9 9 8 8 5 7 A HB 43 35 30 27 24 21 19 18 17 15 14 13 12 11 S3 86 83 81 18 16 15 14 IS 11 11 10 9 9 A 1B 85 70 60 54 48 41 39 36 33 30 28 27 25 23 39 38 87 85 88 19 18 17 16 13 13 18 11 10 a' lH B 180 145 125 115 98 85 80 75 68 60 58 55 51 48 39 S3 SO 87 83 81 80 19 16 16 16 14 47 18 . A IK B 285 230 195 180 160 135 125 120 110 96 92 88 82 54 44 38 S4 SO 86 84 83 81 19 18 . 17 15 75 14 A 2B 540 435 370 340 300 255 240 230 205 180 .175 165 150 64 58 46 40 36 SO 89 87 84 88 81 SO 19 140 17 A 2K B 890 720 610 550 480 420 390 370 330 300 280 270 250 74 60 60 4B 41 35 S3 ' 31 88 34 34 88 81 230 19 A 3B 1650 1340 1130 1000 900 760 720 670 600 540 520 480 450 410 88 70 60 64 48 41 38 36 S3 * 89 88 86 84 88 A 2500 2000 1700 1500 1350 1150 1080 1000 900 800 760 720 670 3K B . 99 78 66 60 64 46 43 40 36 38 31 89 87 620 85 ' 4 A B 3500 2800 2400 2200 1900 1600 1520 1440 1300 1150 1100 1050 960 880 110 87 74 66 58 50 47 46 40 35 34 38 SO 87 A 5B 7000 5600 4700 4300 3700 3200 3000 2750 2500 2200 2100 2000 1800 1700 138 106 90 80 70 60 56 63 43 43 41 38 35 38 A 12.000 9200 7800 7000 6200 5200 4800 4600 4100 3600 3500 3300 3000 2800 6B 156 184 104 94 88 69 64 61 55 48 48 44 41 57 ' ftFor other temperature drops the pipe capacities may be changed correspondingly. For example, with a temperature drop of 30 F, the capacities shown in this table are to be multiplied by 1.5. 338 17.Chapter Hot Water Heating Systems and Piping Table 2. LCapacities foe Type Copper Tube A = Carrying capacity in Mbh B = Velocity in inches per second . Milinch Friction Loss per Foot of Tube Head Loss 720 600 480 360 300 240 ISO 150 120 90 75 60 Ft Equivalent Length of Tube in Feet (Longest Circuit) 2H 3 3K 4K 5H 6 6M 7 7H 8 8H 9 9M TO 10K 11 UJ* 12 33 40 42 50 60 58 70 67 80 75 90 83 100 92 110 100 120 108 130 117 140 125 150 133 160 142 170 150 180 159 190 167 200 175 210 183 220 192. 230 200 240 50 63 75 88 100 113 125 138 150 163 175 188 200 213 225 238 250 263 275 288 300 Nominal Size. Ln. 67 80 100 133 160 200 267 320 83 100 125 167 200 250 333 400 100 120 150 200 240 300 400 480 117 140 175 233 280 350 467 . 560 133 160 200 267 320 400 533 640 150 180 225 300 360 450 600 720 167 200 250 333 400 183 220 275 367 440 200 240 300 400 480 500 667 800 550 733 880 600 800 960 217 260 325 433 520 233 280 350 467 560 250 300 375 500 600 650 867 1040 700 933 1120 750 1000 1200 267 320 400 533 640 283 340 425 567 680 300 360. 450 600 .720 800 1067 1280 850 1133 1360 900 1200 1440 317 380 475 633 760 950 1267 1520 333 400 500 667 800 1000 1333 1600 350 420 525 700 840 1050 1400 1680 367 440 550 733 880 1100 1467 1760 383 460 575 767 920 1150 1533 1840 400 480 600 800 960 1200 1600 1920 Capacity of Tubes Mbh With a 20 F" Drop 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 16001700 1800 1900 2000 2100 2200 2300 2400 A HB 10 9 8 6.8 87 84 81 18 A KB 20 18 16 13.5 S3 SO 85 81 A HB 36 30 26 22.1 57 34 SO A %B 51 46 40 34 43 38 55 87 A 1B 104 94 82 70 48 46 39 84 A 185 169 149 125 IK B 66 51 46 39 A IK B 300 270 235 200 68 67 51 48 A 2B 625 560 495 420 76 68 69 51 A 1130 1010 890 750 2K B 90 80 69 , 68 A 1840 1650 1450 1210 3B 98 90 80 66 A 2750 2480 2170 1840 . 3K B 110 100 89 76 A 3900 3505 3100 2600 4B ISO 108 96 88 6.2 16.5 12 19 20 81 31 34 63 SO 112 35 180 59 375 47 680 49 1100 59 1650 66 2350 75 5.4 14 10.8 17 17.8 19 28 81 56 85 100 SO 160 55 335 43 600 47 980 68 1450 57 2090 . 55 4.6 IS 4 11 3.6 10 3 8.5 98 76 15 IS 18 10 15 13.1 11.8 9.9 17 16 IS 11 23.2 to 20.5 17 18.1 14 15.3 18 * 47 42 37 . 32 88 19 17 14-6 84 75 66 56 85 88 19 17 134 120 105 SO 85 ' 88 90 19 280 250 200 188 86 38 87 88 500 450 395 335 43 57 S3 86 820 740 650 * 550 47 43 86 50 1210 61 1760 55 1100 46 . 1580 49 980 . 1390 44 820 55 .1180 57 2.8 8 5.4 9 9 10 13.9 11.6 28 13 50 15 81 17 170 20 305 23 490 27 740 . SO. 1080 34 2.4 7 4.7 8 7.9 9 12.1 10 25 r12 44 IS 71 15 150 18 270 81 420 83 650 . 86 950 29 "For other temperature drops the pipe capacities may be changed correspondingly. For example, with a temperature drop of 30 F, the capacities shown in this table are to be multiplied by 1.5. ` 339 Heating Ventilating Air Conditioning Guide 1938 Table 3. Iron Elbow Equivalents3 1 90-deg elbow........ ............................................................. .................. ......... ............................ i.o 1 45-deg elbow........ ..............................1.................................. .................................................... 0.7 1 90-deg long turn elbow.... ...................... ................................................................................ 0.5 1 open return bend--................................................................................................................... 1.0 1 open gate valve......................................................... ....... .................................................... .. 0.5 1 open globe valve............................................................. .............................................. .......... 12.0 1 angle radiator valve................... .......................... ................................. ............ ................... 2.0 1 radiator....................................................................................................... ......... .................... . 3.0 1 boiler or heater................................................ ........................................................................ 3 o 1 tee--.............. ....................... .......... .................................................................................. (Noteb) The loss of head in one elbow can be expressed in terms of the velocity head by the formula: where h -- the loss of head in feet, v -- the velocity of approach in feet per second, and 2g =* 64.4 ft per second per second. (1) bThe loss of head in tees when water is diverted at right angles through a branch of the tee varies with the per cent diverted. When the water diverted is less than 60 per cent of that approaching the tee. the loss of head, in elbow equivalents, may be expressed as follows: where K he =* the loss of head in elbow equivalents, vi = the velocity of approach, -- the velocity of water diverted at right angles. (2) Values in elbow equivalents for the most common percentages of water diverted in a lxlxl-in. tee are as follows: ' 25 per cent.......................... ......................... ................................... 16.0 33 per cent...... ...........................................................:...................... 9.0 .. 50 per cent...... ....................................................... .......................... 4.0 = 100 per cent.................................................................. ......... ........... 1.8 Table 4. Copper Elbow Equivalents3 1 90-deg elbow...... ............................................... _........................................................... ........... 1.0 1 45-deg elbow...... ................................................ .................................................................. . 0.7 1 90-deg long turn elbow........... ........................................................... ...... ............................. 0.5 1 open return bend--.................................... ..........................................j................................... 1.0 1 open gate valve......... ........ ....................... .............................................. ...................... ......... 0.7 1 open globe valve................................ ...................................................................................... 17.0 1 radiator valve..... ................................... ................................................................................. 3.0 1 radiator.................... .........................................................................................................'......... 4.0 1 boiler or heater...... .............. ............ ...................... ............ ............................. ..................... 4.0 1 tee......... .................................. ............................. ............................................................. ....(Noteb) The loss of head in an elbow can be expressed in terms of the velocity head by the formula: where h = loss of head in milinches. v in. per second per second). . 0.7 o* *" "2r ' velocity in inches per second, and g (3) acceleration of gravity (386 *>The loss of head in copper tees: where (n1 + w) N - 0.7 pj* (4) N = number of elbows that would cause the same loss as the tee when the velocity of water in the connecting pipe is vu ' pi == velocity of the water in the pipe entering the tee, and - p = velocity of the water in the pipe discharging from the tee at right angles to ri. Values in elbow equivalents for most common percentages of water diverted in a 1 in. x 1 in. tee. 100 per cent_______________ ________________________________ 1.2 50 per centJ----------------------------------------- ----- ------------------ 4.0 30 per centi_16.0 25 per cent___________ 20.0 340 i- j Chapter 17. Hot Water Heating Systems and Piping The pipe sizes may be selected from Fig. 4 or from Table 1 which has been derived from Fig. 4. Size the supply main of the longest circuit first. Section AB carries 98 Mbh. From Fig. 4 it will be noted that at 240 milinches per foot, a IK in. pipe carries 98 Mbh. Therefore, use IK in- pipe in Section AB. Section BO carries 40 Mbh. A 1 in. pipe carries 48 Mbh at 240 milinches per foot. Use a 1 in. pipe. Section OP carries 20 Mbh and this will require K in. pipe. Section PQ carries 10 Mbh and requires K in. pipe. To size the return start from the boiler and proceed backwards. Section IR carries 40 Mbh and from Fig. 4 a 1 in. pipe is required. Section RS carries 30 Mbh which is only slightly over the capacity of a K in. pipe, so use M in. Section ST carries 20 Mbh and requires a K in. pipe. The radiator branches are determined in the same manner. It is evident from the chart that it is impossible to maintain a constant friction loss per foot and therefore as the delivery varies there will be a change in the desired friction loss per foot of pipe. It is desirable to check the various circuits so that if the variation from the calculated resistance is too great, it may be compensated by adding additional resistance at the proper point. This may be accomplished by sizing the short circuits by the procedure previously outlined. Prepare a chart such as Table 5 to be used in calculating the resistance of each circuit. Section AB carries 98 Mbh with a unit head of 240 milinches per foot. In section AB there are 37 ft of pipe and IK in. elbow. At 240 milinches per foot this is equivalent to 9600 milinches total loss in this section. Section BC carries 58 Mbh with a length of 2 ft and 4 elbows. The unit loss in this section is 90 milinches per foot. Loss in this section is then 1080 milinches. Section CD carries 38 Mbh and has 16 ft of pipe and 1 elbow. The unit loss in 1 in. pipe is 155 milinches. The loss in this section is 2790 milinches. The balance of the supply main and the return main are handled in a similar manner. Table 5. Piping Check Chart Load, Mbh Pipe Length Ft Elbows Pipe Size In. Unit Head Milinches per Ft Milinches Total Loss Milinches ` Supply Main AB 98 BC 58 CD 38 DE 23 EF 11 FG 4 37 1 IX 240 9600 9,600 2 4 IX 90 1080 10,680 16 11 155 2790 13,470 9 0 X 220 1980 15,450 12 0 X 240 2880 18,330 16 1 X 50 850 19,180 Return Main HI 98 IJ 58 JK 54 KL 47 LM 35 ' MN 20 5 5 IX 240 4320 4,320 11 1 IX 90 1260 5,580 16 11 300 5400 10,880 11 01 230 2530 13,410 9 01 140 1260 14,670 15 1 X 170 2890 17,560 Radiator Circuits CN 20 DM 15 Supply Return Supply Return FK 7 GJ 4 Return Supply Return Supply Return 3 4 3 4 14 15 3 4 8 9 13 2 19 17 20 20 19 17 5 17 X X X X XX H XX 170 3910 170 1190 5,100 420 9250 96 2880 12,130 270 9180 270 9450 18.630 100 2200 100 2100 4,300 50 650 50 1300 1.950 341 1 Heating Ventilating Air Conditioning Guide 1938 The radiator circuits are then checked. The 20 Mbh radiator on this circuit has 3 ft of supply pipe and 13 elbow equivalents while the return is composed of 4 ft and 2 elbows.. The unit loss in % in. pipe at this delivery is 170 milinches per foot. The total loss in the supply is 3910 milinches. The loss in the return is 1190. Total loss in the radiator circuit is 5100 milinches. Check each radiator circuit in a similar manner. The total calculated loss for the longest circuit was determined as 60,000 milinches. The maximum loss in the short circuit is 18,630 plus 13,410 plus 15,450 or a total of 47,490 milinches. This difference is caused by the variation in length of the two circuits and may be corrected by using a flow control in the return main to supply the additional resistance or by introducing resistance into each separate circuit to compensate for the difference. A10 per cent variation will cause no complication as the flow from the various pipes will not exactly follow the curves of Fig. 4 any closer than this value. Example 8. Design a two-pipe direct return forced circulation system with copper, tubing and fittings for the piping layout as detailed in Fig. 5, based on a 20 F tempera ture drop through the radiation. The piping circuit from the boiler to the highest radiator on the farthest riser and back to the boiler is 250 ft of pipe. There are about 16 elbow equivalents having an equivalent pipe length of about 50 ft, so that the total equivalent pipe length is 300 ft. Assume that'a circulator is'available which will provide a pressure head of 6 ft. ] Fig. 5. A Forced Circulation Direct Return System Solution. Refer to Table 2, which indicates the total equivalent lengths for pressure heads from 2 to 12 ft. With a circulator having a 6 ft pressure head and a system with a total equivalent length of 300 ft, the piping system will be designed on a basis of 240 milinch. Checking the piping diagram it will be noted that sections AB and KA, both supply 117.6 Mbh. Referring to the 240 milinch column of Table 2, 1J^ in. is shown to be the necessary pipe size. Sections BC and JK carry 88.8 Mbh and require 1J4 in. tubing. Sections CD and IJ supply 67.2.Mbh and require 1J4 in. tubing. Sections DE and HI supply 43.2 Mbh, which requires 1 in. tubing. Sections EF and GH with a load of 14.4 Mbh require % in. tubing. The risers are pipe sized in a similar manner. To secure proper distribution of hot water in the direct return system among the several risers, it is necessary to introduce resistances to balance the circuit. - The first riser is 80 ft nearer the boiler than the fifth riser. In order that the two may be balanced, that is, operated under equal pressure heads, resistance must be added to the first riser equal to the friction hedd in the 80 ft of supply main B to F plus the 80 ft of . return main G to K for a total of 160 ft of pipe. . . Having designed the piping system on a 240 milinch basis, the total friction head in the supply and return mains between the first and fifth risers is therefore 160 X 240 = 38,400 milinches, or 3.2 ft which must be supplied by additional resistance in the first' riser. . 342 ! Chapter 17. Hot Water Heating Systems and Piping Table 6. Friction Heads- (in Milinches) of Central Circular . Diaphragm Orifices in Unions . Dumxteb OF Orifices (Inches) ---------2 Velocity or Wateb in Pipe in Inches fee Second 3]4j 6 j8 | 10 ] 12 I 18 %-in. Pipe 24 | 36 0.25 0.30 0.35 0.40 0.45 0.50 0.55 1300 650 330 170 2900 1450 740 380 185 5000 2500 1300 660 330 155 75 11,300 5700 2900 1500 740 350 170 20,800 10,400 5200 2600 1300 620 300 32,000 16,000 8000 4000 2000 970 480 45,000 23,000 12,000 6800 2900 1400 700 57,000 26,000 13,000 6500 3200 1600 47,000 24,000 53,000 12,000 27,000 5700 13,000 2800 6400 . ------------- 0.35 900 2000 3500 0.40 460 1000 1800 0.45 270 570 1000 0.50 160 330 580 0:55 190 530 . 0.60 200 0.65 120 1-in. Pipe 7800 4000 2300 1400 750 440 260 14,000 7200 4100 2300 1300 800 460 22,000 12,000 6400 3700 2200 1300 720 32,000 17,000 9300 5400 3000 1800 1100 37,000 21,000 12,000 7000 4200 2400 65,000 37,000 22,000 50,000 13,000 28,000 7400 17,000 4300 10,000 0.45 0.50 0.55 0.60 0.65 0.70 0.75 1000 660 430 280 190 2250 1450 950 630 420 285 190 4000 2600 1700 1100 750 510 330 l}4-in. Pipe 8900 5800 3800 2500 .1700 1150 750 16,000 10,400 6800 4400 3000 2000 1300 25,000 16,400 10,500 6900 4700 3100 2100 36,000 23,000 15,000 10,000 6700 4500 3000 53,000 34,000 22,000. 15,000 10,000 6700 60,000 40,000 27,000 60,000 18,000 40,000 12,000 26,000 0.55 0.60 0.65 0.70 0.75 0.80 0.85 ly^-in. Pipe 850 1900 3300 7400 13,000 21,000 30,000 600 1300 2300 5400 8600 16,800 21,000 50,000 400 850 1500 3600 7200 10,400 14,000 30,000 53,000 260 600 1100 2600 4400 7000 10,000 21,000 39,000 180 400 760 1800 3000 5000 7000 14,000 28,000 300 540 1200 2200 3200 5000 10,200 19,000 45,000 200 380 860 1600 2300 3000 7800 13,000 30,000 0.70 0.80 0.90 1.00 1.10 1.20 1.30 890 1850 3500 470 975 1800 255 560 1000 160 340 610 214 375 195 2-in. Pipe 7400 3900 2200 1320 850 460 275 14,000 7400 4200 2520 1600 950 525 22,300 11,700 6500 4000 2500 1360 980 33,000 17,000 9500 5800 3700 1910 1375 37,000 20,500 12,500 7900 4200 3100 38,000 23,000 49,000 14,000 30,000 8100 16,800 4400 8850 #o/e.---The losses of bead for the orifices in the 1 J~ih. and 2-in. pipe were calculated from those in the | ~~ smaller pipes, the calculations being based on the assumption that, for any given velocity, the loss of head is a function of the ratio of the diameter of the pipe to that of the orifice. .This had been found to be ` practically true in the tests to determine the losses of head in orifices in $-in., 1-in., and 1^-in. pipe, con ducted by the Texas Engineering Experiment Station, and also in the tests to determine the losses of head in orifices in 4-in.. 6-in., and 12-in. pipe, conducted by the Engineering Experiment Station of the University of Illinois.{Bulletin 109, Table 6. p. 38, Davis and Jordan). .* .' 343 Heating Ventilating Air Conditioning Guide 1938 This resistance can be supplied by a calibrated and adjusted modulating valve or by an orifice resistor in a union. If the orifice resistor is to be used, its size may be selected from Table 6. TEMPEIATUEE Of WATEL. IN FLOW lUEL. Since the first section of riser No. 1 is % in. pipe and supplies 28.8 Mbh, it may be ' noted from Table 2 that a corresponding velocity is approximately 22 in. per second. From Table 6 a % in. pipe with a velocity of 24 in. per second, used with a 0.35 orifice will produce a loss of 47,000 milinches. For a velocity of 22 in. per second the loss of 344 Chapter 17. Hot Water Heating Systems and Piping head will be less, probably about 41,700 milinches, which is approximately 10 per cent more than the required resistance. This is permissible and the 0.35 in. orifice is selected. The sizes of the orifice resistors for the second, third and fourth risers are selected in a similar manner and found to be 0.38, 0.42 and 0.50 in. respectively. GRAVITY CIRCULATION In a gravity system the motive force to supply circulation is the difference in the weight of the water in the supply and the return and is proportional to the height of the risers. In this system, two distinct heads are available, the head provided in the mains by their elevation above the boiler and the head produced by the elevation of the risers above the mains. From Fig. 6 it is possible to determine the head produced per foot of height by the temperature difference to be used in designing the system. A chart such as Table 1 can be arranged using Fig. 4 for black iron. To affect a balanced circulation in a gravity hot water heating system careful consideration must be given in sizing the pipes against the amounts of water to be carried, and the head available. The larger the tempera ture drop, the greater the motive force available. It is generally customary to use a heat emission of 150 Btu per square foot of radiation,, which normally requires an average water temperature of 170 F in the radiator. This can be accomplished by using a 35 F drop with the water entering the radiation at 187 F and leaving at 153 F. Raising the water temperature leaving the boiler will increase the average radiator temperature and alter the heat emission of the radiator. Assuming that the height of mains above the boiler is 4 ft and that a 35 F drop is desirable, it will be noted that from Fig. 6, a maximum tem perature of 200 F and return temperature of 165 F with a pressure head of 150 milinches per foot of height will be produced. A total head of 600 milinches or 0.6 in. is thus produced in the mains. Assuming that the average height of first floor radiators to be 3 ft above the main and second floor radiators to be 12 ft, third floor radiators 21 ft and fourth floor radiators 30 ft, the circulating head will be respectively, 450, 1800, 3150 and 4500 milinches. The data given in Fig. 4 are based on a 20 F temperature drop which may be converted for capacities of 35 F drop by multiplying the capacity by 1.75. From these data, Tables 7 and 8 may be constructed. . The most common piping layouts used in gravity design are the onepipe system of Fig. 7 and the two-pipe system of Fig. 8. The same objections are to be found with direct return design in gravity as in forced circulation and the reverse return system of Fig. 2 is to be preferred. Example S. Design a one-pipe gravity circulation system for the layout shown in Fig. 7. Assume that the main circuit consists of 150 ft of pipe, 7 elbows, and one boiler, Solution. Replace the boiler by 3 elbow equivalents and assume that the size of the main will be about 2 in. According to Table 7 Column 2, a 2 in. elbow is equivalent to 4 ft of pipe, and the total equivalent length of the main will be about 150 plus 40, or 190 ft. Assuming that the center of the boiler will be about 4 ft lower than the horizontal portion of the main and that the temperature drop in the system is to be 35 F, Table 7 may be used to determine the size of the mains. Note from Column 8, for a 200 ft length, that a 2 in. main will supply 48 Mbh and a 2J<j in. main, 75.4 Mbh. Since the system to be designed is to supply 66 Mbh, a 2 in. pipe is too small and a 2H in. pipe 345 Heating Ventilating Air Conditioning Guide 1938 too large. The solution is to use some 2 in. and some 234 in. pipe. Since the 2 34 in. is nearer the correct size than the 2 in., select 2 in. pipe for the first 50 or 60 ft from the boiler and 234 in. for the remaining-pipe back to the boiler. Tables 8 and 9 may be used to design the radiator risers and connections. According to Table 8, for 12 Mbh the flow riser should be 34 in. and the return riser 1 in., and the riser branches should be 1 in. and 134 in-, respectively. Note that according to Table 9, both radiator tappings should be 1 in. To simplify the construction, select 1 in. flow risers with 1 in. riser branches and 1 in. radiator tappings. Also select 134 in. return risers with 134 in. riser branches, and 134 in- radiator tappings. Similarly, for 18 Mbh, select 134 in. flow and return risers and riser branches, and 134 in. radiator tappings. Fig. 7. A One-Pipe Gravity Circulation System Fig. 8. A Two-Pipe Direct Return Gravity Circulation System . To develop a rule for determining radiator sizes, assume a system similar to that of Fig. 7, in which the total temperature drop is to be 35 F and which is equipped with 7 radiators, all radiators dissipating equal ' quantities of heat. The mean temperature of the water in the radiators will be reduced 5 F for each successive radiator. If the mean temperature of .the water in the first radiator is 200 F, the mean temperature of the water in the seventh radiator will be 170 F, and, according to Table 4, Chapter 14, the heat dissipation of these two radiators will be to each other as 1.62 is to 1.15, or as 140 is to 100, and therefore if the last radiator is to dissipate as much heat as the first, its size must be 40 per cent larger. 346 Chapter 17. Hot Water Heating Systems and Piping Table 7. Capacities of Mains in Mbh, for One-Pipe and for Two-Pipe Direct Return Gravity Circulation Systems with a Total Friction Head of 0.6 In., a Temperature Drop of 35 F, when the Mains are 4 Ft Above the Center of the Boiler 11 2 Pipe See (Inches) Equivalent Length op Pipe (Feet) 134 2 234 3 334 .4 3.0 4.0 4.5 5.0 5.5 6.0 3 r4 5 6 | 7 | - 8 | 9 10 11 Equivalent Total Length op Pipe in Feet in Longest Circuit 75 100 12S | ISO | 175 | 200 | 250 300 350 m .Unit Friction Head, Mujnches 8.0 6.0 4.8 4.0 3.4 3.0 14 2.0 1.7 '43.0 37.5 33.0 30.0 27.0 25.0 22.2 20.2 18.7 8S.0 72.0 63.0 57.0 51.0 48.0 42.0 38.0 35.0 140.0 115.0 100.0 90.0 81.5 75.4 67.2 61.0 56.0 234-0 204.0 175.5 160.0 143.0 133.0 110.0 107.5 100.0 347.0 300.0 260.0 236.0 214.0 200.0 177.0 160.0 146.0 490.0 422.0 370.0 334-0 297.0 278.0 248.0 223.0 205.0 .Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies with the velocity. . Example 4- Design a two-pipe, direct return, gravity circulation system for the lay out shown in Fig. 8. Assume that the main circuit from the boiler to the farthest flow riser and from the farthest return riser back to the boiler consists of 160 ft of pipe, 6 elbows, and 1 boiler. Solution. Replacing the boiler by 3 elbow equivalents and assuming that the largest size of the main will be about 3 in., the total equivalent length of the main will be 160 plus 45. or 205 ft. Assuming that the center of the boiler will be about 4 ft lower than the horizontal portion of the main, and that the temperature drop will be 35 F for the system, the pressure head caused by the difference in weight between the water in the flow and return risers joining the mains to the boiler will be about 0.6 in. of water. Table 7 may be used to determine the size of the main as follows: Refer to Column 8 and note that for Sections AB and IA, which supply 105.6 Mbh, a 3 in. pipe is too large and a 234 in- pipe is too small; hence, select 234 in. rather than 3 in! as noted in Fig. 8 for Section AB and 3 in. for Section IA. For Sections BC and HI, which supply 76.8 Mbh, a 234 in. pipe is almost exactly the correct size and is selected for both sections. Tables 7 and 8 are based on the assumption that the boiler pressure head must be equal to the friction head in the mains, and that the several radiator pressure heads must be equal to the respective radiator and riser friction heads. To design the radiator risers, use Table 8 and begin with the set nearest the boiler. The first floor risers must supply 28.8 Mbh. According to the table, 134 in. flow and return risers will supply 26.0 Mbh; if the return riser is increased to 134 in., the capacity will be increased to 34.0 Mbh. This is considerably larger than necessary, and 134 in. flow and return risers are selected. However, it must be remembered that the riser branches, which are the connections from the flow and return mains to the flow and return risers, are to be one size larger than the risers. The second floor risers must supply 19.2 Mbh. According to the table, the capacity of 1 in. flow and return risers is 20.0 Mbh, and that size is selected. The third floor risers must supply 9.6 Mbh. If a 34 in. flow and a 34 in. return riser is used, the capacity will be 8.0 Mbh; if both risers are 34 in-, the capacity will be 14.0 Mbh. The 34 in- pipe is selected for both risers. To design the radiator connections, use Table 9 and note that for the .first floor radiator connections the capacity of a 34 in. flow and Tin. return is 9.1 Mbh, and that of. 347 Heating Ventilating Air Conditioning Guide 1938 Table 8. Maximum Capacities of Risers3 in Mbh, and Velocities of Water in Pipes in Inches Per Second for One-Pipe and for Two-Pipe Direct Return Gravity Circulation Systems with a Drop of . 35 F Through Each Radiator Pipe Size (Inches) Flow Return Equivalent Length op Pipe (Feetc) 1st Floob*> * Mbh VeL (In. per 8ec.d) Flow Return 2nd Floor Mbh 3rd and 4th Floors Mbh xX 1.0 aX XX 1.5 X1 1 1 . 2.0 1 IX m ix 3.0 m IX ix ix 3.5 5 6.4 9 2.3 2.3 10.1 IS 3.2 2.0 1S.8 18 2.5 2.5 SO SI 3.0 2.0 S5.S S6 3.0 3.0 . 43 n 4.0 2.5 48 3.0 3.0 6.S 8.0 - 14-0 17.1 S6.0 34 55 "This table is based on pressure beads of 450, 1800, 3150, and 4500, respectively, for the first, second, third, and fourth floor radiators, and on friction heads of 200 milinches for the first floor radiators and con nections, and 700 milinches for all other radiators and their connections. bThe riser branches, the piping which connects the risers to the mains, are to be one size larger than the risers. . ,. . . ., ... cApproximate length of pipes in feet equivalent to one elbow in friction head. This value vanes with the velocity. ^Velocities apply to the riser branches. a 1 in. flow and a 1 in. return is 12.5 Mbh. The former is more nearly the correct size, but since it is difficult to secure a good flow through first floor radiators, the 1 in. flow and return connection is selected. For the two upper floors, the capacity of a X in. flow . and return connection is 10.5 Mbh, and that size is used. ' As explained in the design of the forced circulation system of Fig. 5, the two-pipe direct return system of Fig. 8 will not function correctly unless its four sets of risers are balanced among themselves. This neces sary balancing is accomplished by adding resistances to all risers, except the one farthest from the boiler, equal to the excess boiler pressure heads available for those risers above the boiler pressure head available for the farthest riser. For example, the first set of risers is 60 ft nearer the boiler than the last set. Since the flow and return mains are designed for a friction head of 3 milinches per foot (see Table 7, Column 8), the boiler pressure head available for the first set of risers is 360 milinches in excess Table 9. Maximum Capacities of Radiator Connections in Mbh, for One-Pipe and for Two-Pipe Direct Return Gravity Circulation Systems with a Temperature Drop of 35 F Through Each Radiator Pipe Size Flow Return Equivalent Length op Pipe (Feet) 1st Floor Mbh 2nd, 3rd, and 4th Floors Mbh X X X X 1 r iM X X X 1 1 IM IX 1.0 1.5 2.0 3.0 4.1 6.9 5.S 7.6 7.0 . 10.5 9.1 13.0 1S.5 17.8 17.6 . SS.S SS.S SS.S . . ^Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies with the velocity. 348 Chapter 17. Hot Water Heating Systems and Piping of that available for the fourth set. The velocity in the riser branch is 3 in. per second (see Table 8) and, therefore, according to Table 6, an 0.65 in. orifice in a 134 in. union should be used. This will provide a resistance of about 420 milinches. In the same manner it is found that for the second set of risers a resistance of 240 milinches is required and that an 0.70 in. orifice in a 1J4 in. union will provide a resistance of 285 milinches. For the third set of risers, a resistance of 120 milinches is required and an 0.60 in. orifice in a 1 in. union will provide sufficient resistance. EXPANSION TANKS When water at ordinary temperatures is heated or cooled, its volume is increased or decreased. This variation in the volume of the water in a heating system is generally provided for by means of an expansion tank Fig. 9. An Open Expansion Tank. Fig. 10. A Closed Expansion Tank into which the water can flow from the system during the heating-up periods and from which it can flow back into the system during the cooling-down 'periods. The expansion tank may be open or closed. In an open expansion tank (Fig. 9), the water is subjected to atmospheric pressure and can expand freely without a material increase in pressure. In a closed expansion tank (Fig. 10), the water is subjected to the pressure of the compressed air within the tank, .and as the-water expands, the volume of the air in the tank is decreased and its pressure increased. The open expansion tank must be placed at a sufficient elevation above the highest radiator to prevent boiling when the water in that radiator is at the highest temperature to which it is to be heated. For example, if the water is to be heated to 225 F on extremely cold days, the absolute pressure on the water in the highest radiator must be at least 19 lb per square inch. This pressure will be secured if the open expansion tank is located 15 ft above the highest radiator. If a closed expansion tank is used and is located 30 ft below the highest radiator, an absolute pressure 349 Heating Ventilating Air Conditioning Guide 1938 of about 32 lb per square inch must be maintained in the expansion tank if the water in the highest radiator is to be heated to 225 F without danger of boiling. The type of expansion tank used in a heating system, whether open or closed, has no influence on the operation of the system. The only function performed by the expansion tank is to provide for the variation in the volume of the water in the system, and at the same time to maintain a sufficient pressure in the system to prevent boiling when the water is at the highest temperature for which the system is designed. The capacity of the cushion or expansion tank should not. be less than the tank sizes indicated in Table 9 and in addition provisions must be made for draining it without emptying the system. ' The capacity of the expansion tank should be at least twice the in crease in volume produced when the water in the system is heated from its normal to its maximum temperature. When 25 gal of water are heated Table 9. Expansion Tank Sizes for Hot Water Heating Systems Tank Size Gallons Equivalent Direct Radiation Installed ' - in Sq Ft Capacity Direct Radiation Installed IN MbH _ 18 21 24 30 35 40 2-30 2-30 2-35 2-40 Up to 350 Up to 450 Up to 650 Up to 900 Up to 1100 Up to 1400 Up to 1600 Up to 1800 Up to 2000 Up to 2400 Up to 52.5 Up to 67.5 Up to 97.5 Up to 135.0 - Up to 165.0 Up to 210.0 Up to 240.0 Up to 270.0 Up to 300.0 Up to 360.0 from 40 F to 200 F, the volume of water increases to 26 gal. A safe rule, therefore, is to make the water capacity of the expansion tank equal to 10 per cent of the capacity of the heating system. _ In a forced circulation system, the expansion tank can either be con nected to the flow'or return main. In a gravity circulation system, the expansion tank should be connected to the flow riser so that air liberated from the water in the boiler may escape through the expansion tank. The expansion tank should be protected so that the water in the' tank or in the connecting pipe lines cannot freeze. If the water should freeze and the water in the system is heated causing further expansion, the resulting force will burst the boiler or some other portion of the system. , RELIEF VALVES A relief valve should be installed on any hot water system using a closed circuit. The valve should be of ample capacity to provide for relief of expansion of the system without allowing anTexcessive pressure rise above the valve setting. .; " 350 Chapter 17. Hot Water Heating Systems and Piping A relief valve should be of the diaphragm-operated or gravity-weighted type without guide wings below the seat. Provision should be made for manual operation to assure that the valve is in the proper operating condition at all times, and valves should be checked periodically. A relief valve installed in conjunction with a compression tank will not operate often provided the tank is of adequate size. It is essential that the relief valve be kept in good condition to eliminate any possible failure when operation is necessary. INSTALLATION DETAILS The detailed installation of the pipe system should be governed by four fundamental rules: 1. All piping must be pitched either up or down so that all gases which are liberated from the water can move freely to a vented section of the system. Whenever practicable, the pipe line should be pitched so that gases flowing to a vent will flow in the same direc tion as the water. When a pipe system cannot be installed without creating air pockets, that is, sections in the system from which liberated gases cannot escape, such sections must be provided with automatic air relief valves or with air valves which may be operated manually when necessary, or trapped into a pressure tank. 2. All piping must be arranged so that the entire system can be drained, either to permit alterations or repairs, or to prevent freezing if the system is not to be operated during a cold period. . It is well to install a gate valve and union in every riser near the main to permit the draining of individual risers without draining the entire system. It is also well, in large installations, to divide the system into branches and to provide each branch with unions and valves so that any one branch can be drained without disturbing the remaining ones. The dividing of large heating systems into branches or zones and providing each zone with individual valves has the further advantage of permitting a varying temperature control. For example, if a building is equipped with a forced circulating system and if the south rooms are on one branch of the main and. the north rooms are on a separate branch, the valves may be set so that the water will circulate through the north branch with a temperature drop of, say, 10 F, and through the south branch with a tempera ture drop of, say, 20 F, thus delivering less heat to the south rooms than to the north rooms. This arrangement is especially valuable when the regulating valves are controlled thermostatically by the temperatures in the two zones, because no.matter how accurately the heating system may have been designed, the heat demand of any group of rooms varies with sunshine and with wind velocity, and these intermittent variations can be provided for only by the individual control made possible by changing the valve settings controlling the heat supplied to particular groups of rooms. 3. All piping must be installed so that it is free to expand and contract with changes of temperature without producing undue stresses in the pipes or connections. For this purpose it is generally sufficient to allow for a variation in length of 1 in. for 100 ft of pipe. 4. The pipe system must be installed so that each circuit has its correct friction head. To bring this about, it is necessary in some cases to minimize the friction, .., to make the pipe line as short as possible and to provide as few fittings as possible; and in other cases it is necessary to increase, the length of the pipe and the number of fittings so that, for every circuit, the friction head will be equal to the available pressure head. The connections from the boiler to the mains should be short and direct, to reduce the friction head. It is frequently possible to avoid an elbow and to reduce the length of the pipe by running the pipe in a diagonal direction, either in a horizontal or in a vertical plane. The mains and branches should pitch up and away from the heater, generally not less than 1 in. in 10 ft. The flow main should always be covered; the return main should be covered except where it is to provide the heating surface for the basement. The connections from mains to branches and to risers should be such that circulation through the risers will start in the right direction. Hence, in a'one-pipe system the flow . 351 / Heating Ventilating Air Conditioning Guide 1938 connection must be nearer the heater than the return connection. In a correctlydesigned two-pipe system, the pressure in the flow main is higher than that in the return main, and a slight variation in the distances of the flow and return connections from the heater is not material; but it is generally best to have the two connections about equally distant from the heater. In some cases it may be advisable to take the flow connection off the top of the main and the return connection from the side, but in most cases both connections should be at an angle of 45 deg. This method shortens the lines and substitutes 45-deg ells for 90-deg ells. Preferably, connection of the flow riser to a radiator should be to the upper tapping, and connection of the return riser to a radiator should be to the lower tapping. When hot water enters at the top of a radiator it will distribute itself along the entire length of the radiator, and as it cools it will settle gradually to the bottom; the cool water may then be taken out of the radiator at either end. Fig. 11. Method of Connecting Radiator to Allow for Expansion of Pipe With forced circulation and high velocities, it is advisable to let the water enter at the top of the radiator and leave at the bottom of the opposite end. With gravity circulation and low velocities it makes little difference whether the water leaves at the end at which it enters or at the opposite end. The connections of the risers to the radiators should be such that provision is made for ' the vertical expansion of the risers. This can be accomplished as indicated in Fig. 11 by using one tee and two ells for each connection. These connections should be pitched upward or downward, whichever may be necessary to prevent the formation of air pockets and to permit draining. \ PROBLEMS IN PRACTICE 1 Will altering a hot water heating system from an open to closed type system (a) increase the circulation and (6) give more heat? o. No. Tests conducted by the A.S.H.V.E. indicate that there is little, if any difference in the circulation when the system is under pressure. The difference in temperature between the supply and return, and the friction are the governing factors. b. With a closed system the water may be carried at a higher temperature without boiling which permits warmer radiators. 2 What tends to prevent or to retard the circulation of water in hot water heating systems? . In both gravity flow and forced circulation systems, the friction which must be overcome when the water is flowing through pipes, fittings, valves, heaters, and radiators tends to 352 Chapter 17. Hot Water Heating Systems and Piping prevent or.retard circulation. For a given pipe the friction varies approximately as the 1.7 power of the velocity; and for given fittings, valves, heaters, and radiators, the friction varies approximately as the square of the velocity. It is therefore sufficiently accurate to express the friction in fittings, valves, heaters, and radiators in terms of the friction in one standard elbow, as shown in Table 3. 3 If a single radiator located 10 ft above a boiler is connected with a flow and return black iron pipe, what is the pressure head maintaining the circulation if the water in the return riser is at 180 F and that in the flow riser is at 200 F? It is found, from Table 7, Chapter 1, that 180 F water weighs 60.61 lb per cubic foot and 200 F water weighs 60.13 lb per cubic foot. The pressure head is independent of the size of the pipe. If the two risers were each 1 ft square, the water in the flow riser would weigh 601.3 lb and that in the return riser would weigh 606.1 lb. Thus the water in the return riser would weigh 4.8 lb more than that in the flow riser. Consequently, the resulting pressure head is 4.8 lb per square foot. . Pressure heads are generally expressed in feet, or inches, or milinches of water of a given temperature. In this case water is at both 180 F and 200 F, so the pressure head is expressed in terms of 190 F water. Such water weighs 60.39 lb per cubic foot, and to secure a pressure of 4.8 lb per square foot, it is necessary to have a column of water having a weight of 4.8 divided by 60.39 = 0.0795 ft, or 0.9540 in., or 954 milinches. This is the pressure head which maintains the circulation; 4 In the elementary system of Question 3, if the radiator dissipates 14,000 Btu per hour, what is the velocity of the water in the pipe line, if the pipes are 1 in', in diameter? What, if they are % in. in diameter? Since the temperature drop through the radiator is from 200 F to 180 F or 20 F, every pound of water flowing through the radiators delivers 20 Btu; consequently, 14,000 divided by 20 = 700 lb of water, or for 190 F water, 700 divided by 60.39 = 11.59 cu ft of water must flow through the radiator and through the pipe lines every hour; The interior area of a 1 in. pipe is 0.864 sq in. The velocity in the 1 in. pipe is 11.59 divided by 0.864 and multiplied by 144 = 1932 ft per hour or 6.44 in. per second. For % in. pipe, the interior area is 0.533, and the velocity is 6.44 multiplied by 0.864 and divided by 533 = 10.44 in. per second. 5 If, in the elementary heating system of Question 3, a 1 in. pipe line is used, what would be the friction head? - -. If the radiator is connected with the heater to provide for freedom of expansion, the heat ing circuit may be assumed to consist of a heater, 25 ft of pipe, 8 elbows, 1 radiator valve, and 1 radiator. Front Table 3 it appears that the heater and radiator are equivalent, in friction, to 6 elbows; hence, the circuit may be placed equal to 25 ft of pipe and 14 elbows. From the diagram of Fig. 4 it appears that the friction head for a 1 in. pipe and a velocity of 6.44 in. per second is about 25 milinches per foot. For 25 ft of pipe, the friction head will be 625 milinches. * pi It appears from Table 3 that the friction head in one elbow is -5-- , or in this case 0.54 multiplied by 0.54 and divided by 64.4 = 0.0045 ft or 54 milinches. Hence, for the 14 elbows the friction is 756 milinches. For the entire circuit, the friction head is the sum of the 625 milinches of the pipe plus the 756 milinches of the elbows, or 1381. milinches which equal 1.381 in. 6 If the elementary heating system of Question 3 is installed with a 1 in. pipe line, how will it function? It is found from the answer to Question 3 that the pressure head is 954 milinches and from the answer to Question 5 that the friction head is 1381 milinches when the water is flowing with such velocity that the specified 14,000 Btu will be delivered with a 20 F temperature drop through the radiators. Since the pressure head is smaller than the friction head, the system will not function as planned for the water will flow through the 353 Heating VentiIiAting Air Conditioning Guide 1938 system more slowly and remain in the radiator longer. The temperature drop through the radiator will be more than 20 F, and the difference in the weight of the water in the return and flow risers will be greater than that intended. The final result will be that the pressure head will become equal to the friction head at a value somewhere between ' 954 and 1381 milinches. Since the average water temperature in the radiator will be less than 190 F, the radiator should be larger .than the size given in Question 4. 7 # Should a hot water heating system be designed to embody small pipes or large pipes? As pipe sizes in gravity circulation heating are reduced, the friction head is increased and it is necessary to increase the temperature drop through radiators; this lowers the average temperature of the water in the radiators and necessitates an increase in the- size of the radiators, so whereas the cost of the pipe in a system is reduced, the cost of the radiators is increased. For each installation there is a definite pipe size which entails' maximum economy. . As pipe sizes in forced circulation systems are reduced, friction heads are increased so a circulating pump of greater size or capacity is required. Thus, by decreasing the size of the piping, both the first cost of the circulating pump and the cost of its operation are* increased. There is a definite pipe size for every installation which is most economical.' For each installation of both types of systems there is a definite pipe size entailing maxi*' mum economy which can be determined by a series of comparative calculations. 8 What should be the size of the radiators for the elementary heating system of Question 3 in which the water enters the radiator with a temperature of 200 F and leaves with a temperature of 180 F? The average temperature of the water in the radiator is, approximately, 190 F. .. If test results are available for the particular radiators to be used, and for the tempera tures named, the size of the radiators should be selected from them. If no such test results are to be had, but if test results are available for. the type of radiator to be usedwhen it is supplied with 215 F steam and placed in a 70 F room, the required size may be determined by the following ratio; The required size is to the corresponding steam radiator size as (215 -- 70)1** is to (190 -- 70)1-*. This ratio works out to 1.281 Hence, the radiators should be 28 per cent larger under the conditions prescribed than are cor responding radiators under standard conditions. It is immaterial whether a radiator is filled with steam or with water, as long as the average temperature of its outer surface is the same in both cases. 354 Chapter 18 PIPE, FITTINGS, WELDING Pipe Material, Types of Pipe Used, Dimensions of Pipe Com mercially Available, Expansion and Flexibility of Pipe, Pipe Threads and Hangers, Types of Fittings, Welding as Applied to Erection of Piping, Valves, Corrosion of Piping IMPORTANT considerations in the selection and installation of pipe and fittings for heating, ventilating, and air conditioning work are dealt with in this chapter. - . PIPE MATERIALS . Use of corrosion-resistant materials for pipe, including special alloy steels and irons, wrought-iron, copper and brass, has increased con siderably during the past few years. The recent development of copper, brass, and bronze fittings which can be assembled by soldering or sweating permits the use of thin-wall pipe and thereby has reduced the initial cost of such installation. The following brief discussion indicates the variety of pipe materials and the types of pipe available. . Wrought-Steel Pipe. Because of its low price, the great bulk of wrought pipe used for heating and ventilating work at the present time is of wrought steel. The material used for steel pipe is a mild steel made by the acid-bessemer, the open-hearth, or the electric-furnace process. Ordinary wrought-steel pipe is made either by shaping sheets of metal into cylindrical form and welding the edges together, or by' forming or drawing from a solid billet. The former is known as welded pipe, the latter as seamless pipe. Many types of welded pipe are available, although the smaller sizes most frequently used in heating and ventilating work are made by the lap-weld or butt-weld process. While the lap-weld process produces a better weld than the butt type, lap-weld pipe is seldom manufactured in nominal pipe sizes less than 2 in. Seamless pipe can'be obtained in the small sizes at a somewhat higher cost. Seamless steel pipe is frequently used for high pressure work or where pipe is desired for close coiling, cold bending, or other forming operation. Its advantages are its somewhat greater strength which permits use of a thinner wall and, in the small sizes, its freedom from the occasional tendency of welded pipe to split at the weld when bent. Wrought-iron Pipe. Wrought-iron pipe is considered to be more corro sion-resisting than ordinary steel pipe and therefore its somewhat higher 355 Heating Ventilating Air Conditioning Guide 1938 first cost can be justified on the basis of longer life expectancy. Wroughtiron pipe may be identified by the spiral line marked into each length, either knurled into the metal or painted on it in red or other bright color. Otherwise, there is little difference in the appearance of wrought iron and steel pipe, although microscopic examination of polished and etched specimens will readily disclose the difference. Cast Ferrous Pipe. There are now available several types of cast ferrous-metal pipe made of a good grade of cast iron with or without additions of nickel, chromium, or other alloy. This pipe is available in sizes from 1in. to 6 in., and in standard lengths of 5 or 6 ft with external and internal diameters closely approximating those of extra-strong wrought pipe. Cast ferrous pipe may be obtained coupled, beveled for welding, or with ends plain or grooved for the several types of couplings. It is easily cut and threaded as well as welded. The fact that it is readily welded enables the manufacturers to supply the pipe in any lengths practicable for handling. Alloy Metal Pipe. Steel pipe bearing a small alloy of copper or other alloying element and iron pipe bearing a small alloy of copper and moly bdenum have been claimed to possess more resistance to corrosion than plain steel pipe and they are advertised and sold under various trade names. . Copper Pipe and Fittings. Owing to its inherent resistance to cor rosion, copper and brass pipe have always been used in heating, venti lating, and water supply installations, but the cost with standard dimen sions for threaded connections has been high. The recent introduction of fittings which permit erection by soldering or sweating allows the use of pipe with thinner walls than are possible with threaded connections, thereby reducing the cost of installations. The initial cost of brass and copper pipe installations generally runs higher than the corresponding job with steel pipe and screwed connections in spite of the use of thin-wall pipe, but the corrosive nature of the fluid conveyed or the inaccessibility of some of the piping may warrant use of a more expensive material than plain steel. The advantages of corrosionresisting pipe and fittings should be weighed against the correspondingly higher initial cost. COMMERCIAL PIPE DIMENSIONS The IPS dimensions of commercial pipe universally used at the present time conform to the recommendations made by a Committee of the A.S.M.E. in 1886. Pipe up to 12 in. in diameter is made in certain definite sizes designated by nominal internal diameter which is somewhat different from the actual internal diameter, depending on the wall thick ness required. There are three weights of wrought iron and steel pipe commonly used, known as standard-weight, extra-strong, and double extra strong. ' Because of the necessity of maintaining the same external dia meter in all three weights for the same nominal size, the added wall thickness is obtained by decreasing the internal diameter. The term full-weight, when applied to sizes below 8 iff., means that the pipe is up to . the nominal weight per foot. When applied to.sizes between 8 and 12 in., inclusive, it often indicates that the pipe has the heaviest of several wall 356 Chapter 18. Pipe. Fittings. Welding thicknesses listed. In sizes 14 in. and upward, pipe is designated by its outside diameter (O.D.) and the wall thickness is specified. While the demands for pipe for the heating and ventilating industry are reasonably well served by the standard-weight and extra-strong pipe, demands for pipe for higher pressures and temperatures in industry resulted in the use of a multiplicity of wall thicknesses for all sizes. Even in heating installations, the erection of piping by welding was deemed to Table 1. Dimensions of Welded and Seamless Steel Pipe Nominal Pipe Size Nominal Wall Thicknesses nob Sgheduls Numbers Outside Diam. Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule 10 20 30 40 60 SO 100 120 140 160 H Vs % 1 m 2 l* 3H 4 5. 6 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 0. D. 24 0. D. 30 0. D. 0.405 0.540 0.675 0.840 1.050 1.315 1.660 1.900 2.375 2.875 3.500 4.000 4.500 5.563 6.625 8.625 10.75 12.75 14.0 0.250 16.0 0.250 18.0 0.250 20.0 0.250 24.0 0.250 30.0 0.312 0.250 0.250 0.250 0.312 0.312 0.312 0.375 0.375 0.500 0.068* 0.095* 0.088* 0.119* 0.091* 0.126* 0.109* 0.147* 0.113* 0.154* 0.133* 0.140* ____ 0.179* 0.191* 0.145* 0.200* 0.154* 0.218* 0.203* 0.276* 0.216* 0.300* 0.226* 0.318* 0.237* 0.337* 0.258* 0.375* 0.280* 0.432* 0.277* 0.322* 0.406 0.500* 0.593 0.307 0.365* 0.500* 0.593 0.718 0.330* 0.406 0.562 0.687 0.843 0.375 0.437 0.593 0.750 0.937 0.375 0.500 0.656 0.843 1.031 0.437 0.562 0.718 0.937 1.156 0.500 0.593 0.812 1.031 1.250 0.562 0.687 0.937 1.218 1.500 0.625 0.437 0.500 0.562 0.718 0.843 1.000 1.062 1.218 1.343 1.500 1.750 0.812 1.000 1.125 1.250 1.437 1.562 1.750 2.062 0.187 0.218 0.250 0.250 0.281 0.343 0.375 0.437 0.531 0.625 0.718 0.906 1.125 1.312 1.406 1.562 1.750 1.937 2.312 All dimensions are given in inches. The decimal thicknesses listed for the respective pipe sizes represent their nominal or average wall dimensions and include an allowance for mill tolerance of 12.5 per cent under nominal thicknesses. Thicknesses marked with asterisk in Schedules 30 and 40 are identical with thicknesses for standardwight pipe in former lists; those in Schedules 60 and 80 are identical with thicknesses for extra-strong pipe in former lists. The Schedule Numbers indicate approximate values of the expression 1000 x P/S. warrant the use of pipe lighter than standard weight. For these reasons, a Sectional Committee on Standardization of Wrought Iron and Wrought Steel Pipe and Tubing functioning under the procedure of the American Standards Association was appointed to standardize the dimensions and materials of pipe. The proposed pipe standard recommended by that sectional committee has set up several schedules of pipe including standard-weight and extra strong thicknesses which are now included in Schedules 40 and 60, re spectively. . The schedules approved by the Sectional Committee are given in Tables 1 and 3 and the corresponding weights in Tables 2 and 4. Standard-weight pipe is generally furnished with threaded ends in 357 Heating . .Ventilating Air Conditioning. Guide 1938 random lengths of 16 to 22 ft, although; when ordered with plain ends, 5 per cent may be in lengths of 12 to 16 ft. Five per cent of the total number of lengths ordered may be jointers which are two pieces coupled together. Extra-strong pipe is generally furnished with plain ends in random lengths of 12 to 22 ft, although 5 per cent may be in lengths of 6 to 12 ft. . In addition to IPS copper pipe, several varieties of copper tubing are in use with either flared or compression couplings or soldered joints. Dimen sions of copper water tubing intended for plumbing, underground water service, fuel-oil lines, gas lines, etc., have been standardized by the U. S. Government and the American Society for Testing Materials. There are three standard wall-thickness schedules of copper water tubing classified in accordance with their principal uses as follows: Class K--Designed for underground services and general plumbing service. Class L--Designed for general plumbing purposes. Class M--Designed for use with soldered fittings only. In general, Type K is used where corrosion conditions are severe, and Table 2. Nominal Weights of Welded and Seamless Steel Pipe Nominal Pips StZB Inches SCHED. 10 Plain Ends SCHED. 20 Plain Ends Schedule 30 Plain Ends Threads and Coup lings Schedule 40 Plain Ends Threads and Coup lings Scbzd. 60 Plain Ends ScHED. 80 Plain Ends SCHED. 100 Plain Ends SCHED. 120 Plain Ends Sched. 140 Plain Ends Sched. 160 Plain Ends 14 Ya. H 14 K l 1M V4 2 214 3 3)4 4 5 6 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 O. D. 24 0. D. 30 0. D. 36.8 42.1 47.4 52.8 63.5 99.0 22.4 28.1 33.4 45.7 52.3 59.0 78.6 94.7 158.0 24.7* 34.3* 43.8* 54.6 62.6 82.0 105.0 141.0 197.0 0.25* 0.25* 0.32* 0.43* 0.43* 0.54* 0.57* 0.57* 0.74* 0.86* 0.86* 1.09* 1.14* 1.14* 1.48* 1.68* 1.69* 2.18* 2.28* 2.29* 3.00* 2.72* 2.74* 3.64* 3.66* 3.68* 5.03* 5;80* 5.82* 7.67* 7.58* 7.62* 10.3* 9.11* 9.21* 12.5* 10.8* 10.9* ` \ 15.0* 19.0 14.7* 14.9* 20.8* 27.1 19.0* 19.2* 28.6* 36.4 25.0* 28.6* 28.8* 35.7 43.4* 50.9 60.7 35.0* 40.5* 41.2* 54.8* 64.4 77.0 89.2 45.0* 53.6 55.0 73.2 88.6 108.0 126.0 63.3 85.0 107.0 131.0 147.0 82.8 108.0 137.0 165.0 193.0 105.0 133.0 171.0 208.0 239.0 123.0 167.0 209.0 251.0 297.0 171.0 231.0 297.0 361.0 416.0 67.8 105.0 140.0 171.0 224.0 275.0 342.0 484.0 1.31 1.94 2.85 3.77 4.86 7.45 10.0 14.3 22.6 33.0 45.3 74.7 116.0 161.0 190.0 241.0 304.0 374.0 536.0 Weights are given in pounds per linear foot and are for pipe with plain ends except for sizes which are commercially available with threads and couplings for which both weights are listed. . . *The weights marked with asterisk in Schedules 30 and 40 are identical with weights for standard-weight, pipe in former lists; those in Schedules 60 and 80 are identical with weights for extra-strong pipe in former lists. The Schedule Numbers indicate approximate values of the expression 1000 x P/S. - 358 Chapter 18. Pipe. Fittings, Welding Types L and M where such conditions may be considered normal as, for instance, in heating work. Types K and L are available in both hard and soft tempers; Type M is available only in hard temper. Where flexibility is essential as in hidden replacement work or where as few joints as possible are desired as in fuel-oil lines, the soft temper is commonly used. New or exposed work generally employs copper pipe of a hard temper. All three classes are extensively used with soldered fittings. Standard dimensions, weights, and diameter and wall thickness tolerances for these classes of copper tubing are given in Table 5. Copper pipe is also available with dimensions of steel pipe. Refrigeration lines used in connection with air conditioning equipment also employ copper tubing extensively. For refrigeration use where tubing absolutely free from scale and dirt is required, bright annealed copper tubing that has been deoxidized is used. This tubing is: available in a variety of sizes and wall thicknesses. EXPANSION AND FLEXIBILITY The increase in temperature of a pipe from room temperature to an operating steam or water temperature 100 F or more above room tem- Table 3. Dimensions of Welded Wrought-Iron Pipe Nominal Pipe Size Y lA% Y % 1 \% 1Y 2 2Y 3 3Y 4 5 6 8 10 12 14 0. D. 16 0. D. 18 O. D. 20 O. D. - Outside Diameter 0.405 0.540 0.675 0.840 1.050 1.315 1.660 1.900 2.375 2.875 3.5 4.0 4.5 5.563 . 6.625 8.625 10.75 12.75 14.0 16.0 18.0 20.0 Nominal Wall Thicknesses fob Schedule Numbers Schedule 10 0.250 0.250 0.250 Schedule 20 0.312 0.312 . 0.312 0.375 Schedule . 30 0.283* 0.313* 0.336* 0.375 0.375 0.437 0.500 Schedule 40 0.070* 0.090* 0.093* 0.111* 0.115* 0.136* 0.143* 0.148* 0.158* 0.208* 0.221* 0.231* 0.242* 0.263* 0.286* 0.329* 0.372* 0.414 0.437 0.500 0.562 0.562 Schedule 60 0.510* 0.574 0.625 0.687 0.750 -- Schedule 80 0.098* 0.122* 0.129* 0.151* 0.157* 0.183* 0.195* 0.204* 0.223* 0.282* 0.306* 0.325* 0.344* 0.383* 0.441* 0.510* 0.606 0.702 0.750 -- All dimensions are given in inches. ' The decimal thicknesses listed for the respective pipe sizes represent their nominal or average wall dimensions and include an allowance for mill tolerance of 12.5 per cent under the nominal thickness. ^Thicknesses marked with an asterisk in Schedules 30 and 40 are identical with thicknesses for standardweight pipe in former lists; those in Schedules 60 and 80 are identical with thicknesses for extra-strong pipe in former lists. The Schedule Numbers indicate approximate values of the expression 1000 x P/S. 359 1 Heating Ventilating Air Conditioning Guide 1938 perature results in an increase in length of the pipe for which provision must be made. The amount of linear expansion (or contraction in the case of refrigeration lines) per unit length of material per degree change in temperature is termed the coefficient of linear expansion of that material, or commonly, the coefficient of expansion. This coefficient varies with the material. The linear expansion of cast iron, steel, wrought iron, and copper pipe, Table 4. Nominal Weights of Welded Wrought-Iron Pipe Nominal Pm Size (Inches) SCBED. ScHED. 10 20 Plain Plain Ends H H Vs ZA i ij< 2 2^ 3' 3H 4 5 6 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 O. D. 36.0 41.3 46.5 44.8 51.4 57.9 77.0 SCHEDULE 30 Schedule 40 . ' Schedule 60 Schedule 80 Plain Ends Threads and Couplings 24.7* 34.3* 43.8* 53.6 61.4 80.5 103.0 25.0* 35.0* 4_5_._0*_ ____ .. . Plain Enda Threads and Couplings 0.25* 0.43* 0.57* 0.86* 1.14* 1.68* 2.28* 2.72* 3.66* 5.80* 7.58* 9.11* 10.8* 14.7* 19.0* 28.6* 40.5* 53.6 62.2 81.2 103.0 115.0 0.25* 0.43* 0.57* 0.86* 1.14* 1.69* 2.29* 2.74* 3.68* 5.82* 7.62* 9.21* 10.9* 14.9* 19.2* 28.8* . 41.2* 55.0 _____ __ __ Plain Plain 54.8* 73.2 87.6 111.0 136.0 0.32* 0.54* 0.74* 1.09* 1.48* 2.18* 3.00* 3.64* 5.03* 7.67* 10.3* 12.5* 15.0* 20.8* 28.6* 43.4* 54.4 88.6 _10_4_.0__ Weights are given in pounds per linear foot and are for pipe with plain ends except for sizes which are commercially available with threads and couplings for which both weights are listed: - Weights marked with an asterisk in Schedules 30 and 40 are identical with weights for standard-weight pipe in former lists; those in Schedules 60 and 80 are identical with weights for extra-strong pipe in former lists. \ The Schedule Numbers indicate approximate values of the expression 1000 x P/S. the materials most frequently used in heating and ventilating work, can be determined from Table 6. . The elongation values in Table 6 were computed from the following formula: , 0) where . Lt length at temperature t degrees Fahrenheit, feet. Lo = length at 32 F, feet. t = final temperature, degrees Fahrenheit. a and b are constants as given on the next page. 360 . *5,31. wi.` Chapter 18. Pipe, Fittings, Welding Metal 0 0.005441 0.006212 0.006503 0.009278 b 0.001747 0.001623 0.001622 0.001244 The three methods by which the elongation due to thermal expansion may be taken care of are: 1. Expansion joints. 2. Swivel joints. ' 3. Inherent flexibility of the pipe itself utilized through pipe bends, right-angle turns, or offsets in the line. Table 5. Standard Dimensions, Weights, and Diameter and Wall Thickness Tolerances for Copper Water Tubes* (All Tolerances Plus and Minus) . Nominal Size, In. Actual Outside DiamETEH, In. Permissible Variation-in Mean Outside Dumeter. In. Annealed Hard Drawn . WALL THICKNESS. IN. Class K Class L Class M Per Per Per Nominal missible Varia Nominal missible Varia Nominal missible Varia tion tion tion Weight per Ft Lb Class K Class L Class M % Mi K 1 i'A 2 2H 3 3A 4 5 6 0.500 0.0025 0.001 0.625 0.0025 0.001 0.875 0.003 0.001 1.125 0.0035 0.0015 1.375 0.004 0.0015 1.625 0.0045 0.002 2.125 0.005 0.002 2.625 0.005 0.002 3.125 0.005 0.002 3.625 0.005 0.002 4.125 0.005 0.002 5.125 0.005 0.002 6.125 0.005 0.002 0.049 0.004 0.049 0.004 0.065 0.0045 0.065 0.0045 0.065 0.0045 0.072 0.005 0.083 0.005 0.095 0.005 0.109 0.005 0.120 0.005 0.134 0.006 0.160 0.006 0.192 0.006 0.035 0.0035 0.040 0.0035 0.045 0.004 0.050 0.004 0.055 0.0045 0.060 0.0045 0.070 0.005 0.080 0.005 0.090 0.005 0.100 0.005 0.110 0.005 0.125 0.006 0.140 0.006 0.025 0.0025 0.269 0.198 0.028 0.0025 0.344 0.285 0.032 0.003 .0.641 0.455 0.035 0.0035 0.839 0.655 0.042 0.0035 1.04 0.884 0.049 0.004 1.36 1.14 0.058 0.0045 2.06 1.75 0:065 0.0045 2.92 2.48 0.072 0.0045 4.00 3.33 0.083 0.005 5.12 4.29 0.095 0.005 6.51 5.38 0.109 0.005 9.67 7.61 0.122 0.005 13.87 10.20 0.144 0.203 0.328 0.464 0.681 0.94 1.46 2.03 2.68 3.58 4.66 6.65 8.91 From Standard Specifications for Copper Water Tube of the American Society for Testing Materials, AJi.T.M. Designation B88-33. Expansion joints of the slip-sleeve, diaphragm, or corrugated types made of copper, rubber, or other gasket material are all used for taking up expansion, but generally only for low pressures or where the inherent flexibility of the pipe cannot readily be used as in underground steam or hot water distribution lines. Swivel joints are used extensively in low-pressure steam and hot water heating systems and in hot water supply lines. The swivel joints absorb the expansive movement of the pipe by the turning of threaded joints. In many cases the straight pipe in the offset of a swivel joint is sufficiently flexible to take up the expansion without developing enough thrust to produce swiveling in the threaded joint. This is preferable since con- 361 Heating Ventilating Air Conditioning Guide 1938 tinued turning in the threaded joint may in time result in a leak, par ticularly when the pressure is high. The amount of elongation which a swivel joint can take up is controlled by the length of the swing piece employed and by the lateral displacement which is permissible in the long pipe runs. Probably the most economical method of providing for expansion, of piping in a long run is to take advantage of the directional changes which must necessarily occur in the piping and proportion the offsets so that sufficient flexibility is secured. Ninety-degree bends with long, straight tangents in either a horizontal or a vertical plane are an excellent means for securing adequate flexibility with larger sizes of pipe. When flexi-. bility cannot be obtained in this manner, it is necessary to make use of some type of expansion bend. The exact calculation of the size of ex pansion bends required to take up a given amount of thermal expansion is relatively complicated1. The following approximate method, however, has been found to give reasonably good results and is deemed to be sufficiently accurate for most heating work. Fig. 1 shows' several types of expansion bends commonly used for taking up thermal expansion. The amount of pipe, L, required in each of these bends may be computed from the following formula: ; L = 6.16 . (2) where L = length of pipe, feet. ' D = outside diameter .of the pipe used, inches. A = the amount of expansion to be taken up, inches. : This formula, based on the use of mild-steel pipe with wall thicknesses not heavier than extra-strong, assumes a maximum safe value of fiber stress of 16,000 lb per square inch. When square type bends are used, the width of the bend should not exceed about two times the height. It is further assumed that the corners are made with screwed or flanged elbows or. with arcs of circles having radii five to six times the pipe diameter. All risers must be anchored and safeguarded so that the difference in *Piping Handbook, by Walker and Crocker, and A' Manual for the Design of Piping for Flexibility by the Use of Graphs, by E. A. Wert, S. Smith, and E. T. Cope, published by The Detroit Edison Company. - 362 Chapter 18. Pipe, Fittings. Weeding length when hot from the length when cold shall not disarrange the normal and orderly provisions for drainage of the branches. It is especially necessary with light-weight radiators so to anchor the piping and so to give it freedom for expansion that no strain therefrom shall be allowed to distort the radiators. When expansion strains from the pipes are permitted to reach these light metal heaters they usually emit sounds of distress which are exceedingly troublesome. Table 6. Thermal Expansion of Pipe in Inches per 100 Ft3 (For superheated, steam and other.fluids refer to temperature column) ,j*p"sf1v* j8f-jj1 Saturated Steam Elongation m Inches pee 100 ft from --20 F UP Vacuum laches of Hg. Pressure Pounds _ Per Square Inch Gage Tem perature Degrees Fahren heit CastIron Pipe Steel Pipe Wrought Iron Pipe Copper . Pipe Saturates Steam Elongation in Inches per 100 ft from --20 F UP Tem perature Degrees Fahren heit CastIron Pipe -Steel Pipe Wrought Iron Pipe Copper Pipe 29.39. ______ 28.89 -27.99 ______ 26.48 ____ ... 24.04 20.27 __ 14.63 ______ 6.45 ____ 2.5 10.3 20.7 34.5 52.3 74.9 103.3 138.3 180.9 232.4 293.7 366.1 451.3 550.3 -20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 . 360 380 400 420 440 460 480 0 0 0 0 664.3 0.127 0.145 0.152 0.204 795.3 0.255 0.293 0.306 6.442 945.3 0.390 0.430 0.465 0.655 1115.3 0.518 0.593 0.620 0.888 1308.3 0.649 0.725 0.780 1.100 1525.3 0.787 0.898 0.939 1.338 1768.3 0.926 1.055 1.110 1.570 2041.3 1.051 1.209 1.265 1.794 2346.3 1.200 1.368 1.427 2.008 2705 1.345 1.528 1.597 2.255 3080 1.495 1.691 1.778 2.500 1.634 1.852 1.936 2.720 1.780 2.020 2.110 2.960 1.931 2.183 2.279 3.189 2.085 2.350 2.465 3.422 2.233 2.519 2.630 3.665 2.395 2.690 2.800 3.900 2.543 2.862 .2.988 4.145 2.700 3.029 3.175 4.380 2.859 3.211 3.350 4.628 3.008 3.375 3.521 4.870 3.182 3.566 3.720 .5.118 3.345 3:740 3.900 5.358 3.511 3.929 4.096 5.612 3.683 4.100 4.280 5.855 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800 820 840 860 880 900 920 940 960 980 1000' 3.847 4.020 4.190 4.365 4.541 4.725 4.896 5.082 5.260 5.442 5.629 5.808 6.006 6.200 6.389 6.587 6.779 6.970 7.176 7.375 7.579 7.795 7.989 8.200 8.406 8.617 4.296 4.477 6.110 4.487 4.677 6.352 4.670 4.866 6.614 4.860 5.057 6.850 5.051 5.268 7.123 5.247 5.455 7.388 5.437 5.660 7.636 5.627 5.850 7.893 5.831 6.067 8:153 6.020 6.260 8.400 6.229 6.481 8.676 6.425 6.673 8.912 6.635 6.899 9.203 6.833 7.100 9.460 7.046 7.314 9.736 7.250 7.508 9.992 7.464 7.757 10.272 7.662 7.952 10.512 7.888 8.195 10.814 8.098 8.400 11.175 8.313 8:639 11.360 8.545 8.867 11.625 8.755 9.089 11.911 8.975 9.300 12.180 9.196 9.547 12.473 9.421 9.776 12.747 "From Piping Handbook, by Walker and Crocker. This table gives the expansion from -- 20 F to the temperature in question. To obtain the amount of expansion between any two temperatures take the difference between the figures in the table for those temperatures. For example, if a steel pipe is inatallpH at a temperature of 60 F and is to operate at 300 F. the expansion would be 2.519 -- 0.593 -- 1.926 in. PIPE THREAPS All-, threaded pipe for heating and ventilating installations uses the American Standard taper pipe thread which is made with a taper of 1 in 16 measured on the diameter of the pipe so as to secure a tight joint. Threads of fittings are tapped to the same taper. The number of threads per inch varies with the different pipe sizes. All threaded pipe should be -- made ,Up with- -a. thread-paste suitable for the service under which the - pipe is to be used. . .: r . ; 363 Heating Ventilating Air Conditioning Guide 1938 HANGERS AND SUPPORTS Heating system piping requires careful and substantial support. Where changes in temperature of the line are not large, such simple methods of support may be utilized as hanging the line by means of rods or perforated strip from the building structure, or supporting it by brackets or on piers. When fluids are conveyed at temperatures of 150 F or above, however, hangers or supporting equipment must be fabricated and assembled to permit free expansion or contraction of the piping. This can be accom plished by the use of long rod hangers, spring hangers, chains, hangers or supports fitted with rollers, machined blocks, elliptical or circular rings of larger diameter than the pipe giving contact only at the bottom, or trolley hangers. In all cases, allowance should be made for rod clearance to permit swinging without setting up severe bending action in the rods. For pipes of small size, perforated. metal strip is often used. For horizontal mains, the rod or strip usually is attached to the joists or steel work of the floor above. For long runs of vertical pipe subject to con siderable thermal expansion, either the hangers should be designed to prevent excessive load on the bottom support when expansion takes place, or the bottom support should be designed to withstand the entire load. TYPES OF FITTINGS Fittings for joining the separate lengths of pipe together are made in a variety of forms, and are either screwed or flanged, the former being generally used for the smaller sizes of pipe up to and including 3J^ in., and the latter for the larger sizes, 4 in. and above. Screwed fittings of large size as well as flanged fittings of small, size are also made and are used for certain classes of work at the proper pressure. The material used for fittings is generally cast iron, but in addition to this malleable iron, steel and steel alloys are also used, as well as various grades of brass or bronze. The material to be used depends on the character of the service and the pressure. As in the case of pipe, there are several weights of fittings manufactured. Recognized American Standards for the various weights are as follows: Cast-iron pipe flanges and flanged fittings for 25,1b (sizes 4 in. and larger), 125 lb, and 250 lb maximum saturated steam pressure. Malleable iron screwed fittings for 150 lb maximum saturated steam pressure. Cast-iron screwed fittings for 125 and 250 lb maximum saturated steam pressure. Steel flanged fittings for 150 and 300 lb maximum steam service pressure. , The allowable cold water working pressures for these standards vary from 43 lb for the 25 lb standard to 500 lb for the 300 lb steel standard. Screwed fittings include: nipples or short pieces of pipe of varying lengths; couplings, usually of wrought iron only; elbows for turning angles of either 45 deg or 90 deg; return bends, which may be of either the .close or open pattern; and may be cast with either a back or side outlet; tees; crosses; laterals or Y branches; and a variety of plugs,.bushings, caps, lock-nuts, flanges and reducing fittings. Reducing fittings as well as bushings, both of which are used in changing from one pipe size to another; 364 Chapter 18. Pipe, Fittings, Welding may have the smaller connection tapped eccentrically to permit free drain age of the water of condensation in steam lines or free escape of air in water lines. Fittings for copper tubing are available in the soldered, flared, or com pression types. Illustrations of each of these types is shown in Fig. 2. Fittings for copper pipe of IPS dimensions are available in screwed or soldered types of connection. The compression type fitting is generally limited to smaller size tubing while the flared and soldered types are used in large and small sizes. While no effort has been made to standardize dimensions of flared tube fittings, manufacturers have quite generally used 5.^4 .E. standard dimensions. Flared tube fittings are widely used in refrigeration work and the use of S.A.E. dimensions and a 45 deg flare renders most fittings SOLDER-TYPE FITTING REFRIGERATOR TYPE FLARED-TU8JNG FITTINGS SAE COMPRESSION TUBING FITTINGS FLARED-TU8ING FITTINGS Fig. 2. Copper or Brass Tubing Fittings * interchangeable, although for refrigeration use, thread fits and tolerances on thread gages must be maintained within close limits. Ammonia pipe fittings made of cast iron are extensively used in handling refrigerants in larger installations. Until recently, no standard dimensions were adhered to in the manufacture of ammonia flanged fittings or com panion flanges with the result that fittings of different manufacturers were not interchangeable. A subcommittee of A .S~4 Sectional Com mittee B16 has prepared proposed American Standard dimensions for ammonia flanged fittings and companion flanges for maximum service pressure of 300 lb per sq in. which will be available soon. Thread Connections . Threads used for fittings are the same American Standard taper pipe threads as those used for pipe, and unless otherwise ordered, right-hand 365 . Heating Ventilating Air Conditioning Guide 1938 threads are used. To facilitate drainage, some elbows have the thread tapped at an angle to provide a pitch of the connecting pipe of in. to the foot: These elbows are known to the trade as pitched elbows and are commercially available. Malleable iron fittings, like brass fittings, are cast with a round instead of a flat band or bead, or with no bead at all. Fittings are designated as male or female, depending on whether the threads are on the outside or inside, respectively. Flanged fittings are generally used in the best practice for connecting all piping above 4 in. in diameter. While screwed fittings may be used for the larger sizes and are satisfactory under the proper working con ditions, it will be found difficult either to make or to,break the joints in these large sizes. A number of different flange facings in common use are plain face, raised face, tongue and groove, and male and female. Cast-iron fittings for 125 lb pressure and below are normally furnished with a plain face, while the 250 lb cast-iron fittings are supplied with a Hs-inch raised face. The standard facing for steel flanged fittings for 150 and 300 lb is a Jf6-inch raised face although these fittings are obtainable with a variety of facings. The gasket surface of the raised face may be finished smooth or may be machined with concentric or spiral grooves often referred to as serrated face or phonograph finish, respectively. The dimensions of elbows, tees and crosses for 125 lb cast-iron screwed fittings are given in Table 7, whereas the dimensions for 125 lb cast-iron flanged fittings are given in Tables 8 and 9. For low temperature service not to exceed about 220 F, a number of paper or vegetable fiber gasket materials will prove satisfactory; for plain raised face flanges, rubber or rubber inserted gaskets are commonly employed. Asbestos composition gaskets are probably the most widely used, particularly where the temperature exceeds 250 F. Jacketed asbestos and metallic gaskets may be used for any pressure and tem perature conditions, but preferably only with a relatively narrow recessed facing. WELDING Erection of piping in heating and ventilating installations by means of fusion welding has been commonly accepted in the past few years as a competitive method to the screwed and flanged joint. Since the question of economy of welding as against the use of screwed and flanged fittings is dependent on the individual job, the use of welding is generally recom mended on the basis of a greatly reduced cost of maintenance and repair, of less weight resulting from, the use of a lighter-weight pipe, and of increased economy in pipe insulation, hangers, and supports rather than on the basis of any economy that might be effected in actual erection by welding. ... . Fusion welding, commonly used in erection of piping, is defined as the process of joining metal parts in the molten, or molten and vapor states, without the application of mechanical pressure or blows. Fusion welding embraces, gas welding and electric arc welding, both of which are com monly used to produce acceptable welds. 366 Chapter 18. Pipe, Fittings, Weeding Welding application requires the same basic knowledge of design as do the other types of assembly, but in addition, requires a generous know ledge of. the sciences involved, particularly as to welding qualities of metal, their reaction to extremely high. temperatures, and the ability to determine and use only the best quality, welding rods. This requirement applies equally to employer and employee with the employer accepting Table 7. 45Tentative American Standard Dimensions of Elbows, Deg Elbows, Tees, and Crosses (Straight Sizes) for 125 Lb Cast-Iron Screwed Fittings f-A-W Elbow A Nominal Pipe Sob CENTER to End, Elbows, Tees and Crosses c. B B Center to End, 45 Deg Elbows Length of Thread Min. Width or Band, Min. F Inside Diameter of Pitting Min. Max. <7 B Metal Thickness, Mm. Outbids Diameter of Band. Mm. H S. .* ill 2 3 m 4 5 6 8 10 12 14 O.D. 16 O.D. 0.81 0.95 1.12 1.31 1.50 1.75 1.94 2.25 2.70 3.08 3.42 3.79 4.50 5.13 6.56 8.08 9.50 10.40 11.82 0.73 0.80 0.88 0.98 1.12 1.29 1.43 1.68 1.95 2.17 2.39 2.61 3.05 3.46 4.28 5.16 5.97 JU1 dimensions given in inches. 0.32 0.36 0.43 0.50 0.58 0.67 0.70 0.75 0.92 0.98 1.03 1.08 1.18 1.28 1.47 1.68 1.88 2.00 2.20 0.38 0.44 0.50 0.56 0.62 0.69 0.75 0.84 0.94 1.00 1.06 1.12 1.18 1.28 1.47 1.68 1.88 2.00 2.20 0.540 0.584 0.675 0.719 0.840 0.897 1.050 1.107 1.315 1.385 1.660 1.730 1.900 1.970 2.375 2.445' 2.875 2.975 3.500 3.600 4.000 4.100 4.500 4.600 5.563 5.663 6.625 6.725 8.625 8.725 10.750 10.850 12.750 12.850 14.000 14.100 16.000 16.100 0.110 0.120 0.130 0.155 0.170 0.185 0.200 0.220 0.240 0.260 0.280 0:310 0.380 0.430 0.550 0.690 0.800 0.880 1.000 0.93 1.12 1.34 1.63 1.95 2.39 2.68 3.28 3.86 4.62 5.20 5.79 7.05 8.28 10.63 13.12 15.47 16.94 19.30 ---------------------------- - _ . ____ _ w.v v.upiu^gi ouuuiu select ms wcicin mechanics with good judgment, provide them with first-class equipmei and tools, arrange for their training and use of acceptable workmansh: standards, and at regular intervals subject their work to prescribed test Industry will not accept the employment of mechanics of undetermine ability nor on the basis of past experience. Neither does industry accej the statement that a weld is only as good as the workman who makes i The control Codes now in process of adoption will be the law govemir ' 367 Heating VentiIiAting Air Conditioning Guide 1938 the use of the welding process. These Codes prohibit individual practices contrary to their specified procedure and rules of control, and this is predicated upon the sound requirement that the employer must assume full responsibility for the deposited weld. It is advisable that this management responsibility be included in all welding specifications and that authoritative standards of workmanship also be specified. The standards of workmanship for this industry are as set forth in the Standard Manual on Pipe Welding of the Heating, Piping and Air Conditioning Contractors National Association. A complete line of manufactured steel welding fittings is now available Table 8. American Standard Dimensions of Tees and Crosses (Straight Sizes) for 125 Lb Cast-Iron Flanged Fittings ~^ Chapter 18. Pipe. Fittings, Welding with plain ends machine beveled for welding and with radii similar to short and long radius flanged fittings. Some typical types of these fittings are shown in Fig. 3. They are made in pipe sizes % to 24 in., standard and extra heavy, in steel, wrought iron; brass, copper, and special alloys. Socket welding fittings of forged steel are also commercially available. These fittings have a machined recess into which the pipe slips. A fillet weld between the pipe and socket edge provides a pressure-tight joint. A proposed American Standard containing dimensions of steel welding-neck flanges for pressures up to 1500 lb per sq in. has been developed in A.S.A Table 9. American Standard Dimensions of Elbows for 125 Lb Cast-Iron Flanged Fittings All dimensions given in inches. Size of all fittings listed indicates nominal inside diameter of port. . bTees, side outlet tees, and crosses. 16 in. and smaller, reducing on the outlet, have the same dimensions center to face, and face to face as straight size fittings corresponding to the size of the larger opening. Sizes 18 in. and larger, reducing on the.outlet, are made in two lengths, depending on the size of the outlet. Tees and crosses, reducing on run only, carry same dimensions center to face and face to face as a straight size fitting of the larger opening. ' .. 368 ! s Nominal Pipe Size* ABc Center to Face Elbow b-o-d Center to Face Long Radius Elbow b-o-d Center to Face 45 Dbg Elbow c Diamete or Flange mi iM 2 3 3M 4 5 6 8 10 12 14 O.D. 16 O.D. 18 O.D. 20 O.D. 24 O.D. 30 O.D. 36 O.D. 42 O.D. 48 O.D. 33%M 4m 5 5M 6 6M 7M 8 9 11 12 14 15 16M 18 22 25 28 31 34 5 6 7 7% 8M 9 10M 11M 14 16M 19 21K 24 26 29 . 34 41^ 49 56H 64 m 2m m 3 3 3M m* 4 5 5M 6M 7M TMt 8 8M 9H 11 15 18 21 24 m m 5 6 7 7M 8M 9 10 11 13M 16 19 21 23M 25 ` 27M ' 32 38M 46 53 59M Thickness or Flange, Mm. Metal Thickness or Boot, Mm. Ms H Me % 1Me X . me mmm1mmmeee lHe lMe imme 2m 2% 2H 2K Vie Me Me Me Me Me Me M M Me % M me M 1 me m m IMe m ime 2 "Size of all fittings listed indicates nominal inside diameter of port. bReducing elbows and side outlet elbows carry same dimensions center to face as straight sizeelbows corresponding to the size of the larger opening. . "Special degree elbows, ranging from 1 to 45 deg. inclusive, have the same center to face dimensions as given for 45 deg elbows and those over 45 deg and up to 90 deg, inclusive, shall have the same center to . face dimensions as given for 90 deg elbows. .The angle designation of an elbow is its deflection from straight line flow and is the angle between the flange faces. . dSide outlet elbows shall have all openings on intersection center-lines. 369 Heating Ventilating Air Conditioning Guide 1938 Sectional Committee B16. Tables 10 and 11 give these dimensions for welding-neck flanges suitable for 150 and 300 lb per sq in. gage pressure. VALVES Valves are made with both threaded and flanged ends for screwed and bolted connections just as are pipe fittings. . The material used for valves of small size is generally brass or bronze for low pressures and forged steel for high pressures, while in the larger sizes either cast-iron, cast-steel or some of the steel alloys are employed. Chapter 18. Pipe, Fittings. Welding the valve is open or closed, although space limitations may prevent its use. The globe valve is less expensive to manufacture than the gate valve, but its peculiar construction offers a high resistance to flow and may prevent complete drainage of the pipe line. These objections are of particular importance in heating work. Check valves are automatic in operation and permit flow in only one direction, depending for operation on the difference in pressure between Table 10. Proposed Dimensions of Steel Welding Neck Flanges for Maximum Steam Service Pressure of 150 Lb per Sq In. (Gage) at a Temperature of 500 F, and 100 Lb at 750 F a. Typical Short Radius Elbows -- b. Teb . c. Forged Cap d. Concentric Reducer Fig. 3. Typical Welding Fittings e. End Closure Practically all iron or steel valves intended for steam or water work are bronze-mounted or trimmed. Brass, bronze, and iron valves are generally designed for standard or extra heavy service, the former being used up to 125 lb and the latter up to 250 lb saturated steam working pressure, although most manufacturers also make valves for medium pressure up to 175 lb steam working pres sure. The more common types are gate-valves or straightway valves, globe valves, angle valves, check valves and automatic valves, such as reducing and back-pressure valves. . Gate valves are the most frequently used of all valves since in their open position the resistance to flow is a minimum. These valves may be secured with either a rising or a non-rising stem, although in the smaller sizes the rising stem is more commonly used. The rising stem valve is desirable because the positions of the handle and stem indicate whether 370 N.. OMZNAL Pbpb Size Diameter or Flange Thickness or Flo. Min. Diameter or Hub Hub Diail Beginning or Chamfer Length Thru Hub 0QX HY 1< m: ix 2 2X : 3 m 4 5 6 8. 10 . .12 14 O D 16 0. D. 18 O. D. 200. D. 24 0. D. 4X 4X 5 6 7 m sx 9 10 11 im 16 --19 21 23H 25 27^ 32 s* iWe : W8 * : We We 3%s 4K in:We We We 4'H %.1 mi We 12 W 14JS 1X 1SK We 18 We iw 1 Hi 22 W 26x 1.32 1.66 1.90 2.38 2.88 3.50 4.00 4.50 5.56 6.63 8.63 10.75 12.75 14.00 16.00 18.00 20.00 24.00 is IS' 2X 2X J6 3 m 3X 4 4 *X 5 5 SX 5% 6 Dux roB Standard Pipe 4. 11.05 1.38 : 1.61 2.07 2.47 3.07 '3.55 4.03 5.05 6.07 7.98 10.02 12.00 13.25 15.25 17.25 19.25 23.25 Diam. or Bolt Circle No. or Bolts !4 4 4 4 4 4 8 8 8 '8 8 12 12 12 16 16 20 20 Size or X X X X X X X X X X X X 17A 1 IX m m Ail dimesisions giveii in inches. A raised face of Vi in. is included in thickness offlange minimum. It is recommended that the taper of the hub should not exceed 6 deg for a reasonable distance bach of the chamfer in order to reduce the heat transfer while welding. - __ _______ a. &ic> iwyj jjiimapai iunas oi ciiecic valves are the swing check in which a flapper is hinged to swing back and forth, and the lift check in which a dead weight disc moves vertically from its seat. Valves commonly used for controlling steam or water supply to radi ators constitute a special class since they are manufactured to meet heating system requirements. These , valves are generally of the angle type and are usually made of brass. Graduations on the heads or lever 371 Heating Ventilating Air Conditioning Guide 1938 handles are often supplied to indicate the relative opening of the valve in any position. Standard roughing-in dimensions for angle-type valves are given in Table 12. Automatic control of steam supply to individual radiators can be Table 11. Proposed Dimensions of Steel Welding Neck Flanges for Maximum Steam Service Pressure of 300 Lb per Sq In. (CageI at a Temperature of 750 F Chapter 18. Pipe, Fittings. Wedding for use in hot water heating systems are of less complex design, one type consisting of a simple butterfly valve, and another of a quick opening type in which a part in the valve mechanism matches up with an opening in the valve body. . In one-pipe steam-heating systems, automatic air valves are required at the radiators. Two common types of air valves available are the vacuum type and the straight-pressure type. Vacuum valves permit the expulsion of air from the radiators when the steam pressure rises and, in addition, act as checks to prevent the return of air into the radiator when Table 12. Standard Roughing-in Dimensions Angle Type Valves Nominal Pipe See *2 m 3 3H 4 5 6 8 10 12 14 0. D. 16 O. D. 18 O. D. 20 0. D. 24 O. D. Diam. OP Flange Thick ness o*p Flange Min. Diam. op Hub Hub Diam. Beginning op Chamfer 0 0X H 6A m 8M 9 10 11 12H 15 17H 20'A 23 25^ 28 30H 36 Vs 3^6 1 3lHe m iVs lMe SM m 1 s% m7 iKe m m iom m l2Vs 2 14M 2Vs 16H V/4. 19 m 21 VA 23Vs m Ws 2.38 2.88 3.50 4.00 4.50 5.56 6.63 8.63 10.75 12.75 14.00 16.00 18.00 20.00 24.00 Length Thbu Hub r 2% 3 3Vs 3Ms 3Vs 3Vs 3J4 m iVs SVs SVs S% 6% 6Vs 6Vs Diam. fob Standard Pipe A 2.07 2.47 3.07 3.55 4.03 5.05 6.07 7.98 10.02 12.00 13.25 15.25 17.25 19.25 23.25 Diam. fob Extra Strong Pipe Diam. op Bolt Circle No. OP Bolts A I.94 2.32 2.90 3.36 3.83 4.81 5.76 7.63 9.75 II.75 5 SVs 6Vs m m 9% ioa 13 15^ 17% 20% 22H 24% 27 32 8 8 8 8 8 8 12 12 16 16 20 20 24 24 24 Size op Bolts As % H % % % Vi Vs 1 IVs m m m 1M . *For sizes below 2 in. use dimensions of 600 lb flanges. \ All dimensions given in inches. _ A raised face of % in. is included in thickness offlange minimum. Jt is recommended that the taper of the hub should not exceed 6 deg for a reasonable distance back of the chamfer in order to reduce the heat transfer while welding. - effected by use of direct-acting radiator valves having a thermostatic element at the valve, or near to it. The direct-acting valve is usually an angle-type valve containing a thermostatic element which permits the flow of steam in accordance with room temperature requirements. These valves usually are capable of adjustment to permit variation in room temperature to suit individual taste. Ordinary steam valves may be used for hot water service by drilling a Jf6-in. hole through the web forming the seat to insure sufficient circulation to prevent freezing when the valve is closed. Valves made particularly 372 . The standardization of the Roughing-in Dimensions of Angle Steam and Hot Water, and Modulating Radiator Valves was made possible by the cooperation of the Manufacturers Standardization Society of the Valves and Fittings Industry. a vacuum is formed by the condensation of steam after the supply pressure has dropped. Ordinary air valves permit the expulsion of air from the radiator when steam is supplied under pressure, but when the pressure dies down and a vacuum tends to be formed the air is drawn back into the radiator. A system operating continuously or intermittently and supplied with vacuum valves will generally heat more quickly than one provided with non-vacuum air valves; thus, it will effect considerable economy of fuel because the idle period during which no heat is delivered is shortened. In those cases, where a system is equipped with vacuum air valves and which has been cold for several days, the system will probably have an 373 Heating Ventilating Air Conditioning Guide 1938 internal pressure within the radiator closely approaching atmospheric. At such times, the vacuum valve will not vent the system any more rapidly than the ordinary type. Automatic air valves are provided with a float to close them in case the radiator becomes flooded with water because it does not drain properly. CORROSION2 Corrosion is sometimes encountered in heating work on the outside of buried pipes or the inside of steam heating systems; it is seldom ex perienced in hot water heating systems unless the water is frequently renewed. Piping buried in the ground is quite successfully protected by coatings of the asphaltic type which are usually applied hot and often reinforced with fabric wrappings. Galvanizing by the hot-dip process and painting with specially prepared mixtures also afford some protection. Internal corrosion in steam heating systems occurs principally in the . condensate return pipes and is nearly always caused by oxygen or carbon dioxide, or both, in'solution in the condensate. Oxygen may enter the heating system with the steam, owing to its presence in the boiler-feed water, or it may enter as air through small leaks, particularly in systems . which operate at sub-atmospheric pressures. When a steam heating system is operated intermittently, air rushes in during each shutdown , period and oxygen is absorbed by the condensate which clings to the interior surfaces of the pipes and radiators. The rate of corrosion depends upon the amounts of oxygen and carbon dioxide present in solution, upon the operating temperature, and upon the length of time that the pipe surfaces are in contact with gas-laden condensate. Another possible cause of corrosion is a flow of electric current some times resulting from faulty electrical circuits which should be corrected. Electrolytic corrosion also may occur because of the presence of two dis similar metals, such as brass and iron, but the condensate in practically all steam heating systems is such a weak electrolyte that this cause of corrosion is very infrequent. If trouble is experienced from corrosion, oxygen should be eliminated from the feed water by proper deaeration with commercial apparatus. The elimination of the oxygen due to air leakage is more difficult because of the multitude of small leaks which exist around valve stems and in pipe joints. In vacuum systems, however, dn attempt should be made to minimize such leakage. ' Carbon dioxide in varying amounts is contained in steam produced from the majority of water supplies. It is formed from the breaking down . of carbonates and bicarbonates which are present in nearly all natural .. waters. It can be partly removed by chemical treatment and deaeration; but there is no simple method whereby it can be entirely eliminated. These gases cause corrosion only when in solution in the condensate; ; ' when they are mixed with dry steam their corrosive effect is negligible. *New Light on Heating System Corrosion, by J. H. Walker {Heating and Ventilating, May, 1933). Cor- rosion Studies in Steam Heating Systems, by R. R. Seeber, F. A. Rohrman and G. E. Smedberg, (A.S.H.V.E. Transactions. Vol 40, 1934, p. 253). Corrosion Studies in Steam Heating Systems, by R. R. Seeber. . -- F. A. Rohrman and G. E. Smedberg, (A.S.H.V.E. Transactions. Vol. 42, 1936, p. 263). Corrosion Studies * in Steam Heating Systems, by R. R. Seeber and Margaret R. Holley (A.S.H.V.E. Journal Section, , Heating, Piping and Air Conditioning, June, 1937, p. 387). ' - 374 . , : i f / Chapter 18. Pipe, Fittings, Welding The amount of gas in solution depends upon the partial pressure of that gas in the atmosphere above the surface of the solution, in accordance with the well known physical law of Henry and Dalton*. The exact application of this law, however, assumes equilibrium conditions which do not always exist under the flow conditions prevailing in a heating system. Distinction should be made between corrosion in heating systems proper and in the condensate discharge lines from other apparatus using steam, such as water heaters, kitchen equipment, and sterilizers. Experience has shown that in heating systems the partial pressures of the gases do not reach such magnitudes as to cause harmful amounts of gas to become dissolved in the condensate when steam supplies are of reasonable purity. In other kinds of steam-using apparatus which are not ordinarily well vented, the gases tend to accumulate in the steam space and to become dissolved in the condensate in appreciable concentrations. Consequently, corrosion is frequently observed in the condensate discharge lines from such apparatus, but this does not necessarily indicate that equally serious corrosion is taking place in the heating system supplied with steam from the same source; . When corrosive conditions are believed to exist, their seriousness should be determined by actual measurement, rather than by inference from isolated instances of pipe failures. The National DistrictHeating Associa tion has perfected a corrosion tester for measuring the inherent corrosive ness of existing conditions. This corrosion tester consists of a frame sup porting three coils of wire which are carefully weighed. After the tester has been inserted in the pipe line for a definite length of time, the loss of weight of the coils, referred to an established scale, indicates the relative corrosiveness of the condensate. Accompanying such corrosion measure ments, a careful chemical analysis should be made of the condensate, and the findings will serve as a basis for an intelligent study of the problem. Corrosion, if found to exist, can be lessened or overcome by several means. If the steam supply is found to be definitely contaminated, proper chemical treatment of the water, followed by deaeration, is an obvious remedy. The leaks in the piping system, particularly in vacuum systems, should be stopped so far as is practicable. . Some success has been reported with the use of inhibitors, chief among which are oil, and sodium silicate. Oil may be fed into the main steam- supply pipe by means of a sight-feed lubricator. The type of oil known as 600-W is usually recommended. In the present state of knowledge on this point, the quantity to be fed can best be determined by trial. The use of sodium silicate, fed in a similar manner, is reported to be successful but it has not been widely used. . In view of the fact that corrosion is most frequently found in the return lines from special equipment, which constitute a relatively small part of the total piping in a building, a simple solution of the corrosion problem may be to use non-corroding materials in those certain portions of the piping system, since the higher cost will usually be an unappreciable portion of the total. Brass and copper are undoubtedly less subject to . F?n,,dJa"en`a' Considerations of Corrosion in Steam and Condensate Lines, by R. E. Hall and A. R. Mumford (A.S.H.V.E. Transactions. Vol. 38. 1932, p. 121). 375 Heating Ventilating Air Conditioning Guide 1938 this type of corrosion than the ferrous metals, and considerable attention is now being given to corrosion-resistant linings for ferrous pipe. Castiron pipe, sometimes alloyed with other metals, also deserves con sideration. PROBLEMS IN PRACTICE 1 What is the meaning of IPS brass pipe? It means that the brass pipe has the same external diameter as steel pipe in the same nominal pipe size and that the wall thickness is sufficient to allow cutting of threads for use with standard size threaded fittings. 2 Why is thin-walled copper pipe made up with sweated joints? If the pipe were threaded it would be necessary to use at least standard-weight wall thickness on account of the metal removed in threading. Flared ends with coupling nuts may be used, but this construction is expensive and hard to keep tight. 3 $ How are pipes designated in diameters of 12 in. and less? By weight and nominal size, referring to the approximate inside diameter, 4 # How are pipe sizes designated in diameters of 14 in. and more? By wall thickness and outside diameter. 5 Why are expansion joints required in steam pipes? To care for the change in length of the line brought about by a change in temperature. 6 What devices are used for taking up expansion? Expansion joints, swivel joints, and the inherent flexibility of the pipe itself. - 7 0 Where are swivel joints principally used? - In branch connections to radiators, and in the risers of multi-story buildings where they are installed between the floor joists. 8 Name three grades of American Standard screwed pipe fittings. 125-lb cast-iron, 150-lb malleable iron, and 250-lb cast-iron. 9 In what sizes are American Standard cast-iron flanges and flanged fittings for 25-lb saturated steam pressure made? \ . In nominal sizes from 4 in. to 72 in., inclusive. 10 What fittings are generally used for threaded connections in low pressure heating systems? . Cast-iron. .. * 376 Chapter 19 GRAVITY WARM AIR FURNACE SYSTEMS Design Procedure, Estimating Heating Requirements, Leader Pipe Sizes, Proportioning Wall Stacks, Register Selections, Recirculating Ducts and Grilles, Furnace Return Connection, Furnace Capacity, Examples, Booster Fans WARM air heating systems of the gravity type are described in this chapter1, and those of the mechanical type are described in Chapter 20. In the gravity type, the motive head producing flow depends upon the difference in weight between the heated air leaving the top of the casing and the cooled air entering the bottom pf the casing, while in the mechanical type a fan may supply all or part of the motive head. Booster fans are often used in conjunction with gravity-designed systems to increase air circulation. ' In general, a warm-air furnace heating plant consists of a fuel-burning furnace or heater, enclosed in a casing of sheet metal or brick, which is placed in the basement of the building. The heated air, taken from the top or sides near the top of the furnace casing, is distributed to the various rooms of the building through sheet metal warm-air pipes. The warm-air pipes in the basement are known as leaders, and the vertical warm-air pipes which are run in the inside partitions of the building are called stacks. The heated air is finally discharged into the rooms through registers which are set in register boxes placed either in the floor or in the side wall, usually at or near the baseboard. The air supply to the furnace may be taken (1) entirely from inside the building through one or more recirculating ducts, (2) entirely from outside the building, in which case no air is recirculated, or (3) through a combination of the inside and the outside air supply systems. DESIGN PROCEDURE The design of a furnace heating system involves the determination of the following items: 1. Heat loss in Btu from each room in the building. 2. Area and diameter in inches of warm-air pipes in basement (known as leaders). 3. Area and dimensions in inches of vertical pipes (known as wall stacks). ' 4. Free and gross area and dimensions in inches of warm-air registers. 5. Area and dimensions of recirculating or outside air ducts, in inches. 6. Free and gross area and dimensions in inches of recirculating registers. *AU figures and much of the engineering data which follow are from University of Illinois, Engineering vS. Day1 and Konzo?' War" ^ FUnlaCeS and Sy5tems- by 377 Heating Ventilating Air Conditioning Guide 1938 7. Size of furnace necessary to supply the warm air required to overcome the heat loss from the building. This size should include square inches of leader pipe area which the furnace must supply. It is also desirable to call for a minimum bottom fire-pot diameter in inches, which is the nominal grate diameter. . 8. Area and dimensions in inches of chimney and smoke pipe. If an unlined chimney is to be used, that fact should be made clear. The heat loss calculations should be made in accordance with the procedure outlined in Chapter 7, taking into consideration the trans mission losses as well as the infiltration losses. LEADER PIPE SIZES In a gravity circulating warm-air furnace system the'size of the leader to a given room depends upon the temperature of the warm air entering the room at the register. A reasonable air temperature at the registers must, therefore, be chosen before the system can be designed.- The National Warm Air Heating and Air Conditioning Association has ap proved an air temperature of 175 F at the registers as satisfactory for design purposes. At this temperature, the heat-carrying capacity (heat available above 70 F) per square inch of leader pipe per hour for first, second or third floors is shown by Fig. 1 at 175 F to be 105, 170 and 208 Btu, respectively. For average calculations, the values 111, 166 and 200 will simplify the work and may be satisfactorily substituted for these heat-carrying capacities. If H represents the total heat to be supplied any room, the resulting equations are: . H Leader areas for first floor, square inches = = approximately 0.009JJ . (1) _ jy . . Leader areas for second floor, square inches = jgg = approximately 0.00677 (2) Leader areas for third floor, square inches = H approximately 0.00577 (3) In designing for a lower warm-air register temperature, say 160 F, the factors 111, 166 and 200 become 80, 140 and 166 (Fig. 1 at 160 F), and the resulting equations are: * Leader areas for first floor, square inches = H ** approximately 0.012/7 (4) Leader areas for second floor, square inches = ---- = approximately 0.00717 140 . (5) Leader areas for third floor, square inches = = -~ = approximately 0.00671 loo ` (6) These equations are applicable to straight leaders from 6. to 8 ft in length. Longer leaders must be thoroughly covered or the vertical stacks must be increased in area as discussed under wall stacks, if some pro vision is not made for these longer leaders, the air temperature may be much lower than anticipated and the room will not be properly heated. The values shown in Fig. 1 apply only to the case where the straight, leader pipe is 8 ft in length and is connected to stacks whose cross sectional area is approximately 75 per cent of that of the leader pipe. 378 AmChapter 19. Gravity Warm Furnace Systems Any deviation from these conditions requires a modification of the con stants used in Equations 1, 2, and 3. The temperature drop in leaders of various lengths at three different register temperatures is shown in Fig. 2, and should be used to obtain new register temperatures, lower than 175 F, on which to base selections from the curves of Fig. 1, and thereby new constants for Equations 1, 2 and 3. . Leader sizes should in general be not less than those obtained by Equations 1 to 3 nor should leaders less than 8 in. in diameter be used. It is not considered good commercial practice to specify diameters except in whole inches. The tops of all leaders should be at the same elevation as they leave the furnace bonnet, and from this point there should be a uniform up-grade of 1 in. per foot of run in all cases. Leaders over 12 ft in length should be avoided if possible. In cases where such leaders are required, the use of a larger size pipe, than is required by the application of the equations, smooth transition fittings, and duct insulation are. recommended. Heating Ventilating Air Conditioning Guide 1938 PROPORTIONING WALL STACKS The wall stack for an upper floor should be made not less than 70 per cent of the area of the leader. In cases where the leader is short and straight as was the case for Fig. 1, such a practice is probably justified, since the loss (Fig. 3) in capacity occasioned by the smaller stack is not serious for stacks having areas in excess of 70 per cent of the leader area. For leaders over 8 ft in length or for leaders which are not straight, the ratio of stack area to leader area should be greater than 70 per cent in Chapter 19. Gravity Warm Air Furnace Systems REGISTER SELECTIONS The registers used for discharging warm air into the rooms should have a free or net area not less than the area of the leader in the same run of piping. The free area should be at least 70 per cent of the gross area of the register. No upper-floor register should be wider horizontally than the wall stack, and it should be placed either in the baseboard or side wall, if this can be done without the use of offsets. First-floor registers may be of the baseboard or floor type, with the former location preferred. High Fig. 2. Influence of Leader Pipe Length on Temperature Loss in Air Flowing through Pipe order to offset the greater temperature losses (Fig. 2) in the longer leader. In gravity circulating systems, this ratio of stack to leader area is a very important matter. The curves in Figs. 4 and 5 indicate that for rooms having a heat requirement exceeding approximately 9000 Btu per hr, exceedingly high register temperatures are required for stacks whose width is less than' 3p2 in. For such requirements either multiple stacks, or stacks having .larger cross-sectional area (placed in 6 in. studding spaces) will be required. , 380 Fig. 3. Relative Heating Effect of Stacks at Constant Heat Input to Furnace sidewall locations for warm air registers in gravity circulating systems are not recommended on account of the tendency for stratification of the air in the room, resulting in high temperatures at the ceiling. RECIRCULATING DUCTS AND GRILLES The ducts through which air is returned to the furnace should be designed to minimize friction and turbulence. They should be of ample area, in excess of the total area of warm-air pipes, and at all points where 381 Heating Ventilating Air Conditioning Guide 1938 the air stream must change direction or shape, streamline fittings should be employed. Horizontal ducts should pitch at least J4 in- per foot upward from the furnace. The recirculating grilles (or registers) should have a free area at least equal to the ducts to which they connect, and their free area should never be less than 50 per cent of their gross area. The location and number of return grilles will depend on the size, details and exposure of the house. Small compactly built houses may frequently be adequately served by a single return effectively placed in a central hall. More often it is desirable to have two or more returns, provided, however, that in two-story residences one return is placed to effectively receive the cold air returning by way of the stairs. Chapter 19. Gravity. Warm Air Furnace Systems advisable in such ducts. It is important that these ducts be free from unnecessary friction and turbulence, and that they be located to prevent preheating of the air before it reaches the furnace. Furnace Return Connection Circulation of the air is accelerated if the return connection to the furnace is through a round inclined pipe connected to two 45 deg elbows rather than through a vertical pipe connected to two 90 deg elbows. The top of the return shoe should enter the casing below the level of the grate in the furnace. In order to accomplish this the shoe must be wide as is indicated in Fig. 6, No. 1 arrangement. . Tests of six different systems of cold air returns, Fig. 6, made at the University of Illinois*, resulted in the following conclusions: Where a divided system of two or more returns is used, the grilles must be placed to serve the maximum area of cold wall or windows. Thus in rooms having only small windows the grille should be brought as close to the furnace as possible, but if the room has a bay window, French doors, or other large sources of cooling or leakage of cold air, the grille should be placed close by, so as to collect the cool air and prevent drafts. When long ducts of this type are employed they must be made oversize. This precaution is particularly important when long ducts and short ducts are used in the same system. The long ducts must be over-' size, if they are to operate satisfactorily in parallel with short ducts. Return'ducts from upstairs rooms may be necessary in apartments , or other spaces which are closed off or badly exposed. Metal linings are 382 Fig. 5. Heating Effect at Registers for Various Stacks with 8-in. Leader 1. In general, somewhat better room temperature conditions may be obtained by returning the air from positions near the cold walls. 2. Friction and turbulence in elaborate return duct systems retard the flow of air, and may seriously reduce furnace efficiency, and lessen the advantages of such a design. 3. The cross-sectional duct area is not the only measure of effectiveness. Friction and turbulence may operate to make the air flow out of all proportion to the various duct areas. FURNACE CAPACITY The size .of furnace should, of course, be such as will provide the necessary air heating capacity, usually expressed in square inches of leader pipe area, and at the same time provide a grate of the proper area to burn the necessary fuel at a reasonable chimney draft. The total leader pipe area required is obtained by finding the sum of the leader pipe areas as already designated. 'Investigation of Warm Air Furnaces and Heating Systems. Part IV, by A. C. Willard. A. P. kratz. and V. S. Day (University of Illinois, Engineering Experiment Station Bulletin No. 189). 383 Heating Ventilating Air Conditioning Guide 1938 The grate area will depend on several factors of which four are very important. First of all, the air temperature at the register for which the plant has been designed must be determined. Usually, this tempera ture is taken at 175 F. Second in importance is the combustion rate, which must always correspond with the register air temperature, as is shown by a set of typical furnace performance curves (Fig. 7) for a cast-iron, circular radiator furnace with a 23 in. diameter grate and 50 in. diameter casing. The third factor is efficiency, which is a function of the com bustion rate, and varies with it as shown by the efficiency curve of Fig. 7. The fourth factor is the heat value per pound of fuel burned, which was 12,790 Btu. This is not shown on the curves since it was constant for all combustion rates. Chapter 19. Gravity Warm Air Furnace Systems of the furnace is 62 per cent. Under this condition the capacity at the furnace bonnet per square foot of grate is 43,200 Btu per hr and per square inch of grate is 300 Btu per hr, the required area of the grate in square inches in this case will be = 0.0042 H. It should be oUU noted that a larger grate area is required if the furnace is to deliver air at a lower register temperature. The typical performance curves shown in Fig. 7 are not applicable to Fig. 6. Arrangement of Cold Air Returns for Six Installations It may be noted from Fig. 7 that for this particular furnace a register temperature of 175 F was accompanied by a combustion rate of approxi mately 7.5 lb per sq ft per hr, a capacity at the bonnet of 152,000 Btu per hr and a furnace efficiency of 58 per cent. Under these conditions the capacity at the bonnet per square foot of grate was equivalent to a value of 52,800 Btu per hr and per square inch of grate was equivalent to 367 Btu per hr. If it is desired to use these curves to select a furnace to deliver air at 175 F register temperature in a house where the total heat loss is H Btu per hour and the loss between the furnace and the registers is 0.25 H Btu per hour, the area of the grate in square inches will be 1.25 H 0.0034 H. 367 If, on the other hand, it is desired to select a furnace to deliver air at . ' 160 F register temperature, the combustion rate is 5.5 lb and the efficiency 384 Fig. 7. Typical Performance Curves for a Warm-Air Furnace and Installation in a Three-Story Ten Leader Plant, Operating on Recirculated Air all furnaces and hence for ordinary design purposes the values recom mended in the Standard Code3 should be used. The equation for a furnace having a ratio of heating surface to grate area of 20 to 1 is equal to: ' GXpXfX Ei XE,X 0.866 ... Standard Code Regulating the Installation of Gravity Warm Air Heating Systems in Residences* This code has been sponsored by the National Warm Air Healing and Air Conditioning Association, the and theNational Association of Sheet Metal Contractors, American Society of Heating and Ventilating Engineers. It is recommended that the installation of all gravity warm air heating systems in residences be governed by the provisions of this code, the ninth edition of which may be obtained from the National Warm Air Heating and Air Conditioning Association, 50 W. Broad St., Columbus, Ohio. 385 Heating Ventilating Air Conditioning Guide 1938 386 Chapter 19. Gravity Warm Air Furnace Systems where G P f Ei Et 0.866 H grate area, square inch. : combustion rate, pound coal per square foot of grate per hour, heating value of the coal, Btu per pound. efficiency at bonnet, ratio of heat delivered at bonnet to heat developed in furnace. efficiency of duct transmission, ratio of heat delivered at register to heat delivered at bonnet. factor of safety to allow for contingencies under service conditions such as accumulations of soot and ashes, ineffective firing methods, etc. total heat loss from structure. An addition of 2 per cent of the furnace capacity is proposed for each . unit that that, ratio of heating surface to grate area exceeds 20. This addition is based on .tests4 conducted at the University of Illinois on seven types of furnaces having varying ratios of heating surface to grate area. This correction does not, however, apply to values of the ratio less . than 15 nor greater than 30. . By transposing the terms in Equation 7 and adding the correction term for ratios of heating surface to grate area other than 20 to 1, the following equation is obtained: . . 144 X H : pX/X Ei,X E, X 0.866 [1 + .0.02 (E-20)] (8) in which R = ratio of heating surface to grate area. . In the case of the Standard Code6 the numerical values used in Equa tion 8 were based on those determined from the tests conducted on the different types of furnaces. 7.5 X 12,790 X 0.55 X 0.75 X 0.866 [1 + 0.02 (E-20)] H G = 0.004205 [1 + 0.02 (.R-20)] (10) As used in these calculations, H = Btu heat loss from the entire house per hour =-summation of all room losses Hi + Ht + etc. + the Btu necessary to heat the outside air, if any, at intake. This outside air loss in Btu per hour will be approximately 1.27 times the cubic feet of air admitted through the intake per hour on a zero day. For systems which recirculate all the air this value will be zero. For systems which have a outside air intake, controlled by damper, this value might well be approxi mated, since this loss will probably be reduced to a minimum on a zero day. Assume for such cases that the building loss is increased by 25 per cent, and that there is the usual 25 per cent loss between furnace and registers. ' TYPICAL DESIGN The application of the preceding data to an actual example may be of assistance to the designer. Figs. 8, 9, 10 and 11 represent the plans of `University of Illinois Engineering Experiment Station Bxdletin No. 246, by A. C. Willard. A. P. Kratz, and S. Konzo, Chapter X, pp. 126*146. . ' `Loc. Cit. Note 3. ' 387 s' Heating Ventilating Air Conditioning Guide 1938 388 JcmoL Chapter 19. Gravity Warm Air Furnace Systems the Warm Air Research Residence of the National Warm Air Heating and Air Conditioning Association erected at the University of Illinois6. Leaders. Stacks and Registers. (Direct Method) : . Living Room, 1st floor: 17,250 + 111 = 155 sq in. leader area. See summary, Table 1; also example under Standard Code7, Art. 3, Basis of Working Rules for Pipes. Leader diameter = 14 in. : Register size = 155 sq in. net area. Gross area = net area + 0.7 = 14 in. X 16 in. Owner's Room, 2nd floor: 15,030 + 167 = 90 sq in. leader area. See summary Table 1; also example under Standard Code7, Art. 3, Basis of Working Rules for Pipes. , Leader diameter = 11.4, say 12 in. Stack area = 0.7 X 90 = 63 sq in. = say 5 in. X 12 in. Register area = 90 sq in. net area. Gross area = net area + 0.7 = 12 X 12 or 12 in. X 14 in. In like manner the leaders, stacks and registers are calculated for each room in the house. Leaders, Stacks and Registers. (Code7 Method. See Art. 3, Sec. 1, 2, 3) Living Room (Glass = 90, Net wall = 405, Cubic contents = 2405) .. / 90 . 405 , 2405 ... . Leader = ^_ + _ + wj9 = 155sq.n. Register, same as Direct Method. Owner's Room (Glass = 68, Net wall = 394, Cubic contents = 2275) tLead.er = (^_68 +, 3--94 +, 2w275 \^,,6 = ,,90sqm. . Stack and Register, same as Direct Method. Assuming all air recirculated, the minimum furnace for the plant will be: Grate area = 0.0042 X 132,370 = 556 sq in. Use 27 in. diameter grate. (Equation 10). If provision should be made for certain outside air circulation, then increase the building heat loss by, say 25 per cent and obtain by Equation 10 a 30 in. grate. : Experiments at the University of Illinois8 have shown that the capacity of a furnace may be increased nearly three times by an adequate fan, with a constant register or delivery temperature maintained, provided that the rate of fuel consumption can he increased to provide the necessary heat. In other words, the capacity of a forced circulation system is limited by the ability of the chimney to produce a sufficient draft, and the ability of the fan to deliver an adequate amount of air. Plans used with permission. Bathroom on third floof not heated. 7Loc. Cit. Note 3. . University of Illinois. Engineering Experiment Station Bulletin No..120, p. 129. 389 Heating Ventilating Air Conditioning Guide 1938 Tablb 1. Summary of Data Applied to Warm Air Research Residence Rooms From Chapter 7 Estimating Heat Losses Btu Heat Losses H Leader Area Sq In. Stack Area Sq In. 0.7 X LA Leader Diameter Inches Stack Sire Net Register Sire Gross First Floor I Jm'njr Breakfast___ Sun ___ Hall and stair Second Floor Owner's_____ S. W. BedBath .. _ N. Bed______ Third Floor E. Bed. .. W. Bed_____ 17250 6810 2300 9210 25710 12570 15030 9800 2450 14800 8220 8220 = 0.009H 155 61 21 83 230 113 = 0.00677 90 59 15 89 = 0.00577 41 41 . _ 63 41 10 62 29 29 14 9 8 11 or 12 Two 12 ______ 12 14 X 16 8 X 12 8 X 10 12 X 14 Two 12 X 14 12 X 14 11 or 12 9 8 11 or 12 5 X 12 X 12 3X10 5 X 12 12 X 14 8 X 12 8 X 10 12 X 14 8 3 X 10 8 3 X 10 8 X 10 8 X 10 BOOSTER FANS - Booster fans often may be arranged to operate when gas oir oil burners are running and to stop automatically when the burners shut down. The booster equipment is mbst effective in increasing output at low operating temperatures. According to tests, efficiencies may be advanced from 60 per cent for gravity to 70 per cent with, boosters at low operating tem peratures, but at high operating temperatures gravity and booster efficiencies are almost identical9. ., University of Illinois, Engineering Experiment Station Bulletin No. 141, p. 79, and No. 246. PROBLEMS IN PRACTICE ' 1 What may prohibit the use of a gravity warm air system in a large house having several exposed wings? - In a gravity warm air system, excessive vertical distances above the furnace cause little trouble in the design of the wall stacks, but excessive horizontal distances from the furnace should be carefully considered in the design of the leaders. To work effectively, a gravity warm air system should be balanced and leaders over 12 ft in length should be avoided if possible. Long leaders, if used, must be of ample size, well pitched, and well insulated. Large houses having exposed wings may require leaders much longer than 12 ft; infiltration may create severe back-drafts in the exposed wings; and the basement ceiling height may not be sufficient to allow the leaders to have a pitch of more than one inch per foot. These conditions may make the exposed wings very difficult to heat with a gravity system because of its low air head differentials. 2 A first story dining room has a calculated heat loss of 12,000 Btu per hour. a. What size leader pipe should be used for 17S F register air temperature?' b. What size register? . 390 b<(; Chapter 19. Gravity Warm Air Furnace Systems .. a. Leader area = ^ - = 108.1 sq in. Use leader with diameter of 12 in. b. Register gross area = ^ ^ = 154 sq in. Use 12 in. by 14 in. register. 3 A third-story bedroom has a calculated heat loss of 12,000 Btu per hour. a. What size leader pipe should be used for a 175 F register air temperature? b. What size stack? c. What size register? ' 12 000 ' - a. Leader area =. = 60 sq in. Use leader with diameter of 9 in. . i. Stack area = 0.7 X 60 = 42 sq in. Use stack 3J in. by 12 in. c. Register gross area = 85.7 sq in. Use register 8 in. by 12 in. . 4 0 The calculated heat loss of a house is 130,000 Btu per hour. Find the grate area required for the furnace under the following conditions: Heating value of coal 12,790 Btu per pound. Furnace efficiency 55 per cent. Combustion rate = 7.5 lb per sq ft per hr. Ratio of heating surface to grate area of furnace -- 20 to 1. - Register temperature = 175 F. Loss between furnace and registers 25 per cent. See Equations 9 and 10: . Grate area = 0.004205 X 130,000 = 547 sq in. Grate diameter = 26.3 in. Use grate with diameter of 26 in. ' . . - 5 If in Question 4 the conditions were the same except that the ratio of heating surface to grate area of furnace was 24 to 1, what size grate would be required for the furnace? . Grate area = 0.004205 X 130,000 1 + 0.02 (24-20) . Grate diameter = 25.4 in. Select grate with-diameter of 25 in. 547 = 506 sq in. 1.08 6 Name the items involved in the design of a furnace heating system. a. Heat loss from each room, Btu. b. Area and dimensions of warm-air pipes in basement, inches. c. Area and dimensions of vertical pipes, inches. d. Free and gross area and dimensions of warm-air registers, inches. e. Area and dimensions of recirculating or outside air ducts, inches. /. Free and gross area and dimensions of recirculating registers, inches. g. Size of furnace necessary to supply the warm air to overcome the heat loss. h. Area and dimension of chimney and smoke pipe, inches. 7 Discuss the design features of recirculating ducts. . Their area should be equal to or greater than that of the supply ducts. . They should be streamlined, and have a minimum number of turns. c. All runs should be as short as possible. d. Account should be taken of all cold walls and window areas in determining sizes and positions of return air inlets. ' 391 9 Heating Ventiuiting Air Conditioning Guide 1938 e. The return line should be pitched downward toward the furnace. designed to minimize friction. /. The top of the shoe or boot should never be above the grate level. It should be 8 0 Discuss the use of a booster fan. What effect has a booster fan at low operating temperatures? At high ones? A booster fan is useful in accelerating the air flow past the surface of a low temperature furnace, where only a small weight differential in the air is created, and in unbalancing a gravity system so flow is established. The first use involves the entire plant, and increases efficiency about 10 per cent with low temperature operation; the second involves only the leaders in which air flow is accelerated." At high operating tempera tures the difference in weight between warm outgoing air and cool incoming air is great enough to make a booster unnecessary with ordinary gravity systems. . 9 Is it desirable to use high side wall locations for warm air registers in gravity circulating systems? High side wall locations are not recommended on account of the tendency for stratifica tion of the air in the room resulting in high temperatures at the ceiling. \ 392 Chapter 20 MECHANICAL WARM AIR FURNACE SYSTEMS Furnaces, Fans and Motors, Sound Control, Air Washers and Filters, Air Distribution Design, Automatic Controls, Design o Heating System, Selecting the Furnace, Selecting the Fan, Heavy Duty Fan Furnaces, Humidification, Cooling Methods, Cooling System Design . * MECHANICAL warm air or fan furnace heating systems1, which are a special type of central fan systems, are particularly adapted to residences, small office buildings, stores, banks, schools, and churches. Circulation of air is effected by motor-driven fans instead of by thedifference in weight between the heated air leaving the top of the-casing and the cooled air entering its bottom, as in gravity systems described in Chapter 19. The advantages of mechanical systems, as compared with, gravity systems are: ' 1. The furnace can be installed in a comer of the basement, leaving more basement' room available for other purposes. 2. Basement distribution piping can be made smaller and can be so installed as to give full head room in all parts of the average basement, or be completely concealed from view except in the furnace room. . 3. Circulation of air is positive, and in a properly designed system can be balanced in such a way as to give a greater uniformity of temperature distribution. 4. Humidity, control is more readily attained. 5. The air may be cleaned by air washers or filters, or both. 6. The fan and duct equipment may be utilized for a complete cooling and dehumidifying system for summer, using either ice, mechanical refrigeration, or low temperature water for cooling and dehumidifying, or adsorbers for dehumidifying. 7. The use of the fan increases the volume of air which can be handled; thereby increasing the rate of heat extraction from a given amount of heating surface and insuring sufficient air volume to obtain proper distribution in a large room. Much of the equipment used in central fan systems is the subject matter of other chapters. It is the purpose of this chapter to discuss the co ordinated design and to deal in detail only with problems not covered elsewhere which refer particularly to the whole problem of fan warm air furnace heating and air conditioning. , University of Illinois, Engineering Experiment Station Bulletin No. 266 by A. P. Kratz and S. Konzo tor details of tests conducted in Warm Air Research Residence. 393 Heating Ventilating Air Conditioning Guide 1938 FURNACES Furnaces for mechanical warm air systems may be made of cast-iron, steel, or alloy. Cast-iron furnaces are usually made in sections and must be assembled and cemented or bolted together on the job. Steel furnaces are made with welded or riveted seams. The proper design of the furnace depends largely on the kind of fuel to be burned. _ Accordingly, various manufacturers are making special units for coal, oil and gas. Each type of fuel requires a distinct type of furnace for highest efficiency and econ omy, substantially as follows: 1. Coal Burning: a. Bituminous--Large combustion space with easily accessible secondary radiator or flue travel. ' b. Anthracite or coke--Large fire box capacity and liberal secondary heating surfaces. 2. Oil Burning: a. Liberal combustion space. b. Long fire travel and extensive heating surface. . 3. Gas Burning: a. Extensive heating surface. b. Close contact between flame and heating surface. A combustion rate of from 5 to 8 lb of coal per square foot of grate per hour is recommended for residential heaters. A higher combustion rate is permissible with larger furnaces for buildings other than residences, depending upon the ratio of grate surface to heating surface, firing period, and available draft., . Where oil fuel is used, care must be exercised in selecting the proper size and type of burner for the particular size and type of furnace used. If is recommended that the system be designed for blow-through installations, so that the furnace shall be under external pressure in order to minimize the possibility of leakage of the products of combustidn into the air circulating system. ` In residential furnaces for coal burning, the ratio of heating surface to grate area will average about 20 to 1; in commercial sizes it may run as high as 50 to 1, depending on fuel and draft. Furnaces may be installed singly, each furnace with its own fan, or in batteries of any number of furnaces, using one. or more fans. \ Furnace Casings . Casings are usually constructed of galvanized iron, 26-gage or heavier, but they may also be constructed of brick. Galvanized iron casings should be lined with black iron liners, extending from the grate level to the top of the furnace and spaced from 1 in. to llA in. from the outer casing. Casings for commercial or heavy duty furnaces, if built of galvanized iron, should be insulated with fireproof insulating material at least 2 in. thick. It is generally believed that either brick or sheet metal casing should be equipped with baffles to secure impingement of the air to be heated against the heating surfaces. Brick furnace casings should be supplied with access doors for inspection. For furnace casings sized for gravity flow of air, where a fan is to be 394 Chapter 20. Mechanical Warm Air Furnace Systems used, many manufacturers recommend the use of special baffles to restrict the free area within the casing and to force impingement of the air against the heating surfaces. The method of making these baffles for furnaces with top horse-shoe radiators and for furnaces with back crescent radia tors is illustrated in Fig. 1. Either square or round casings may be used. Where square casings are . Fig. 1. Usual Method-of Baffling Round Casings for Fan Furnace Work 4* C. JBr,anffeler*, 1cloinse* d{rtooap caanadoKb*ottoBm.. Hole D. tOo uvteenr tcbaasfinfleg.. Fig. 2. Method of Baffling Square Furnace Casing for Fan Furnace Work A. Baffle, closed top and bottom. B. Liner, 1 in. from casing. C. Outer casing. D. Hole to vent baffle. used, the corners must be baffled to reduce the net free area and to force impingement of. air against the heating surfaces. Fig. 2 shows the usual. method of baffling square furnace casings for fan-furnace work. The hood or bonnet of.the casing above the furnace should be as high as basement conditions will allow, to form a plenum chamber over the top of the furnace. This tends to equalize the pressure and temperature of the air leaving the bonnet through the various openings. It is generally con sidered advisable to take off the warm air pipes from the side of the bonnet near the top, as this method of take-off allows the use of a higher bonnet 395 Heating Ventilating Air Conditioning Guide 1938 and thus provides a larger plenum chamber. Fig. 3 illustrates a complete residence fan furnace installation showing location of fan, furnace, filters, plenum chamber-and method of take-off of warm air pipe. FANS AND MOTORS Centrifugal type fans are most commonly used, and these may be equipped with either backward or forward curved blades. Low tip speed is desirable for the elimination of air noise, especially where forward curved blades are Used. Motors may be mounted on the fan shaft or outside of the fan with belt connection. Multi-speed motors or pulleys are desirable to provide a factor of safety and to allow for increased air circulation. For additional information on fans and motors, see Chapters 27 and 38. . SOUND CONTROL Special attention should be given to the problem of noise elimination. The fan housing should not be directly connected with metal, either to the furnace casing-or to the return air piping. It is common practice to use canvas strips in making these connections'. Motors and their mountings must be carefully selected for quiet operation. Electrical conduit and water piping must not be fastened to, nor make contact with fan housing. The installation of a fan directly under a cold air grille is not recommended on account of the noise objection. See also Chapter 30. AIR WASHERS AND FILTERS Washers for residence systems may be provided in separate housings to be installed on the inlet or outlet side of the fan, or they may be . integral with the fan construction. They operate at water pressures of from 10 to 30 lb and use two or more spray nozzles for washing and humidification. The sprays should be adjusted to completely cover the air passages. Washers are usually controlled by solenoid valves wired in parallel with the fan motor. The water supply may, in turn, be controlled by a humidity-controlling device located in one of the living rooms, so that the washer will operate at all times when the fan is in operation, unless the relative humidity should rise beyond a desirable percentage. Washers used in connection with commercial or heavy duty plants should be a regulation type of commercial washer. / There are many satisfactory types of'filters on the market. These include dry filters, viscous filters, oil filters and other types, some of which must be cleaned, some of which must be cleaned and recharged with oil, and some of which are inexpensive and may be discarded when they become dirty, and replaced with new ones. .' The resistance of a filter must be considered in the design of the system since the resistance rises rapidly as the filter becomes dirty, thus im pairing the heating efficiency of the furnace, in fact, endangering the life of the furnace itself. Manufacturers' ratings of filters must be carefully regarded, and ample filter area must be provided. Filters must be replaced or cleaned when dirty. See also Chapter 26. 396 Chapter 20. Mechanical Warm Air Furnace Systems AIR DISTRIBUTION The conditions of comfort obtained in a room are greatly influenced by the type of register used and the locations of the supply registers and return grilles. In general it has been found that changes in the type, air velocity, and location of the supply register affect the room conditions much more than the changes in the location of the return grilles. Due to the economic considerations involved, it is common practice to locate the supply openings on the inside walls of a residence and the return openings nearest the greatest outside exposure. Many designers prefer, however, to locate the supply registers so that the warm air from the registers blankets a cold wall, and mikes with the cold air dropping off from the exposed walls. This may be accomplished either by the use of a supply register located on the exposed wall with warm air blowing into the room, or by the use of a supply register placed close to an outside wall in such a position that the warm air sweeps the cold wall surface. The ducts leading to supply registers which are located on the exposed walls should be adequately insulated to reduce the heat loss from the ducts. Register and Grille Openings Supply registers located in the floor are effective, but as they require frequent attention to keep them clean they should be avoided where another effective register location can be found. Tests conducted in the Warm Air Research Residence2 have indicated that excellent results are obtainable with the use of a deflecting-diffuser type-of baseboard register which throws the air downward toward the floor and diffuses the air at the same time. Unless registers located in the baseboard are well proportioned *Loc. Cit. Note 1. Heating Ventilating Air Conditioning Guide 1938 and designed to harmonize with the trim, they may be unsightly. Better air distribution for cooling is obtained when high side wall registers are used, and this same location is satisfactory for heating when the openings are installed at least 7 ft above the floor line, providing .the air velocity through the registers is greater than 600 fpm. Registers which are located in side walls above the baseboard or in the ceiling should be of an effective air-diffusing type. All registers should be equipped with dampers, and should be sealed against leakage around the borders or margins. Velocities through registers may be reduced by the use of registers larger than the connecting pipes. Some suggestions for equalizing veloci ties over the face area of the register by means of diffusers are illustrated in Fig. 4. Merely to use a larger register may not result in materially reduced velocities unless diffusers are used. Dampers Suitable dampers are essential to any trunk or individual duct system, as it is virtually impossible to so lay out a system that it will be absolutely in balance without the use of dampers. Special care must be used in the Chapter 20. Mechanical Warm Air Furnace Systems AUTOMATIC CONTROLS Air stratification, high bonnet temperatures, excessive flue gas tem peratures, and heat overrun or lag in the system can be largely elimi nated through proper care in the planning and installation of the control system.3 The essential requirements of the control are: 1. To keep the Ere burning when using solid fuel regardless of the weather. ' 2. To avoid excessive bonnet temperatures with resultant radiant heat losses into the basement. . 3. To avoid the overheating of certain rooms through gravity action during off periods of blower operation. . 4; To have a sufficient supply of heat available at all times to avoid lag when the room thermostat calls for heat. 5. To prevent cold air delivery when heat supply is insufficient. 6. To avoid heat loss through the chimney by keeping stack temperatures low. Fig. 4. Diffusers in Transition Fittings to Equalize Velocities Through Register Faces design of any system to avoid turbulence and to minimize resistance. Sharp elbows, angles, and offsets should be avoided. See Figs. 1 and-2/ Chapter 29. Three types of dampers are commonly used in trunk and individual ' duct systems. Volume dampers are used 'to completely cut off or reduce' the flow through pipes. (See A and B, Fig. 5.) Splitter dampers are used where a branch is taken off from a main trunk. (See C, Fig. 5.) Squeeze dampers are used for adjusting- the volume of air flow and resistance through a given duct. (See D, Fig.. 5.) It is essential that a damper be provided for each main or duct branch. A positive locking device should be used with each type of damper. . Ducts , The ducts may be either round or rectangular. Rectangular ducts- should be as nearly square as possible; the width should not be greater than four times the breadth. The radii of elbows should be not less than one and one-half times the pipe diameter for round pipes, or th6 equiva lent round pipe size in the case of rectangular ducts. . 398 Fig. 5. Three Types of Dampers Commonly Used for Trunk and Individual Duct Systems 7. To provide quick response to the thermostat, with protection against overrun. 8. To provide for humidity control: 9. To provide a means of summer control of cooling. , 10. To protect against fire hazards. . The following controls are desirable: 1. A thermostat located at a point where maximum fluctuation in temperature can be expected, in order to secure frequent operation of fans, drafts, and brnmers. This location would be near an outside wall but not upon it, in a sun room, or in a room with some unusual exposure. The thermostat, of course, should not be located where it will be affected by direct radiant heat from the sun or from a fireplace, or by direct heat from any warm air duct or register. 2. A furnacestat located in the bonnet to permit blower operation only between the temperatures of 100 F and 150 F. In certain extreme cases it may be necessary, or weather conditions may make it advisable, to adjust the high limit to a higher tempera ture than that given. Another location sometimes used for the furnacestat is in the main duct near the frame opening from the bonnet: TraSSSSns, Vof'To1? lf9LFOp.C^Air Heating Systems- by s- Ko" and A. F. Hubbard (A.S.H.V.E. 399 Heating Ventilating Air Conditioning Guide 1938 3. A protective limit control located in the bonnet to shut down the system inde pendently of the thermostat if the bonnet temperature exceeds 225 F. 4. On oil and gas burner installations, a control is usually included which will shut down the system if the fire goes out or if there is a failure of the ignition system. 5. A humidistat to regulate the moisture supplied to the rooms. 6. On automatic stoker installations, a control is usually included which will start the operation regardless of thermostat settings whenever the bonnet temperature indicates that the fire is dying. METHOD OF DESIGNING FORCED-AIR HEATING SYSTEMS 1. Determine heat loss from each room in Btu per hour. (See Chapter 7). 2. Locate warm air registers and return registers on plans of house, beginning with ' the upper story rooms. 3. Sketch in duct layout to connect all registers and grilles with the central unit. 4. Determine equivalent length of duct for each register, allowing 10 diameters of straight pipe as equivalent to each 90 deg elbow having an inner radius not less than the diameter of the round pipe or the depth of the rectangular pipe. 5. Select a value for temperature of the air at the furnace bonnet. It is customary to use some value lying between 150 to 165 F. Use lower value if larger number of air recirculations is desired. It is recommended that the number of air recirculations should be in excess of 5 per hour. 6. Determine approximate value of temperature reduction in each duct caused by heat loss from the ducts. A value of from 0.3 to 0.6 F per foot of duct has been obtained from tests conducted in the Research Residence installation for uninsulated duct lengths up to approximately 60 ft. 7. Subtract this temperature reduction from the assumed bonnet air temperature to obtain an approximate value of the register air temperature for each register. 8. Determine the required air volume for each room from the following equation, or from the values listed in Table 1: jy ' ' ^ = 60 X 0.24 Xd(tr - 65) (1) where Q = required air volume, cubic feet per minute. H = heat loss of room, Btu per hour. d = density of air at register temperature, pounds per cubic foot. tr = register, temperature, degrees Fahrenheit. 0.24 = specific heat of air. 65 - return air temperature. . , For any given register temperature the solution of this equation simplifies to the following form: ? = HX Factor , (2) in which the values of the Factor, ipay be obtained from Table 1. 9. Determine register size /from the air volume delivered to each room by the following formula: /. Free area of register, square feet ` . (3) Gross area of register, square feet = ^ree^rea where Q = required air volume, cubic feet per minute. V = velocity at register face, feet per minute. R = ratio of free area to gross area of register. 400 (4) .. Chapter 20. Mechanical Warm Air Furnace Systems Table 1. Factors Corresponding to Register Temperature for Equation 2 Register Temperature Factor 110 0.02210 120 0.01840 130 0.01585 140 0.01397 150 0.01253 160 0.01140 170 0.01049 Allowable register velocities to be used in Equation 3 are approximately as follows: Baseboard, non-deflecting type, maximum 300 fpm, Baseboard, deflecting toward floor, maximum = 500 fpm. Baseboard, deflecting and diffusing = up to 800 fpmg High sidewall = not less than 600 fpm. 10. Duct systems for forced-air installations may consist of either trunk systems or individual duct systems. Trunk Systems. Determine duct sizes and friction losses as outlined in Chapter 20, except that for residence applications the velocities in the main duct and in the various parts of the system should approximate the values recommended in Table 2. Individual Duct Systems. An individual duct system is one having separate ducts extending from the heating unit to each register. In designing such a system select first the duct having the greatest equivalent length. Select a reasonable velocity using Table 2 as a guide. From friction chart on page 566 determine unit friction loss per 100 ft of run, and from this the total friction loss in the duct selected. If this total friction loss exceeds a reasonable value a lower velocity should be used. The remaining ducts are proportioned so that the total pressure in each duct is the same as that calculated for the longest duct. The added resistance necessary in the shorter ducts is accomplished by increasing the velocity in these ducts. No duct should be less than 6 in. in diameter, nor should the velocity in any duct exceed approximately 1200 fpm. The final adjustment in a duct system may be made by employing dampers. Instead of proportioning the ducts as outlined in the preceding paragraph it is more usual in practice to proportion all the ducts so that they have the same velocity as that used in the longest duct and to balance the system by employing dampers in the shorter ducts. ' Return duct systems are designed making use of the same principles as those used in the design of supply duct systems. In this case the design may be based on the volume of air corresponding to the' density of air existing in the return ducts, or in order to provide a factor for air leakage, it may be based on the same volume as used for the supply ducts. Table 2. Recommended Velocities Through Ducts and Registers Description Low Velocity System (fpm) Medium Velocity System (ppm) High Velocity System (ppm) Main ducts.............. . 500 Branch ducts.............. 450 Wall stacks.. _ ... . 350 Baseboard registers [irm| 300 750 600 500 350 1000 750 600 400 Wall registers above 5 ft (min.) 500 550 600 Heating Ventilating Air Conditioning Guide 1938 11. Determine frictional resistance in: - a. Supply side of system as outlined in item 10. b. Return side of system as outlined in item 10. c. Furnace units, casing or hood, which is usually considered as equivalent to 0.03 to 0.10 in. of water. d. Accessories such as washers or air filters, from manufacturer's data. e. Inlet and outlet registers and grilles, from manufacturer's data. /. Other accessory equipment such as cooling coils, from manufacturer's data. Choose a fan which, according to its manufacturer's rating, is capable of delivering a volume of air, expressed in cubic feet per minute, against a frictional resistance^ expressed in inches of water, computed by adding together the items listed in the preceding discus sion. In practice it is recommended that liberal allowances should be made so that the fan will be capable of delivering air against pressures that may not have been foreseen during the design of the duct system. 12. Select a furnace capable of delivering heat at the register outlets equal to the total heat loss of the structure to be heated. The following formula may be used for coal burning furnaces: qB__________________________________ U ~ f X p X , X Ej [1 + 0.02 (R - 20)] (5) where .. G required grate area, square feet. H = total heat loss from building, Btu per hour. / = calorific value of coal, Btu per pound. p = combustion rate in pounds of fuel per square foot of grate per hour. Ei = furnace efficiency based on heat available at bonnet. Et efficiency of transmission based on ratio of heat delivered at register to heat available at bonnet. . R = ratio of heating surface to grate area. In practice it is customary to use the following constants: . / = 12,000 (for specific values, see Table 1, Chapter 9). p = 7.5 lb. . El = 0.65 lower efficiency must be used with highly volatile solid fuel. E, = 0.85. The foregoing procedure for determining the size of the furnace to be used applies . to continuously heated buildings. 13. Although intermittently heated buildings usually have their heat losses computed according to the standard rules for determining such losses, these rules do not take into' account the heat which will be absorbed by the cold material of the building after the air is raised in temperature. This heat absorption must lie added to the normal heat loss of the building to determine the load which the heating plant must carry through the warming-up process. It is customary to increase the normal heat loss figure by from 50 to 150 per cent depending upon the heat capacity of the construction material, the higher percentage applying to materials of. high heat capacity such as concrete and brick. Fan furnace systems are well adapted for heating intermittently heated buildings as these systems do not require the warming of intermediate piping, radiators, or convectors, the, generation of steam, or the heating of hot water. 14. Follow the same methods for an oil furnace as for coal where a conversion unit is to be used, making sure that the ratio of heating surface to grate area exceeds 20 to 1. If it does not, a size larger furnace should be selected. Use the manufacturers Btu ratings of furnaces designed for exclusive use with oil, and select a burner with liberal excess capacity. . 402 Chapter 20. Mechanical Warm Air Furnace Systems 15. The selection of the proper size gas furnace for a constantly heated building can be easily made by using the following American Gas Association formula: where H = total heat loss from building, Btu per hour. R = official A. G. A. output rating of the furnace, Btu per hour. In the case of converted warm air furnaces a slightly different procedure is necessary, as the Btu input to the conversion burner must be selected rather than the furnace out put. The proper sizing may be done by means of the following formula: where I = Btu per hour input. I = 1.59 H (7) The factor 1.59 is the multiplier necessary to care for a 10 per cent heat loss in the distributing ducts and an efficiency of 70 per cent in the conversion burner. 16. Specify location and type of all dampers in both supply air and return air sides of system. Specify controls including location of all thermostats. Arrange for proper control of humidifying equipment. ' HEAVY DUTY FAN FURNACES Fan furnaces for large commercial and industrial buildings are available in sizes ranging from 400,000 to 3,000,000 Btu per hour per unit. Heavy duty heaters may be arranged in combinations of one or more units in a battery. A few possible arrangements are shown in Figs. 6 to 9 in clusive. Most manufacturers of heavy duty furnaces rate their furnaces in Btu per hour and also in the number of square feet of heating surface. Con servative practice indicates that at no time in the heating-up period should the furnace surface be required to emit more than an average of 3500 Btu per square foot. A higher rate of heat emission tends to increase the heat loss up the chimney, and raise fuel consumption, to shorten the life of the furnace, and to overheat the air. The ratio of heating surface to grate area on furnaces for this type of work should never be less than 30 to 1 and as indicated previously may run as high as 50 to 1. Control of temperature is secured through (1) controlling the quantity of heated air entering the room, (2) using mixing dampers, or (3) regu lating the fuel supply. The design of heavy duty fan furnace heating systems is in many respects similar to that of the central fan heating systems described in Chapter 21. Ducts are designed by the method outlined in Chapter 29. HUMIDIFICATION Mechanical warm air systems offer a means of proportioning and distributing moisture-bearing air; consequently, during the winter months humidifiers may be employed to deliver water vapor to the fan-driven air stream in proper amounts to produce a more humid atmosphere, with increased comfort for people and increased life for household furnishing^. Temperatures and relative humidities should be governed within the 403 HEATING VENTURING AlR CONDITIONING GUIDE 1938 gg<g agaa W<38i Sn^ a8SS< Cs, P. H OMjH wH SS (/&i g|ow wgi? als** <POQ gSag2ge a.sgoj r[x,<o fi 404 Chapter 20. Mechanical Warm Air Furnace Systems limits of the generally accepted standards. See Chapters 3 and 25 for more detailed information on this point. In earlier types of furnaces, water evaporating pans were usually placed in the cool portions of the air stream, but modern types usually locate them in air which has been heated by contact with the heating surfaces. To change water into vapor capable of being carried in an air stream as part of the mixture, about 1000 Btu per pound are required. Without the addition of this heat, termed the latent heat of evaporation, water injected into the air will be carried along in the form of tiny globules until it falls out of the stream or is deposited upon some surface. Furthermore, when dry air is in contact with water for a sufficient length of time without the presence of a sizable body of water or a source other than air from which this latent heat of evaporation can be taken, such heat is supplied from the air. There is, therefore, a trend in present practice toward heating the water in addition to heating the air. Equip ment for doing this may make use of sprays, or it may take the form of water circulating coils placed within the combustion chamber and con nected by pipes to the humidifier pans where a constant water level is maintained by some separate float device. (See Chapter 25:) Residence Requirements . The principles underlying humidity requirements and limitations for' residences are summarized in University of Illinois Bulletin No. 230\ as follows: 1. Optimum comfort is the most tangible criterion for determining the air conditions within a residence. 2. An effective temperature of 65 deg5 represents the optimum comfort for the majority of people. Under the conditions in the average residence a dry-bulb tempera ture of 69.5 F with relative humidity of 40 per cent is the most practical for the attain ment of 65-deg effective temperature. 3. Evaporation requirements to maintain a relative humidity of 40 per cent in zero weather depend on the amount of air inleakage to the average residence, and vary from practically nothing to 24 gal of water per 24 hours. 4. Relative humidity of 40 per cent indoors cannot be maintained in rigorous climates without excessive condensation on the windows unless tight-fitting storm sash or the equivalent is installed. ' 5. The problems of humidity requirements and limitations cannot be separated from considerations of good building construction, and the latter should receive serious atten tion in the installation of humidifying apparatus. The following condusions were drawn from the experimental results reported in the aforementioned bulletin: 1. None of the types of gravity warm air furnace water pans tested proved adequate to evaporate sufficient water to maintain 40 per cent relative humidity in the Research Residence except only in moderately cold weather. 2. The water pans used in the radiator shields tested did not prove adequate to main tain 40 per cent relative humidity in a residence similar to the Research Residence when the outdoor temperature approximated zero degrees Fahrenheit. `See Humidification for Residences, by A. P. Kratz (University of Illinois, Bulletin No. 230). *66 deg is the optimum winter effective temperature recommended by the A.S.H.V.E. Committee on Ventilation Standards. 405 Heating Ventilating Air Conditioning Guide 1938 COOLING METHODS A slight cooling effect may be obtained under certain conditions by the use of basement air. A more positive cooling effect may be obtained through air washers where the temperature of the water is sufficiently low (55 F or lower), and where a sufficient volume of water can be pro vided. Unless the temperature of the leaving water is below the dew point temperature of the indoor air at the time the washer is started, both the relative and absolute humidities will be somewhat increased. Coils of copper finned tubing through which cold water is pumped are available for cooling. They require less space than air washers and have the advantage that no moisture is added to the air when the temperature of the water rises above the dew point. Ample coil surface is necessary with this type of cooling. It is thoroughly feasible to use ice or mechanical refrigeration in con nection with the fan and duct system for the heating installation, and to cool the building by this method, provided the building is reasonably well constructed and insulated. Windows and doors should be tight, and awnings should be supplied on the sunny side of the building. See also Chapters 22 and 24. Results at Research Residence The following conclusions may be drawn from the studies thus far completed in the Research Residence, subject to the limitations of the conditions under which the tests were run6. 1. An uninsulated building of ordinary residential type may require the equivalent of three tons of ice in 24 hr on days when the maximum outdoor temperature reaches 100 F if an effective temperature of approximately 72 deg is maintained indoors. 2. The use of awnings at all windows in east, south, and west exposures may result in savings of from 20 to 30 per cent in the required cooling load. . 3. The cooling load per degree difference in temperature is not constant but increases as the outdoor temperature increases. 4. The heat lag of the building complicates the estimation of the cooling load under any specified conditions and makes such estimates, based on the usual methods of computation, of doubtful value. 5. The seasonal cooling requirements are extremely variable from year to year, and the ratio between the degree-hours of any two seasons occurring within a 10 year period may be as high as 7.5 to 1. Hence an average value of the degree-hours cooling per season is comparatively meaningless. ' 6. The duct system in a forced-air heating installation can be successfully converted to a system for conveying cool air for the purpose of cooling the structure. No con densation of moisture was observed when the duct temperatures were not less than 65 F. 7. Cooling by means of water at a temperature of 60 F is not satisfactory unless an indoor temperature of less than 80 F is maintained. " 8. In the selection of cooling coils, the frictional resistance of the coil to flow of air must be given careful consideration. - 9. Cooling the structure by introducing large quantities of air from outdoors at night tended to reduce the amount of cooling required on the following day and was a practical means of providing more comfortable conditions in those homes where cooling systems were not available. - Study of Summer Cooling in the Research Residence at the University of Illinois, by A. P. Kratz and S. Konzo (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 95); Study of Summer Cooling in the Research Residence for the Summer of 1933. by A. P. Kratz and S. Konzo (A.S.H.V.E. Transactions, Vol. 40, 1934. p. 167). 406 Chapter 20. Mechanical Warm Air Furnace Systems method of designing cooling system The general procedure for the design of a cooling system in a forced-air installation is as follows: 1. Calculate heat gain for each room or space to be conditioned. (See Chapters 5 and 8). Allowance for addition of outside air must be included in this calculation. 2. Select a temperature of air leaving supply inlets. In Research Residence tests7 a value of from 65 to 70 F was found satisfactory. 3. Determine indoor conditions to be maintained. In Research Residence 80 F dry bulb and 45 per cent relative humidity was found satisfactory. 4. Determine the quantity of air to be introduced into each room. (See Chapter 22). 5. Estimate heat loss in duct system between cooling unit and supply registers. 6. Calculate the heat to be removed by the cooling unit, in the form of sensible heat and latent heat. 7. Determine size of ducts in duct system and size of registers, as explained in this chapter under the heading of Method of Designing Forced-Air Heating Systems. 8. Determine pressure loss in duct system and select fan as also explained in the same section. 9. Select cooling unit from manufacturer's data. Specify temperature and pressure of available cooling water, voltage and characteristics of electrical supply, and method of control of apparatus. , 10. Select cooling coils from manufacturer's data to take care of latent heat load and to give required drop in air temperature with the weight of air flowing. See Chapter 22 on section Surface Type Dehumidifier. 11. If system is to be used for both winter heating and summer cooling, duct sizes must be checked to insure that velocities and friction losses are reasonable for both conditions of operation. Adjustable dampers will be necessary to make changes in air distribution for the two seasons. Provision must also be made for changing fan speeds for summer and winter operation. 'Loc. Cit. Note 6. problems in practice 1 A residence furnace, having a ratio of heating surface to grate area equal to 20 to 1, is to be selected to heat a house which has a computed load of 225,000 Btu per hour. If coal having a calorific value of 12,000 Btu per pound is to be burned, if the furnace will burn 7.5 lb of coal per square foot of grate per hour, and if the furnace efficiency is 65 per cent, determine the square feet of grate area necessary in the furnace to be selected. Substituting in Equation 5: G 12,000 X 7.5 X 0.65 X 0.85 4 53 ** ft of Srate area- A furnace having' at least 4.5 sq ft of grate area should therefore be selected. ' 2 Why should secondary surface be designed for easy cleaning? ' If the combustion is not perfect, soot is formed immediately above the fire and is apt to form a deposit on the secondary surface from which it should.be removed. If the secondary surface is so designed that there are horizontal passages, fine gray ash will settle out in these to form an insulation between the hot gases of combustion and the meted of the furnace; consequently, these should be readily cleaned. If the passages are vertical they are largely self-cleaning of ash, but provision should be made for easy and thorough cleaning of the collection chamber below them. 407 1 Heating Ventilating Air Conditioning Guide 1938 3 Why is baffling inside the casing necessary on fan systems? Because the movement of air is independent of its temperature, air must be guided by baffles of one form or another to bring it in contact with the hot surfaces so it will not pass through the casing unheated. On the other hand, if the air is held against a hot surface too long it might become overheated, for the average register temperature on a fan system should not exceed 120 F. 4 # What practical points should be observed in designing a fan system in order, to eliminate noise? - a. Use a large fan so it can be run at slow speed. b. Set the fan and motor on a solid foundation. c. Insulate the fan and motor from the foundation with rubber, cork, or other springy material according to the principles given in Chapter 30, provided, of course, that sucn idn.suSleaetitohnaitsthoef vaairluvee. locity is not too high in the ducts. Properly designed splitters in the elbows will avoid high velocities at the turns in cases where the velocity through the ducts themselves is not too high. - e. Use canvas connections between the ducts.and any running equipment. /. Be sure the ducts have a relatively smooth interior and are rigid. 5 i Why do furnaces designed to burn bituminous coal) oil) or gas require larger combustion spaces than those designed for anthracite? Anthracite bums largely as fixed carbon whereas gas and oil burn as gases, and as much as 50 per cent of bituminous coal burns as a gas. Ample space must be provided for the intimate mixture of these gases with the oxygen of the air to secure proper combustion. 6 A furnace Has the following dimensions: Grate diameter, 24 in.; casing diameter for gravity air flow, 56 in.; combustion chamber diameter, 30 in. What is the unobstructed area required for passage of air across the heating surface when a motor-driven blower, operating at an outlet velocity of 1200 fpm, delivers 1600 cfm into the casing near its bottom? For residence applications using small blowers, an air outlet velocity of about one third ' of the blower outlet velocity is considered good practice. Air-pass velocity -- -- 400 fpm. .. ` 1600 . , _. Air-pass area -- --* 4 sq ft = 576 sq in. 7 .# In Question 6 what would be the gap between the chamber and the baffle when the chamber is centered in the casing? Area of combustion chamber (30-in. diam) . 1 Area of air pass s 706.9 sq in. 576.0 sq in. Total area 1282.9 sq in. . The diameter of a circle with an area of 1282.9 sq in. is 40.4 in. One half of the difference between the diameters is the amount of gap. G~ap = -4--0--.4s---^--3--0--.-0-- -- 5e.2oi.n. = approximately 534 in. 408 . Chapter 21 CENTRAL SYSTEMS FOR HEATING AND HUMIDIFYING Types of Systems, Blow-Through, Draw-Through, Heating Units, Design, Temperatures, Weight of Air to be Circulated, Temperature Loss in Ducts, Heat Supplied Heating Units and Washer, Grate Area, Boiler Selection, Weight of Con - densate. Static Pressure, Fans and Control AFAN system of heating depends upon fans and blowers to distribute air through ducts from one centrally located plant. This chapter considers heating and humidifying systems of this type whereas similar systems arranged for cooling and dehumidifying are discussed in Chapter 22. A special type of central fan system, the mechanical warm air or fan furnace system, which is especially adapted to residences, churches, halls, and other small buildings, is covered in Chapter 20. TYPES OF SYSTEMS In the indirect type of central fan heating and air conditioning systems, steam is usually the medium by which heat is transferred from the boiler, or other source of heat, to the heating units. If the system is intended solely for heating, the air is passed over one or more stacks or batteries of heating units and then conveyed to the spaces for which it is intended through a system of ducts. In some cases, a predetermined amount of outside air is introduced for ventilating purposes, whereas in others the moisture content is controlled by passing the air through a washer or humidifier. If the apparatus is designed to control simultaneously the temperature, humidity, air motion, and distribution, it is known as an air conditioning system. . In the split system, the heating is accomplished by means of radiators or convectors, and the ventilating or air conditioning by means of the central fan apparatus. In the combined system, the entire operation of heating, ventilating, and air conditioning is handled by the central fan system. A common arrangement of the central fan system of heating is illus trated by Fig. 1 and consists of a fan, a heating unit (heater) enclosed by a sheet metal casing connected with the suction side of the fan, a sheet metal casing connected to the heating unit casing run to the outside of the budding and provided with an adjustable opening inside the building for recirculation of the air when desired, and a duct system attached to the fan outlet to convey and distribute the air to various parts of the building to be warmed by the apparatus. The fan is ordinarily motor-driven; there are, however, many cases when a direct-connected steam engine may be used to advantage. In this event the exhaust from the engine can be con 409 Heating Ventilating Air Conditioning Guide 1938 nected to one or more sections of the heater, depending upon the con densation rate of the engine. The recirculation duct connected with the opening in the suction duct should be extended to a point as near the floor as possible. When ventilation is not a requirement or is considered relatively unim portant, as in shop and factory heating, and the number of persons vitiat ing the air is small compared with the cubical contents of the building, or the process does not generate obnoxious gas or vapors, the air may be recirculated, sufficient outside air for ventilation being supplied by infiltra- Fig. 1. 8y*pass Damper Arrangement of a Central Fan Heating System (Draw-Through) Canvas Connection Heater Fig. 2. Arrangement for Heating Unit (Blow-Through) tion. The amount of heat to be supplied the heating unit in this case is the same as would be required for a direct radiation installation. When ventilation is a requirement to be met, an arrangement similar to that shown by Fig. 1 may be employed. Since the amount of air necessary for heating is generally in excess of the amount required for ventilation, considerable fuel economy may be effected by, recirculating a portion of the air. In this case only sufficient outside air is drawn into the system to meet the ventilation requirement and the remainder of the air, required for heating, is recirculated. This may be readily effected by an arrange ment of ducts and dampers on the suction side of the fan as previously mentioned. If the outside air, introduced is to be washed or conditioned the washer or humidifier and tempering coil may be added between the inlet for the recirculated air and the fresh air intake. , 410 Chapter 21. Central Systems for Heating and Humidifying Blow-Through, Draw-Through When the heating unit is located on the suction side of the fan, the system is known as draw-through. (See Fig. 1.) When the heating unit is located in the discharge from the fan, the system is known as blowthrough. (See Fig. 2.) The draw-through combination is used for factory and toilet room installations. because a more compact arrangement of the apparatus usually is possible. In addition, air leakage will be inward. The blow-through combination is used principally in schools and public buildings, and for all booster coil arrangements where different tempera tures and independent temperature regulation are required for different heated spaces. In public building, installations, the fan frequently blows the heated air into a plenum chamber from which the air ducts radiate to the various rooms of the building; this arrangement is sometimes called the plenum system. HEATING UNITS The heating units for central fan systems using steam as the heating medium may be classified as (1) tempering coils, (2) preheater coils, (3) reheater coils, (4) booster coils, and (5) water heaters, either open or closed. Tempering coils are used with ventilating and air conditioning systems for raising the temperature of the outside cold air to above freez ing, or 32 F. They are not required for heating systems where all of the air is recirculated, since the temperature of the recirculated air will be above freezing. Preheater coils are used with air conditioning systems to raise the temperature of the air from that leaving the tempering coils to such a temperature that in passing through the water sprays of the washer (without water heater) the air will become partially saturated (adiabatically) having a moisture content corresponding to the required dew point temperature. Preheater coils therefore supply heat as necessary to control the dew-point temperature. The reheater coils are used to raise the temperature of the air leaving the tempering coils (in the case of a heating or ventilating system) or the air leaving the washer (in the case of an air conditioning system) to that necessary to maintain the desired tempera ture in the rooms or spaces to be heated or conditioned, except where booster coils are used, in which case the reheater coils raise the air tem perature to approximately room temperature, or slightly higher. Booster coils are installed in the duct branches to control the temperature of the air entering the rooms or spaces for which it is intended. Water heaters are used on an air conditioning system to control the dew-point temperature. They are used mainly for industrial work, seldom for comfort conditioning. They are not used where preheater coils are employed. The open type supplies steam directly to the spray water, while the closed type utilizes a heat interchanger by which the steam imparts its heat to the spray water. Where water heaters are required for comfort conditioning, the closed type is used. The heating units for central fan systems in use at the present time con sist either of pipe coils, finned tubes of steel, copper, brass or other metal, cast-iron sections with extended surfaces, or the cellular type. Steam is passed through these heating units and the air to be heated is passed over their exterior surfaces. '' 411 Heating Ventilating Air Conditioning Guide 1938 In selecting a heating unit for any particular service, the choice should be based on the desired requirements as follows: 1. Final temperature desired. 2. Loss in pressure (or friction) of air passing over the heating unit. 3. Air velocity over the heating unit. 4. Free area or face area of heating unit. 5. Ratio of heating surface to net free (or face) area. 6. Air volume required. . 7. Number of rows of pipes, tubes, or sections. 8. Amount of heating surface. 9. Steam pressure drop through the heating unit. 10. Weight of heating unit. Final Temperature Desired. The choice of a heating unit is largely influenced by the final temperature desired, when the entering air tem perature and steam pressure available at the heating unit are specified. These data are obtainable from manufacturers' catalogs. Loss in Air Pressure (or Friction). The allowable friction through the heating unit is one of the first factors to be determined in the selection of the apparatus. The velocities of air through various types of heating units will not necessarily be the same, but for any particular job the velocity through the heating unit should be a secondary consideration and the allowable friction or air pressure loss should be fixed approximately before proceeding with the selection of the heating unit. The loss in air. pressure (or friction) through the heating unit should not exceed a pre determined maximum allowable amount for economical operation, and for moderate size and first cost of installation. . In public building work, the maximum allowable friction through both tempering coils and reheater coils should never exceed % in. of water and it is advisable that the friction be kept considerably lower than this figure if possible. A tempering coil friction ranging from 0.10 to 0.20 in. of water is considered satisfactory. The air pressure loss for reheaters ordinarily ' ranges from 0.20 to 0.40 in. of water. In factory work, the maximum friction through the heater should never exceed 0.8 in. or 1 in. of water and it is advisable to figure the heaters at lower frictions if possible. Velocity through Heating Unit. This velocity has generally been given in manufacturers' tables as being measureci at 70 F and in most cases refers to the velocity through the net free area of the heating unit, or through the net space between the' pipes, tubes or sections. Although most manufacturers give suitable velocities measured at 70 F, certain manufacturers show velocities measured at 65 F and others indicate velocities measured at the average air temperature through the heating . unit. Many new heating units, however, specify net face areas with cor responding velocities instead of velocities through net free areas. In either case, manufacturers publish the corresponding friction or airpressure loss in tables. The velocity through the net free area of the heating unit averages about 1000 fpm and that through the net face area about 500 fpm. The volume of air to be heated in any particular case is determined after consideration of the ventilation requirements, heat losses, and quantity of air required for proper circulation, as explained in Chapters 3 and 7. Chapter 21. Central Systems for Heating and Humidifying The number of rows of pipes, tubes, or sections or the amount of heating surface to be used may. be selected from manufacturers' catalogs after the quantity of air handled and the heat load are known. Savings in oper ating expense or cost of installation should result from a proper selection of heater and by-pass areas. For example, instead of having the entire air quantity go through a one-row heating unit, it may be advantageous to use a two-row heating unit and a properly sized by-pass. Thus, when no heating is being done, a suitable by-pass damper may be opened to place a lighter load on the fan. The steam pressure drop through the heating unit is also tabulated in manufacturers' data tables. The sizing of steam supply and return piping, allowing for drops through heating units, is explained in Chapter16. Weight of Heating Unit. In the design of a heating system, the weight limitations of heating units are determined by the location of the units. Obviously, if there is no loading limitation imposed, any type of heating unit may be selected. On the other hand if the heating unit is to be hung from the ceiling,, it may be desirable to use the lightest unit which will accomplish the work required. ' DESIGNING THE SYSTEM The general procedure for the design of central fan systems is as follows: . 1. Calculate the heat loss for each room or space to be heated. 2. Determine volume of outside air to be introduced. 3. Assume or calculate temperature of air leaving registers or supply outlets. 4. Calculate weight of air to be circulated. 5. Estimate temperature loss in duct system. 6. Calculate heat to be supplied the heating units and washer. 7. Select heating units and washer from manufacturers' data and performance curves. 8. Calculate total heat to be supplied. 9. Calculate grate area and select boiler. . 10. Design duct system. 11. Calculate total static pressure of system. 12. Select fan, motor, and drive. The heat losses (H) should be calculated in accordance with the pro cedure outlined in Chapter 7. If a positive pressure is maintained by the central fan system in the room or space to be ventilated or conditioned, there will ordinarily be very little infiltration of cold outside air through the cracks and crevices of the space. Consequently; the volume of air introduced into the space at the assumed or calculated outlet temperature need only be sufficient to provide for the transmission losses, plus about one-third of the infiltration losses. The exfiltration of heated or con ditioned air through the cracks and crevices of the space should be pro vided for by making the usual allowance for the infiltration losses in arriving at the total heat loss of the space. The air required to make up for this exfiltration of heated or conditioned air will be brought in at the outside air intake and may be included as a part of the outside air neces- 413. Heating Ventilating Am Conditioning Guide 1938 sary for the ventilating requirements. The heat required to raise this air to the conditions maintained in the room must be provided by the tem pering coils, preheater coils, and reheater coils. If a positive pressure is not maintained in the room or space to be conditioned, the normal in filtration of outside cold air will take place in this room, and the outlet temperature, together with the required air volume at this temperature, must be sufficient to provide for both infiltration and transmission losses. Volume of Outside Air The volume of outside air required for ventilation or air conditioning purposes may be determined from data in Chapter 3. In no case shall less than 10 cfm per person be introduced. The heat required to warm the outside air introduced for ventilation purposes (Ha) may be determined by means of the following formula: where Ho = 0.24 (J - Jo) Mo . (1) 0.24 = specific beat of air at constant pressure. 1 = room temperature, degrees Fahrenheit. Jo = outside temperature, degrees Fahrenheit. M0 = weight of outside air to be introduced per hour, in pounds = 60 doQ0. Qo = volume of outside air to be introduced, cubic feet per minute. do = density of air at Jo, pounds per cubic foot. Example 1. A building in which the temperature to be maintained at 70 F requires 10,000 cfm. If the outside temperature is 20 F, how much heat will be required to warm the air introduced for ventilation purposes to the room temperature? Solution. 10,000 X 60 = 600,000 cfh; do = 0.08273 (Table 1, Chapter 1) ; Ma = 0.08273 X 600,000 = 49,656 lb; J = 70 F; Jo = 20 F; H0 = 0.24 X (70 - 20) X 49,656 = 595,872 Btu per hour. . Temperature of Air Leaving Registers If the system is to function only as a heating system, that is, entirely as a recirculating one, the temperature of the air leaving the register outlets must be assumed. For public buildings, these temperatures may range from 100 to 120 F, whereas for factories and industrial buildings the out let or register temperature may be as high as 140 F. In no case should the outlet temperature exceed these values. \ . For ventilating or conditioning systems, the temperature of the air leaving the supply outlets may be estimated by means of the following formula: . .. . h = 60 d e X 0.24 + ' (2) where - Jy = outlet temperature, degrees Fahrenheit. . H = heat loss of room or space to be conditioned, Btu per hour. Q = total volume of air to be introduced at the temperature J, cubic feet per minute. d = density of air, pounds per cubic foot. . If the outlet temperature (ty) as determined from Equation 2 exceeds 120 F for public buildings, or 140 F for factories or industrial buildings, .414 ' these respective outlet temperatures should be used as factors in the following equation to determine the volume of air to be introduced into the room or space: = 60 d X 0.2JJ4 (Jy - t) ` Example 2. The heat loss of a certain auditorium to be conditioned is 100,000 Btu per hour. The ventilating requirements are 1,500 cfm and the room temperature 70 F. Determine the outlet temperature. Solution. Substituting in Formula 2, . hr = 100,000 60 X 0.07492 X 1500 X 0.24 + 70 = 131.7 F Inasmuch as this temperature is excessive, it will be necessary to assume an outlet temperature, which will be taken as 120 F, and to calculate the amount of air to be introduced into the room at this temperature to provide for the heat loss. Substituting in Equation 3, <3 =' 60 X 100,000 0.07492 X 0.24 (120 -- 70) 1850 cfm ^at temPerature 0 Weight of Air to be Circulated The total weight of air (M) to be introduced into the room or space to be heated or conditioned is given by the following formulae: where M= H ` 0.24(Jy - J) M = Mo + M, M0 60 doQo 60dQ (4) (5) (6) d = density of air at temperature J, pounds per cubic foot. do = density of air at temperature Jo, pounds per cubic foot. Qo = volume of outside air at temperature to, cubic feet per minute. Mo = weight of outside air, pounds per hour. Mr = weight bf recirculated air, pounds per hour. Example 3. Using the data of Example 2 and an outside temperature of 20 F, what will be the values of M, M0 and Mil. Solution, d 0.07492; do = 0.08273; Q = 1850; Qa = 1500; H = 100,000. M 100,000 : 0.24 X (120 - 70) = 8,333 lb Mo = 0.08273 X 60 X 1500 = 7,448 lb Mr = M - Mo = 8,333 - 7,448 = 885 lb Temperature Loss in Ducts The allowances (k) to be made for temperature drop through the duct system are as follows: 1. When the duct system is located in the enclosure to which the air is being delivered, as in a factory, it may be assumed that there is no loss between the reheater coil and the point or points of discharge into the enclosure. ' 415 X Heating Ventilating Air Conditioning Guide 1938 2. For ducts in outside walls, basements, attics or other exposed places temperature drops should be determined in accordance with the procedure as outlined in Chapter 39. 3. For ducts run underground an allowance shall be made based on the assumption that the average ground temperature will be 55 F. Heat Supplied Heating Units and Washer The following cases may arise in practice: A. The heating of the building is done entirely by means of a central fan system, all of the air being drawn from the outside. ' B. Similar to A, except that all of the air is recirculated. C. A portion of the air is recirculated, and the remainder is drawn in from the outside. D. Air at the same temperature is to be delivered to all the rooms. A constant relative humidity is maintained in the building and all of the air circulated is drawn from outside the building. (Not applicable to the heating of various rooms where individual control of each room is desired.) E. Outside air, return air, and by-pass air are used with the reheater located in by pass air chamber. F. Arrangement of apparatus where individual control of the temperature for each room is required in conjunction with air washer equipment to maintain a constant relative humidity in the rooms. The air washer is provided with a water heater for the spray water, capable of fully saturating the air. A section of preheater may be used for this purpose in place of the water heater. - With this arrangement and with a uniform temperature of air entering the rooms, it is impossible to maintain the same room tem perature throughout the building because the weight of air to be delivered to each room is determined and fixed by the ventilating requirements. In analyzing these cases, the following symbols will be used: H = heat loss of the room or building, Btu per hour. Hi = heat to be supplied to the reheater coil, Btu per hour. H, = heat supplied tempering coil, or tempering coil and preheater, Btu per hour. H, = heat supplied air washer by water heater, Btu per hour. H, = heat to be supplied booster coil, Btu per hour. M = weight of air to be introduced into the room or building, pounds per hour. Mr = weight of recirculated air, pounds per hour. Mb = weight of air by-passing washer, pounds per hour. M0 = weight of air drawn in from outside, pounds per hour. to = mean temperature of outside air, degrees Fahrenheit. t = mean air temperature to be maintained in the room or building, degrees Fahrenheit. ti = mean temperature of the air entering the reheater coil. tr = mean temperature of the air leaving the reheater coil. h = temperature loss in the duct system. = temperature of the air leaving the duct outlets. = average temperature of air entering tempering coil. fw = temperature of air entering washer. 0.24 = specific heat of air at constant pressure. 416 Fir,. 3. Heating Unit and Fan Arranged for Outside Air Circulation (Case A) Case A. (Fig. 3) All of the air circulated to be drawn from outside the building, in which case tz = to- H, = 0.24 (I. - to) M0 . (7) Hi = 0.24 (t, - tr) M0 (g) Example 6. The heat loss H for a certain factory building is 700,000 Btu per hour. The mean inside temperature t to be maintained is 65 F. The assumed outside air tem perature to is 0 F; ti = 0, ty -- tr and is assumed to be 140 F. The temperature leaving the tempering coil is assumed to be 35 F. Required, Hr and Hr- From Equation 4, M= 700,000 0.24 (140 - 65) 38,889 lb per hour. Hr = 0.24 X {35 - 0) X 38,889 = 326,667 Btu per hour. Hr = 0.24 X (140 - 35) X 38,889 = 980,003 Btu per hour. Hr + Hi = 326.667 + 980,003 = 1,306,670 Btu per hour. ELEVATION Fig. 4. Arrangement for Recirculation (Case B) Case B. (Fig. 4) All of the air is to be recirculated, in which case tr = t. , Mr = 38,889 lb . Hr = 0.24 (tr - tr) Mr Hr = 0.24 (140 - 65) X 38,889 = 700,000 Btu per hour. This example illustrates the saving in. fuel consumption by the recir culation of the air. The heat to be supplied the apparatus is the same as that required for a direct system of heating and is equal to the heat loss. of the building (Hi = H), in the example 700,000 Btu. per hour as compared with 1,306,670 for Case A. ' 417 Heating Ventilating Air Conditioning Guide 1938 Chapter 21. Central Systems for Heating and Humidifying Case C. (Fig. 5) A portion of the air circulated is recirculated air and the remainder, as may be required for ventilating purposes, is drawn in from the outside. According to Equations 4 and 5, , M = Mo + Mr H 0.24 (ly -- f) The temperature of the resulting mixture of outside and recirculated air entering the tempering coil is: . Mato + 3/rt <x = M (9) Example 7. Assuming that a positive supply of outside air (do = 0.08633) is required for ventilation at the rate of 90,000 cu ft per hour in the preceding example, then Af0 0.08633 X 90,000 = 7776 lb per hour are required, measured at 65 F. MT = M -- M0 = 38,889 - 7776 = 31,113 lb 7776 X 0 + 31,113 X 65 38.889 52 F Hr = 38,889 X 0.24 (140 - 52) = 821,336 Btu. This amount of work may be accomplished with one or more banks of heating units, that is, either a single reheater or a tempering coil and reheater. The three preceding cases refer to installations in which conditioning the air to maintain certain relative humidity requirements does not enter into the problem, as for example, certain types of industrial installations. In practically all modern public buildings, theaters, schools, and in many industrial installations, the ventilating requirements include the provision. for Wcishing and humidifying the air delivered to the various rooms of the structure. ". , In'the following cases it is assumed that in addition to maintaining a mean room temperature t, the heating and ventilating apparatus is required to maintain a constant relative humidity in the rooms. 418 Fig. 6. Outside Air Circulated: Constant Relative Humidity in Room (Case D) . Case D. (Fig. 6) The maximum relative humidity that may be maintained within the building without the precipitation of moisture on single glazed sash when the outside temperature is 30 F isapproximately 35 per cent. If the inside temperature t is 70 F, 35 . per cent relative humidity corresponds to a dew-point temperature of 41 F. (See psychrometric chart.) The installation shown in Fig. 6 contemplates the use of a tempering coil, an air washer provided with a water heater, and a reheater. The tempering coil, one section in depth, warms the incoming air to approximately 35 F to prevent freezing any of the spray water. The air passing through the spray chamber is saturated and leaves at a tempera ture of tr = 41 F, The heat to be supplied the reheater is: ' . ( Hr -- 0.24 (Ij -- 41)M Btu per hour. The heat to be supplied the tempering coil is: H = 0.24 (35 -- lo)M Btu per hour. The amount of heat, per pound of air circulated, to be supplied the humidifying washer or humidifier is the difference between the heat content of the assumed dry air entering the washer at a temperature of /w = 35 F and that of the leaving saturated air at tr = 41 F (Table 6, Chapter 1), or: . 15.657 -- 8.397 = 7.26 Btu per pound of dry air. The amount of heat required for the washer is: . Fir = 7.26 M Btu per hour. The total amount of heat required by the apparatus is, therefore: Hr + Ht + Hr Btu per hour. . .. If a washer having a humidifying efficiency of 67 per cent without water heater is em ployed it will be necessary to heat the outside air drawn into the apparatus by means of the tempering and preheater coils to such a temperature that the air in passing through 419 Heating Ventilating Air Conditioning Guide 1938 the water sprays will become partially saturated (adiabatically) having a moisture con tent per pound of air equal to saturated air at 41 F. If the incoming air is warmed to tw = 88 r (requiring a two-section-depth heating unit) it will be cooled in the washer to 64 F, with a temperature drop of 88 -- 64 = 24 deg. If the humidifying efficiency of the washer were 100 per cent, the air would become adiabatically saturated at 52 F after a temperature drop of 88 -- 52 = 36 F. The efficiency of the washer is, however, only 67.per cent, so that the actual temperature drop will be 0.67 X 36 deg of 24 deg, as used. The heat to be supplied the reheater is in this case Hi = 0.24 (It -- 64) Jf Btu per hour, and the heat to be supplied to the tempering coil and preheater is Hi = 0.24 (88 -- fo) M. The total heat required by the apparatus is Hi + Hi, no heat being supplied to the washer. Fig 7 Outside Air Circulated; Constant Temperature and Relative Humidity Maintained in Each Room (Case E) Case E. (Fig. 7) The temperature ly will ordinarily be different for each room. With H and M fixed, 0.24 (ly - t)M = H, or u h = 0.24 M + 1 In order to provide the proper temperature for each room, a booster coil is generally installed in each supply duct near the outlet to control the out let temperature ty. The amount of steam supplied to these booster units is usually controlled automatically by individual thermostats. The heat required by the booster coils depends on the temperature range through which the air is heated and the quantity of air, or Hi = 0.24 (ty - t, + QM . (10) Heat to be Supplied The amount of heat to be supplied (ff1) is equal to the sum of the heat requirements of the various heating units and the water heater of the washer, if any, plus the allowance for piping tax. (See preceding Cases A to E.) 420 o- Chapter 21. Central Systems for Heating and Humidifying Grate Area, Boiler Selection The required grate area may be determined by the following formula: where H G = FX EXC (11) G = required grate area, square feet. F = calorific value of fuel, Btu per pound. C = combustion rate, pounds per square foot of grate per hour. E = boiler and grate efficiency, per cent. . Example 8. Using the data in Example 6, and assuming coal having a calorific value of 12,000 Btu per pound, a combustion rate of 7 lb per square foot, and a performance efficiency of 0.60, and neglecting the piping tax, ,,_ 1,306,670 _ 12,000 X 0.60 X 7 Weight oi Condensate . The normal weight of condensate to be handled from central fan sys tems may be estimated by means of the following formula: where . w _ 60 dQ X 0.24 X Af - kg ' W -- weight of condensate, pounds per hour. Q total volume of air, cubic feet per minute. . At = temperature rise of air, degrees Fahrenheit. kg -- latent heat of steam in the system, Btu per pound.' Ducts and Outlets, Air Filters, Air Washers The design of the duct system should be based on data contained in Chapter 29. Air washers and humidifiers are described in Chapter 25. For information on air filters, see Chapter 26. . Static Pressure The total static pressure against which the system must operate may be found by summing up the static losses through, the complete system from the outside air intake to the discharge outlets or nozzles. This means that the loss due to friction must be determined for each piece of apparatus involved. Most of these values may be obtained from manu facturers' data tables. For a simple system, the following static pressure drops may be assumed: 1. Outside air inlet, comprised of screen, louver and short duct, may have a loss of 0.2 in. of water. 2. A typical oil filter at rated capacity and velocity has a drop of 0.25 in. of water. 3. The loss of one row of a standard make tempering stack equals 0.09 in. water. 4. The loss of one row of a standard make preheater equals 0.10 in. water. 5. A standard humidifier at rated velocity may have a loss of about 0.35 in. water. 6. The loss through one row of a standard make reheater equals 0.12 in. water. 7. A fair assumption for duct losses on a simple system is 0.25 in. water. 8. The static pressure for a nozzle type outlet may be taken as 0.1 in. water. 421 Heating Ventilating Air Conditioning Guide 1938 The sum of these values equals 0.2 + 0.25 -f- 0.09 0.10 + 0.35 4- 0.12 + 0.25 0.1 = 1.46 in. which is the static pressure against which the system must operate. Fans and Control The selection of fans may be based on data contained in Chapter 27 and for motors in Chapter 38. Because centrifugal fans reach their maximum efficiency when working against the resistance offered by the average central fan heating system, they are well adapted to such systems and are generally used. Information on temperature control for central fan systems is given in Chapter 37. PROBLEMS IN PRACTICE 1 Consider a blast beating system handling 10,000 cfm. The resistance to air flow offered by one coil arrangement is 0.9 in. of water and by another coil arrangement is 0.2 in. of water. The fan operates 4000 hours per year and the combined efficiency of motor and fan is 60 per cent. Determine the annual energy saving if the second coil is used. Difference in system resistance = 0.9 -- 0.2 -- 0.7 in. of water. ,,Red, uc.t.ion .m power inpu.t = 10,000 X 0.7 = ,1.,,8,,3 thp. Annual energy saving = 1.83 X 0.764 X 4000 = 5480 kwhr. 2 What saving results from recirculating some of the room air and reducing the amount of outside'air? Because outside air must be heated to room temperature, reducing the amount of outside air produces a proportionate saving in heat or fuel. 3 What items make up the total heating load in a central fan heating system? 1. The net heat loss from the conditioned space. J< 2. The heat required for evaporation of water for humidification. 3. The heat required to raise the temperature of outside air to room temperature. 4. Heat losses from pipes and ducts. ; 4 A group of three drafting rooms, having a total volume of 27,000 cu ft, a transmission loss of 110,100 Btu per hour, and an infiltration loss of34,200Btu per hour on the basis of 0 F outdoors and 70 F room temperature, is to be heated by a recirculating hot blast heating system with air entering the rooms at 116 F. How many cubic feet per minute, measured at 70 F, will be required? Substitute in Equation 3. H -- 110,100 + 34,200 = 144,300 Btu per hour; ty = 116 F; 1 = 70 F i Q = go x 0.07492 X 0.24 (116 - 70) = 2900 rfm 5 In the preceding question, if the warm air loses 4 F between heater and rooms, how many pounds of steam per hour at 1-lb gage will the heating sections condense? Substitute in Equation 12. Q -- 2900 cfm, from solution of Question 4; At = 116 + 4 -- 70 = 50 F; hig = 968 Btu, from steam table in Chapter 1. 60 dQ X 0-24 X At W= Afg 60 X 0.07492 X 2900 X 0.24 X 50 968 161.8 lb per hour. 422 Chapter 22 CENTRAL SYSTEMS FOR COOLING AND DEHUMIDIFYING Classification of Systems, Spray and Surface Type Dehumidi fiers. Designing the System, Zoning, Location of Apparatus, Air Temperature Leaving Room Inlets, Calculations and Selection of Apparatus, Quantity and Temperature of Air Required, Heat Removed by Apparatus, Reheating Dehumidi fied Air, By-Pass System CENTRAL systems, equipped for cooling and dehumidifying, are used principally in the air conditioning of theatres, restaurants, office buildings, or other places where people gather, and in manufacturing establishments where air conditions have an important influence on the quality of product or rate of production. A central cooling and de humidifying plant is one in which the fans, dehumidifiers, and other related apparatus are assembled'in suitable apparatus rooms from which supply and return ducts lead to the conditioned spaces. The design of such systems is considered in this chapter, while in Chapter 21 Central Systems for Heating and Humidifying are described. Air conditioning for industrial processes is considered in Chapter 33. A discussion of the dehumidifying equipment only, will be found in Chapters 24 and 25. CLASSIFICATION OF SYSTEMS Dehumidification or cooling of air may be accomplished by several methods, and by use of many heat transfer media. Most central station comfort air conditioning systems employ cold water or the direct expansion of a refrigerant in either spray type or surface type equipment to accomplish the required cooling and dehumidification. Hence this chapter will be concerned mainly with the design of such systems. Two other methods of summer air conditioning are used to some extent. In regions where the summer wet-bulb temperature is low (see Chapter 8, Table 1), evaporative cooling can be used. A spray type unit is employed, with recirculation of the spray water arid usually a supply of 100 per cent outside air. The dry-bulb temperature of the air is reduced but the relative humidity of the air is increased, as the air passes through the sprays and its sensible heat is converted into latent heat. The wet-bulb temperature remains constant, and for comfort conditioning it is ad visable, to have the final dry-bulb temperature a few degrees higher than the wet-bulb. . 423 ? Heating Ventilating Air Conditioning Guide. 1938 Another method of summer air conditioning is that in which the air is passed over a dehydrating agent, and then the dry-bulb temperature is lowered to the proper level. This latter step is usually accomplished by means of water, and the water temperature need not be as low as is required for dehumidification by condensation. For the common method of dehumidifying the air by cooling it below the dew-point, either the air is conducted through a low temperature Chapter 22. Central Systems for Cooling and Dehumidifying system, is intended solely for summer conditioning, the apparatus will consist essentially of a dehumidifier of spray or surface type, filters, fan and motor, duct work for outside air, return air and conditioned air supply, air inlets and outlets and suitable controls. For the spray unit or for water coils a pump will be required, and some form of cooling equipment must be installed unless a supply of sufficiently low temperature natural water is available. In many cases a reheater will be necessary, as de scribed in the next paragraph. Frequently a central, air conditioning system is designed for year-round service. This means that properly sized heaters and humidifiers, with their respective controls, must be added. With few exceptions, systems designed to meet summer capacity requirements will have ample capacity for winter and intermediate season conditioning. . In lowering the dew-point temperature to enable the air to carry off the latent heat load, the dry-bulb temperature may be lowered excessively. The air must then be reheated before being delivered to the rooms. --- -- Fig. 2. Dehumidifying Equipment with Reheater liquid spray, or it is directed over surface coils through which cold water or evaporating refrigerant is circulated. The same principle governs the operation of both spray and surface type dehumidifiers, viz.: The dew point temperature of the air leaving the dehumidifier should be such that when the air is raised to room conditions it will have absorbed the latent heat load of the rooms. . The arrangement of a simple summer air conditioning plant is shown in Fig. 1. The plant may be designed to condition 100 per cent outside air, 100 per cent return air, or a mixture of outside and return air. If the 424 Fig. 3. Summer Dehumidifying Equipment with By-Pass Fig. 2 shows a central plant conditioner with a surface reheater added. The reheater may be installed in the fan inlet chamber as shown, or in the fan discharge duct, depending on apparatus space and other design conditions. The use of surface coils, of improved air distribution systems in the rooms, and of smaller refrigeration units with automatic control, are all tending to make the use of reheaters less essential. Another method for raising the dry-bulb temperature of the conditioned air supplied to the rooms, is to by-pass some of the return air1 so that it enters on the downstream side of the dehumidifier, as shown in Fig. 3. This method of reheating the air may be more economical in operation than using a surface reheater where such a reheater cannot be supplied with waste heat. '' In some cases the main supply fan delivers the dehumidified air to several other fans rather than to the conditioned space directly. ^These booster fan units may be arranged to deliver a mixture of conditioned air 1Patents exist covering the use of the by-pass for cooling and dehumidifying systems. 425 Heating Ventilating Air Conditioning Guide 1938 and return air as shown in Fig. 4, or they may be equipped with reheaters and take in 100 per cent dehumidified air. The systems illustrated in Figs. 1 to 4 may have either spray dehumidi fiers or surface coils, and the latter may use either cold water or direct expansion refrigerant. In a few cases both sprays and coils are used. The coils may then be installed within the spray chamber, either in series with the sprays or below them. In making the selection between spray and surface dehumidifiers, certain advantages of each should be consider ed. The fact that a spray dehumidifier is usually designed to deliver saturated or nearly saturated air, tends to simplify the control problem. In this case the dry-bulb temperature is also the dew-point, and hence a dew-point control can be arranged by using a simple duct thermostat. Other advantages of the spray system are that it may be used for hu- Fig. 4. Central Dehumidifying Plant and Local Recirculating Fans midifying in winter or for evaporative cooling when the outside wet-bulb temperature is low. % Surface coil dehumidifiers seldom deliver saturated air. A wet-bulb depression of 2 to 5 F (or more) is usual, and with this higher dry-bulb temperature (for a given dew-point), reheating may be unnecessary as indicated in Table 1. Where the surface coil system can be used with direct expansion of refrigerant, it is comparatively low in initial and operating costs, but some localities have refrigeration codes which restrict the use of direct-expansion coils'in the air stream. Therefore, local codes should be consulted by the engineer before a system employing direct expansion methods is designed. The performance of a surface type dehumidifier is affected by air velocity, refrigerant velocity, temperature and moisture content of the entering air, piping arrangement and coil design, and these variations must be taken into account in the design of a system which includes a surface-type unit. . 426 **5355? Chapter 22. Central Systems for Cooling and' Dehumidifying Table 1. Room Heat Load Ratios for Typical Summer Comfort Conditioning Room Heat Load Ratios* Sensible Heat Total Heat Total Heat Sensible Heat Latent Heat Total Heat Total Heat Latent Heat Sensible Heat Latent Heat Latent Heat Sensible Heat Typical Classes op Rook Service or Load - - No. Occupants or Sources of Vapor Private Office or Residence 1.00 0.90 Restaurant or Crowded Office Auditorium at Capacity or Crowded Restaurant 0.80 0.70 Ballroom at Capacity 0.60 1.00 1.11 1.25 1.43 1.67 0 0.10 0.20 0.30 0.40 10.00 5.00 3.33 2.50 9.00 4.00 2.33 1.50 0 .0.11 0.25 0.43 0.67 Dry-bulb Temperature of Air at Room Inlets, to Maintain Typical Room Conditions of 80 F Dry-bulb, 60 per cent Relative Humidity Air entering saturated1* Air entering with 4 F wet-bulb depression Air entering with 8 F wet-bulb depression 60.0 66.5 72.6 58.6 65.4 72.1 56.5 64.1 71.6 53.0 61.8 70.5 35.0 56.0 68.0 The overall heat load ratio for the dehumidifier will be different from the heat load ratio for the room. The extent of the difference will depend on the quantity and condition of the outside air used, upon the magnitude of the duct losses, and upon whether or not reheat or by-pass are used. ^Typical air conditions leaving the central conditioner are: With spray dehumidifier, 0 to 2 F wet-bulb depression. With surface-type dehumidifier, 1 to 6 F wet-bulb depression. With by-pass or reheat, 4 to 10 F wet-bulb depression. DESIGNING THE SYSTEM The general procedure for the design of a central system is as follows: 1. Calculate the* sensible heat and latent heat, gains for each room or space to be conditioned. (See Chapters 6,7 and 8). ,. . 2. Establish the temperature of air leaving the supply inlets. 3. Calculate the quantity of air to be circulated. 4. Estimate the temperature rise in the duct system. 5. Determine the volume of outside air to be introduced. (See Chapter 3). . 6. Calculate the heat to be removed by cooling and dehumidifying apparatus, and the type and arrangement of apparatus to be used. 7. Calculate the size of the reheating equipment, if any. ' 8. Select cooling and dehumidifying equipment, and refrigerating and reheating equipment, from manufacturers' data and performance curves. 9. Design the air filtering and distribution system, the air outlets and inlets. (See Chapters 26, 28 and 29). ; 10. Calculate the total static pressure of' the system. ` 11. Select the fan, motor and drive. (See Chapters 27 and 38). . 12. Select the pump and motor. . 13. Design the control system. (See Chapter 37.) 427 X Heating Ventilating Air Conditioning Guide 1938 ZONING THE SYSTEM The foregoing general outline of procedure will prove satisfactory for the smaller and less complex installations. However, when dealing with air conditioning systems for large buildings, after a proper analysis has been made of the conditions to be maintained and the heat loads en countered, it is generally considered good practice to divide the complete job into a number of suitably sized units. In some cases a unit per floor or group of floors may complete the design satisfactorily, whereas in others it may be advantageous to have separate units for each of the various outside exposures of the building. The heat loads on inside rooms are apt to be less variable since the fluctuations of the outside weather conditions are not directly involved. Where the floor area is large in relation to the outside wall exposure, it is obvious that special provision must be made for the variable load to which the outside exposures, are subjected. Such conditions often result in the natural zoning or segre gation of rooms having similar exposures and internal heat loads. Varia tions in the hours of occupancy in different portions of a building also frequently require careful zoning for.successful operation. LOCATION OF APPARATUS Availability of space for apparatus and duct work is of primary im portance when selecting the type of system for a given design. In general, for large installations,, the refrigeration equipment, because.of its size, weight, and operating characteristics, is located in the basement along with the boilers, fire pumps, and other equipment. The air conditioning apparatus is generally located where clean outdoor air is readily available, the designer bearing in mind that supply and return air ducts, steam con nections, water and drain connections, and electrical connections must be made to the equipment proper. AIR TEMPERATURE LEAVING ROOM INLETS In comfort conditioning applications, air has been distributed from properly designed inlets without producing drafts at temperatures varying from approximately 5 to 30 F below- the required room temperature. Factors influencing the design and selection of air inlets afe: ceiling height, contour of ceiling, length of blow,"'and temperature and quantity of air to be distributed. Most summer conditioning installations are designed to supply the air to the conditioned space at. from 8 to 18 F below room temperature. Recently the use of specially designed nozzles has indicated the possibility of reducing the air quantity necessary to dissipate a given heat load by introducing the air into the room as much as 30 F below room temperature. Directional flow inlets which spread the air fanwise permit lower inlet temperatures than single direction inlets. Comfort conditioning systems employing differentials greater than 18 F require special consideration and design experience because high pressure inlets or nozzles are usually used. Further, care must be taken to allow a sufficient air quantity under all load conditions to insure good distribution. If winter heating, as well as summer conditioning, is to be accomplished by the same distributing system, the design of the 428 Chapter 22. Central Systems for Cooling and Dehumidifying inlets will be influenced as discussed in Chapter 21. Industrial systems in which drafts are not objectionable usually employ a temperature dif ferential equal to the dew-point depression. CALCULATIONS AND SELECTION OF APPARATUS When the cooling loads in the rooms to be served have been calculated as outlined in Chapter 8, they are combined to obtain the total room load, However, all loads must be calculated in two parts: (1) the sensible heat or dry load, and (2) the latent heat or moisture load. For convenience it is customary to state this division of loads by a ratio, as for instance the ratio of sensible heat load to total load. Unfortunately there is as yet no uniform practice in the statement of this ratio, and hence in Table 1 all the common ways of stating the load ratio are given. It should be noted that the heat load ratio for the dehumidifier is not exactly the same as the heat load ratio of the room except in the case of 100 per cent recirculation and zero reheat. > ... The heat load ratio of a room depends upon its occupancy as well as upon the heat transmitted through its walls and windows. This is approxi mately indicated in Table 1, Since human occupants are one of the greatest sources of latent heat or moisture load; this load is frequently A minimum when there is a large room space per occupant and the occu pants are not doing physical work. ' Examples of the solution of a typical problem of treating air tcrproduce room conditions of 80 F dry-bulb and 50 per cent, relative humidity are also given in Table. 1. In these examples it is assumed that as the air is discharged into the room and diffuses with the room air, it is required to absorb sensible and latent heat in the ratio indicated, and that its final condition after absorbing this heat is the room condition of 80 F dry-bulb and 50 per cent relative humidity. Table 1 deals with the room only, and the heat load ratios for the dehumidifier and the temperatures leaving the same will not be identical with those given for the room;. However, if the heat gains in the duct work have been included as part of the. room load, the dry-bulb temperatures in Table 1 will be those at the discharge of the central conditioning apparatus. To obtain the total heat load on the dehumidifier, and its corresponding heat load ratio, the load due to outside or ventilating air must of course be added. The significance of these statements is illustrated in the examples following, . Quantity and Temperature of Air Required . . ' ; , The quantity of air to be circulated is;.usually determined on the basis of the sensible heat load, although in some cases the air quantity will be determined by the latent heat load, or by the air distribution or venti lation requirements. . Example 1. A room is to be maintained at a dry-bulb temperature of 80 F and a relative humidity of 55 per cent, (68.5 F wet-bulb, 62.5 F dew-point, 85.5 grains of moisture per pound). The sensible heat gain in this room is 100,000 Btu per hour, and the latent heat gain is 33,000 Btu per hour, or a heat load ratio, sensible to total, of 75 per cent. A temperature differential of 12 F between the room air and the conditioned supply has been selected, i.e., the air is to be supplied at 68 F dry-bulb. Find the quan tity and condition of the air supply required. ' '. 429 ___---m ~~-----I p Heating Ventilating Air Conditioning Guide 1938 Solution. From a table of air properties, (Chapter 1, Table 6), it is found that the sensible heat content of air at 80 F is 19.19 Btu per pound, and that of air at 68 F is 16.31 Btu per pound. Hence the sensible heat load which can be absorbed by 1 lb of air is 19.19 -- 16.31 = 2.88 Btu. Then the total air quantity required is 100,000/2.88 = 34,700 lb per hour. Expressed in terms of standard air at 0.075 lb per cubic foot, this is: 34,700/(60 x 0.075) = 7,720 cfm. Since a latent heat load of 33,000 Btu per hour must be absorbed by 34,700 lb of air per hour, the latent heat to be absorbed per pound of air is: 33,000/34,700 = 0.952 Btu. The latent heat per pound of vapor is approximately 1060 Btu (from steam tables), and since 1 lb = 7,000 grains, the moisture to be added to each pound of air is: (0.0952 x 7000)/1060 = 6.3 grains. Hence the dew-point tem perature of the conditioned air supply will correspond to 85.5 -- 6.3 = 79.2 grains per pound, and from the psychrometric chart or tables this is found to be 60.7 F dew-point. At ajdry-bulb temperature of 68 F this corresponds to a wet-bulb temperature of approxi mately 63.3 F, or a relative humidity of 78 per cent. Summarizing, the required air supply is: 7,720 cfm at 68 F dry-bulb and 63.3 F wet-bulb. In the previous example and solution, no consideration was given to the type of air conditioner to be used. The solution is dependent on room conditions only, and the method is generally applicable regardless of the heal load ratio or the size of the system. Of course if the air quantity or the temperatures obtained in the solution are not practicable for the actual installation, the original selection of a dry-bulb temperature of the inlet air may be changed as required, providing the design of the distribution system is modified accordingly. A higher dry-bulb temperature of the air supply, i.e., a smaller temperature differential, will call for a larger quantity of air and a larger wet-bulb depression at the supply inlets. Heat Removed by Apparatus The total cooling and dehumidifying load will depend on the total room load, the duct losses, the outside air or ventilation load, and the amount of reheat, if any. The necessity for reheat will in turn be determined by the type of system, and by the dry-bulb temperature required at the room supply inlets. Example 2. To maintain a room at 80 F dry-bulb and 55 per cent relative humidity requires a conditioned air supply of 7,720 cfm at 68 F dry-bulb and 63.3 F wet-bulb temperature (see Example 1.). The air is to be conditioned in a central plant unit of the type shown in Fig. 2. The conditioned air is to consist of 30 per cent outside air (2320 cfm) and 70 per cent recirculated air (5400 cfm). The outside air enters the conditioner at 95 F dry-bulb and 75 F wet-bulb temperature, arid the return air is assumed to enter at 80 F dry-bulb and 68.5 F wet-bulb, (neglecting radiation and duct losses). Find the total refrigeration load, and the air conditions entering and leaving the dehumidifier, for both spray and surface type units. .. \ Solution. The simplest method of solution is on the basis of wet-bulb temperatures and total heats, calculating the return air and outside air loads separately. Before this can be done, the air conditions at the exit of the dehumidifier must be determined. It is known that the dew-point of the conditioned air must be 60.7 F. The dry-bulb tempera'ture at the exit of the dehumidifier will then depend on whether sprays or coils are used, and on the design of each. Assume in this case that the spray dehumidifier saturates the air, and that the air discharged from the surface dehumidifier has a 3 F wet-bulb depres sion. (These are common assumptions, but other values may be obtained, depending on the designs). Air conditions at the discharge of the dehumidifier are then: For the spray dehumidifier, dry-bulb = wet-bulb = dew-point = 60.7 F. For the surface type' dehumidifier, dry-bulb 65.5 F, wet-bulb = 62.5 F, dew-point = 60.7 F. The total refrigeration load for each.type of dehumidifier may be calculated as follows: Spray Type Dehumidifier. 2320 cfm of outside air cooled from 75 F wet-bulb (38.46 Btu per pound, total heat content), to 60.7 F wet-bulb (26.86 Btu per pound, total heat content.) Refrigeration load: 2320 X 0.075 X 60 X (38.46 - 26.86) = 121,000 Btu per hour. 5400 cfm of return air, cooled from 68.5 F wet-bulb (32.71 Btu per pound). 430 Chapter 22. Central Systems for Cooling and Dehumidifying to 60.7 F wet-bulb (26.86 Btu per pound). Refrigeration load: 5400 X 0.075 X 60 X (32.71 -- 26.86) = 142,000 Btu per hour. The total refrigeration load for the dehumidi fier is therefore 263,000 Btu per hour or 21.9 commercial tons of refrigeration. .>uij 1M.0 i yyi iscnumunjier. zozu cim oi outside air cooled from 75 F wet-bulb (38.46 Btu per pound), to 62.5 F wet-bulb (28.12 Btu per pound). Refrigeration load: 2320 X 0.075 X 60 X (38.46 -- 28.12) = 108,000 Btu per hour. 5400 cfm of return air, cooled from 68.5 F wet-bulb (32.71 Btu per pound) to 62.5 F wet-bulb (28.12 Btu per pound). Refrigeration load: 5400 X 0.075 X 60 X (32.71 -- 28.12) = 111,500 Btu per hour. The total refrigeration load for the dehumidifier is therefore 219,500 Btu per hour or 18.3 commercial tons of refrigeration. A summary of the results with the two types of dehumidifiers is given in Table 2. Table 2. Comparison of Spray and Surface Type Dehumidifiers for Example 2 Air Conditions or Load Exit Air Conditions: Dry-bulb temperature, dee F . Wet-bulb temperature, dee F Dew-point temperature. Heg F Total refrigeration load, tons...... ........... .......... ......................... Rebeat necessary to raise dry-bulb temperature of exit air to 68 F. Btu per hour Spray Type Dehumidifier 60.7 60.7 21.9 60.900 Surface Type Dehumidifier 65.5 62.5 60.7 18.3 . 20.800 60 F diy-bulb t ) C Air in 95 F d y- bulb 78 F wiet-bulb Water in 50 F Water out 50V+30F80F Fig. 5. Counter-Flow Surface Cooling Diagram The design and selection of both spray and surface dehumidifiers is usually made largely on the basis of manufacturers' data, although there are certain general precautions to be observed. Air velocities in spray dehumidifiers are usually limited to 500 or 600 fpm, and the highest temperature of the spray water should be 2 or 3 F below the required exit dew-point. Surface units using cold water should be designed to obtain as near true counterflow as possible as shown in Fig. 5. Face velocities are usually from 400 to 600 fpm, and water velocities should be high enough to obtain good heat transfer, but low enough to avoid excessive pumping costs (preferred range is usually 1 to 3 fps). A close approxi mation of surface coil area can be made on the basis of the sensible heat transfer, if the latent heat load is not more than 25 of 30 per cent of the total. In this calculation the dry coil heat transfer coefficients are used, and the computation is the same as that used in selecting an air heating coil. If the coil loads, the entering air conditions, and the.refrigerant and air velocities are specified by the designer, then the refrigerant tem-. perature and the depth of coil to be used are dictated by the coil design, and cannot be arbitrarily selected. Surface coil performance is greatly affected by the refrigerant temperature, and if the refrigerant temperature 431 Heating Ventilating Air Conditioning Guide 1938 can be varied, as in a cold water system, the performance of the unit may to a certain extent be varied with the weather and load changes. reheating dehumidified air Table 2 (Example 2) indicates that the amount of reheating necessary to raise the dry-bulb temperature to the selected room inlet condition of 68 F, is greater in the case of the spray type dehumidifier than with the surface-type unit. The reheating process is a simple addition of sensible heat, arid the calculation for the spray-type unit is as follows: Example 8. Find the capacity of the reheater required in connection with the spray dehumidifier in Example 2. Solution. The heat to be supplied in Btu per hour by reheaters equals sensible heat to raise air from 60.7 to 68 F = 0.24 X 7720 X 0.075 X 60 X (68 - 60.7) = 60,900. Surface coils of this capacity must therefore be selected. ..................................... ` By-Pass System Example 4. The total sensible Heat gain in a restaurant when the dry-bulb tempera ture is held at 80 F is 200,000 Btu per hour. The conditioned space shown in Fig. 6, Fresh air 95 F (db) 75 F (wb) ............. Return air 301 lb per min Dehumidifier 51.2 F (dp) 80 F (db) 65 F (wb) . 1'<8 977 lb per min n c SI V%cc sar.Wna-------54.17 F (dp) || ^68 F (db) Conditioned 54.17 F (dp) enclosure 1146 lb per min Fig. 6. Diagram of By-Pass Method also^has a moisture gain of 384,000 grains per hour, and an outside air ventilation require ment of 2250 cfm.' Assume (as in Examples 1 and 2), a 12 F dry-bulb temperature differential between the entering air and the room temperature, which is the same as assuming the dry-bulb temperature of the entering air to be 68 F. It is required to maintain the room conditions at 80 F dry-bulb, 65 F wet-bulb, 56.5 F dew-point. .Cal culate the air capacity of the system, the amount'of return air to be by-passed, and the dew-point temperatures at room inlet and dehumidifier outlet. Solution. In this system, instead of passing all of the air through the dehumidifier for cooling and dehumidifying, a portion of the return air is. mixed with the conditioned air at the leaving end of the dehumidifier. The mixture is proportioned so that the resultant conditions are those required at the room inlets, (neglecting losses). ' As in Example 1, the sensible heat load which can be absorbed by one pound of air is 2.88 Btu, and the total air quantity required is then: 200,000/2.88 X 60 = 1146 lb per minute, or about 15,300 cfm. _ From Table 6, Chapter 1, the grains per pound of saturated air at 56.5 F is 68.0.- The latent heat load is already expressed in terms of grains of moisture, hence the mols-: ture to be added to each pound of air is: 384,000/1146 X 60 = 5.6. This gives the moisture content in the entering air which equals 68.0 -- 5.6 = 62.4 grains per pound, cor responding to a dew-point at the room inlet, of 54.17 F. . .. . The quantity of air to be dehumidified, the quantity to be by-passed, and the appa ratus dew-point temperature may be approximately calculated as follows: .Let X - percentage of air to be'by-passed. Y = percentage of air to be passed through the dehumidifier. : Id = apparatus dew-point temperature, degrees Fahrenheit. 432 - Chapter 22. Central Systems for Cooling and Dehumidifying The quantity X of 80 F air must mix with the quantity Y of dehumidified air to produce air with a resultant 68 F dry-bulb temperature. Also, X quantity of air at 56.5 F dew-point must be mixed with Y quantity of dehumidified air to give a resultant dew-point temperature of the mixture of 54.17 F. It is assumed that the air passing through the dehumidifier is saturated. Solving simultaneous equations, 80.0X + Yta = 68.00 56.5X + Ytd = 54.17 . 23.5AT + 0 = 13.83 ' (1) ' ,, 13.83 X 100 . .. , X = ----- 235------- 59 per cent, air by-passed. Y = 100 -- X =41 per cent, air passed through dehumidifier. The second step is to determine the apparatus dew-point temperature. Substitute X in either Equation 1 or Equation 2, and solve for Id: . 80 X 0.59 + Id X 0.41 =68 Id = = 51.2 F, the apparatus dew point. _ PROBLEMS IN PRACTICE . 1 What is meant by the term evaporative cooling? Evaporative cooling, or adiabatic saturation of the air, is only effective when the air to be cooled is very dry. It is accomplished by passing the air in an unsaturated condition through a water spray which evaporates a part of the water at the expense of the sensible heat. In this adiabatic transfer the total heat content of the air remains constant while the dew point rises and the dry-bulb falls until the air is saturated. 2 In central systems for cooling and dehumidifying what factors fir the quantity of air required? The weight or volume of air required depends wholly on the sensible heat gain in the room conditioned and on the difference between the dry-bulb temperature of the air at the room inlets and the dry-bulb temperature maintained in the room. 3 In central systems for cooling and dehumidifying can the dry-bulb tem perature change be fixed arbitrarily? No, because the change depends on factors at both the conditioner and the room. At the conditioner, temperature of the available water supply may limit the dry-bulb temperature of the leaving air. At the room, the dry-bulb temperature of the entering air may be further limited by: 1. The duct and supply grille arrangement permitted by architectural and structural requirements for the particular space, e.g., ceiling height and obstructions on ceilings, such as beams. 2. The state of activity of the occupants. 3. The velocity at the inlet grille, as limited by noise level requirements. 4. The direction of the jet relative to the occupants. 4 What factors determine the dew-point of the air entering the space? The maximum dew-point desired in the conditioned space, and the moisture gain in the space per unit weight of air supplied. 5 Why must the air leaving a dehumidifying type air washer often have its dry-bulb temperature raised before delivery to the occupied zone of room? The air leaves the dehumidifying air washer saturated at a relatively low temperature which in most cases is lower than the allowable delivery dry-bulb temperature as fixed by factors outlined under Question 3. Also, the air may possibly be carrying a small amount of entrained water which might settle out in the ducts near the washer and cause cor rosion difficulties. 433 Heating Ventilating Air Conditioning Guide 1938 6 What methods may be used to raise the dry-bulb temperature of the air after it leaves the dehumidifying air washer and before it enters the room? a. Sensible heat may be added by a reheating method from a source outside the air stream. This method passes all or part of the cold, dehumidified air over steam or hot water coils at the central conditioner or in the ducts, or over electric grids or similar devices. Any available source of sensible heat can be used. b. A mixing method using sensible heat already in the air stream. In this method the cold, dehumidified air is mixed with air at a higher dry-bulb temperature and the drybulb temperature of the resulting mixture is higher than that of the air when it left the conditioner. The air at high dry-bulb temperature is obtained by not passing it through the dehumidifying washer. The mixing may take place at a central conditioner or in the rooms themselves. c. Combinations of these methods. - 7 What are the advantages of using counter flow of air and water in surface cCoooulenrtse?r flow results in' a higher mean temperature difference than does parallel flow for the same range of air and water temperatures, which means that less cooling surface is required. Counter flow permits higher initial water temperatures and also allows a greater temperature rise for the water. These factors combine to reduce the cost of circulating and refrigerating the cooling water. \' 434 Chapter 23 UNIT HEATERS, VENTILATORS, AIR CONDITIONING, COOLING UNITS Classification of Unitary Equipment and Related Systems, Unit Heaters, Heating Medium, Estimating Heat Losses, Air Temperatures, Output of Heaters, Direction of Discharge, Boiler Capacity, Quietness, Piping Connections, Unit Ventila tors, Split and Combined Systems, Vents, Cooling Units, Air Conditioning Units, Heating, Humidifying and Dehumidi fication, Filtering, Location of Units, Air Distribution, Resi dential Central System Units, Capacities, Costs, Accessories to Unitary Equipment IN other chapters, complete descriptions have been given of heating, cooling, ventilating, humidifying, and dehumidifying systems. These descriptions have covered the detailed principles of each and have, in general, described the assembled equipment included in the complete systems. The success of such completely engineered, heating, cooling, and air conditioning systems has inevitably led to the production of smaller factory-assembled equipment employing a majority of the principles of these complete systems. As a result, present day practice involves the use of this unitary equipment in the majority of smaller installations where capacity demands are within the limits of such units. Thus, unit heaters, unit ventilators, cooling units and air conditioning units have come to occupy a place of their own in the industry. With the growth of this unitary industry, it becomes increasingly evident that there is no sharp line of demarcation, on the basis of capacity, between a unit and a central station system. Definitions contained in a code, Standard Method of Rating and Testing Air Conditioning Equip ment1, have helped to clarify and identify the various types available. A unit is a factory-made encased assembly of the functional elements indicated by its name, such as air conditioning unit, room cooling unit, humidifying unit, etc. Such units are shipped substantially complete or built and shipped in sections so that the only field work necessary is the assembling together of the sections, without resorting to any field fabri cation. A unit of this type may be complete in itself, employing its own direct means of air distribution and sources of refrigeration or heating, in which case, it thus represents a complete self-contained unit. Or it may be coupled with separate means of air distribution such as duct work and outlets, in which case, it will still be considered as a unit system, in dis- ^Proposed code prepared by Joint Committee of American Society of Refrigerating Engineers, American Society of Heating and Ventilating Engineers, Refrigerating Machinery Association, National Electric ' Manufacturers Association and Air Conditioning Manufacturers' Association. 435 Heating Ventilating Air Conditioning Guide 1938 tinction to the generally accepted term of a field fabricated central station system. The manufacturer of the unit is responsible for the output and performance of the unit under rated conditions, whereas the contractor installing the complete unitary system is normally held responsible for the complete performance of the system. Unit equipment justifies its existence due to the following features: 1. Lower cost per unit capacity. Standardized design and volume production makes possible low cost factory assembly thereby eliminating individual design and handling of every part for each installation. ' 2. Flexibility and mobility of equipment. Unitary equipment can be readily located in existing buildings without the necessity of running large ducts through floors and many partitions. Such equipment can be shifted to meet changing requirements. Tenants may obtain the advantages of conditioning when the entire building is not equipped with a conditioning system. In industrial process work, the flexibility of unitary equipment is also advantageous. 3. Lower installation costs. The fact that the equipment arrives on the job in an assembled condition, coupled with the lesser problems of duct work and connecting piping, materially reduces installation costs. 4. Small capacities. The small capacities available in unitary equipment have brought the advantages of controlled air conditions to a number of small offices, stores, shops, and individual rooms where specially designed and built central system equip ment would have been uneconomic. SUB-DIVISION OF UNITARY EQUIPMENT For descriptive purposes unitary equipment is sub-divided on a purely functional basis. The following definitions are included in the:previously, referred to code2. . 1. A Heating Unit is a specific air treating combination consisting of means for air circulation and heating within prescribed temperature limits. 2. A Cooling Unit is a specific air treating combination consisting of means, for air circulation and cooling within prescribed temperature limits. 3. A Humidifying Unit adds water vapor to and circulates air in a space to be humidified. 4. A Dehumidifying Unit removes water from and circulates air in a space to be dehumidified. 5. An Air Conditioning Unit is a specific air treating combination consisting of means for ventilation, air circulation, air cleaning and heat transfer with control means for maintaining temperature and humidity within prescribed limits. 6. A Cooling Air Conditioning Unit is a specific air treating combination consisting of means for ventilation, air circulation, air cleaning and heat transfer with control means for cooling and maintaining humidity within prescribed limits. 7. A Heating Air Conditioning Unit is a specific air treating combination consisting of means for ventilation, air circulation, air cleaning and heat transfer with control means' for heating and maintaining humidity within prescribed limits. 8. A Self-Contained Air Conditioning or Cooling Unit is one in which a condensing unit is combined in the same cabinet with the other functional elements. . 9. A Free Delivery Type Unit takes in air and discharges it directly to the space to be treated without external elements which impose air resistance. 10. A Pressure Type Unit is for use with one or more external elements which impose air resistance. ............ * *Loc. Cit. Note 1. 436 Chapter 23. Unit Heaters, Ventilators, Air Conditioning. Cooling Units There has grown up in the industry definite branches, in which the engineering and application of the equipment vary quite widely. Thus common acceptance recognizes the following groups of the unitary equip ment defined above. 1. Unit Heaters consisting of an encased heating surface through which air is forced by means of a fan or blower, located either in or closely adjacent to the heated space, and normally employed only for industrial and commercial applications. 2. Unit Ventilators which are similar in principle to unit heaters but are designed to use outside air with or without provision for recirculation of the air. While unit heaters are largely used for commercial and industrial applications, unit ventilators are intended primarily for school, offices and semi-commerciai applications. 3. Cooling Units which are similar to unit heaters except that a cooling medium is used in place of a heating medium and provision is made to collect and remove the con densate. Cooling units are normally applied to the. cooling of products for their pre servation or processing (commercial air conditioning) and air conditioning units are used for cooling for comfort. 4. Air Conditioning Units which consist of equipment to provide control of heating with humidifying or cooling with dehumidifying, coupled with air circulation; all com pactly housed in a single casing. 5. Miscellaneous Unit Equipment and Accessories such as filtering equipment, attic fans, humidifying units and special controls. UNIT HEATERS A unit heater consists of the combination of a heating element and fan or blower having a common enclosure and placed within or adjacent to the space to be heated. Generally no ducts are attached to inlets or outlets, although it is common practice with many unit heaters to equip them with directional outlets or adjustable louvers. While unit heaters are designed primarily to handle all recirculated air, they may be installed to handle either partial or total outdoor air. Compared with the older method of heating by means of radiation, properly designed and applied unit heaters should: 1. Circulate air in the building at a rapid ra.te but without objectionable draft. 2. Reduce the temperature differential between the floor and ceiling. 3. Direct the heated air so that uniform temperature distribution be obtained throughout the heated space. 4. Prevent or remove the cold stratum of air commonly found at the floor level. 5. Reduce the number of heating elements required and thereby decrease the cost and extent of the piping necessary. 6. Maintain a closer control of room temperature either manually or by means of simple thermostats. '' 7. Produce an economy in heating costs resulting from the sum total of the above advantages. ' TYPES OF UNITS There are two major types of unit heaters, propeller fan type and centrifugal housed fan type. The housed fan, high velocity (1500 to 2500 fpm) discharge units with outlets adjustable to deliver air in several directions, are able to project their heating effect over distance of from 30 ft to as much as 200 ft from the unit.. This makes possible the location of these units -at considerable distances from each other, thus reducing 437 Heating Ventilating Air Conditioning Guide 1938 Fig. 2. Floor Mounted Unit Heater, Housed Type Fan Fig. 3. Suspended Type Unit Heater, Housed Type Fan 438 Chapter 23. Unit Heaters, Ventilators, Air Conditioning, Cooling Units greatly the piping and loss of floor space due to the heating equipment. Propeller-type units, illustrated in Fig. 1, with outlet velocities of from 300 to 1000 fpm are usually placed from 30 up to 100 ft apart. Two methods of application of unit heaters are commonly used. Floor mounted units, shown in Fig. 2 are available either with or without the air by-pass, and withdraw the cold air from the floor and discharge the heated air above the working zone. Suspended type units are located in an elevated position withdrawing air from this higher level and dis charging the heated air down into the working zone. In closely occupied spaces where direct air drafts into the working zone are not permitted, the floor mounted unit will give more uniform temperature distribution. On the other hand, if opportunity is provided to deliver the heated air from suspended units down into the working zone, excellent'temperature distribution is possible. A suspended high-velocity type unit heater con nected to an outside air intake with damper to control the volume of ventilation is shown in Fig. 3. . A wide variety of structural designs is available. All employ some form of convector, supplied with either steam or hot water, although occasionally equipped for gas or electric heat. Air is always forced over these con vectors by a fan of either the propeller or centrifugal type. Heating sur faces may be in the form of steel pipe coils, non-ferrous tubes or pipes with extended surfaces, cast iron, and pressed or built-up sections of the cart ridge or automotive type. AIR TEMPERATURES8 For recirculating heaters with intakes at the floor level, the temperature to be maintained in the room should be considered as the temperature of the air entering the heater. Where outside air is introduced, the tem perature of the mixture must be calculated and used as the entering air temperature to the heater. Where suspended heaters are used without any intake boxes extending down to the floor level, a higher entering air temperature should be used than that at which the room is to be main tained. With suspended unit heaters taking air at some distance above the floor, the temperature variation from floor to ceiling may reach as much as 1 deg for each foot of elevation during the periods when the maximum capacity of the heaters is required. Thus this allowance should be made in calculating the capacity of suspended heaters. High velocity discharge units (blower type) will maintain slightly lower temperature differences than will low velocity units (propeller type). Unit heaters taking in recirculated air at the floor level should maintain temperature differentials of less than 0.5 deg per foot of elevation when the maximum capacity of the heaters is required. This temperature difference per foot of elevation is less than the corresponding variations for spaces heated by direct radiation. . `Temperature Gradient Observations in a Large Heated Space, by G. L. Larson. D. W. Nelson, and O. C. Cromer (A.S.H.V.E. Transactions, Vol. 39. 1933, p. 243). Tests of Three Heating Systems in an Industrial Type of Building, by G. L. Larson, D. W. Nelson, and John James (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 185). 439 T a b l e 1. " C o n stan ts fo r D e t e r m in in g , t h e C a p a c it y of U n it H e a te r s fo r V a r io u s St e a m P ressures , . An d T em per atu r es of E n t e r in g A ir ( Based on Steam Pressure of 8-lb Gage and Entering A ir Temperature o f 60 F) 1.538 1.585 1.640 1.730 1.799 1.861 1.966 .2.058 2.134 2.196 2.256 2.283 2.312 2.361 2.409 1.446 1.495 1.550 1.639 1.708 1.769 1.871 li959 2.035 2.094 2.157 2.183 2.211 2.258 2.307 1.369 1.405 1.456 1.545 1.614 1.675 1.775 . 1.862 -'1.936 1.997 2.057 2.085 2.112 2.159 2.204 1.. 273 1.320 1.370 1.460 1.525 1.584 1.684 1.771 1.845 1.902 l:9 6 l 1.990 2.015 2.063 . 2.108 1.191 1.110 1.237 1.155 1.289 1.206 1.375 1.290 1.441 - 1.335 1.498 1.416 1.597 1.509 1.683 1.596 1.034 1.078 1.127 1.211 1.275 1.333 1.429 1.511 1.582 1.640 1.696 1.721 1.748 1.792 1.836 0.956 1.000 1.050 1.131 1.194 1.251 1.346 1.430 1.498 1.555 1.610 1.635 1.660 1.705 1.749 0.881 0.809 0.926 0.853 0.974 0.901 1.056 0.982 1.117 1.043 1.174 1.097 1.266 1.190 1.349 1.270 0.739 0.782 0.829 0.908 0.970 1.024 1.115 1.194 1.262 1.314 1,368 1.392 1.418 1.461 1.502 0.671 0.713 0.760 0.838 0.897 0.952 1.042 1.119 1.187 1.239 1.293 1.316 1.342 1.383 1.424 . Heating Ventilating Air Conditioning Guide 1938 8 & eOoQ "s 8 S o li fe T 1 SE geo OfNUDO^lOOOOOOJOOOO al P 440 1.755 1.666 1.416 1.338 1.811 1.725 1.472 1.393 ' 1.872 1.782 1.527 1.447 1.896 1.808 1.552 1.472 1.925 1.836 1.577 1.497 1.968 1.880 1.621 1.541 2.015 1.927 1.663 1.581 N ote.__ T o determine capacity a t any steam pressure and entering temperature, m u ltip ly constant fro m table b y rated capacity a t 60 F entering and 2 lb pressure. Chapter 23. Unit Heaters, Ventilators, Air Conditioning. Cooling Units OUTPUT OF HEATERS It is standard practice to rate unit heaters in Btu per hour at a given temperature of air entering the heater and at a given steam pressure main tained in the coil. Steam at 2 lb pressure and air entering at 60 F are used as the standard basis of rating4. The capacity of a heater increases as the steam pressure increases, and decreases as the entering air temperature increases. The heat capacity for any condition of steam pressure and entering air temperature may be calculated approximately from any given rating by the use of factors in Table 1. This table is accurate within 5 per cent. Unit heaters are customarily rated as free delivery type units. If outside air intakes, filters, or ducts on the discharge side are used with the heater, proper consideration should be given to the reduction in air and heat capacity that will'result because of this added resistance. The percentage of this reduction in capacity will depend upon the characteristics of the heater and on the type, design, and speed of the fans employed, so that no specific percentage of reduction can be assigned for all heaters for a given added resistance. In general, however, disc or propeller fan units will have a larger reduction in capacity than housed fan units for a given.added resistance, and a given heater will have a larger reduction in capacity as the fan speed is lowered. When confronted with this problem the ratings under the conditions expected should be secured from the manufacturer. DIRECTION OF DISCHARGE Heaters may be distributed through the central portions of a room discharging toward exposed surfaces, or may be spaced around the walls, discharging along the walls and inward as well, especially when there are considerable roof losses. In general, it is better to direct the discharge from the unit heaters in such fashion that rotational circulation of the entire room content is set up by-the system rather than to have the heaters discharge at random and in counter-directions. Various types and makes of unit heaters are illustrated in the Catalog Section of this edition. Usually hot blasts of air in working zones are objectionable, so heaters mounted on the floor should have their discharge outlets above the head line and suspended heaters should be placed in such manner and turned in such direction that the heated air stream will not be objectionable in the working zone. In the interest of economy, however, the elevation of the heater outlet and the direction of discharge should be so arranged that the heated air shall be brought as close to the head line as possible, yet not into the working zone. In general, the higher the elevation of the unit, the greater the volume and velocity required to bring the warm air down to the working zone, and conse quently, the lower the required temperature of the air leaving the unit. Vol'li'6'193(jEp S165)dard Colle for Testing and Steam Unit Heaters (A.S.H.V.E. Transactions, 441 Heating Ventilating Air Conditioning Guide 1938 BOILER CAPACITY The capacity of the boiler should be based on the rated capacity of the heaters at the lowest entering air temperature that will occur, plus an allowance for line losses. Ordinarily for recirculating heaters the lowest entering temperature will occur at the beginning of the heating period and is usually taken as 40 F, while for ventilators taking air from outdoors the lowest entering temperature will be the extreme outdoor temperature expected in the district. No greater allowance in boiler capacity beyond the calculated heat demand need be added in order to supply unit heaters than for any other type of system. It is unwise to install a single unit heater as the sole load on any boiler, particularly if the unit heater motor is started and stopped by thermostatic control. The wide and sudden fluctuations of load that occur under such conditions would require closer attendance to the boiler than is usually possible in a small installation. Where oil or gas is used to fire the boiler, it is possible by means of a pressurestat to control the boiler, in response to this rapid fluctuation. In most cases, however, and particularly where the boiler is coal-fired, it is advisable to use two or more smaller heating units instead of one large unit. Steam pressures below 5 lb can be used with safety for recirculating unit heaters when their coils are designed for the purpose and when proper provision is made for returning the condensate. If ventilators are to take in air that may be at a temperature below freezing, however, a steam pressure of not less than 5 lb should be maintained on the convector or a corresponding differential in pressure between the supply and returns be maintained by means of a vacuum. QUIETNESS Fan speed alone is not a measure of relative quietness of fans having different designs and proportions. Quietness is a function of type, diameter, blade form and other variables besides speed, and all these must be considered. In general for a given design, the higher the fan speed, the greater the noise, and centrifugal fans are more quiet than disc or propeller fans. . PIPING CONNECTIONS Piping connections for unit heaters are similar to those for other types of fan-blast heaters. Typical connections are shown in Figs. 4 and 5. One-pipe gravity and vapor systems are not recommended for unit heater work. For two-pipe closed gravity return systems the return from each, unit should be fitted with a heavy-duty or blast trap, and an automatic air valve should be connected into the return header of each unit. Pres sure-drop must be compensated for by elevation of the heater above the water line of the boiler or of the receiver. In pump and receiver systems the air may be eliminated by individual air valves on the heaters, or it may be carried into the returns the same as for vacuum systems and the entire return system be free-vented to the 442 Chapter 23. Unit Heaters, Ventilators. Air Conditioning. Cooling Units atmosphere, provided all units, drip points, and radiation are properly trapped to prevent steam entering the returns. On vacuum or open vented systems the return from each unit should be fitted with a large capacity trap to discharge the water of condensation and with a thermostatic air valve for eliminating the air, or with a heavyduty trap for handling both the condensation and the air, provided the air finally can be eliminated at some other point in the return system. For high pressure systems the same kind of traps may be used as with vacuum systems, except that they must be constructed for the pressure used. If the air is to be eliminated at the return header of the unit, a high pressure air valve can be used; otherwise the air may be passed with the condensate through the high-pressure return trap, with some danger of return pipe corrosion and the problem of its elimination at some other point in the system. Fig. 4. Unit Heater Connections Where Condensation Is Returned to Vacuum Pump or to an Open Vented Receiver Fig. 5. Unit Heater Connections Where Condensation Is Returned to Boiler Through Wet Return ' All Electric OTHER TYPES OF UNITS The foregoing discussion relates generally to units in which steam or hot water is used as the heating medium. On rare occasions electrical resistances are used as the heating element. These are applied only where electric power is abundant and. cheap and where other forms of fuel are scarce and expensive. (See Chapter 40.) Direct Fired A recent development in. gas burning equipment is the direct-fired industrial unit heater. These heaters are of the warm-air type and are equipped with fans which cause the air to pass over the heating surfaces at a fairly high velocity and then direct the warm air in to the space to be heated. As is the case with the steam-fed unit heaters, the gas-fired appliances may be used for heating stores, shops, and warehouses. They usually are suspended in the space to be . heated and in most instances 443 Heating Ventilating Air Conditioning Guide 1938 leave the entire floor and wall area free for commercial use. Partial or complete automatic control also may be secured on appliances of this type. This type of heater is often used for. temporary heat during building construction or where the installation of a steam or hot water plant is for some reason not justified. For permanent installations, it is usually advisable to provide an exhaust duct from the gas-fired unit heaters to remove products of combustion from the occupied space. While this is not necessary in large open industrial plants, in smaller closed rooms, it becomes essential. . Turbine Driven Where high pressure steam is available it is sometimes used to drive a steam turbine direct-connected to the unit heater. The exhaust from this turbine, reduced in pressure, is then passed into the heating coil where it is condensed and returned to the boiler. INDUSTRIAL USES In addition to their prime function of heating buildings, unit heaters may be adapted to a number of industrial processes, such as drying and curing, with which the use of heated air in rapid circulation with uniform distribution is of particular advantage. They may be used for moisture absorption, such as fog removal in dye-houses, or for the pre vention of condensation on ceilings or other cold surfaces of buildings in which process moisture is given off. When such conditions are severe, it is necessary that the heaters draw air from outside in enough volume to provide a rapid air change and that they operate in conjunction with ventilators or fans for exhausting the moisture-laden air. (See discussion of condensation in Chapter 7.) UNIT VENTILATORS5 Unit ventilators while designed primarily for ventilation must incor porate controlled heating. A typical unit ventilator is illustrated in Fig. 6. They usually consist of a semi-decorative cabinet containing the following necessary or optional parts: 1. Outside air inlet. 2. Inlet damper for closing the opening to the outside air inlet when the unit is not in use. 3. Adhesive or dry type filters for cleaning the air (optional). : 4. A heating element usually of special design and intended for low pressure steam. 5. Motor and fan assembly. 6. Mixing chamber where warm and cold air streams are brought together. (No mixing chamber is normally provided where sectional type convectors are used.) 7. Outdoor air inlet and recirculating air mixing damper (optional). 8. Discharge grille or diffuser. 9. Temperature control arrangement. '. A roof ventilator is sometimes termed a unit ventilator. For information on roof ventilators, see Chapter 36. 444 23.Chapter Unit Heaters, Ventilator Air Conditioning. Cooling Un^ The primary functions of a unit ventilator are: . -' 1. To supply a given quantity of outdoor air for ventilation or to. mix indoor and outdoor air. (See A.S.H.V.E. Ventilation Standards, Chapter 45). 2. To warm the air to approximately the room temperature if the unit is intended for ventilation only, or to a higher temperature if it is intended to take care of all or a part of the heat transmission losses from the room. ' 3. To control the temperature of the air delivered so as to prevent both cold drafts and overheating. (See Chapter 37). :: 4. To deliver air to the room in such a manner that proper distribution is obtained without drafts. - 5. To recirculate room air for the purpose of heating or promoting comfort when ventilation is unnecessary. (Ordinances should be consulted). 6. To perform all its functions without objectionable noise. 7. To clean the air properly. Fig. 6. Typical Unit Ventilator Showing One of Many Arrangements of Dampers and Heating Coils SPLIT AND COMBINED SYSTEMS In a split system the unit is used primarily for ventilation. Air is delivered to the room at very near the room temperature, and enough separate direct heaters are placed in the room to warm it to the desired temperature, independently of the unit. Their principal advantage lies in offsetting the cooling effect of window and wall surfaces long before these can be heated to room temperature and in retaining heat for this purpose after the ventilation is shut down. _ Where the unit ventilator selected has a capacity more than sufficient to warm the air needed, to meet the ventilating requirements, a cor responding reduction may be made in the amount of direct heating surface installed. The greater the amount of excess capacity of the unit, the more efficient will be the temperature regulation of the room. The split system permits the heating of the room during failure of electric current, 445 Heating Ventilating Air Conditioning Guide 1938 ' since the direct radiators will furnish heat, but it permits a careless operator to avoid operating the ventilating equipment. A combined system employs the unit ventilator alone, its capacity being sufficient both for ventilation and for supplying the heat loss. Direct heating surface is omitted altogether. It becomes necessary then that the fan be running whenever the room is to be heated but this also gives assurance of ventilation, especially if automatic dampers are used in the air intake from out-of-doors and in the recirculating intake arranged so as to give a certain quantity of air from the outside (commensurate with weather conditions) whenever the unit is operating and after the room is heated. The cost of installation of a combined system is usually less than that of a split system and there is less danger of overheating, but if the electric energy fails there will be practically no heating. LOCATION OF UNIT The location of the unit ventilator in a room is important. Wherever possible it should be placed against an outside wall. It is difficult to obtain proper air distribution if the unit is erected either on an inside wall or in a comer of the room. Standard units discharge the air stream up . ward, but for special cases units may be installed to discharge air hori zontally. Units may be set away from the wall or partially recessed into the wall to save space without materially affecting the results. The air inlet may enter the cabinet at the back at any point from top to bottom. VENTS6 The size and location of the vent outlet is important. In many cases the sizes for public buildings are regulated by law, but the location of the vents generally is left to the discretion of the engineer. Best results have been obtained with a velocity through the vent openings nearly equal to that at which the air is introduced into the room, thus maintaining a slight pressure in the room. Calculated velocities at the vent openings of from 600 to 800 fpm produce the best diffusion results from this system. The cross-sectional area of the vent flue itself may be figured on the basis of 15 sq in. of flue for each 100 cfm. Thus the vent flue area of a . flue for a room equipped with one 1200 cfm unit ventilating machine would be 180 sq in. The area of vent flue opening from the room may be figured on the basis of 25 sq in. per 100 cfm. In school buildings provided with wardrobes or cloakrooms the vents may be so located that the air shall pass through these spaces, heating and ventilating them with air which otherwise would be passed to the outside ' without being used to the best advantage. Many state codes for vend-. lation of public buildings make this arrangement mandatory. There has been much controversy over the use of corridor ventilation in school building practice, one group holding the view that when each `Investigation of Air Outlets in Class Room Ventilation, by G. L. Larson, D. W. Nelson, and R. W. .Kubaste (A.S.H.V.E. Transactions. Vol. 38, 1932, p. 463). . Air Supply to Classrooms in Relation to Vent Flue Openings, by F. C. Houghten, Carl GutberleL and M. F. Uchtenfels (A.S.H.V.E. Transactions, Vol. 41. 1935, p. 279). 446 Chapter 23. Unit Heaters, Ventilators. Air Conditioning, Cooling Units classroom has a separate vent flue there is a minimum fire risk and less likelihood of cross-contamination, while others emphasize the economy features of the corridor discharge and minimize the fire, contamination, and other hazards. . CAPACITIES Unit ventilators are available in air capacities ranging from 450 cfm to 5000 cfm and with corresponding heat capacities (above that required for ventilation purposes based upon an outside temperature of zero and an inside temperature of 70 F) ranging from 15 Mbh to 144 Mbh (1 Mbh = 1000 Btu per hour). Some manufacturers furnish a unit with several heating capacities for each air capacity, thus enabling the engineer to select the unit best adapted to the heating and ventilating load. Typical capacities are given in Table 27. Table 2. Typical Capacities op Unit Ventilators fob __________ an Entering Air Temperature op Zero Cubic Feet of Am feb Minute 600 750 1000 1200 1500 Total Capacitt in Square Feet of Equivalent Direct Heating Surface (Radiation) EDR 285 350 455 ' 565 705 Mbh 68 84 110 136 169 Capacitt Available fob Heat ing the Room in Square Feet of Equivalent Direct Heating Surface (Radiation) . Final Am Tempera ture (Deo Farr) EDR . Mbh 95 115 . 150 190 235 23 ' 28 36 46 56 105 105 105 105 105 ii no airect nesting surface (radiation) is installed, the combined heating and ventilating requirements must be taken care of by the unit ventilators, and the total heat to be supplied is obtained by means of the following formulae: When all of the air handled by the unit is taken from the outside. Hi = 0.24 W(ty-to) W = d 60 Q (1) (2) where b -- 0.24W +1 (3) d = density of air, pounds per cubic foot. H = heat loss of room, Btu per hour.' Hv - heat required to warm air for ventilation, Btu per hour. Hi = total heat requirements for both heating and ventilation, Btu per hour -- H Hv Q = volume of air handled by the ventilating equipment, cubic feet per minute. t = temperature to be maintained in the room. to -- outside temperature. (y = temperature of the air leaving the unit. ^*"1VoL^MB^pf Code for Testint: and Stean* Unit Ventilators (A.S.H.V.E. Transacttons. 447 Heating Ventilating Air Conditioning Guide 1938 W = weight of air circulated, pounds per hour. 0.24 = specific heat of air at constant pressure. From Equations 1, 2 and 3: Ht = H + 0.24 d 60 Q (I - to) . (4) . Example 1. The heat loss of a certain room is 24,000 Btu per hour, and the ventilating requirements are 1000 cfm. If the room temperature is to be 70 F and all air is taken from the outside at zero, what will be the total heat demand on the unit if it is required to provide for both the heating and ventilating requirements (combined system)? Solution. H = 24,000; d = 0.075 Q = 1000 cfm; < = 70 F; t0 = 0 F. Substituting in Equation 4: ' Ht = 24,000 + 0.24 X 0.075 X 60 X 1000 (70 - 0) = 99,600 Btu i _ ________ 24,000 . 4- 7ft s Q2 9 F ^ 0.24 X 0.075 X 60 X 1000 ^ When part of the air handled by the unit is taken from the room and the remainder from the outside, ' Ht = 0.24Wo (/y - to) + 0.24 Wi(ty - t) (5) where W0 = weight of air, pounds per hour taken from out-of-doors. Wi = weight of air, pounds per hour taken from the room. Wo = do SO Q0 ' Wi = dj 60 (2i . (6) - -j,7) where 0d = density of air, pounds per cubic foot at temperature to- di = density of air, pounds per cubic foot at temperature t. Qo = volume of air taken in from the outside, cubic feet per minute. Qi = volume of air taken in from the room, cubic feet per minute. -' h = 0.24 (Wo + Wi) + 1 , (8) . Ht = H + 0.24 do 60 Qo (f -- (o) (9) Equations 5, 6, 7, 8, and 9 may be used in the same manner as is illustrated above for Equations 1, 2, 3, and 4. It may be noted in Equa tion 9, representing the total heat requirements, that as the quantity Qo is diminished the heat requirements for the unit diminish very materially.: . In Example 1, if the quantity of air taken in from the outside is reduced to zero, or all of the air handled by the unit is recirculated, the total heat requirements Ht reduce from 99,600 Btu to 24,900 Btu, or to about one fourth. Such a unit handling one third of its air volume from the outside .and two thirds from the room would show a total heat requirement of 24,000 + ,600 _24,000 _ 59 200 Btu. Units designed and operated U. 448 Chapter 23. Unit Heaters. Ventilators. Air Conditioning, Cooling Units on this principle show an average heat requirement and, therefore, a boiler capacity requirement of less than 50 per cent of that required for units taking all their air from the outside. If all of the air is recirculated, the total heat required is the same as the heat loss of the room, or Ht = H = 0.24 W (fy - t) (10) If the heat loss of the room is to be taken care of by the direct heating surface, the unit ventilators will be required to warm the air introduced for the ventilating requirements. Therefore: : . Hv = 0.24 W y - to) . (11) In this case U, should be equal to or slightly higher than /. If the unit ventilator were of such capacity as to exactly provide for the ventilating , requirements, the direct radiation would be selected on the usual basis. However, it is necessary to employ a unit which may not exactly meet the ventilating requirements, since standard Units are usually rated in terms of the volume of air that will be delivered at a certain temperature U, for an initial temperature of to- Therefore a certain amount of heat (.Hi,) may be available from the unit ventilator for heating purposes, as pre viously stated, and the amount of equivalent direct heating surface may, if desired, be deducted from the amount required for heating the room. COOLING UNITS Cooling units as applied to industrial product conditioning and pro cessing are similar in construction to unit heaters except that the heat transfer surface is supplied'with refrigeration instead of with steam or hot water. They are normally installed within the space to be served, or at least closely adjacent thereto. Occasionally they are provided to receive outside air in which case this air is invariably filtered.or washed to prevent any possible contamination of the product. . .. . Cooling units are provided in two major types similar to unit heaters, either floor mounted with housed fan, or suspended, with propeller type fans. 'Normally, air outlet :velocities are lower than for heating, due largely to the effect of high velocities on the product. Cooling units are' normally of the free delivery type although they occasionally are sup plemented with duct work to provide more careful air distribution. Product cooling originally, was accomplished by means of stationary pipe coils. This was later supplemented with the forced fan bunker systems in which air was passed over banks of coils. The present trend in this field is toward a more accurate control of both temperature and humidity, thus placing these units in the classification of complete air conditioning units as discussed in the next section. However, in the majority of these cases dry-bulb temperature is controlled separately from the control of humidity, thus classifying these units as cooling units. The principal field for cooling units is in cold storage plants,, fur storage, fruit packing houses, provision stores, brewery fermentation and stock rooms, candy plants, and other industrial process work. In replacing bunker and wall coils in meat storage plants, cooling units give distinct 449 Heating Ventilating Air Conditioning Guide 1938. advantages in compactness, lower first cost and maintenance expense, ease of defrosting, freedom from drip and the maintenance of sanitary conditions, as well as uniform temperature and humidity under variable load conditions. Cooling units by means of their positive air circulation prevent dead-air spots, frequently objectionable in this industry. Typical cooling units are shown in Figs. 7 and 8. The former indicates a suspended type cooling unit which may be designed with or without a moisture eliminator. If high air velocities are maintained, an eliminator will be necessary to prevent the drops of moisture from being carried through with the air. The condensation that occurs is collected in a drip pan and removed from the system through a drain pipe. Fig. 8 indicates a typical floor-mounted unit of the housed fan type.' The illustration shows a common form of distributing outlet designed to give low outlet velocities together with a controlled distribution. In process work, it is often important that direct air distribution does not impinge on the Chapter 23. Unit Heaters. Ventilators. Air Conditioning. Cooling Units In order to prevent the collection of frost in low temperature rooms where high latent heat loads are present, unit coolers equipped with a constant brine spray are frequently used. These are normally of the housed fan type similar to Fig. 9, but equipped with a pump for recircu lating brine over the coil. It is, of course, necessary to strengthen the brine at intervals to maintain a non-freezing mixture. Ratings of cooling units may be expressed in Btu per hour, or in tons1o2f3 4 5 refrigeration and should specify the quantity, temperature and humidity of the air entering the unit with a stipulated refrigerant temperature product. Cooling units are normally constructed of galvanized steel or non-ferrous material in order to reduce the corrosive effect of their constant wetted condition. . Cooling units are often called upon to operate in rooms where a tempera ture below freezing is maintained and low refrigerant temperatures are required. This results in the collection of frost on the heat transfer surface which in turn leads to a rapid loss in capacity and requires eventual defrosting. Such defrosting is accomplished by the following methods: 1. When the room is above freezing the source of refrigeration is cut off and the fan allowed to operate until the unit has defrosted. 2. A reversal of the refrigeration system may be provided and the so-called hot gas defrosting method used. This is accomplished by reversing the flow of the hot gas so that it is delivered directly from the compressor to the evaporator of the cooling unit. As soon as the ice and frost has been melted, the system is again returned to its normal cycle. 3. Where brine is used as a refrigerant, heated brine may be sent through the cooler to remove the ice. 4. When the room is at very low temperatures, warm air defrosting is sometimes used by providing for the admission and removal of warm air from outside the cooled space. 5. The surface may .be sprayed with a strong brine solution: . 450 within the coil. When chilled water or brine is used, the rate of circu lation of the cooling media as well as its entering temperature must be given. . AIR CONDITIONING UNITS Air conditioning with unit equipment has gained in popularity during the last few years and this type of apparatus now represents the bulk of the production of the industry.' It is to be noted that some equipment does not fulfill all of the basic requirements of a true air conditioning unit. True air conditioning equipment involves not only the ability to alter temperature and humidity conditions within the conditioned space, but it* must also be able to control these conditions.- The means for accomplishing these functions are outlined herewith: 451 Heating Ventilating Air Conditioning Guide 1938 Heating The normal air conditioning unit derives its heating function from a heating coil, usually of the non-ferrous finned tube type supplied with either steam or hot water. Steam may be supplied directly from a self- contained and built-in oil or gas fired unit, from a separate domestic steam boiler, or even from an outside source of a central heating plant. Hot water is-supplied either from a separate hot water boiler or in rare instances from a domestic water heater. . . . . In domestic of household conditioning units, adapted from a warm-air heater to which humidification is added, or possibly all-year-round con ditioning, a direct-fired air interchanger is frequently used. The source of heat in this case may be from the combustion of coal, oil, or gas. A wide variety of designs and structures are used. In such direct-fired systems, the bulk and volume of the heat transfer surface is necessarily large in proportion to the rest of the equipment. Where electric power is low in cost, electric heat has been furnished for air conditioning units either in the form of encased heaters, or open wire heaters. (See Chapter 40.) Radiant electric heaters are seldom used except as their radiant heat is absorbed by some receiving wall and there transmitted to the air in the form of convected heat. Another method of applying electric heat is by means of the reversed refrigeration cycle, whereby electric energy is used to compress a re frigerant and to deliver the heat of compression, withdrawn from a lower temperature source, to the conditioned space by locating the condensing coils in the air circulation circuit of the air conditioning unit. While this method of heating has gained wide interest, it is practical only in a limited number of applications. .. Humidifying . - A variety of methods have been used to furnish humidification in winter to air conditioning units. The oldest and best known is by means of a direct spray which is used in many different ways. The simplest system.is where the spray water is furnished from a constant water source, such as city water, and is permitted to run to waste. Under such con ditions, the spray may be either of the direct atomizing type where, by means of the nozzles, the water is broken into fine particles, or of the so- called target spray type, where a fine stream of water under pressure; is caused to impinge upon a flat surface or target. Such methods are normally rather inefficient in the use of water. In some units, in order to increase the humidifying capacity and to utilize a greater portion of the. spray water, the atomized spray-is per mitted to impinge against a heated surface thereby forcing its evapora tion. While this is practical in some instances, there is danger of scale formation where hard water is employed.. ' One of the simplest methods of humidification in winter is by means of a direct steam spray.. This is seldom used in air conditioning units for .comfort applications due to the resulting odors. In industrial appli cations, however, it finds frequent use. The steam is usually introduced to the air through a perforated tube or through some type of porous material. . ' .. !. . - '--; . ." .452 Chapter 23. Unit Heaters. Ventilators. Air Conditioning, Cooling Units If a small atomizing spray is not used in comfort conditioning units, the evaporative pan type of humidifier is usually employed. This consists of a container offering as much water surface as possible and equipped with means of heating the water.- This heat may be applied either electrically, by steam, hot water, or by circulation of the water from a heated space through the evaporating pan. Since the humidification is accomplished by surface evaporation only, it is essential that the air stream be directed across the surface and that the evaporating surface be large. While this system eliminates the dusting hazard when hard water is used with a spray system, hard water tends to scale the heating surface and results in loss of capacity and the need for frequent cleaning. The rate of evaporation per unit surface exposed is low, thus it fre quently becomes difficult to provide sufficient surface for adequate capacity. The higher the temperature of the water, the lower the relative humidity of the air; the greater the velocity over the surface, the greater is the rate of humidification; The evaporative pan type of humidification limits the water wastage and is usually supplied with water through a float valve. Due to the collection of salts in this evaporating pan such humidifying, systems require occasional drainage and cleaning. . Other methods of humidification attempted in air conditioning units are through the use of.wetted fabrics, porous eathernware plates, or other capillary surfaces. These methods rely upon the capillary absorption of the moisture up from the liquid level into, the portion exposed to the air. They have a tendency to lose their effectiveness due to the resulting deposit of mineral salts at the evaporating surfaces thereby clogging the pores and reducing the contact of the air with the water. Also they frequently become foul and often support bacterial growth. Cooling and Dehumidification . Those units that employ recirculated water sprays will undoubtedly use such sprays as their means of cooling and dehumidification by furnishing refrigeration to the water in. circulation. Occasionally where an adequate source of cold well water is available, this may be used as a direct spray and run to waste. Other methods of dehumidification accomplished by direct contact with the transfer medium are by means of the so-called adsorption and absorption systems. (See Chapter 24.). It must be recognized that these methods of dehumidification do not in themselves provide cooling. The substance removes the water vapor from the air thereby heating it. This highly dehumidified air may then be cooled either, by partial rehumidi fication or by direct contact with a cooling medium of cold -water or direct expansion refrigerant. There are now on the market solid adsorbents such as silica gel and activated alumina. Water solutions of the chlorides of various inorganic elements such as calcium and lithium chloride are the absorbents most frequently used. . . . . Finally a common direct means of cooling and dehumidification is through the use of ice. In such units the ice is brought into as intimate contact as possible with the air handled. Provision is made for the removal of the moisture as rapidly as it is formed from the melting of the 453 Heating Ventilating Air Conditioning Guide 1938 ice. Ice is also used to cool water which is circulated through the sprays. In conditioning units, the use of surface cooling is probably more common than direct spray or other direct transfer means. The type of surface employed may, of course, be cast or fabricated from tubes. In present day practice finned tubes or plate fins through which tubes are passed form the most generally used cooling surface. The detailed fabri cation of this surface and the arrangement of the tubes will depend largely upon the type of refrigerant for which it is intended. The simplest construction is where chilled water or brine is used as the refrigerating medium. With direct expansion refrigerant it is usually necessary to provide a special arrangement of headers so that proper distribution of refrigerant through all the surface is obtained. In some cases, ordinary brine coils can be used when operated as a flooded refri gerant system. In some units a combination of a direct spray and a refrigerant surface is used, the spray being directed against the surface. Such systems claim the advantage of air washing together with the maintenance of a clean and effective cooling coil. It should be noted that when surface coolers are used, adequate pro tection in the.form of filters or at least lint screens are necessary to prevent fouling of the surface from the air borne dirt. Surface not so protected frequently becomes completely matted with lint, grease, and similar dirt. The sources of refrigeration used with these surface type conditioning units are discussed in Chapter 24. However, they may be divided into the following groups: 1. Direct expansion refrigerant in which the liquid refrigerant is evaporated within the coils of the unit. The vapor from these coils may be recompressed in centrifugal, rotary, or reciprocating type compressors, and the refrigerant again returned to the evaporator coil. . 2. Indirect refrigeration by means of: . o. Cold well water. . b. Cold city water. . c. Artificial refrigerated water provided by direct expansion of refrigerant in a water cooler, direct steam jet refrigeration, or by the melting of ice. Filtering--Air Cleaning ' A variety of methods are employed as a means of controlling air purity. In unit systems where filtering alone is considered satisfactory, the degree of filtering varies widely and in proportion to the actual needs. If the air is chiefly recirculated with but little outside air used for ventilation, filtering requirements are largely limited to keeping the coils in.a clean and operable condition. Thus such units are frequently furnished with simple lint screens of low resistance and formed of moderately close meshed wire. Where outside air is used for ventilation, more complete filtering of dust particles is necessary and for this purpose, there are a large number of filters available on the market. Some of these filters are of the so-called throw-away type, constructed of inexpensive material so that when they become dirty or clogged they may be thrown away and replaced with new ones. All of these filtering methods are described in detail in Chapter 26. 454 Chapter 23. Unit Heaters, Ventilators, Air Conditioning, Cooling Units Ventilation Inasmuch as air purity is one of the factors that constitute true air con ditioning, ventilation or the introduction of outside air is an essential part of any air conditioning unit or system. While a unit that recirculates all its air capacity is still considered an air conditioning unit, the better type system provides for the introduction of a certain proportion of outdoor air. In some instances one of several units may operate entirely on out side air, while in other cases only a portion of the air handled by the unit is drawn from out-of-doors. In such cases a damper is provided either in the unit or in the duct connections for controlling the proportion of outdoor air. Location ol Air Conditioning Units The characteristics of the conditioned space, the building construction, the type of system employed, the duct connections as well as the source of power, piping and refrigeration influence directly the location of air conditioning units. Primarily a unit is either of the portable or fixed type. The portable unit is usually a simple self-contained air conditioning or cooling unit either with or without ventilation, but includes the condensing unit. If the condensing unit is of the air-cooled type, the unit must be located adjacent to a window or other source of outside air. On the other hand, if it is of the water-cooled type, its location should be convenient to sources of water and drainage. Portable units are invariably located within the conditioned space. Non-portable units, or units of fixed location may or may not be located within the occupied space. Naturally units that are located in such spaces must be built with decorative cases in order to harmonize with the surroundings. Such units are normally of comparatively small capacity varying from a fraction of a ton up to as much as five or six tons. Many conditioning units and particularly those of the larger sizes are located externally to the occupied and conditioned space and are connected thereto by means of delivery and return ducts. Such an arrangement permits the location of the conditioning unit convenient to either the sources of refrigeration or outside air. It frequently permits the use of the basement or of space less valuable than that on the level or floor of the occupied zone. Oftentimes the same type of unit may find application in an exposed position for one job and in a concealed location for another. Thus it can be seen that it is not possible to define a unit merely on the basis of its location. Frequently conditioning units are built into the structure or into the architectural design of a room so that they are entirely concealed except for the discharge and return grilles or openings which are designed so as to correspond to the decorative scheme of the room. Air Distribution With portable units or units exposed within the conditioned space, the distribution is usually through grilles or louvres built entirely into the equipment. The discharge of the air from this unit, in general, should be . 455 Heating Ventilating Air Conditioning Guide 1938 upward immediately at the unit, with sufficient horizontal component to carry it to the most remote point in the room. Such a distribution permits the cool air to drop slowly over the entire zone and return to the inlet of the unit below the breathing line and along the floor. The location of doorways, air vents, and heat exposed walls should be carefully observed, as they have a marked effect on the direction of the air flow and on its uniformity of temperature. With the suspended type of unit, located within the conditioned space, sufficient outlet air velocity should be provided to give adequate induction and mixing with the room air thereby preventing the immediate dropping of the air stream and resulting objectionable cold drafts. ! ' Where the units are located outside the conditioned space, air dis tribution is more frequently provided through multiple outlets located in ducts from the conditioning unit. The location of these outlets is quite Chapter 23. Unit Heaters, Ventilators, Air Conditioning. Cooling Units of current makes and models will be found in the Catalog Data Section. A few typical designs of conditioning units will be described in detail. An all-year floor type heating and cooling unit for an exposed location and with direct expansion coil supplied with refrigerant from a remotely located compressor is shown in Fig. 10. A cooling coil for use with chilled water may be substituted for the direct expansion coil indicated. The fans below the separate cooling and heating elements deliver the air against deflectors thereby obtaining distribution across the face of the element and preventing condensate from dripping down into the fans. The plate upon which the fans are mounted serves as the drip pan from which the water is conducted to the drain. Separate elements are used for heating and for cooling. Thus this unit may be used automatically for heating and cooling without manual control. When the unit is used for summer conditioning only, the heating coil may be omitted for the Fig. 10. Floor Type Heating and Cooling Unit critical and is influenced both by the building construction, economies of connections and by the distribution of load. There are a wide variety of outlet types^ used, and most of these have fixed delivery characteristics, thus-requiring careful consideration.in their location. Some types of outlets are now available with adjustable vanes thereby permitting some alteration in the delivery of the air stream after installation. This frequently eliminates objectionable down drafts re sulting from the impingement of the air stream against posts, pillars, lighting fixtures, and beams. .. ' . TYPES OF UNITS Several types and designs of air conditioning units in production and proposed are available for selection. New designs are constantly ap pearing, with new improvements, greater capacities, wider range of application and superior construction. It will be impossible to cover in this chapter the many types of construction on the market. Illustrations 456 Fig. 11. Conditioning Unit with Top Inlet and Outlet installation. The illustration indicates an evaporative type humidifier and drain pan. Other units are available in which a target spray humidifier is sub stituted for the evaporative type thereby providing a unit for. summer cooling and dehumidification, at the same time supplying humidification in winter for application in rooms with other existing heat sources. Still another unit is available in which the fans are mounted at the top of the unit delivering directly through a grille and drawing their air supply through the cooling and heating coils. Other variations in pro portion and details of construction of this general arrangement are common. With this type of unit, ventilation is usually provided. by means of a separate duct connected to the inlet of the unit. An entirely different arrangement shown in Fig. 11 places both the air inlet and the discharge at the top of the unit. The fan at one side dis charges the air downward to the bottom where it turns and passes hori- 457 yy-: Heating Ventilating Air Conditioning Guide 1938 zontally through an atomizing spray air washer. The path then con tinues upward through eliminators, a cooling surface and a.heating surface before it leaves the unit. With steam or hot water connected to the heating element, tempered water to the sprays and refrigerated water to the cooling element, this unit gives controlled temperature, humidity, air cleaning, and air movement in both summer and winter. Air washing may be connected in summer, or in intermediate'season to remove room Chapter 23. Unit Heaters. Ventilators. Air Conditioning. Cooling Units chamber to prevent external condensation. The drip from the coil is collected in an insulated drip pan and carried to a drain. The inlet to the unit is provided with a lint screen to protect the cooling surface. Such units are normally used for recirculation only but may be connected for ventilation through short full-size ducts. Similar units are available with twin housed fans of the same general construction, although usually such fans draw the air instead of blow it through the coils. A self-contained completely portable cooling air conditioning unit is ' illustrated in Fig. 13. For the operation of this unit, it is only necessary that it be located adjacent to a window or shaft to which air connections can be made and to plug in the motors to a convenient light socket. In this unit, the conditioned air enters on the side, passing through a grille, filter, and cooling coil and is delivered vertically to the room through a I special motor and fan assembly. Refrigeration is furnished by a recipro- VALVE Fig. 12. Suspended Propeller Fan Tvpe Cooling Air Conditioning Unit Fig. 13. Portable Self-Contained Conditioning Unit for Cooling odors. Excess water is run to waste. Acoustical treatment of the housing and outlet baffles permits installation where noise requirements are exacting. A common type of suspended type unit for exposed location utilizing a propeller type fan and suitable for summer conditioning only is illustrated in Fig. .12. Such units are equipped with either a direct expansion coil or one for chilled water or brine circulation. The outer cabinet is commonly of wood-grained steel or baked enamel and is insulated from the cool air 458 Fig. 14r- Vertical Remote Type All Year-Round Conditioning Unit Fig. 15. Spray Type Air Conditioning Unit eating compressor driven from a motor located in the base. This com pressor utilizes an air cooled condenser. Air is drawn into the base by a fan mounted on the compressor motor, so arranged that the air passes through the refrigeration condenser, and is again discharged out through the window connection. A novel feature of this design is that the con densate from the cooling coil is sprayed over the condenser surface and there vaporized, thus eliminating the need for drain connections. One advantage of this type of conditioning unit is that it may be removed from the occupied space during the winter season when cooling is not needed. Another type of portable unit for occupied space locations differs from the former in that the compressor is water cooled and a connection to water and drain must be provided in addition to the electric connection. Water and drain lines are carried in a composite hose, especially built for this purpose and connections are usually made to a nearby -washbowl. 459 Heating Ventilating Air Conditioning Guide 1938 In order to reduce the starting load, one model has two separate motors brought on to the line at delayed intervals thereby decreasing the initial line surge and reducing light flicker. These water cooled units either eliminate or reduce the need for outdoor air connections. Due to the necessity of water and drain connections they are not as portable as the air cooled type. Remotely located conditioning units vary widely in details of con struction. Figs. 14,15 and 16 indicate one type built-in sections thereby permitting interchangeability of application with a minimum change in parts. The vertical unit shown in Fig. 14 consists of a fan section, housing one or more fans, mounted on a coil section in which are located a heating coil and a cooling coil, which may be built for either direct expansion refrigerant, chilled water, or brine. These two sections are supported on a third or drip-pan section. The distributing duct system is attached to the fan outlets and returned fresh air connections are made to the drip pan. A filter box is illustrated attached to the drip-pan section. By Chapter 23. Unit Heaters. Ventilators, Air Conditioning, Cooling Units application. The smaller units have, of course, been applicable to residences. There remains a. field of air conditioning units primarily adaptable to residence work. They are in general the outgrowth or adaptation of mechanical warm air systems to conditioning, which are covered in Chapter 20. However, the following illustrations will cover details not included in that Chapter. In Fig. 17 is shown a conditioning unit which may be operated in conjunction with a hot water or steam boiler. Heat generated in the boiler is supplied to an exchanger which raises the air temperature as it is circulated through the unit. The connection of a cooling coil to a Fig. 16. Horizontal Remote Type All-Year-Round Conditioning Unit eliminating the vertical type drip pan and substituting a horizontal drip pan, this unit is converted into a horizontal suspended type conditioning unit for connection to duct work, both with and without filters, as shown in Fig. 16.. v A spray type conditioning unit is illustrated in Fig. 15. This spray type unit, which is similar to the arrangement given in Fig. 14, provides for the complete washing of the air and the cooling coil. For winter operation the spray provides means for humidification. The units may also be obtained with by-pass dampers as shown in Fig. 15, to provide control of cooling in summer and humidification in winter. The spray type unit without the cooling coil may be used for humidification and heat control. This type of air conditioning unit is used in industrial process air conditioning as well as for comfort air conditioning. Residential Central System Units The previous figures have largely confined themselves to the illustration of all-year-round or summer conditioning units for office of commercial 460 ' source of refrigeration will provide year-round air conditioning.- This type of system is particularly adaptable to a split system in which a portion of the residence may be conditioned in the winter and summer while the garage, servants' quarters and less freqently used rooms may be . provided with radiator or convector heating directly from the boiler in the winter. A gas-fired winter conditioning unit is illustrated in Fig. 18 which is, equipped with apparatus to filter, heat, humidify and circulate the air in a residence. If a cooling coil is added to the arrangement this unit may also become a year-round conditioner. A diagram of a direct-fired fuel oil conditioning unit is given in Fig. 19. A circulating fan forces the filtered air over a heat exchanger through which the combustion gases from the oil burner are being directed. A 461 Heating Ventilating Air Conditioning Guide 1938 cooling section may be placed in the air inlet, with cold water, or re frigerant being circulated through the cooling element. BASIS OF RATING In the past, the unit air conditioning industry has been handicapped by the lack of any standard method of rating. A proposed code giving a Standard Method of Rating and Testing Air Conditioning Equipment8 has recently been prepared. . On the basis of this new'code, air conditioners are to be classified primarily as free delivery type and pressure type, where delivery will be measured in cfm standard air at specified fan speed. Pressure type units will specify the delivery against various total fan static pressures. Cooling Supply air to rooms Chapter 23. Unit Heaters. Ventilators, Air Conditioning. Cooling Units METHODS OF CALCULATING CAPACITIES The methods of calculating heating and cooling loads for conditioning units are similar to those described under Chapters 7 and 8. Certain manufacturers have adopted simplified and approximate methods which through experience they have found applicable to unitary equipment. Such methods involve certain averaging approximations which are suitable for estimating purposes but many of which require rechecking on a more accurate basis before actual installations are made. The greatest error in calculating cooling loads is apt to be introduced in the failure to appreciate the magnitude of the latent heat loads and the Fig. 18. Gas-Fired Furnace Conditioning Unit capacity will be expressed in total Btu per hour and this total will be sub divided into sensible heat cooling effect and dehumidification or latent heat effect. Cooling capacities will be given on entering air temperatures of 85 F, .50 per cent relative humidity with 40 F refrigerant temperature for comfort conditions and 45 F, 85 per cent relative humidity with 30 F refrigerant temperature for commercial applications. The duty for heating surfaces will be specified in Btu per hour for 70 F entering air temperature based on 2 lb gage steam pressure or 180 F entering water temperature with 20 F drop. Humidification will be specified in pounds of water evaporated per hour at 70 F and 30 per cent relative humidity entering air conditions. The Catalog Data Section gives ratings of current models offered by leading manufacturers. Loc. Cit. Note 1. 462 Fig. 19. Oil-Fired Conditioning Unit relationship between the latent heat removal and the refrigerant tem perature. It is extremely important that the proper balance be obtained between the refrigerant temperature, the conditioning unit surface and the conditions to be maintained within the occupied space. Unsatisfactory conditions often result through the attempt to apply units with a source of refrigeration which gives too high a surface temperature. Such con ditions may be obtained when well water of too high a temperature is used or when a direct expansion evaporator is connected to a refrigeration compressor of inadequate size. The high refrigerant temperature even though it may give adequate dry-bulb temperatures, due to over-size conditioning units, will not give proper humidity control due to its inability to furnish sufficient dehumidification. . The use of surface coolers with widely extended fins may lead to similar results since the large ratio of extended surfaces gives an average surface temperature considerably above the refrigerant temperature within the tubes. All these factors must be kept in mind when making the selection 463 Heating Ventilating Air Conditioning Guide 1938 of equipment. It is furthermore vital that the calculation of a cooling load be based on an accurate survey before the selection of the equipment is made. COSTS Due to the rapid development of the air conditioning industry and the great progress that is being made each year, it is impossible to give any cost figures that will be of value. There are, however, certain factors that influence the cost of unit air conditioning installations. 1. Since the cost of the total job involves material cost plus installation labor and since through the use of unitary equipment, material costs can be kept to a minimum, every effort should be made to simplify installation. 2. Self-contained units in the small sizes now available, probably represent the lowest cost individual installations. They have, however, their limitations. 3- The floor type all-year-round air conditioning units for the occupied space with a remotely controlled compressor, heating sources being either the existing heat system or steam connections to the unit, probably afford the lowest cost all-year-round service for most individual rooms. This is particularly true in the case of residences. With offices, this will probably be true if the compressor can be located immediately adjacent to the conditioned space, as for example in a closet or nearby storeroom. The expenses increase rapidjy as the distance from the unit increases. ' 4. For multiple rooms or offices, the remotely located unit with connecting ducts probably represents the most economical installation. Such installations are also par ticularly adaptable to stores, residences and small commercial installations. Costs of` operation vary widely depending entirely upon the cost of power and water. Water costs in the larger installations are being materially reduced through the use of cooling towers and special types of condensers. The normal expense of operating the cooling system is considerably in excess of. that of winter heating both as to the first cost and as to operation. Consequently, the more rapid growth of air con ditioning has been along commercial lines where it has represented an actual profitable investment resulting in increased business returns rather than along the lines of residential comfort cooling where it still represents a luxury in comfort. .. ... MISCELLANEOUS UNITARY EQUIPMENT There are a number of units available which were not covered in the previous discussion that accomplish only one or two of the functions of air conditioning. Attic Fans Attic fans, used during the warm months of the year to draw large volumes of outside air through a house, offer a means of using the com parative coolness of outside evening and night air to bring down the inside temperature of a house. Because the low static pressures involved are usually less than J4 in. of water, disc or propeller fans are generally used instead of the blower or housed types. The fans should have quiet operating characteristics, and 464 1 Chapter 23. Unit Heaters. Ventilators, Air Conditioning, Cooling Units they should be capable of giving about twenty air changes per hour. The two general types of attic fan installations in common use are: " Open attic fans, in which the fan is installed in a gable or dormer and one or more grilles are provided in the ceilings of the rooms below. Fresh air, which enters the house through open windows, is drawn into the attic through the grilles, and is discharged out-of-doors by the fan. An attic stairway may be used in place of the central grille. It is essential that the roof and the attic walls be free from air leaks. Boxed in fans, in which the fan is installed within the attic in a box or housing directly over a central ceiling grille, or in a bulkhead enclosing an attic stair. The fan may be connected by a duct system to the grilles in individual rooms. Fresh air entering through the windows of the rooms below is discharged into the attic space and escapes to the outside through louvers, dormer windows, or screened openings under the eaves. The locations of the fan, the outlet openings, and the grilles should be selected after consideration of the room and attic arrangement in order to give uniform air distribution in the individual rooms served. If the outlet for the air is not on the side away from the direction of the prevailing ; wind, openings should be provided on all sides. Kitchens should be separately ventilated because of the fire hazard, and to prevent the spread of cooking odors. . The operating routine which will secure best results with an attic fan is an important consideration. A typical routine might require that in the late afternoon when the outdoor temperature begins to fall, the windows on the first floor and the grilles in the ceiling or the attic floor should be opened, and the second story windows should be kept closed. This will place the principal cooling effect in the living rooms. Shortly before bedtime, the first floor windows may be closed and those on the second' floor opened, to transfer the cooling effect to the sleeping rooms. A time clock may shut off the fan before waking time, or the fan may be stopped manually a.t a later hour. A disadvantage arising from the passing of a great amount of outside air through a house is the dust nuisance, which varies considerably in' different locations. Persons suffering from allergic diseases caused by air borne pollens will have their troubles increased with attic type coolers. Some typical data on an attic fan installation in. an average six-room house of frame construction containing 14,000 cu ft and located in. the southern part of this country are: . ' 1, : Installation cost......... Fan data Operating period....:... Power consumption-- $75 to $400, average $250 9000 cfm average, 280 rpm if belt driven, 570 rpm if direct connected, 500 watts input April 15 to October 15, intermittently as weather con ditions demand . . ... : . ,. 500 kwh per year for 8 months' operation ' 465 i I Heating Ventilating Air Conditioning Guide 1938 Humidifiers . ., Humidifying units may be installed as part of an air conditioning unit system, or may be installed individually to furnish additional humidity. Fig. 20 illustrates a humidifying unit for installation in connection with a warm air heating system, and as such it is located at the intake of the furnace. The air passes through a lint filter, then through the fans and finally through an air washer or spray system. Surplus spray.is eliminated and the air delivered to the air distribution system. In other cases, similar spray type apparatus is used to deliver humidified air through ducts to openings beneath existing radiators in a steam heated residence. For other steam heated homes, there is a humidifying unit as illustrated in Fig. 21. This unit is normally placed at some central location on the INTAKE Fig. 20. Humidifying Unit for ' Warm Air Furnace Fig. 21. Humidifying Unit for Radiator Heated Homes first floor, and receives the air from the floor into fans, delivering it through a heating coil and up through a target spray atomizer. Surplus moisture is removed by means of an eliminator filter and the humidified air is delivered upward through the other half of the floor grille. Since a large percentage of the heater.capacity is transformed into the latent heat of humidification, this unit does not eliminate any existing steam radiation. It may also be used with hot water systems but its capacity is considerably reduced. .' AUTOMATIC CONTROLS The controls of all unitary equipment represent a vital part of their successful operation. This is particularly true in the case of conditioning equipment where .a close iiiter-relationship exists between the thermo static room controls and the refrigerating unit controls. 466 Chapter 23. Unit Heaters. Ventilators, Air Conditioning. Cooling Units The proper selection of controls and the proper adjustment is extremely important to prevent short cycling of compressors. Furthermore, the proper adjustment of direct expansion valve controls is likewise extremely important. A detailed discussion of control problems is contained in Chapter 37. . . PROBLEMS IN PRACTICE 1 Distinguish between a unit and a central type of air conditioning system. In a unit system, the air treating apparatus consists of factory assembled equipment which is shipped substantially complete or in sections and is installed without field fabrication except for the duct connections between the equipment and the point of delivery of the air. Usually, the air treating equipment is located closely adjacent to the conditioned space and serves a limited area. A central type of air conditioning system localizes the air treating equipment for the entire area at one point and involves the field assembly of a large number of individual elements. Manufacturer of the unit is responsible for the output and performance of the unit under-rated conditions, whereas, the contractor installing the completely unitary or central type equipment is held re sponsible for the complete performance of the system. 2 Is it satisfactory to use superheated steam in unit heaters? Superheated steam can be satisfactorily used in unit, heaters provided the'capacity is based on the saturated steam temperature and not on the total temperature. If un usually high superheat is used, trouble may be experienced from the excessive expansion and contraction of the heating elements. 3 Is it satisfactory to install one unit heater as the total load on a coal fired boiler? ... - Such an arrangement is impractical if the unit heater is started and stopped in keeping with the room temperature. However, if the room temperature controls the steam pres sure and the unit heater is arranged to start when there is steam in the mains and to stop when there is no steam in the mains, such an installation will be satisfactory. 4 Will a .unit heater with a slow speed fan be more quiet than one with, a high speed fan? . . Quietness is a function of the type, diameter, blade form, and location of the fan, as well as the speedy. For a given fan, slower speeds mean less noise. - . 5 Is it satisfactory, to use steam at pressures less than atmospheric for unit heaters or unit ventilators? . . If the air inlet temperature is above freezing, steam at any pressure may be used in the heating element of the unit heater or unit ventilator^ If the inlet temperature is below freezing the heating element should be filled with steam of at least 5 lb pressure (or with a positive 5 lb pressure differential between supply and return) and the steam supply, should never be throttled or the heating element may be frozen. . 6 In general, what is the primary function of a unit ventilator? To maintain the desired room air conditions as to temperature, air change, and air cleanliness, without drafts regardless of variations in outdoor temperature, occupancy, sun, heat, and wind. 7 What are the usual working parts of a unit ventilator? The fan and motor assembly, a set of heating elements, outdoor and indoor air dampers, filters (optional), outlet grille, some method of varying the outlet temperature in keeping with the room requirements, and, in the case of some unit ventilators, a method of limiting the outlet temperature to a minimum of 60 F. 467 Heating Ventilating Air Conditioning Guide 1938 8 Do all unit ventilators introduce a constant amount of outdoor air? Certain types employ full recirculation except when outdoor air is obtained by throttling the steam valve on the heating element so the proportion of outdoor air to room air is varied. This is a very economical type of unit ventilator but in some communities it cannot be used because of existing laws which require that some fixed amount of outdoor air be introduced whenever the room is occupied. Certain types of units are designed to always take in a minimum quantity of air from the outside and to automatically vary this with the weather. 9 Why are metal surface cooling elements instead of liquid spray chambers used in the design of most air conditioning units and cooling units? . The first cost of. the surface cooling type of unit is considerably less than the cost of spray type equipment. Further, the requirements of many industrial air conditioning jobs and of all comfort cooling jobs where unit equipment is applicable can often be effectively met with the use of surface type units, with a reduction in the space required for making the installation. Where space conditions are especially limited, the cross sectional area of the surface cooler can be reduced because the resulting increase in velocity over the coil surface increases the effectiveness of the surface, whereas an increase in velocity through a liquid spray would reduce its effectiveness. 10 Why are air conditioning units with metal cooling surfaces not desirable for all industrial jobs? Wherever unusually close control of relative humidity is required, a spray type unit will prove to be more satisfactory. Relative humidity control and accurate temperature control, however, can be maintained without difficulty with the use of metal surface units. 11 Why is accurate control of relative humidity with surface coolers more or less complicated? A surface cooler cannot add moisture to the air, and moisture is removed only when the surface temperature is below the entering dew-point temperature. Any change in condition of the entering air will result in a change in the dry-bulb depression of the leaving air. This change in entering condition requires not only a readjustment of the air volume but also a change in the coil temperature, if accurate control over the relative humidity is to be maintained. '12 12 What in general are the characteristics of operation of a unit using surface coils? For a constant entering dry-bulb temperature and a constant refrigerant temperature any increase in the entering wet-bulb temperature will produce a rise in the leaving dry- bulb temperature with an accompanying reduction in the wet-bulb depression of the leaving air. The sensible heat removed by the unit decreases and the latent heat in creases, while the total heat removed also increases. When the dry-bulb temperature of entering air is increased, with constant refrigerant terhperature and constant wet-bulb temperature of entering air, the wet-bulb depression of the leaving air increases, and since it is this depression which determines the maintained relative humidity it must be carefully considered when selecting the unit. 468 Chapter 24 COOLING AND DEHUMIDIFICATION METHODS , . Air Cooling Processes, Dehumidification Processes, Practical Combination Methods, Compression Systems, Mechanical Refrigeration, Steam Jet System, Condensers, Evaporators, Refrigerant Pipe Sizes, Operating Methods, Adsorption System, Absorption System, Evaporative Cooling, Reverse Cycle, Ice Systems COOLING and dehumidifying are closely related in most air condi tioning work. Usually a reduction in both temperature and humidi ty is necessary to produce comfort. Also, it should be borne in mind that: (1) there is a reduction in moisture content whenever air is cooled below its dew-point, and (2) there is a rise in temperature whenever moisture is removed from air by either adsorption or absorption. Con sequently, cooling and dehumidification must in most cases be considered together, not as two separate problems, although each can be accom plished separately. . AIR COOLING PROCESSES In air conditioning either of two arrangements, or a combination of them, is used to accomplish air cooling. The two arrangements are: (a) surface cooling, where the air is passed across a cold metal surface: and (b) spray cooling, where the air is passed through a cold liquid spray, usually water. In either case the surface or the spray liquid must be at a temperature sufficiently low so that heat may be removed from the air. Suitable temperatures for the purpose are obtained by the proper use of ' 1. Refrigeration; or 2. Water from a cold natural source such as a well, from melting ice, or from applica tion of refrigeration; or 3. Evaporative cooling. The choice of most suitable source of cooling in any specific case will depend on the accompanying circumstances and can be determined only by a thorough analysis made by a competent engineer. 469 Heating Ventilating Air Conditioning Guide 1938 DEHUMIDIFICATION PROCESSES Dehumidification may be accomplished in any of three ways, or by a suitable combination of them: 1. By cooling the air below its dew-point temperature thus causing a part of the moisture contained to condense and precipitate. 2. By extracting moisture by adsorption. 3. By extracting moisture by absorption. As in the case of air cooling, the best dehumidification method can be determined only by a complete analysis taking into account all the circum stances of the particular case being considered. In Chapter 2 the nature' of the adsorption and absorption processes are explained and the principal properties of the materials used are presented. PRACTICAL COMBINATION METHODS As applied in actual practice these several processes frequently have to be combined in order to produce the desired results. Any or all of the three processes of air cooling listed may be combined with any or all of the three dehumidifying processes to produce both air cooling and de humidification. One form of combination consists of a multi-stage method whereby moisture is removed from the air and then the resulting mixture is cooled. Stage methods are common where dehumidification is accomplished by the use of adsorbent or absorbent substances. Another method, and one in common use, is to combine the air cooling and de humidification processes into, one step. This is made possible by keeping the temperature of the surface or liquid spray used for cooling below the dew-point temperature of the air to be conditioned. It is the method most commonly associated with comfort air conditioning in current practice. Still another general method consists of what may be called a parallel-flow method wherein the cooling or dehumidification, or both, may be performed by splitting the air stream, performing the process on part of it and then bringing the two parts back together again. Obviously with so many possible combinations much leeway is left to the designer to determine what shall be done in a practical case. The remainder of this chapter is devoted to a discussion of some of these possible practical methods and the equipment used in applying them. Space does not permit discussing all the great variety possible and only those in reasonably frequent use are included here. Others will occur readily and can be analyzed in a fashion similar to those here treated.' COMPRESSION SYSTEMS Comfort air conditioning imposes requirements on refrigeration equipment not usually found in general cooling applications so that specially designed apparatus is often required to replace that normally used for industrial cooling. Standard equipment can be adapted to meet air conditioning requirements but extreme care must- be taken to deter mine the limits of its applicability. ' In industrial or process cooling systems the load is fairly constant, 470 Chapter 24. Cooling and Dehumidification Methods noise in operation is not of paramount importance, space is available or relatively cheap, and the cooling system is to a great extent separate or independent of other mechanical equipment. By contrast, air condition ing for space cooling and comfort work in office buildings, theaters and places of public assemblage requires special consideration of all these factors. Space in public buildings is limited, noise interferes with the occupants and the cooling equipment must be adaptable to the other air handling apparatus. Most important, the load fluctuates tremen dously and is seasonal. Types of Compressors There are many different types of compressors, a number of refrig erants, different types of evaporators, condensers and arrangements of cycle and each type has its particular place in usage. Compressors generally used are of the following types: 1. Reciprocating compressors using a volatile refrigerant. 2. Centrifugal compressors. a. Using a volatile refrigerant. b. Using water as a refrigerant. 3. Rotary compressors using a volatile refrigerant. 4. Steam jet or vacuum systems using water as a refrigerant. Reciprocating compressors are generally used with any. low pressure refrigerant such as dichlorodifluoromethane, monofluorotrichloromethane, methyl chloride, ammonia and sulphur dioxide. These compressors have been developed to a point where their efficiency is high and their operation very satisfactory. Relatively low speed operation makes them desirable for general use in large installations. Generally they are of two types, vertical and horizontal either single or double acting. The horizontal double-acting compressor is not generally used in air conditioning, except when carbon dioxide is used as a refrigerant in the larger indus trial systems. Vertical, single acting, encased crank, reciprocating compressors of the uniflow type with valves in the pistons have proven reliable and are used in capacities from 1 hp to more than 100 hp. At present reciprocating compressors are used with more refrigerants than any other type of compression unit. When carbon dioxide is used as a refrigerant, a reciprocating compressor is required because of. the ex tremely high pressures and the relatively high ratio of compression. Centrifugal compressors using monofluorotrichloromethane, methylene chloride or water vapor can theoretically be used with any of the other refrigerants, but the resulting loss in efficiency with the higher pressure gases limits the centrifugal compressor to the refrigerants sighted. At the present time centrifugal compressors are limited to air conditioning systems of a minimum of about 50 tons. Centrifugal com pressors are usually built in two or more stages where the compression ratio is high and their design follows closely that of any other centrifugal equipment such as is found in general service pumps and fans. Rotary compressors are expanding in use due to the development of new refrigerants. These units are of four common designs, consisting of rotating elements generally referred to as centrifugal, eccentric, gear and blade types. The rotation of the shafts and blades traps the refrig- 471 Heating Ventilating Air Conditioning Guide 1938 erant vapor between the moving elements and the case and delivers it to the condenser at the required pressure. The rolling together of the impellers as in the case of the gear compressor prevents the return of the refrigerant vapor to the low side of the system. Steam jet compressors which are particularly adapted to large tonnage installations are simple, compact, have no moving parts and produce practically no vibration. However, they are not economical for water temperatures much below 40 F or where the cost of generating steam is higher than the cost of operation with other prime movers. MECHANICAL REFRIGERATION While the mechanical refrigeration systems differ in the methods used for compression of the refrigerant vapor, they are fundamentally similar.. Heat of Compression Added to Gas -S Chapter 24. Cooling and Dehumidification Methods Theoretical Mechanical Refrigeration Cycle The complete mechanical refrigeration cycle may be illustrated on the temperature-entropy diagram, and also on the pressure-volume diagram both of which are shown in Fig. 2. ' Considering the theoretical cycle, saturated vapor is drawn into the compressor at a and compressed at constant entropy (adiabatically) and then delivered to the condenser at b. Condensation occurs at constant temperature 7*2 from b to c with a contraction from the vapor to the liquid volume. The line cd represents cooling from, the temperature of the condenser to that of the evaporator by an external cooling means. At the same time, the pressure is lowered to Pi. Evaporation then occurs from d to a at temperature Tu completing the work cycle abcda. Since no external means of cooling the refrigerant liquid is normally available, the __--- ------ Refrigerant vapor usually saturated or slightly superheated, is drawn into the compressor as diagrammed in Fig. 1. It is then compressed and dis charged at a higher pressure to a condenser. The vapor is condensed as it contacts a heat transfer surface over which is flowing a cooling medium such as water, air or a combination of the two. The liquid refrigerant flows to the evaporator through an expansion valve which reduces its pressure and regulates its flow. In the evaporator the refrig erant absorbs heat from the medium which is to be cooled. When this medium is water or brine, the evaporator is known as a water or brine cooler and the refrigeration system, if used for air cooling, is known as an indirect system. When the medium cooled is air, the evaporator is known as a direct expansion cooler and the system is known as a direct expansion system. ' Fundamentally, the function of the system is to absorb heat at one temperature and pump it to a higher temperature, where it may be re moved by an available cooling medium. In order to conserve refrigerant, virtually all refrigeration systems are completely closed and the same refrigerant is recirculated. . 472 Fig. 2. Theoretical Dichlorodifluoromethane (F,,) Cycles cooling is generally accomplished by evaporation of a portion of the refrigerant. Since the work of expansion is usually used up as friction in the expansion valve, this process is assumed to be carried on at constant total heat, as represented by the line ce on the temperature-entropy diagram. Thus the refrigerating effect is represented by an area eagfe. While the normal theoretical cycle starts with saturated vapor, operation . is common at a condition of superheated vapor (as at <ii). Moreover, expansion may start either with a mixture of liquid and vapor or with a sub-cooled liquid, as at cu with expansion to et. It is obvious that this latter is desirable as it increases the refrigerating effect. Area aj>icdaai represents the work of such a superheated cycle, while the area eidigi/iei represents the refrigerating effect of the cycle with superheated vapor and sub-cooled refrigerant liquid. It will be noted on the pressure-volume diagram the volume of the saturated liquid is indicated by a dotted line close to and parallel to the ordinate. In the discussions in this chapter a slight error is introduced by not including all of the work of pumping the liquid, from the low to the high 473 Heating Ventilating Air Conditioning Guide 1938 pressure. This occurs because the liquid line is not a line of equal pressure but of saturation pressures. The error in work per pound of refrigerant figured from total heats, which should be added to the indicated figures is roughly the specific volume of the liquid at the lower pressure and tem perature multiplied by the pressure difference in appropriate units. This error may become of some importance in calculations involving carbon dioxide or in problems involving the liquid of any of the refrigerants, as in figuring expansion valve orifices. .. Theoretical Work per Pound The temperature-entropy and pressure-volume diagrams are based on one pound of the refrigerant.. Likewise, the theoretical work and the refrigerating effects are conveniently based on a pound of refrigerant. The compression work per pound may be found by several methods. The temperature-entropy method starts with state point a. Since the quality of a is known, the heat content of the vapor H& is known, and also the entropy 5a- Since point b lies near the saturation curve it is customary to assume 5a: = 5b and with T2 given, H\, can be determined. If W = work in foot-pounds per pound of refrigerant, then . W = (Hb - Ha) X 778 (1) The pressure-volume method starts with state point a, whose pressure and specific volume are known. The work of compression is the adiabatic work of compression from Pi to Pi, plus the work of expelling the vapor at constant pressure Pi minus the external work of evaporation of the vapor to volume Vi at pressure Pi. . It is frequently helpful to think of the compression of the vapor in terms of head. The head may be likened to a vertical column of vapor in which is located the vapor to be compressed. The compression occurs when the vapor is moved down from a level corresponding to Pi to a new level corresponding to Pi, in equilibrium with the surrounding vapor. If this process is carried on isentropically, the result will be the same as indicated previously. Then if h is the head in feet, W=h (3) This relationship may easily be seen from the fact that a small difference ' of head dh divided by the specific volume of the vapor V is equal to the increment of pressure difference dP. .. .. Head is very useful in considering the performance of centrifugal com pressors, which merely substitute a centrifugal for the gravity head/ It is also useful in considering problems of fluid flow. In these problems, the head per degree can be obtained either by direct calculation or approximately by dividing the total head by the temperature difference Ti--Ti. The velocity head loss can then be calculated in degrees, using the customary formula V2 = 2gh. . 474 Chapter 24. Cooling and Dehumidification Methods Refrigerating Effect per Pound The refrigerating effect per pound is computed by the same method, regardless of the type of refrigeration system. The solution is indicated on the temperature-entropy diagram of Fig. 2. Assuming that the vapor leaving the evaporator is saturated, the refrigerating effect in Btu per pound is obtained by subtracting from the heat content of the vapor at temperature Tu the heat content of the liquid at T2, or if the liquid is sub-cooled, the liquid temperature. Thus, the refrigerating effect in Btu per pound is equal to ira - He - Ha - fle (4) If the vapor entering the compressor is superheated or supersaturated, a correction in the heat of the vapor is made accordingly. The unit of refrigeration is the ion, based on the latent heat of fusion of one ton of ice in 24 hr. Thus one ton = 200 Btu per minute = 12,000 Btu per hour. Coefficient of Performance The coefficient of performance of a refrigeration system is the ratio of the refrigerating effect to the work of compression, both expressed in the same units. ; The ideal or Carnot coefficient of performance depends upon the tem peratures Ti and Ti in much the same way as the ideal efficiency of a steam engine depends upon its working temperature, with an inverse relationship. Ideal C. of P. = -r~ T}~t- (5) Evidently the smaller the compression range, the less power will be required to produce a given refrigerating effect. The theoretical. coefficient of performance of actual refrigerants is always less than the ideal due to the tendency-of most refrigerants to superheat when compressed, and due to the heat of the liquid which must be removed,- The cycle efficiency is the theoretical C. of P. divided by the ideal for the same temperatures. The cycle efficiency usually changes as the compression temperatures change. Practical Cycle .. Fig. 3 illustrates the pressure-volume and temperature-entropy dia grams for an actual cycle. These diagrams are based upon the com pressor receiving vapor superheated and upon sub-cooling of the liquid going to the evaporator. The theoretical cycle is aLbiccie,ai. However, the vapor during compression actually follows line aib2 due to superheating as a result of the inefficient work of compression. The theoretical work of compression is aibicdai. Added to this is the area bibigjiibi on the tem perature-entropy diagram which represents the inefficient work of com pression (assuming no compressor heat losses). The sum of these areas represents the total work of the compressor per pound of refrigerant, and the ratio of theoretical cycle work to the actual work represents the over all efficiency. It should be noted that area aj>2biai is considered as part 475 Heating Ventilating Air Conditioning Guide 1938 of the inefficient work and is commonly termed the superheat loss. The refrigerating effect per pound is the same for the practical as for the theoretical cycle, working with the same sub-cooling of liquid and super heating of vapor, that is, area eiOtgifiti. Sources of loss which are usually recognized as reflected by the overall efficiency referring particularly to reciprocating and rotary systems, are as follows: 1. The superheat loss. 2. A pressure loss to and from the cylinder of the compressor. (The line pressure' drop between the compressor and the evaporator and condenser, respectively, is usually taken into account separately in the design of the refrigeration system.) 3. Leakage loss through valves and past pistons is quite small in most compressors. 4. With an oil soluble refrigerant, there may be an absorption loss due to absorption and re-evaporation of refrigerant in the oil of the cylinder. 5. Mechanical losses are always present and are usually a large part of the total. Fig. 3. Practical Dicblorodifluoromethane (Fm) Cycles Reciprocating and rotary compressors always take in less vapor than that which corresponds to the displacement. The overall volumetric efficiency is the ratio of the suction vapor volume to the piston displace ment. On reciprocating compressors part of the loss is the re-expanded volume, at suction pressure, of the vapor which was in the. clearance volume. This is expressed by the following equation: Volumetric Efficiency = 1 -- X " -- lj (6) where vc = clearance volume. = cylinder displacement volume. . The balance of the overall volumetric efficiency is known as the super heat volumetric- efficiency even though it includes some other sources of capacity loss. - 476 . Chapter 24. Cooling and Dehumidification Methods The mechanical efficiency of a reciprocating and rotary compressor must be multiplied by the superheat volumetric efficiency to give the overall efficiency of the compressor. Eff.overall = x Mech. Eff. = Super. Vol. Eff. X Mech. Eff. VOl. fc'ti.reexp* (7) Normally, the volumetric efficiency of a compressor varies with the ratio of compression, while the mechanical efficiency remains virtually fixed. Good standard practices for dichlorodifluoromethane compressors are: Vol. Eff.reoxp* Vol. Eff-BupcrVol. Eff.overall Mech. Eff. Low comp, ratio = 2.5 to 1 94 to 96 per cent 75 to 85 per cent 70 to 81 per cent 75 to 85 per cent High comp, ratio = 5 to 1 88 to 92 per cent 73 to 77 ,per cent 64 to 71 per cent 75 to 85 per cent These values are for one ton or larger compressors. Part of the dif ference expresses the change with capacity. With other refrigerants and other types of compressors there will be some further variation. STEAM JET SYSTEM The steam jet type of compressor, under certain circumstances, is desirable for use in air conditioning. The power used for compressing the refrigerant is steam, taken directly from the boiler, thus eliminating the mechanical losses of manufacturing electric current. As the com pression ratio between the evaporator and condenser under normal circumstances is large, the mechanical efficiencies of the equipment are somewhat lower than those of the positive mechanical type of compressor; also the condensing water requirements are considerably greater, as both the refrigerant and the impelling steam must be condensed. The steam jet system functions on the principle that water under high vacuum will vaporize at low temperatures, and steam ejectors of the type commonly used in power plants for various processes will produce the necessary low absolute pressure to cause evaporation of the water. A diagrammatic representation of a typical steam ejector water cooling system is shown in Fig. 4. The water to be cooled enters the evaporator and is cooled to a temperature corresponding to the vacuum maintained. Because of the high vacuum, a small amount of the water introduced in the evaporator is flashed into steam, and as this requires heat and the only source of heat is the rest of the water in the evaporator tank, this other water is almost instantly cooled to a temperature corresponding to the boiling point, determined by the vacuum maintained. The amount of water flashed into steam is a small percentage of the total water circulated through the evaporator, amounting to approximately 11 lb per hour per ton of refrigeration developed. The remainder of the water at the desired low temperature is pumped out of the evaporator and used at the point where it is required. The ejector compresses the vapor which has been flashed in the evaporator, plus any entrained air taken out of the water circulated, to a somewhat higher absolute pressure, and the vapor arid air mix with the impelling steam on the discharge side of the jet. The total mixture of 477 Heating Ventilating Air Conditioning Guide 1938 entrained air, evaporated water, and impelling steam is discharged into a surface condenser at a pressure which permits the available condensing medium to condense it. The resulting condensate is removed from the condenser by a small pump, from which it can be discharged to the sewer or returned to the system in the form of make-up water, or part of it may be returned to the boiler feed pump. The slight amount of air which may be entrained in the cooled water is removed by a small secondary ejector which raises the pressure sufficiently so that the air can be discharged to the atmosphere. A small secondary condenser, of course, is necessary to condense the steam used in the . secondary jet. The performance of the steam ejector may be studied theoretically by the use of the temperature-entropy diagram, Fig. 5. Unlike its usual Chapter 24. Cooling and Dehumidification Methods application, however, the amount of working fluid is different for one portion of the cycle than for the other. Diy saturated steam under high pressure, for example 100 lb per square inch gage, at a, is expanded through the nozzle of the steam ejector. With 100 per cent efficiency, the expansion-would occur along isentropic line ab. Actually, however, most nozzles are only about 90 per cent efficient, the real expansion being along the line abi. Since the exact path of the line abi is not known, the work area is normally assumed by using the isentropic giving a work area abgea. The velocity at the mouth of the nozzle may be determined in the usual manner using this area and the velocity coefficient of the nozzle. At the evaporator pressure or slightly below, the vapor from the nozzle mixes with virtually dry saturated vapor from the evaporator. An impact loss also occurs at this point due to the mixture of vapors at different velocities. This results in bringing the state point of the mixture to c. Compression then occurs along the line cd, the work of compression per pound being cdfgc. In computing the work area, however, the point c is not actually known. Therefore, the work area C\djgc\ is Used in express ing the efficiency of the ejector, the line cxd being an isentropic. The losses are expressed by nozzle efficiency, impact loss and diffuser efficiency. The work of compression, however, is performed on the mass of the mixture. Thus, the available work is reduced in proportion to: ' M primary M mixture The impact loss is commonly determined from the formula: ^primary h Af Vsec0ndary = ATVmixture (8) Common efficiencies for commercial ejectors are: nozzle efficiency 90 per cent, diffuser efficiency 60 to 70 per cent. Customary steam rates in pounds per ton are approximately as follows: Evaporator temp. 50 F Steam press. 100 lb per sq in. . Steam press. 12 lb per sq in. Condenser temp. 105 F Steam rate. 30 lb per hour per ton , Steam rate 45 lb per hour per ton Evaporator temp. 40 F Steam press. 100 lb per sq in. Condenser temp. 105 F Steam rate 40 lb per hour per ton Steam press: 12 lb per sq in. Steam rate : 70 lb per hour per ton . r' CENTRIFUGAL VAPOR VACUUM SYSTEMS The centrifugal vapor vacuum system functions on the same general principle as the steam jet system, except that a centrifugal evacuator is used to produce the low absolute pressure instead of the velocity of the steam through a jet. Less condenser water is required and a vacuum pump is employed instead of a steam jet purge. . CHARACTERISTICS OF COMPRESSION SYSTEMS The different types of compression systems have quite different characteristics of capacity and power with varying, evaporator tempera ture and with varying condenser temperature, as will be seen from curves in Figs. 6 and 7. : The capacity of the reciprocating and rotary compressor varies slowly with a change of evaporator temperature, and the variance of power 479 Heating Ventilating Air Conditioning Guide 1938 requirements, in the air conditioning range of operation, is small for a change of evaporator temperature. On the other hand, the capacity and power of the centrifugal machine vary rapidly, and the capacity of the steam ejector also varies considerably. Thus, both these latter types tend to be more nearly self-regulating than the reciprocating and rotary com pression type. On the other hand, the operating range of the latter near standard capacity is superior. Although the capacity of the reciprocating and rotary compressor is little affected by the condenser temperature, the power of the compressor is greatly affected, while the reverse is true Chapter 24. Cooling and Dehumidification Methods densing water is rather high in temperature. From Fig. 6 it is evident that steam jet refrigeration is better suited for use with evaporator temperatures above rather than below 40 F. CONDENSERS Condensers used in connection with refrigerating equipment for ab sorbing the work of compression are of three general designs: (1) air, (2) water, and (3) evaporative. Air Cooled Air cooled condensers are seldom used for capacities above 3 tons of refrigeration, unless an adequate water supply is extremely difficult to Fig. 6. Performance Characteristics of Compression Refrigeration Machines at Constant Speed for the centrifugal compressor. As previously indicated, the condenser temperature has no effect on the capacity of the steam ejector type of compressor until a certain point is reached, beyond which the capacity is zero. The steam consumption for the performance characteristic curves shown in Figs. 6 and 7 remains constant for all evaporator and condenser temperatures. . . . Steam jet refrigeration, requires from 3 to 10 times as much condenser water as other types of mechanical refrigeration, but its capacity is not effected by condensing water temperature as long as the water does not greatly exceed'. 100 F. Consequently, steam jet systems are well suited to those applications where condensing water is cheap, or where con 480 . Fig. 7. Performance Characteristics of Compression Refrigeration . ' Machines at Constant Speed obtain, as for instance in railway air conditioning. Even on fractional tonnage installations, air is used as the condensing medium only where water is expensive or where simplicity of installation warrants the higher condensing pressure, and consequent higher power costs than can be obtained using water as the condensing medium. The conventional air cooled condenser consists of an extended surface coil across which air is blown by a fan. The hot refrigerant gas enters the coil at the top and as it is condensed flows to a receiver located below the condenser. Air cooled condensers should always be located in a well ventilated space so that the heated air may escape and be replaced by cooler air. 481 Heating Ventilating Air Conditioning Guide 1938 The principal disadvantages to air cooled condensers are the power required to move the air and the reduction of capacity on hot days. This loss of capacity due to high condensing pressures on warm days requires that equipment of reduced capacity be selected to meet the peak load. Thus, at normal loads the equipment is oversized. Water Cooled ... Water cooled condensers are usually of the double pipe type or the shell and tube type. Double pipe condensers are arranged so that water passes through the inner of two concentric pipes, and refrigeration circulates through the annular space in the outer pipe. .Where possible, there should be counter-flow of the refrigerant and the condensing water to maintain maximum temperature differences. The amount and temperature of the condensing water determine the condensing temperature and pressure, and indirectly the power required for compression. It is,- therefore, necessary to determine a balance so that the quantity of water insures economical compressor operation. Because there is a decided tendency to conserve the water in city mains and because most large cities are restricting the use of water for air conditioning and refrigeration equipment, it is often necessary to install cooling towers or evaporative condensers. Cooling towers, unfortunately, produce the warmest condensing water at the time when the load on the system is greatest, so that the refrigeration equipment must be designed to meet not only the maximum load at normal conditions, but also the maximum load at abnormal condensing water temperatures. If properly designed, this makes little difference in the efficiency of operation through out the year except at those times when the condensing water temperature is highest. As'this occurs only for 5 per cent of the entire cooling period it can be disregarded as a factor in establishing yearly operating costs. The cooling tower has a certain advantage over the use of water from the city mains in that the temperature of the condensing water varies ' directly with the outdoor temperature and, as pointed out, the refrigera tion load also varies with this temperature. Certain economies are pos sible when a cooling tower is used which cannot be achieved by the use of condensing water from city mains, even where the city water temperature is extremely low. Normally, the lowest city water temperature met during the .summer months is from 65 to 70 F. This temperature range takes place for the entire cooling period, regardless of the outdoor tempera tures. With the cooling tower, the temperature of the condensing water may rise to 80 or 85 F under maximum conditions, but under less' than maximum conditions the temperature of the water leaving the cooling tower drops considerably, and it has been established that 50 per cent of the time the outdoor wet-bulb temperature varies from 60 to 70 F and the cooling tower water, for the same periods, varies from 65 to 75 F. When the outdoor wet-bulb temperature drops below 60 F, which occurs approximately 30 per cent of the time, the condensing water temperature is still lower. The cost of water used for condensing is negligible, as the only water required is that used to make up the loss by evaporation in the cooling tower itself. Refer to the section on cooling towers in Chapter 25. 482 Chapter 24. Cooling and Dehumidification Methods Evaporative . Due to the high cost of city water for condenser purposes and due to ordinances in some localities prohibiting the discharge of large quantities of such water into the sewage systems, there has been developed a con denser which uses a minimum amount of water on a finned surface, cooling it to approximately the wet-bulb temperature of the surrounding atmosphere. A diagram of a typical small evaporative condenser is shown in Fig. 8 which includes a fan that forces the air over a finned tube condenser coil to the outside atmosphere through a connecting duct. A fine spray of water keeps the coil surface wetted. The hot refrigerant gases enter the top of the condenser coil and the liquid collects in the receiver below Water thermostat* Fig. 8. Diagram of Evaporative Condenser the condenser unit. A thermostatic control valve and pressure regulator are arranged on the condenser water supply for regulating and adjusting the water flow to the nozzle. It is desirable that a condenser of this type be located near the compressor. Units of this design are available in sizes ranging.from 2 tons of re frigeration up to about 6 tons. About 10 per cent as much water is required for this unit as is normally used in a shell and tube type con denser. For larger capacities evaporative condensers are usually equip ped with a pump for recirculating the water. Such units are available in capacities ranging from 5 to 40. tons of refrigeration. They require no more water than a cooling tower, i.e., from 3 to 5 per cent as much water as required where all water is taken from the city main. EVAPORATORS AND COOLERS The types of coolers used in connection with air conditioning work fall into three general groups. The first, is the direct cooling of water; the second, direct cooling of air; and the third, cooling of brine for circulation in a closed system, which can cool either water or air. One method of the direct cooling of water is to install direct expansion coils in the spray chamber so that the water sprayed into the air comes in direct contact 483 Heating Ventilating Air Conditioning Guide 1938 with the cooling coils.. Another common and efficient method of cooling spray water is to use a Baudelot type of heat absorber where the water flows over direct expansion coils at a rate sufficiently high to give efficient heat transfer from water to refrigerant. Another type of spray water cooler is the shell and tube heat exchanger in which the refrigerant is expanded into a shell enclosing the tubes through which the water flows. The velocity of the water in the tubes affects the rate of heat transfer, and as the refrigerant is in the shell com pletely surrounding the tubes at all times, good contact and a high rate of heat transfer are insured. The disadvantage of such a system is that with the falling off of load on the compressor the suction temperature or the temperature in the evaporator drops and there is a possibility of freezing the water in the tubes, which, of course, might split the tubes and allow the refrigerant to escape into the water passage. This danger can be eliminated by automatic safety devices. Another system of cooling spray water is to submerge coils in the spray collecting tank, or in a separate tank used for storage. The heat trans mission through the walls of the coils, however, is low and a great deal more surface is required than for any other type of cooler. However, with large storage tanks this type of cooling can be utilized to advantage. When direct cooling of air is employed, the refrigerant is inside the coil and the air passes over it. Cooling depends upon convection and con duction for removing the heat from the air. The type of coil used can be either smooth or finned, the finned coil being more economical in space requirement than the smooth coil. The fins, however, must be far enough apart so as not to retain the moisture which condenses out of the air. The indirect cooler, where brine is cooled by the refrigerant and the resulting cold brine is used to cool either air or water, introduces several other considerations. It is not the most economical from a power con sumption standpoint, as it is necessary to cool the brine to a temperature sufficiently low so that there is an appreciable difference between the average brine temperature and that of the substance being cooled. This requires that the temperature of the refrigerant must be still lower, and consequently the amount of power required to produce a given amount of refrigeration increases due to the higher compression ratio, but there are other considerations which make such a system desirable. In the first place, where a toxic refrigerant is undesirable or cannot be used, due to fire or other risks especially in densely populated areas, the brine can be cooled in an isolated room or building and then be circulated through the air conditioning equipment in perfect safety because it is used to cool the water or air, without any possibility of direct contact between the air and refrigerant. . REFRIGERANT PIPE SIZES The selection of proper pipe sizes and frictional pressure losses varies with the installation and the capacity of the system. Generally the suction piping should be selected so that the pressure loss is between 2 and 3 lb per square inch. The pressure drop in liquid lines should be maintained so as to permit no vaporization in the pipes with limiting pressure drops not to exceed 5 lb per square inch. Hot or discharge gas 484 Chapter 24. Cooling and Dehumidification Methods lines should be limited to approximately 4 lb per square inch pressure drop. For installations involving piping connections between compressors and evaporative or other remote condensers, pressure drops for discharge or hot gas lines may be referred to in Table 1. Pressure losses in liquid refrigerant lines of various sizes and capacities are given in Table 2. Pressure drops of suction refrigerant pipe lines at varying capacities and refrigerant temperatures may be referred to in Table 3. AJ1 tables are for 100 ft of pipe, including an average number of fittings, and for other lengths the losses are proportionate. Allowances should be con sidered for drops through control and regulating valves which must be added to the other pipe losses to determine the total drop. All copper pipe referred to in these tables are of type L wall thickness and are designated by outside diameter. OPERATING METHODS There are various methods of designing and operating air conditioning systems to obtain economical operation. Peak outside conditions seldom exist for periods of greater than 3 hr. On many installations there is a peak internal load which may or may not coincide with the peak outside conditions. Thus, each application must be carefully analyzed by the engineer, and the proper equipment installed to satisfy the requirements. Adequate automatic controls should be installed for any system selected. Where there are a number of small rooms to be conditioned, as for example, a group of hotel bedrooms where the load varies with occupancy and exposure, it may be best to employ individual room units, each with its own control. These individual units may be of the self-contained type (condensing unit, evaporator, fan and controls all in one cabinet) or of the remote type with the condensing units located outside of the room. In some cases it is good practice to use one large condensing unit to serve a group of room evaporator units. Where this is done, the condensing unit must have some type of control which will prevent freezing evaporator temperatures when only a portion of the evaporators are in use. This can be accomplished by means of a back pressure regu lating valve which maintains the evaporator pressure at a safe limit, but allows the crank case pressure to fall. Other methods of accomplish ing the same result are the use of a variable speed compressor or the use of a partial by-pass from the high side to the low side of the compressor. Any of these three methods of lowering the condensing unit capacity drop the operating cost at the reduced loads, but the operating cost per ton is higher. Central Distribution Systems On air conditioning systems using duct distribution, the same general . types of control are employed to meet the varying load conditions, i.e. (1) the system may consist of several condensing units and evaporators which are cut in or out, depending upon the demand, or' (2) condensing unit capacity may be reduced by using back pressure regulating valves, by-pass valves, or variable speed compressors. ' 485 Heating Ventilating Air Conditioning Guide 1938 Table 1. Pressure Losses in Dichlorodifluoromethane Discharge or Hot Gas Lines* . Capacity BTU peb Hour 10,000 15.000 20.000 25.000 30.000 40.000 50.000 60.000 70,000 80,000 90,000 100,000 125.000 150.000 175.000 200,000 250.000 300.000 400.000 500.000 600.000 800,000 1,000,000 1,250,000 . 1,500,000 2,000,000 Pressure Drop in Pounds peb Squabs Inch peb 100 Ft* Line Sizes, Inches . X X - X iX IX IX 2X 2X IX 2.3 1.0 0.6 4.9 2.0 1.0 8.5 3.4 1.7 0.6 5.3 2.6 7.5 3.6 6.4 0.9 1.2 0.5 2.1 0.7 9.8 3.1 1.0 0.5 4.4 1.3 0.7 6.0 1.9 0.9 8.0 2.5 1.1 10.2 3.1 1.4 3.8 1.7 0.5 6.0 2.6 0.7 8,5 3.8 1.0 11.6 5.1 1.3 6.7 10.4 1.7 0.6 2.6 0.9 3.7 1.2 0.5. 6.7 2.2 0.9 10.5 3.5 1.5 5.0 2.1 0.7 1.0 9.0 3.8 5.8 9.5 1.8 2.9 4.4 6.4. 11.3 &Soft annealed copper tubing up to and including % in. outside diameter, outside diameter and larger. , bLength of tubing includes the average number of fittings. Hard copper pipe K in* Another method of providing for economy of operation is to have storage capacity which can be utilized during the peak period. The refrigerating system can be operated for a longer period at maximum efficiency with tanks to store cold water or brine for supplementing the actual output of the refrigerating equipment. However, storage tanks require space and extra apparatus, which increase the cost of the entire system, and further, it is difficult to determine the. exact size of the compressor because of the other variables which enter the problem. Depending upon the availability of storage space, the compressor may be designed for any reasonable percentage of the maximum load. On this basis of selection, the smaller the compressor, the larger the storage space, and vice versa. ' 486 Chapter 24. Cooling and Dehumiditication Methods Table 2. Pressure Losses in Dichlorodifluoromethane Liquid Refrigerant Lines . Capacitt BTU per Hour Pressure Drop in Pounds peb Square Inch peb 100 Ft* Pipe Sizes, Inches 100,000 . 125,000 150,000 175,000 200,000 225,000 j 250,000 275,000 300,000 325,000 350,000 375,000 400,000 450,000 500,000 : .550,000 600,000 700,000 800,000 : 900,000 : 1,000,000 1,200,000 1.400.000 1.600.000 1,800,000 . 2,000,000 2,200,000 : X 0.6 ! 0.9 1.3 1.8 . 2.3 .2.9 3.6 4.3 5.1 : 5.9 6.9 7.9 9.0 IX 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.1 2.3 2.9 3.S 4.3 . 5.0 6.7 8.7 iX 0.8 1.0 1.3 1.5 1.8 2A 3.1 3.9 4.7 6.7 9.0 m 0.7 08 11 1.4 1.7 2.1 3.0 4.0 5.1 6.3 7.9 9.2 Length of tubing includes the average number of fittings. There is a further method of controlling the compressor output which is particularly adaptable to the centrifugal type of machine. This is accomplished by varying the amount of condensing water used with the fluctuation in load demand. Because of the characteristics of the cen trifugal type of apparatus, as the condensing water quantity is reduced and the condensing temperature consequently raised, the discharge pressure of the centrifugal machine rises correspondingly and the horse power input to the machine drops proportionately. While this reduces the total power input'to the machine, it does not necessarily reduce the power input per ton of refrigeration developed, as the power input does not drop with a rising discharge pressure as fast as the refrigerating effect is reduced. 487 Heating Ventiuiting Air Conditioning Guide 1938 Table 3. Pressure Losses in Dichlorodifluoromethane Suction Refrigerant Lines Coppeb Pipe Actual O.D. Inches Capacity BTU peb Houb Pbxssube Deop in Pounds peb Square Inch pee 100 Ft -10 Repbiqebant Tempera-tube Deo F 0 10 20 30 40 50 2,000 4,000 6,000 0.3 0.3 0.2 0.2 0.2 0.1 0.1 1.3 1.0 0.8 0.7 0.6 0.5 0.4 2.8 2.2 1.8 1.5 , 1.2 1.0 0.9 8,000 4.8 3.8 3.1 2.6 2.1 1.8 1.5 10,000 7.4 5.8 4.8 3.9 3.3 2.8 2.3 X 12,000 10.5 8.4 6.8 5.6 4.7 4.0 3.3 .14,000 14.0 11.0 9.1 7.6 6.4 5.4 4.5 16,000 14.5 12.0 9.8 8.3 7.0 5.8 18,000 15.0 12.3 10.4 8.7 7.2 20,000 15.0 12.7 10.7 8.9 7,000 10,000 15,000 0.4 0.3 0.3 0.2 0.2 0.2 0.1 1.0 0.7 0.5 0.5 0.4 0.3 0.3 1.9 1.5 1.2 1.0 0.8 0.7 0.6 20,000 3.3 2.6 2.1 1.7 1.4 1.2 1.0 ix 25,000 35,000 5.0 4.0 3.2 2.7 2.2 1.9 1.6 9.7 7.7 6.2 5.1 4.3 3.6 3.0 45,000 60,000 70,000 15.8 12.6 10.0 8.4 14.8 7.0 12.2 5.9 10.2 14.0 4.9 8.6 11.7 10,000 15,000 20,000 0.3 0.2 0.2 0.2 0.1 0.1 0.1 0.7 0.5 0.4 0.3 0.3 0.2 0.2 1.2 0.9 0.7 0.6 0.5 0.4 0.4 30,000 2.6 2.1 1.6 1.3 1.1 0.9 0.8 m 40,000 50,000 4.6 3.6 2.8 2.3 1.9 1.6 1.4 7.0 5.5 4.4 3.5 2.9 2.5 2.1 60,000 '80,000 100,000 10.0 7.8 14.0 6.2 11.0 5.0 8.7 13.5 4.2 7.3 11.3- 3.5 6.2 9.5 3.0 5.2 8.2 30,000 40,000 50,000 1.6 1.3 1.0 0.8 0.7 0.6 0.5 2.7 2.1 1.7 1.4 1.1 0.9 0.8 4.2 3.2 2.5 2.1 1.7 1.4 1.2 60,000 6.1 4.5 3.6 2.9 2.4 2.0 1.7 IX 70,000 80,000 8.7 6.3 4.8 3.8 3.1 2.6 2.2 8.4 6.3 4.9 4.0 3.3 2.8 90,000 100,000 *- 120,000 8.0 6.2 4.9 4.1 3.5 10.0 7.6 6.1 5.0 4.2 8.6 7.0 . 5.9 140,000 9.5 7.9 Length of tubing includes the average number of fittings. 488 Chapter 24. Cooling and Dehumidifxcation Methods Table 3. Pressure Losses in Dichlorodifluoromethane Suction Refrigerant Lines (Continued) Coppeb Pipe Actual O.D. Inches Capacitt BTU peb Houb Pressube Drop in Pounds peb Square Inch PEB 100 Ft Repbiqebant Tempebatube Deq F 2X 2X 3Vs 3X 50,000 100,000 150,000 200,000 250,000 300,000 350,000 400,000 50,000 100,000 150,000 200,000 250,000 300,000 350,000 400,000 450,000 500,000 550,000 600,000 200,000 300,000 400,000 500,000 600,000 700,000 -800,000 900,000 1,000,000 300,000 400,000 500,000 600,000 700,000 800,000 900,000 1,000,000 1,100,000 1,200,000 1,300,000 1,400,000 -10 0.7 2.6 5.6 9.8 14.8 0.2 0.7 1.6 2.8 4.3 6.1 8.2 1.2 2.6 4.5 7.3 1.2 2.0 3.2 4.6 6.4 8.7 0 0.5 1.8 3.9 6.7 10.3 14.5 19.5 0.2 0.6 1.2 2.1 3.4 4.5 6.0 7.8 1.0 2.0 3.4 5.4 8.1 0.9 1.6 2.5 3.6 4.9 6.4 8.2 10 0.4 1.4 3.0 5.2 8.0 11.3 15.3 19.6 0.1 0.5 1.0 1.7 2.6 3.7 5.0 6.5 7.7 0.8 1.6 2.6 4.1 6.0 8.4 0.7 1.3 1.9 2.8 3.8 4.9 6.2 7.7 9.4 20 0.3 1.1 2.4 4.1 6.3 9.0 12.0 15.3 0.1 0.4 0.8 1.4 2.1 3.0 4.0 5.1 6.4 7.8 0.6 1.3 2.1 3.3 4.7 6.5 8.6 0.6 1.0 1.6 2.2 3.0 3.9 4.9 6.1 7.3 8.7 30 0.3 0.9 2.0 3.4 5.1 7.2 9.7 12.5 0.1 0.3 0.6 1.1 1.7 2.4 3.2 4.2 5.3 6.'4 7.7 0.5 1.0 1.7 2.7 3.8 5.2 6.8 8.7 0.5 0.8 1.3 1.8 2.5 3.2 3.9 4.9 5.8 6.9 8.0 9.3 40 0.2 0.8 1.6 2.8 4.2 6.0 7.8 10.0 0.1 0.2 0.5 0.9 1.3 1.9 2.5 3.3 4.0 5.0 6.2 7.4 0.4 0.8 1.4 2.2 3.1 4.2 5.5 7.0 8.9 0.4 0.7 1.0 1.5 2.0 2.5 3.2 4.0 4.8 5.6 6.6 7.6 so 0.2 0.7 1.4 2.4 3.6 5.0 6.7 8.5 0.1 0.2 0.4 0.7 1:1 1.5 2.0 2.7 3.5 4.2 5.1 6.2 0.4 0.7 1.3 1.9 2.7 3.5 4.6 5.9 7.3 0.3 0.6 0.9 1.3 1.7 2.2 2.7 3.3 4.0 4.8 5.6 6.4 Length of tubing includes the average number of fittings. 489 [ Heating Ventilating Air Conditioning , Guide 1938 Table 3. Pressure Losses in .DichlorodifluoromethanE Suction Refrigerant Lines (Concluded) Coppeb Pipe Actual O.D. Inches . Capacity BTU per Hour . Pressure Drop'in Pounds per Square Inch per 100 Ft ' Refrigerant Temperature Deo F -10 0. .. . 10 .. . . 20 . 30 40 50 . .. . _... " 400,000 1.0 0.8 o.6 ; 0.4 ; 0.4 0.3 0.3 600,000 2.4 1.8 1.4 , i:i 0.9 0.7 0.6 800,000. . 4.1 3.1 2.4. . .. 2.0 ; . 1.6 1.3 1.1 1,000,000 6.6 4.8 3.7 3.0 ; 2.'5 2.0 1.6 1,200,000 10.0 7.1 5.4 4.4 3.5 2.9 2.4 4ys 1,400,000 10.0 7.5 5.9 4.8 3.9 3.3 1,600,000 . 1,800,000 2,000,000 10.0 7.7 ; 6.2 5.1 10.0- 7.9 6.4 9.7 . 7.9 4.2 5.3 6.6 , 2,i00,000 9.5 7.9 Length of tubing includes the average number of fittings. ADSORPTION SYSTEMS A diagrammatic representation of an open solid material adsorption system is shown in Fig. 9. Two or more beds of the adsorbent are used so that one bed may be used as an adsorber while another is being re activated. Most adsorption systems use some internal means of heating the adsorbent bed before activation, and cooling it after activation. Thus, the use of relatively high room temperatures and comparatively large amounts of. outside air are. desirable in connection with these systems. In order to offset the effect of high air temperature, some effort is made to keep the humidity lower than usual. ' . Fig.'9. Open Solid Material AdsorptionSystem'.. .490 Chapter 24. Cooling and Dehumidification Methods Silica Gel \ Silica gel has two applications when used to replace refrigeration. . In the one principally used,- the air from which moisture is to be extracted is taken through silica gel beds by suction or pressure fans, and by means of this process the moisture becomes adsorbed by the. silica gel and the air leaves at a lower dew-point and a higher sensible temperature than those at which it entered. If this air is passed over surface coolers in which tap water or another- cooling medium is flowing through tubes, a certain amount of sensible heat will be removed. The air leaves the surface cooler or interchanger with the same dew-point with which it emerged from the silica gel beds, but with a lower dry-bulb temperature, although the drybulb temperature may be higher than the temperature of the air entering the silica gel beds. In another method, the first two of the steps outlined are duplicated, and in addition the air is carried through a spray type washer. Because the air enters the washer with a low wet-bulb, and because adiabatic saturation will take place at a temperature close to the entering wet-bulb, considerable cooling of the air can be accomplished; but this can be done only with a consequent increase of the dew-point. It is necessary to reactivate the silica gel after it has adsorbed about 25 per cent of its own weight in the form of moisture. As reactivation requires a high temperature and since silica gel is only active at low tem peratures, cooling of the beds must also be completed before they can be used again. This necessitates three stages in the silica gel containers and requires either three beds of silica gel or one bed divided and automatically put in position. The reactivation is usually done by means of gas or oil fires and the cooling of the beds by means of indirect water cooling or by means of small quantities of dehydrated air taken from the system beyond the interchanger. Activated Alumina The application is quite similar to that employed for silica gel; that is, the material is exposed to the air flow and after reaching about 75 per cent saturation is reactivated by removing the moisture adsorbed. by means of applied1 heat.' The actual scheme generally followed in the use of this material for continuous service varies somewhat from silica gel inasmuch as the material , is placed in three units which are used consecutively for the different steps. ; These steps permit each, unit to, operate as follows: (1) in series with the preceding unit, (2) alone, and (3) in series with the following unit. This plan allows for adsorption, reactivation, and cooling, in a manner similar to that used with silica gel. Taking a single unit, when it is in the (1) step and operating with the preceding unit, the alumina adsorbs approximately 25 per cent of the moisture in the air and takes up about 1.3 per cent .of its weight of water.. During the second step when it is operating alone, it takes up 100 per cent of the moisture in the air until the weight of the water adsorbed is.brought up to about 6.7 per cent. During the third step when .the unit is operating with the succeeding unit, it extracts about 75 per cent of the moisture in the air until the water weight adsorbed comes up to about 10 per cent of 491 Heating Ventilating Air Conditioning Guide 1938 the weight of the adsorber. The time allowable for reactivating is equal to the time occupied by the second unit adsorbing alone, plus the time when the second and third units are adsorbing in series, plus the time when the third unit is adsorbing alone, at the expiration of which time the first unit will be again required. The temperature of air used for alumina reactivation is usually between 300 and 700 F and the air flow rate will have to be higher with the low temperature air than it will be with reactivating air of higher temperature. For example, air at 400 F for reactivating will, at 10 cu ft per hour per pound of alumina, require about 6 hr for reactivation. In the three unit system, after reactivation the cooling of the activated alumina may be carried out with considerable rapidity by using dry air from the adsorp tion unit for circulation through the unit which has just completed reacti- To condition Conditioned air Dry bulb dependent upon cooling medium Fig. 10. Diagram of Lithium Chloride Absorption System vation. The. final temperature of the unit before it goes back into service should be not over 200 F. As a basis for computing the amount of cooling air required for reactivation, each cubic foot of cooling air has been found capable of removing 2.2 Btu when heated from 85 to 200 F and of provid ing a sufficient margin of safety in operation. OPEN ABSORPTION SYSTEMS The cycle of liquid absorbents are fundamentally the same. A diagram of a lithium chloride absorption system is shown in Fig. 10. The liquid absorbent is brought in contact with air having a certain vapor pressure due to its contained water vapor. The absorbent having a lower vapor pressure, absorbs moisture in the forni of water from the water vapor that is in the contacting air. A change of state takes place because there is a rise in temperature in the liquid absorbing the moisture, which is a function of the amount of water vapor condensed from the air stream. 492 Chapter 24. Cooling and Dehumidification Methods Absorption of moisture by the liquid weakens the concentration of the liquid so that its absorbing capacity is reduced and regeneration, or the driving off of the excess moisture in the liquid, must be performed. A constant density can be maintained by continuously withdrawing a small portion of the total liquid for intensive concentration without varying the vapor pressure of the total mass. There are two methods of regeneration. One is to boil off the excess moisture by raising the temperature of the solution above the boiling point of the particular concentration. As the salt in the solution does not vaporize, it is not carried off in the boiling process. In the small amounts of liquid diverted to the regenerator for concentration, care should be taken that too much moisture is not driven off, which may cause freezing or solidification of the salts. The second method of regeneration is to raise the temperature of the solution with ordinary steam coil interchangers to about 225 F, and then passing the solution at this temperature over various types of scrubbers, through which untreated air is circulated. The increase in temperature of the liquid raises its vapor pressure to such an extent that there is an exchange of vapor between the liquid and the air, as well as an equali zation of temperature between the air and the liquid absorbent. The air is then capable of taking up part of the moisture from the liquid and carries this excess moisture into the atmosphere with the leaving air. After this vaporization has taken place, the highly concentrated, hot brine is circulated through an interchanger through which the water used in cooling the main solution can be re-used to reduce the temperature of the concentrated solution to a point where it may be introduced into the main solution tank at only a slightly higher temperature than the main body of the solution. There are two places in the operation where there is a tendency to raise the temperature of the liquid. One is the absorption of vapor from the air, which changes the latent heat of the vapor absorbed to sensible heat, thus raising the temperature of the liquid and consequently, the temperature of the air. The other is the heat added to the regenerator liquid in order-to re-evaporate and carry off the excess moisture which has been condensed in the first stage. CLOSED ABSORPTION SYSTEMS The fundamental rule governing the absorption (in a closed system) of a gas by a liquid is Raoult's Law, which states that at any given temperature the ratio of the partial pressure of a volatile component in a solution to the vapor pressure of the pure component at the same temperature is equal to its mol fraction in the solution. The mol fraction, in turn, is equal to the number of mols of substance divided by the total number of mols present. The number of mols in a given weight of a compound is equal to the weight divided by the molecular weight. This law applies strictly, only to what is known as an ideal solution, that is, one in which the intermolecular forces between the substances present in the solution afe equal. Actually, no such solutions exist, so that deviations from Raoult's Law are always found in practice. The 493 1 i j j j |i S :j . jj ;| Heating Ventilating Air Conditioning Guide 1938 deviation is called positive when the observed pressure is greater than that calculated from Raoult's Law, while the term negative deviation refers to the opposite case. Negative deviations are found wherever chemical attraction exists between the solvent and the solute. Positive deviation occurs when there is a difference in the internal pressure of the com ponents, chemical attraction between them being absent. In order to make an effective absorption machine, large negative deviations from Raoult's Law must be shown by solutions of the refrig erant in the liquid absorbent, because, the larger the negative devia tion, the greater is the amount of refrigerant that can be cycled, using a given weight of absorbent. Cycling a large amount of refrigerant for a given weight of absorbent is important because of the heat required to raise the temperature of the mixture and disassociate the refrigerant and the absorbent. Only the latent heat of the refrigerant can be recovered for useful, work. 't at a maximum. 494 i Chapter 24. Cooling and Dehumidification Methods Like the steam ejector system, the absorption, system compares most favorably when a cheap source of cooling water and steam or other, heat source is available. Unlike the ejector system, the comparative performance is usually best with a wide range of temperature between the evaporator and absorber, since with a good refrigerant-absorbent combination, the amount of heat and water required for a given refrig erating effect increases slowly with an increase of evaporator-condenser temperature range. . . . At the present, time the most used refrigerant-absorbent combinations are: (1) water and ammonia and (2) monofluoroclichloroinethane and dimethyl ether of tetraethylene glycol. With the latter combination the boiling points of the refrigerant and absorbent are sufficiently wide apart that- almost pure refrigerant is obtained without the use of a rectifier. EVAPORATIVE COOLING Evaporative cooling is accomplished by passing air through a water spray in which the water is being continually recirculated. The air, entering in an unsaturated condition, evaporates a part of the water at. the expense of the sensible heat. As this is an adiabatic transfer, the total heat content of the air remains constant, while the dew-point rises and the dry-bulb falls until the air is saturated. . The reduction in dry-bulb temperature is a direct function of the wet-bulb depression of the air entering the spray chamber and the re sulting air temperature is governed entirely by the entering wet-bulb temperature of the outside air and the efficiency of the spray. : * THE REVERSE CYCLE The idea of heating by the reverse refrigeration cycle has captured the imagination of many people and has been much discussed. In principle, heat is absorbed in an evaporator from some available source of heat, pumped to a higher temperature and delivered to a condenser. The heat from the condenser is used for heating purposes. The compressor acts as a heat pump whose fundamental function is to raise the potential of the heat. The theoretical work of compression in relation to the heat delivered is: . r. I* r (9) where Ti = absolute temperature of evaporator. Tt -- absolute temperature of condenser. Thus, with- a small spread of temperature between the evaporator and the condenser, 6 .or 8 times as much heat may be obtained theoretically and .4 or 5 times practically, as the work put in. There are a number of limitations, however, the most serious of whichr is the lack of ready availability of a practical source of heat. - ' . -. ' 495 Heating Ventilating Air Conditioning Guide 1938 1. Well water is the most desirable since its temperature is high even in the winter and thus a large amount of heat may be removed in relation to the weight of water handled. 2. Air may be used but its specific heat is low and its temperature uncertain. When the most heat is needed, the temperature of the air is lowest, thus resulting in the least favorable temperature combination. 3. It has been proposed to obtain heat by freezing water, but this is still in the theoretical stage. Some of the other factors which act as limitations are the large tem perature spread when using air as a source of heat and when attempting to cool with even moderately low outside temperatures, the frequent dis parity between the size of the cooling load and heating load requiring extra equipment for a complete heating load, and the relatively high initial cost of equipment at present available for the reverse cycle in comparison with that available for heating by conventional means. Because of these limitations, the present application of the system is largely limited to temperate climates, such as Florida and Southern California, or to heating only for intermediate seasons, or to other locali ties which have peculiar advantages as, for instance, the ready availa bility of well water. In these.locations it is frequently possible to do all of the heating necessary with the refrigeration equipment so that the extra cost is only that of reversing the functions of the condenser and evaporator. , ICE SYSTEMS Ice may be used for chilling water for air conditioning work, but its application is limited because of the cost of ice and the difficulty of handling it. While not impossible, the direct cooling of air by ice is rather impractical. The most general method of cooling water with ice is to spray the water over the surface of the ice, insuring as much contact as possible, and approximating the same performance as the Baudelot type of cooler.' This cold water is then circulated through cooling coils in the air by means of a pump. PROBLEMS IN PRACTICE V 1 0 Electrically driven dichlorodifluoromethane condensing units are to be used in an air conditioning system, requiring 20 tons refrigerating capacity for conditions of maximum load. An overall analysis of the seasons operating conditions shows an average load factor of 62.5 per cent, and allowing for varia ble time intervals of operation of refrigeration units installed, three-quarters of the operating season, or 750 hr, would require operation of the equipment at one-half load, and one-quarter of the operating season or 250 hr full load capacity of the refrigeration equipment would be required. ' The increased first cost of 2-10 hp, 10 ton condensing units over 1-20 hp, 20 ton condensing unit is, $830.00 installed price,'to the customer. The increased first cost of a 2-speed compressor motor of 20 hp size over a con stant speed 20 hp size motor including increased starter cost is $210.00. The efficiency of the 2-speed motor above is 83 per cent at full load speed, and 79 per cent for full load at speed. At speed, full load is ^ total bhp of full load speed. Discuss the considerations involved in making a decision as to whether a single unit with a 20 hp motor of the 2 speed type would be used in preference to 2-10 hp. constant speed units. 496 Chapter 24. Cooling and Dehumidification Methods The cost of 2-10 hp 10 ton units in excess of 1-20 hp, 20 ton unit with 2-speed motor, is $830.00--8210.00 or $620.00, increased first cost. At 15 per cent fixed charges, this represents an increased annual cost of $93.00 for 2 compressors over one compressor; The advantage of 2 compressors instead of one compressor on an installation of this type, is in the breakdown service provided in the event one compressor is shut down for repairs the system could be operated at one-half capacity utilizing the duplicate machine. The motor efficiency of the constant speed unit would be higher at full load than would be the efficiency of the 2-speed motor at low speed. Offsetting this latter advantage however, is the fact that the condenser on the condensing unit would provide a lower, refrigerant condensing temperature for load operation with the same final condensing water temperature than would be the case with duplicate units each furnished with its own compressor and condenser. Operation at a lower condensing temperature would provide for a power saving compensating for the lower efficiency of the 2-speed motor when operated at slow speeds. It is, in a case of this kind, purely a question as to whether or not the purchaser would deem an investment of $620.00 more and an increased fixed charge of $93.00 a year, advisable to get breakdown service through the installation of duplicate units. In most cases, this increased first cost would not be warranted because of the fact that satisfactory indoor conditions could not be obtained at full load if only one-half the refrigeration capacity were available. 2 For.condensing purposes, an air conditioning system uses city water which has an average 70 F supply temperature. The following table lists the number of hours per year during which definite wet-bulb temperatures and corre sponding refrigeration rates pertain. Wet-Bulb Temperature - F 80 79 - 75 74 - 70 69 - 65 64 -- 60 59 - 55 54-50 No. of Hours per Year 6 100 277 330 277 158 52 Refrigeration Required Tons 284 233 183 157 144 79 37 . Total 1200 hours If the power requirements of a dichlorodifluoromethane refrigeration system are in accordance with the following data on the seasonal power cost at 2 cents per kwhr: partial load operation, determine Tons of Refrigeration Kw per ton Seasonal power cost: 284 233 183 157 144 79 37 0.89 0.89 0.87 0.86 0.86 0.93 0.97 Wet-Bulb Temperature 'F Ton-Hours . Kwhr 80 79 - 75 74 - 70 69 65 64-60 59 - 55 54-50 6 X 284 = 1,704 100 X 233 = 23,300 277 X 183 = 50,700 330 X 157 = 51,800 277 X 144 = 39,900 158 X 79 = 12,500 52 X 37 = 1,920 1,704 X 0.89 = 1,517 23,300 X 0.89 = 20,750 50,700 X 0.87 = 44,100 51,800 X 0.86 = 44,500 39,900 X 0.86 = 34,300 12,500 X 0.93 = 11,600 1,920 X 0.97 = 1,860 Totals 181,824 ton-hours The 158,627 kwhr at 2 cents per kwhr will cost $3,173. 158,627 kwhr The average consumpti.on w.i.l.l ,be 158,62.7--kwr-h---r---- -- 0..873 k. w per ton 181,8Z4 ton-hours 497 / Heating Ventilating Air Conditioning Guide 1938 3 .Using the data from Question 2, if city water costs 20 cents per thousand gallons, and if 1.25 gallons are used per minute per. ton, estimate the annual Iva nnet * 60 X X.25 = 75 gal per ton-hour. . . 181,824 ton-hours X 75 = 13,620,000 gal per year. . --13--,-6--2-0--,0--0-0---X----$--0-.-2--0-= $2,724 th^e yearly cooling water cost_. . 4 Using the data of Question 2, if a cooling tower were installed for re-using the condensing water, estimate, the annual compressor power cost of a dichlorodifluoromethane refrigeration system if the final temperatures of the water leaving-the cooling tower and the kilowatt input per ton are the following: Tons . 284 233 183 157 144 79 37 Temperature of water . leaving tower, F. 86.7 81.8 76.5 72.1 66.4 61.3 55.6 Kw input per ton 1.10 0.94 0.85 0.80 0.74 0.59 0.62 Wet-Bulb Temperature F 80 79 -- 75 74 - 70 69-65 64 -- 60 59-55 54-50 Ton-Hours 1,704 . 23,300 50,700 51,800 39,900 12,500 1,920 Kw per Ton . X 1.10 X 0.94 X 0.85 X 0.80 X 0.74 X 0.59 X . 0.62 Kwhr 1,875 21,900 43,300 41,400 29,500 7,370 1,200 . , Totals: 181,824 ton-hours_________________146,545. kwhr The 146,545 kwhr at 2 cents per kwhr will cost $2,931. TM, The average consumpt.on will be 146,545 kwhr lon-houre = 0.805 kw per ton. 5 If a steam ejector system were used to secure the refrigeration for the air conditioning system of Question 2, compute the annual steam cost if steam is sold for 53 cents per thousand pounds and if there is an average steam con sumption of 20 lb of steam pier hour per ton when used with a cooling tower system. ... . .' 181,824 tons X 20 lb of steam per ton -- 3,636,480 lb of steam. ' The 3,636,480 lb at 53 cents per thousand pounds will cost $1,929.' ' '. 6 Discuss the difference in results obtained in cooling and dehumidifycng in an air washer from those obtained in a surface cooling coil. Air leaves a dehumidifying air washer in a saturated condition at a dew point tempera ture which can be easily maintained at a constant level by controlling the spray water temperature. This saturated air may then be reheated to proper delivery temperature by reheating cods or by mixing with by-passed air. . For a set air velocity and a set mean refrigerant temperature, a given cooling-coil is capable of absorbing a definite amount of heat. Whether the air leaving the coil is saturated or not depends then on the entering dry- and wet-bulb temperatures.' From, practical operating standpoint, the easiest way to control the output of the cooling coil is by means of the dry-bulb temperature of the conditioned space. This means then that the final dew point wiH vary somewhat depending on entering air conditions. ` Summarizing then, the air washers permit close control over both final dry-bulb and final .dew point temperatures, while the surface coolers permit close control over the final dry-biilb only. 498 Chapter 25 SPRAY EQUIPMENT FOR HUMIDIFICATION AND DEHUMIDIFICATION Air Washers, Apparatus for Direct Humidification, Spray Generation and Distribution, Self-contained Humidifiers, Atmospheric Water Cooling Equipment, Design Wet-bulb Temperatures, Cooling Ponds, Spray Cooling Towers, Natural Draft Deck Type Towers, Mechanical Draft Towers, Winter Freezing ' . AIR humidification is effected by the vaporization of water which . always requires heat from some source. This heat may be added to the water prior to the time vaporization occurs or it may be secured by a transformation of sensible heat of the air being humidified to latent heat as the vapor is added to the air. The thermodynamics of the .process are discussed in Chapter 1. Dehumidification consists of the removal of moisture from air and may or may not involve the removal of heat from the air-vapor mixture. With spray equipment dehumid ification of air necessitates the removal of heat. AIR WASHERS Air washers may be used as either humidifiers or dehumidifiers de pending upon the method of their operation and the temperature of the spray water. The functions of an air washer are to regulate the moisture-, and heat content of air passing through it and to remove dust and dirt from the air. As cleaning devices air washers are not as effective as air filters in the removal, of dust and dirt. .. The construction of commercial air washers is indicated in Figs. 1 and 2. Any air washer consists essentially of a chamber through which the air passes and comes in intimate contact with water. This chamber may be built of either wood, stone, or sheet metal; the latter being the almost universal material of construction. The lower portion of the washer chamber serves , as a sump for the water passing to its bottom. Contact between the air. and the washer water is secured: (1) by breaking the water into a very fine mist, (2) by passing the air over, surfaces which are continuously wetted by water, or (3) by a.combination of water sprays, and wetted plates. Scrubberrplate types of washers are 499 Heating Ventilating Air Conditioning Guide 1938 used largely to wash heavy reclaimable products from the air, and are generally composed of one to three eliminator-type baffle scrubber plates across the air stream. Water is generally supplied at the tops of the scrubber plates by flooding nozzles placed across the top of the washer. Spray washers have, one or more banks of water atomizing nozzles placed in the air stream above the level of the water in the sump. The direction of the water sprays may be against the air stream, with . the air stream, or with one bank spraying with the air stream and one bank of nozzles spraying against it. The number of nozzles required depends upon their design, the quantity of air handled, and the arrange ment of the nozzles. Scrubbers generally consist of eliminator-type baffle plates placed in the air stream to cause several reversals of the direction of air flow. . The scrubber plates are more effective as air cleaners than as humid- Fig. 1. Typical Single Bank Air Washer Fig. 2.x Typical Two Bank Air Washer ifiers. All washer chambers should have inlet diffuser plates to aid in producing more uniform velocities of air flow through the washer spray chamber. These inlet vanes also aid in preventing spray water from being thrown into the air duct ahead of the washer. At the outlet end of the washer suitable flooded eliminator plates, which will cause from 4 to 6 reversals of the direction of air flow, should be installed for the purpose of removing drops of unvaporized water from the leaving air. When the air carries sulphur and gases mixed with it the spray water may become acidulated and special consideration must be given to the selection of eliminator plates to reduce the corrosive action. Essential items in air washer operation are: uniform distribution of the air across the chamber section above the level of the water in tile 500 Chapter 25. Spray Equipment for Humidification &^Dehumidification sump; moderate velocities of air flow, 300 to 600 fpm in the spray cham ber; an adequate amount of spray water broken up into a fine mist throughout the air stream; sufficient length of air travel through the water spray and over thoroughly wetted surfaces, and the elimination of free moisture from the air as it leaves the unit. Washers are sometimes arranged in two or more stages to cool through long ranges or to increase the overall efficiency of heat transfer between the air and the heating or cooling medium. A multi-stage washer is equivalent to a number of washers in a series arrangement. Each stage is in effect a separate washer. Usually the catalog capacity of a washer is expressed in cubic feet of air per minute and is based upon an air velocity of 500 fpm through the gross cross-sectional area of the unit above the tank. At this rating spray type washers handle about 23^ gpm of water per bank per square .foot of area, that is, about 5 gpm per bank per 1000 cfm. These propor tions of air, water, area, and velocity may be departed from to meet the needs of some particular job, but certain limiting relationships should be observed. For a single stage air washer, a 15 F drop in wet-bulb temperature of the air passing through the washer is about the maximum that should be anticipated. For greater decrease in wet-bulb temperature, multi-stage : washers should be utilized. A rise of 6 F should be the calculated maxi mum for the spray water. > The area of a washer may be dictated by space limitations outside the washer, such as headroom, or by the inside space requirements, such as face area needed by a bank of cooling coils. The length of a washer is determined by the number of spray banks, or scrubber plates, and if cooling coils are installed in the unit, by the number of banks of coils: .Roughly, a spray space of about 2 ft 6 in. in length is required for each bank of sprays, (the leaving eliminators require about 1 ft 6 in., entering eliminators about 1 ft). The resistance to air flow through an air washer varies with the type of eliminators, number of banks of sprays, direction of spray, air velocity, type of scrubber plates, size and type of cooling coils if located in the washer. ' Manufacturers should be consulted to obtain the resistance for a particular installation. ' HUMIDIFICATION WITH AIR WASHER Air humidification can be accomplished in three ways with an air washer. These are: (1) use of recirculated spray water without prior treatment of the air, (2) preheating the air and washing it with recircu lated spray water, and (3) using heated spray water. In any problem of air washing the air should not enter the washer with a dry-bulb tempera ture less than 35 F so that there will be no danger of freezing the spray water. When method 1 is used the principles of adiabatic saturation des cribed in Chapter 1 are involved. The process is one of evaporative cooling as the dry-bulb temperature of the air is reduced and the total heat of the air and water-vapor mixture is unchanged. Moisture is added 501 Heating Ventilating Air Conditioning Guide 1938 to the air and a part of the sensible heat of the initial mixture is trans-. formed to latent heat as evaporation of some of the spray water takes place. Theoretically the spray water and the dry- and wet-bulb temv peratures of the air should come to the wet-bulb temperature of the air entering the washer and the air should leave the washer adiabatically saturated at the entering wet-bulb temperature. Due to limitations of air washer, construction and operation air is not generally completely adiabatically saturated. This introduces an- item into the calculations which is known as humidifying or saturating efficiency. This efficiency is the ratio of the actual reduction of dry-bulb temperature to the reduction of dry-bulb temperature theoretically possible. Expressed as a percentage humidifying efficiency is: .. _ (h-k) 100 . eh - -- . . (1) where ' .- ..eh = humidifying efficiency, per cent. h = initial dry-bulb temperature, degrees Fahrenheit. k = final dry-bulb temperature, degrees Fahrenheit. t' = initial wet-bulb temperature of the entering air, degrees Fahrenheit. .- ' , The humidifying or saturating efficiency of a washer is dependent upon the number of spray banks and nozzles, the effectiveness of the nozzles in breaking an adequate quantity of water into a fine spray, the velocity of air flow through the water sprays, and the time of the contact of the air with the spray water. Other conditions being the same, low velocities of air flow, are more conducive to higher humidifying efficiencies than high velocities of air flow. The following may be taken as representative humidifying or saturating efficiencies of air washers for the conditions stated:' .' 1 bank--downstream..................................................................................... 60-70 per cent 1 bank--upstream .................................. .................. :.............................. 65-75 per cent 2 banks--downstream.. .............................................. ...... ................ 85-90 per cent 2 banks--1 upstream and 1 downstream............................................. 90-95 per cent 2 banks--upstream..;.................................:................................................. 90-95 per cent The air leaving the washer may require the use of a reheater coil to produce the required dry-bulb temperature and relative humidity. When air of a given specific humidity has a low initial dry-bulb tem perature it. may be preheated before it enters a washer using recirculated spray water. The preheating of the air increases both the dry- and wet-bulb temperatures and lowers the relative humidity, but riot the specific- humidity of the air. With an increased wet-bulb temperature, the air is capable of accumulating more moisture by the process of adiabatic saturation and the final specific humidity and the final dry-bulb temperature of the air as it leaves the washer will be higher. An addition of sensible heat by the preheater takes place prior to the air entry into the washer. In the case of method 2 the process of humidification within the washer is similar to method 1. The final desired conditions are secured by adjusting the wet-bulb temperature, of the entering air an'd the use of a reheater when such is necessary. -. 1 Method 3 involves heating the spray water to a temperature equal 502 Chapter 25. ..Spray Equipment for Humidification. & Dehumidification to the dew-point temperature of the air at the final desired conditions. The water heater may be located either in the washer sump .or external to it as in Fig. 3.: The air tends to become saturated as it comes in con tact with the heated spray water, and if the humidifying efficiency of the washer is 100 per cent, the air will leave the washer saturated .at the spray-water temperature. Reheating of the air will give the necessary final dry-bulb temperature and relative humidity of the air if the spray water has been maintained at the proper temperature;- In -this process both heat and moisture are added to the air as it passes through the washer and the dry-bulb temperature of. the leaving air is greater than its entering dry-bulb temperature. , Example 1. Air is to be maintained at 70 F with a relative humidity of 40 per cent when the outside air is at 0 F and 70 per cent relative humidity and a barometric pres sure of 29.92 in. of Hg. Find the required temperature of the spray water, weight of water, vapor to be added, and the heat added in the process. : .... Fig. 3. Am Washer with Spray Water Heating Arrangement Solution. From Example 2, Chapter 1, the final dew-point temperature is 44.5 F, Wv = 0.000548, ftk = 0.00618, and ;W% -- W\ -- 0.005632 lb per pound of dry air. Therefore; the spray water temperature should be maintained at 44.5 F and the moisture addition per pound of dry air is 0.005632 lb. Assuming that the air after being pre heated enters the washer at 40 F and that it leaves the washer saturated at 44.5 F the heat added per pound of dry air is: _- -Preheater: [0.24 (40 - 0) ] + [ 0.45 X 0.000548 (40 - 0) ] = 9.61 Washer: [0.24 (44.5 - 40) ] + [0.45 X 0.000548 (44.5 - 40) ] + (0.005632 X 1079.2) = : 7.16 Reheater: [ 0.24 (70 - 44.5) ] + [ 0.45 X 0.00618 (70 - 44.5) ] .= 6.19 - - ..' . 22.96 .. If the make-up spray water enters the heater at 40 F its initial heat of the liquid per pound of dry air is 0.005632 X 4.5 = 0.03 Btu making the total heat per pound of dry air, excluding pipe losses, chargeable to the heaters equal to 22.96 -- 0.03 = 22.93 Btu. The chargeable heat for humidification alone is (0.005632 X 1079.2) + [0.45 X 0.005632 (70 - 44.5) 1 - (0.005632 X 4.5) = 6.11 Btu per pound of dry air. . APPARATUS FOR DIRECT HUMIDIFICATION Humidifiers may be divided into the following general types, according to the method of operation: (1) Direct, which spray into the .room; (2) Indirect, .which introduce moistened air; and (3) Combined direct and indirect. : . .' . :................... . ' :' Heating Ventilating Air Conditioning Guide 1938 As in the cases of humidification by use of an air washer the heat necessary for the vaporization of the moisture added to the air is secured either from heat stored in the spray water or by a transformation of sensible to latent heat in the air humidified. In the latter case the total heat of the air remains constant but the dry-bulb temperature of the air humidified is reduced. Spray Generation. Spray generation is obtained by (1) atomization, (2) impact, (3) hydraulic separation, and (4) mechanical separation. Atomization involves the use of a compressed air jet to reduce the water particles to a fine spray. With the impact method, a jet of water under pressure impinges directly on the end of a small round wire. Where hydraulic separation is employed, a jet of water enters a cylindrical chamber and escapes through an axial port with a rapid rotation which causes it immediately to separate in a fine cone-shaped spray. In the mechanical separation process, water is thrown by centrifugal force from the surface of a rapidly revolving disc and separates into particles suf ficiently small to be utilized in certain types of mechanical humidifiers. Spray Distribution Spray distribution is obtained by (1) air jet, (2) induction, and (3) fan propulsion. The air jet which generates the spray in atomizers also carries the spray through a space sufficient for its distribution and evaporation, and this method of distribution is termed air jet. Where distribution is obtained by induction, the aspirating effect of an impact or centrifugal spray jet is utilized to induce a current of air to flow through a duct or casing, and this air current distributes the spray. Fan propulsion obviously consists of the utilization of fans to entrain and distribute the spray. Industrial type direct humidifiers are commonly classified ' as (1) atomizing, (2) high-duty, (3) spray and (4) self-contained or centrifugal. Atomizing Humidifiers There are several types of atomizing humidifiers, all of which rely upon compressed air as the atomizing and distributing agency, similar to the familiar method used in ordinary nasal atomizers. Compressed air (ordinarily about 30 lb per square inch) is supplied from a centrallylocated air compressor through pipe lines to the atomizing units. The air lines are usually horizontal and parallel to water lines which supply . water by gravity from a float tank. The water in the tank is maintained at a constant level slightly lower than the outlets of the atomizers theim selves and is drawn constantly to the atomizer by aspiration when comr pressed air is supplied. This aspiration ceases and the flow of water stops when the air supply is cut off. The water should not be supplied under pressure to atomizers because of the possibility of leakage, drip, or coarse spray which cannot be permitted when water is supplied by aspiration. High-Duty Humidifiers . .' Water is supplied to high-duty humidifiers under high pressure (usually about 150 lb per square inch) through pipe lines from a centrally-located 504 Chapter 25. Spray Equipment for Humidification & Dehumidification pumping unit. The spray-generating nozzle which is of the impact type is located in a cylindrical casing. A drainage pan provides for the collec tion and return of unevaporated water which-flows through a return pipe to a filter tank, from which it is recirculated. A powerful air current is forced through the humidifier by means of a fan mounted above the unit. The air enters from above, is drawn through the head, charged with moisture, and cooled to the wet-bulb temperature. It then escapes from the opening below at a high velocity in a complete and nearly horizontal circle. The spray is quickly evaporated and the resulting vapor is rapidly and thoroughly diffused. This effective distribution of fine spray over the maximum possible area insures complete and extremely rapid vapori zation even at the highest humidities. ' Spray Humidifiers This type of humidifier consists of an impact spray nozzle in a cylin drical casing with a drainage pan below it. The aspirating effect of the spray nozzle induces a moderate air current through the casing which . distributes the entrained spray. The general method of circulating and returning the water is similar to that employed for high-duty humidifiers. A suitable pump and centrally-located filter tank are required. . The spray and high-duty types of humidifiers have many features in common but the latter, because of its finer spray and greater capacity, is often considered better adapted for producing high humidities. . Self-Contained Humidifiers The self-contained or centrifugal humidifier has the ability to generate and distribute spray without the use of air compressors, pumps, or other ' auxiliaries. These may be used either singly or in groups. In large installations, where suitable connections are provided to permit the . cleaning and servicing of individual units without affecting the room as a whole, group control of the water and power may be employed. Where large quantities of power are generated in a limited space and where a comparatively high relative humidity is required, it is often feasible and economical to use a combination of direct and indirect humidification. The indirect humidification provides the desired quantity of ventilation and cooling, and the additional direct humidification pro vides for increase in humidity without interfering with the ventilation or the cooling effected by the indirect system. In general, it may be stated that direct humidification is most satis factory where high humidities are desired but where little cooling, ven tilation or air motion is required. Therefore, the indirect system is most applicable where either low or high relative humidities are desired with maximum cooling and ventilation effect. For conditions that require an unusually large amount of heat to be absorbed by ventilation, together with the maintenance of high humidities, it is often preferable to make use of the combination system of indirect and direct humidification. If the indirect system alone were used it would mean an unusually large volume of air to be handled, which might interfere, due to air motion, with production, even though it would result in greater cooling effect. If direct humidification alone were used, no ventilation would be obtained, with consequently higher room temperatures. 505 Air Conditioning Guide 1938 Heating Ventilating SOS F ig . 4 . ' A p p r o x im a t e W e l l W a t e r e m p e r a t u r e sT a t Chapter 2S.. Sprat Equipment for Humidification & Dehumidification AIR DEHUMIDIFICATION WITH WASHERS Moisture removal from an air-vapor, mixture can be accomplished by use of an air washer so long as the temperature of the spray medium is less than the dew-point of the air passing through,the unit. The final dry-bulb temperature and the percentage of the saturation of the air leaving a dehumidifier washer are dependent upon: the air velocity, the length of air travel through the sprays, the dry- and wet-bulb tempera tures of the entering air, the spray temperature, the number of spray banks and nozzles, the quantity of spray medium handled, and the effectiveness of the nozzles in breaking the spray into a fine mist. Both sensible and latent heat are removed in the process of dehumid ification by cooling.-' Abstraction of sensible heat occurs during the entire time that the air is in contact with the spray medium. Latent heat removal takes place as condensation occurs. Therefore, the lower the spray temperature the greater the amount of moisture removal per pound of dry air all other conditions remaining the same. The spray temperature should be controlled to 1 or.2 F below the desired leaving dew-point temperature of the air. Washers with two or more banks of sprays are usually selected for comfort air conditioning installations. Such washers will cool the air to within 1 or 2 F of the spray temperature. Where a limited supply of cold water is available multiple stage washers may be used to an advantage. The cool water is pumped through . the multiple spray systems in series. By this arrangement the entering air is cooled first by the warmer water and finally by the cooler water which gives the maximum amount of cooling with the minimum amount of water. The approximate temperatures of water from non-thermal wells at depths of 30 to 60 ft are given in Fig. 41. Frequently the tempera ture of the city water main supply is low enough during the summer to permit an appreciable cooling effect. Table 1 lists the maximum city water main temperatures for various localities in this country and Canada. Air washers using refrigerated spray media generally have their own recirculating pumps. These pumps deliver to the washer sprays a mixture of water from the washer sump, which has not been re-cooled, and re frigerated water. The quantities of each of the portions of the spray medium are controlled by a three-way or mixing valve actuated by a dew point thermostat located in the washer air outlet. . An illustration of a cooling and dehumidifying calculation is given in Example 3 of Chapter 1. ATMOSPHERIC WATER COOLING EQUIPMENT In the operation of a refrigerating plant or a condensing turbine, one of the main problems is the removal and dissipation- of heat from the compressed refrigerant or the discharged steam. This is accomplished ordinarily by first transferring the heat of the gas to water in a heat exchanger, from which water it may then be dissipated in a number of ways. If the plant is situated on the banks of a river or lake, an intake Temperature of Water Available for Industrial Use in the United States, by W. D.',Collins (U. S. Geological Survey, Water Supply Paper No. 520 F). . ` . 507 Heating Ventilating Air Conditioning Guide 1938 Table 1. Average Maximum Water Main Temperatures3 State ClTT Tump. F Statb Ala......... Ariz------Calif....... Burraingham..... ..... I Mobile____ Phoenix__ Tucson___ Anaheim.... Berkeley._ Fresno____ Fullerton__ Glendale. Los Angeles...... . Oakland.............. I Ontario.............. Pasadena........... . Pomona....... ...... Colo-- Conn.. D. C.. Del-- Fla-- Ga-- i Riverside........... Sacramento....... San Bernardino.. San Diego.......... San Francisco.... Whittier____ ___ Denver____ ___ | Bridgeport-....... Hartford............ New Haven...... Waterbury........ Washington ....... Wilmington....... Jacksonville___ Miami.............. Tampa.............. 1 Atlanta.-.......... Macon_______ JU___ Chicago______ Cicero....... ....... I Evanston......... Peoria.. Ind........... Iowa._ Kans.. j Rockford__ | Springfield-. Evansville-- | Gary-- Indianapolis........... South Bend_____ _ Terre Haute......... Cedar Rapids.____ Des Moines........... Sioux City............. Concordia________ Kansas City._____ Topeka....... ........... Wichita.................. Ky.. Louisville________ La- Baton Rouge___ ... New Orleans......... Me-- Augusta... .......... . Md-- Baltimore....... ...... 84 73 81 80 60 69 72 75 68 75 69 70 82 75 78 72 65 82 62 75 75 66 73 76 72 84 83 80 80 77 87 80 76 76 73 67 59 82 86 75 80 61 82 78 77 62 57 86 88 72 85 85 85 60 67 Mass-- Mich.. MumMo...... Nebr._ Nev,, N. H.. N. J._ N. Y.. N. C.. N. M. lOhio-- Cm Teup. F Boston_____ Cambridge.. Fall River.. Lowell........... Lynn.................. New Bedford.. Salem................. Worcester.------ Detroit.., Flint.. Grand Rapids.... Highland ParkJackson............... Kalamazoo-------Lansing.________ Saginaw.............. Duluth.. Minneapolis.............. St. PauL--.--........... Jefferson City.......... Kansas City...........St. Joseph.................. St. Louie.................... Springfield................. Lincoln........................ Omaha......................... Reno.. Manchester.. Jersey City-- Newark_____ Paterson____ Trenton_____ Albany........... Buffalo_____ Jamaica.. Mt. Vernon............ New Rochelle-----New York................ Rochester-------------Schenectady-........ Syracuse................... Utica__________ ____ Yonkers------- --------Asheville.. Charlotte--......... Winston-Salem.. Albuquerque....... Akron.... ................ CantonCincinnati-----------Cleveland-----------Columbus.............. Dayton__________ Lakewood--........... Springfield............ Toledo....... ............. 80 70 76 50 68 70 68 76 77 70 84 77 56 53 64 82 55 . 80 77 82 84 84 85 70 87 87 61 76 63 74 78 79 68 75 56 74 75 72 70 60 74 69 70 74 85 82 65 76 50 84 74 82 60 82 72 83 .These averages taken from various city water main locations, with some actual values slightly higher and some lower than values shown. 508 Chapter 25. Spray Equipment for Humidification & Dehumidification Table 1. Average Maximum Water Main Temperature3 (Continued) Statb ClTT Temp. F State ClTT Temp. F Okla.......... . Tulsa--........................ Portland..................... Pa................ Erie.............................. McKeesport.............. Philadelphia' ......... R. I--.... . S. C............ S. Dak....... Tenn........... Chattanooga............. Knoxville................... Nashville.... ............. Texas.......... AustinTM...................... Beaumont.................. San Antonio.............. Wichita Falls............ 82 85 60 64 74 75 74 82 83 67 68 80 81 78 55 84 89 70 90 65 90 86 86 84 90 84 83 76 85 Salt Lake City_____ Va Lynchburg...... .......... W. Va........ 44 . 60 75 73 80 58 62 51 57 85 78 78 54 58 70 68 Province Alta............ B. C............ Vancouver..... P. F- 1 Que............. Montreal................... Quebec........................ 64 60 50 63 48 78 68 aThese averages taken from various city water main locations, with some actual values slightly higher and some lower than values shown. * may be taken upstream or at a considerable distance from the discharge, to prevent mixing of the heated discharged water with the inlet water. If the source of cooling water is a city supply or a well, the discharge water may be-run into the nearest sewer or open waterway. Lacking an unlimited water supply, or in cases where city water is too expensive or where the water available contains dissolved salts which would form scale on the heat-exchanging apparatus, it is necessary to recirculate the water, and to cool it after each passage through the heat-exchanger by exposure to air in an atmospheric water cooling apparatus. Air has a capacity for absorbing heat from water when the wet-bulb temperature of the air is lower than the temperature of the water with which it is in contact. The rapidity with which this transfer of heat occurs depends upon (1) the area of water in contact with the air, (2) the relative velocity of the air and water,'and (3) the difference between the wet-bulb temperature of the air and the temperature of the water. Because the changes in rate do not occur in direct proportion to changes in the govern ing factors, data on the performance of atmospheric water cooling equip ment are largely empirical. As the heat content of the air increases, its wet-bulb temperature rises. (See Chapter 1.) Because it is impractical to leave the air in contact 509 Heating Ventilating Air Conditioning Guide 1938 . with water for a long enough time to permit the wet-bulb temperature of the air and the temperature of the water to reach equilibrium, atmos pheric water cooling equipment aims to circulate only enough air to cool the water to the desired, temperature with the least possible expenditure of power.... In an air washer, humidifier or dehumidifier, die air is first conditioned by water to change its moisture and temperature, and it is then sent to the place where it is to be used. In water cooling equipment the tem perature of the water is reduced by air, and the cooled water is carried to its point of usage. In the air washer, an excess of water is used to con dition a fixed quantity of air, while in water cooling equipment, an excess quantity of air is used to cool a fixed quantity of water. Both types of equipment have a common basis of design, however, in that the size of the equipment is determined by the quantity of air that must be handled. With the air washer, the size of the equipment is fixed by the quantity of air to be conditioned, and the amount of conditioning is controlled by the quantity and temperature of the water supplied and its method of application. With water cooling apparatus, its size and the quantity of air required bear no direct relation to the quantity of water being cooled, but vary through a wide range for different services and conditions. .' Sizes of Equipment Assuming a definite quantity of water to be cooled, the size and design of atmospheric cooling equipment are affected by the following factors: 1. Temperature range through which the water must be cooled. 2. Number of degrees above the wet-bulb temperature of the entering air to which the water temperature must be reduced. . 3. Temperature of the atmospheric wet-bulb at which the required cooling must be performed. 4. Time of contact of the air with the water. (This involves height or length of the . apparatus and velocity of air.) . . 5. Surface of water exposed to each unit quantity of air. 6. Relative velocity of air and water. Items 1, 2, and 3 are established by the type of service and geographical location, while items 4, 5, and 6 depend upon the design of the equipment. .The establishment of a proper cooling range-.depends upon: 1. Type of service (refrigerating, internal combustion engine and steam condensing). - 2. Wet-bulb temperature at which the equipment must operate satisfactorily. 3. Type of condenser or heat-exchanger used. . .. Because the design of an entire plant is usually affected by the quantity and temperature of the cooling water supply, plants should be designed for cooling water conditions which can be most efficiently attained. The first consideration is usually the limiting temperature of the plant. For example, if an ammonia compressor refrigerating plant is to be designed , for 185 lb head pressure as a normalmaximum, the limiting temperature of the ammonia in the condenser is 96 F. Should the ammonia tempera ture go above this figure the head pressure will exceed 185 lb and power consumption increases... To obtain this head pressure, the. temperature of 510 WflUJ..!........ - ' 1 ' ______________ ___________________________________________________ . .. . . X, Chapter 23; Spray Equipment for Humidification & Dehumidification the circulating water leaving the condenser must always be less than 96 F by an amount'depending upon the size, and design of the condenser, the quantity of water being circulated; and the refrigerating tonnage being produced. A condenser having a large surface per, ton of refrigeration may be designed to operate satisfactorily with the: leaving-hot water temperature within 3 or 4 F of the ammonia temperature corresponding to the head pressure, while a small condenser`might require a 10 F difference. . . :. Table 2 lists several gases with data as to the temperatures and pres sures for which commercial condensers are designed'. Internal combustion engines have limiting hot water temperatures of 125 F to 140 F. The cooling of such fluids as milk or wort has variable requirements and is usually done in counter-flow heat-exchangers in. which the leaving circu lating water is at a much higher temperature than, is the leaving fluid. Table 2. Condenser Design Data Gas Maxotuu Pressure Desired in Condenser . Steam... 28 in. vacuum.... Steam.,, 27 in. vacuum.... Steam., 26 in. vacuum.... Ammonia| 185 lb gage ' head pressure.. Carbon dioxide..i 1030 lb gage Methyl . chloride......._ Dichlorodi- fluoromethane head pressure.. 102 lb gage head pressure- 1171b gage head pressure.: Gas Temperature in Condenses Deg F Leaving Hot Water Temperature Deg F Best Condenser Design Average Condenser 101.2 115.1 125.9 96.0 86.0 , 100.0 100.0 97 110 120 92 83 96 96 93 105 114 88 81 ?2 93 The temperature range, once the hot water temperature'-is approxi mately known, depends upon: : ... 1. Maximum wet-bulb temperature at which the full quantity of heat must be dissipated. ' 2. Efficiency of the atmospheric cooling equipment considered. . . Design Wet-Bulb Temperatures The maximum wet-bulb temperature at which the full. quantity of water must be cooled through the entire range' is never, in commercial design, the maximum wet-bulb temperature ever:known to exist at the location nor the average wet-bulb temperature over any period. The former basis would require atmospheric cooling equipment several times greater than normal size, and the latter would result during a large part of the time, in higher condenser water temperatures than those for which the plant was designed. For instance, the maximum wet-bulb temperature recorded in New York City is 88 F, and the July noon average for 64 years is close to 68 F. Yet in the years 1925 to 1934, inclusive, there were but 8 hours per .year when the wet-bulb temperature reached 80 F or more, and there were 975 hours in the average summer (June to September, inclusive) when the wet-bulb, temperature was 68 F or above. As these ' 511 Heating Ventilating Air Conditioning Guide 1938 975 hours represent a third of the summer period, cooling equipment based upon the noon average July wet-bulb of 68 F would be inadequate. Commercial practice is to choose a wet-bulb temperature for refrigeration design purposes which is not exceeded during more than 5 to 8 per cent of the summer hours (75 F for New York City), with somewhat lower requirements for steam turbines and internal combustion engines. This difference is made because the heaviest load on a refrigerating plant is coincident with high wet-bulb temperatures, whereas the heaviest electric power demand occurs either in the winter or after nightfall in summer, when the wet-bulb temperature is low. Table 1, Chapter 8, shows design wet-bulb temperatures which will not be exceeded more than 8 per cent of the time in an average summer. Knowing the hot water temperature and the wet-bulb temperature for which the equipment must be designed, the cold water temperature must Table 3. Efficiency of Atmospheric Water Cooling Equipment . Equipment Spray Ponds................................................. Natural Draft Deck or Atmospheric Cooling Efpicienct--Peb Cent Minimum Usual - Maximum 30 45 to 55 60 40 45 to 55 60 35 50 to 70 90 35 55 to 75 90 be chosen to place the requirement within the efficiency range of the type of atmospheric water cooling apparatus to be used. Efficiency of atmos pheric water cooling apparatus is expressed as the percentage ratio of the actual cooling range to the possible cooling range. Since the wet-bulb temperature of the entering air is the lowest temperature to which the water could possibly be cooled this is: Percentage cooling efficiency of atmospheric water cooling equipment = (hot water temperature -- cold-water temperature ) X 100 hot water temperature -- wet^bulb temperature of entering air Efficiencies of various types of atmospheric water cooling apparatus vary through wide limits, depending upon air velocity, concentration of water per square foot of area, and the type of equipment. The commercial range of efficiencies is given in Table 3 although unusual designs may operate outside these ranges. From consideration of the factors which include the cooling range and design wet-bulb temperature, the quantity of water required can be calculated from the amount of heat to be dissipated. The normal amounts of heat to be removed from various processes of the cooling equipment are: Compressor refrigeration__________ Condenser turbine............................... Steam jet refrigerating apparatus. Diesel engine........................................ . 220 to 270 Btu per minute per ton. . 950 to 880 Btu per pound of steam. .1030 to 1150 Btu per pound of steam. .2800 to 4500 Btu per horsepower. 512 Chapter 25. Sprat Equipment for Humidification & Dehumidification Cooling Ponds A natural pond is often used as a source of condensing water. The hot water should be discharged close to the surface at the shore line. Natural air movement over the surface of the water will cause evaporation and carry away heat. Because increased density due to the loss of heat causes the cooled water to sink to the bottom of the pond, the suction connection for intake water should be placed as far below the surface as possible, and at as great a distance from the discharge as practicable. Spray Cooling Ponds The spray pond consists of a basin, above which nozzles are located to spray water up into the air. Properly designed spray nozzles break up the water into small drops, but not into a mist because the individual drops must be heavy enough to fall back into the basin and not drift away with the air movement. The water surface exposed to the air for cooling is the combined area of all the small drops. Since the rate of heat removal by atmospheric water cooling is a function of the area of water exposed to the air, the difference in temperature between the water and the wetbulb temperature of the air, the relative velocity of air and water, and the duration of contact of the air with the water, a much larger quantity of heat may be dissipated in a given area with the spray pond than with the cooling pond, because of (1) the speed with which the drops travel as they are propelled into the air and fall back into the water basin, (2) the increased wind velocity at a point above the surrounding structures or terrain, (3) the increased volume of air used, and (4) the vastly increased area of contact between air and water. Spray pond efficiencies are increased by (1) elevating the nozzles to a higher point above the surface of the Water in the basin, (2) increasing the spacing between nozzles of any one capacity, (3) using smaller capacity nozzles, to decrease the concentration of water per unit area, and (4) using smaller nozzles and increasing the pressure to maintain the same concentration of water per unit area. Usual practice is to locate the nozzles from 3 to 7 ft above the edge of the basin, to supply from 5 to 12 lb. pressure-at the nozzles, using nozzles spraying from 20 .gpm to 60 gpm each and spacing them so the average water delivered to the surface of the pond is from 0.1 gpm per square foot in a small pond to 0.8 gpm per square foot in a large pond. ' Increasing the pressure, spacing the nozzles farther apart, or increasing the elevation of the nozzles will increase the cross-section of spray cloud exposed to the air, and therefore increase the quantity of air coming in contact with the water. Best results are obtained by placing the nozzles in a long relatively narrow area located broadside to the wind. Spray ponds may be located on the ground if they have an earthen or a concrete basin, or they may be placed on roofs having special waterproof roofing. To prevent excessive drift loss, or the carrying of entrained water beyond the edge of the pond by the air on the leeward side, louver fences are required for roof locations and for those ground locations where space is so restricted that the outer nozzles cannot be located at least 20 ft to 25 ft from the edge of the basin. Such fences usually are con structed of horizontal louvers overlapping so the air is forced to turn a 513 Heating Ventilating Air Conditioning Guide 1938 comer in passing through the fence, and the heavier drops of water, are thrown back, owing to their inertia. The louvers also restrict the flow of air, particularly at the higher wind velocities, and thus further reduce the possibility of water being carried off. The height of an effective fence should be equal to the height of the spray cloud. Louver boards are preferably of red gulf cypress or California redwood supported on castiron, steel or wood posts. Where building ordinances forbid the use of combustible materials, sheet metal is customarily used.. . Algae growths, during warm weather, in cooling towers and spray ponds may be eliminated while the plant is in operation by the use of potassium permanganate. This chemical can be dissolved at the rate of 1 lb in 1]/i to gal of hot water. About 10 parts of permanganate should be used per million parts of cooling water. The permanganate attacks the algae, forms a brown covering over it, and causes it to settle. Enough of the permanganate solution should be added periodically to cause the water to have a pink color for a period of from 15 to 20 min. Small additions of the permanganate daily do riot give concentrations which are effective. The best results are obtained when sufficient quantities are added periodically at intervals of several weeks, the time intervals being dependent upon local operating conditions. The chemical is non-poisonous and is non-corrosive when used as directed. Spray Cooling Towers Where not more than 30,000 Btu per minute are to be dissipated, the spray cooling tower is a satisfactory apparatus. The word tower in this connection is somewhat of a misnomer as the apparatus is essentially a narrow spray pond with a high louver fence. As usually built, the nozzles spray down from the top of the structure and the distance from the center of the nozzle system to the fence on either side is not more than half the distance that the nozzles are elevated above the water basin. Heights range from 6 ft to 15 ft and the total width of a" structure is not usually . greater than its height. Spray cooling towers occupy less space on small jobs than spray ponds of equivalent, capacities because the towers have a capacity'of from 0.6 gpm to 1.5 gpm per square foot of tower area. The louvers are continually wet, and so add to the surface of water exposed to the cooling air. ' ' '' Natural Draft Deck' Type Towers ' ' In past years most of the atmospheric water cooling , on refrigeration work has been done with natural draft deck type towers, which are also referred to as wind or atmospheric towers. These towers consist of heavy wooden or steel framework from 15 to 80 ft high and from 6 to 30 ft wide, having open horizontal lattice-work platforms or decks at regular intervals from top to bottom, and a catch basin at the foot. The hot water is distributed over the upper part of the structure by means of troughs, splash heads, or nozzles, and it drips from deck to deck down to the basin.. The object of the decks is to. arrest the fall of the water so as to present efficient cooling surfaces to the air, which passes through the tower parallel to the decks. The decks also add to the area of water surface exposed to the;air, but since they furnish a resistance to air flow, . too many decks, are a.,detriment.' . . 514 Chapter 25. Spray Equipment for Humidification & Dehumidification . To prevent the loss of water on the leeward side of the tower, wide splash boards are attached at regular intervals from top to bottom. These boards or louvers extend outward and upward, and in most designs the top edge of each louver extends above the bottom edge of the brie above it. Efficiency of a deck tower is improved, within limits, by increased height, increased length, or increased width. The first-two increase the area of water exposed to the wind, and the latter increases the .time of contact of the air with the water. Wind Velocities on Natural Draft Equipment . Since natural air movement is the prime requirement for a deck type tower, spray cooling tower, or spray pond, the apparatus iriust be de signed to produce the desired cooling on days when the wind velocity is below average when the wet-bulb temperature is at the maximum chosen for design, and when the plant is operating at full load. The apparatus must also, for best results, be located with its longest axis at right angles to the'direction of the prevailing hot weather breeze. Table 1, Chapter 8, gives the average summer wind velocities arid directions in representative cities. Natural draft cooling equipment should be designed to operate properly with not more than one-half of the average wind velocity, and in no case for a wind velocity of more than 5 mph. It is obvious that natural draft towers and other natural draft equipment must be so located that . they are not obstructed by trees, buildings, or other wind deflectors. Mechanical Draft Towers .- Mechanical draft towers usually consist of vertical shells, constructed . of wood, metal, or masonry, in which water is distributed uniformly at the' top and falls to a collecting basin at the bottom. The inside of the tower may be filled with wood checker-work over which the water drips, or the water surface may be presented to the air by filling the.entire inside of,the. structure with spray from nozzles. Air is circulated through the tower from bottom to top by forced or induced draft fans;. Since the air flows counter to the water, the air is in contact with the hottest of the water just before leaving the top of the tower, and each unit of air picks up more heat than a similar unit would on natural draft equipment, so- the me chanical draft tower cools water by using less air than the other types of equipment need. As movement of the air through the towers is obtained by power-consuming fans, it is essential that the air used be reduced to a minimum so as to secure the lowest possible operating cost. The efficiency of a mechanical draft tower is increased by increasing height, area, or air quantity. Increasing the height increases the length of time the air is in contact with the water without affecting seriously the fan power required, but it increases the pumping power needed. In creasing the area while maintaining constant fan power increases the air quantity somewhat and because of lowered velocities it increases the time this air is in contact with the water. The surface area of water in contact with the air is increased in both cases. Increasing the air quantity decreases the time the air is in contact with the water, but, since a greater quantity is passing through, the average differential between the water temperature and the wet-bulb temperature of the air is increased, and 515 Heating Ventilating Air Conditioning Guide 1938 this speeds up the heat transfer rate. Increased air quantities are obtained only at the expense of increased fan power, which increases approximately as the cube of the air quantity. Air velocities through mechanical draft towers vary from 250 to 600 fpm over the gross area of the structure. Mechanical draft water cooling equipment may be set up inside build ings, where it usually draws its air supply from the general space in which it is installed, and discharges its exhaust air through a duct to the outside. Indoor cooling towers may be either of the wood-filled or the spray-filled type. In many cases where little height but considerable area is available, water is cooled in a spray-filled structure similar to an air washer, with the air passing horizontally through the apparatus and being discharged Table 4. Comparison of Various Types of Atmospheric Water Cooling Equipment Figures indicate order of desirability Pond Suitability for congested districts............... Water quantity required for definite X 5 1 X 6 1 1 1 2 X 6 Sprat Pond 2 4 2 X 3 6 6 2 1 5 Sprat Tower Decs Tower Mechanical Indoor' Draft Tower i3 32 3 4-5 13 45 54 54 3 4-5 34 43 45 1X 4-5 X 42 1-2 1-2 2-3 2-3 2-3 2-3 4-5 6 56 12 5 4 1-2 1-2 3 xNot comparable. through a duct to -the outside. Such apparatus does not have the counter flow advantage of the vertical mechanical draft water cooling equipment, and therefore requires a much larger excess of air for proper operation. Air velocities and operating powers are considerably above those required by vertical mechanical draft water cooling equipment. Make-Up Water Since the atmospheric water cooling equipment performs its functions chiefly by evaporating a portion of the wateY in order to cool the re . mainder, there is a continual drain on the quantity of water in the system, and this loss must be replaced. Approximately 1 gal of water is lost for every 1000 gal of water cooled per degree of cooling range; so if 1000 gpm of water are cooled through a 10 F range, 10 gpm of water will be re quired to replace evaporated water. Replacement supply is usually regulated by a float control valve. Because the evaporation of the water leaves behind the salts which the water contained, high concentration of salts may make chemical treatment of the make-up water necessary to avoid excessive deposits in the condensers. An additional amount of make-up water must be added to replace windage, or drift loss. This additional amount of water varies from 0.1 to 3 per cent of the quantity of water being circulated, this percentage depending upon the type of equipment and the wind velocity. -. ' 516 Chapter 25. Spray Equipment for Humidification & Dehumidification Winter Freezing ' If atmospheric water cooling equipment is operated in freezing weather, the water may be cooled below freezing temperature so ice forms and collects until its weight causes damage. To obviate freezing during con tinued operation, the efficiency of the apparatus may be lowered. This is done on the spray pond and the spray cooling tower by reducing the quantity of water fed to the apparatus, thereby lowering the pressure at the nozzles and increasing the size of the drops produced. On the deck tower the upper system may be shut off and a secondary distribution system put in service midway down the height of the tower. The water will be kept above freezing because it will have shorter contact with the air. The mechanical draft tower can be protected by reducing the air flow through the tower, by stopping or reducing the speed of the fans, or by partially closing dampers. If the system is operated intermittently in freezing weather, water in the basin may freeze and the expansion of the ice may do harm. Freezing during intermittent operation can be prevented only by draining the water basin when it is out of service. On small roof installations, a tank large enough to hold all the water in the system is often installed inside the building and the basin is drained into this by gravity, the pump suc tion being taken from this inside tank. A comparison of various types of water cooling equipment is given in Table 4. PROBLEMS IN PRACTICE 1 # What performance tests should he given air washers? a. Capacity, b. Resistance, c. Visible entrainment of free moisture, and d. Humidifying or dehumidifying efficiency. ' 2 # What are different types of air washers? a. Spray, b. Wet scrubber, and c. Combination spray and scrubber. 3 # Upon what air velocity are air washers usually rated? 500 fpm through the area above the tank. 4 What is the difference between direct and indirect humidification? Direct humidification signifies that the humidifiers are within the space to be humidified with distribution produced by the number of humidifiers. With direct humidification there is relatively little air movement. Indirect humidification signifies that the air is drawn from the enclosure and passed through the humidifier (air washer) and distributed by means of a duct system. 5 # Where is direct humidification desirable? Direct humidification is desirable when high humidity is required accompanied with cooling, ventilation, or air motion. 6 # Where is indirect humidification desirable? Indirect humidification is desirable when high humidity is required with simultaneous removal of heat by ventilation. .. Heating Ventilating Air Conditioning .Guide 1938 7 Why do cooling towers give best results when the humidity of the air. is low? The cooling of the water by dropping it through the air depends mostly upon the evapor ation of the water. If the relative humidity of the air is low, the water vapor will be readily absorbed and carried away, while if the relative humidity is high, its capacity to pick up water vapor is less and the water is cooled less with the same exposure to the air. 8 What are some of-the advantages and disadvantageous of a forced draft cooling tower compared with a natural draft wind tower? * . Advantages: a. Does not depend on wind, b. Less space required, and c.-Less drift loss and less make-up. . . .. Disadvantages: a. Higher first cost, and b. Higher maintenance cost; 9 What wet-bulb temperature for outside air is usually, selected in air con ditioning design when cooling is to be accomplished? .. One which is not exceeded more than 5 to 8 per cent of the time in the locality where the plant is situated. . . 10 t Where should the suction connection be placed .in a cooling pond? . As far below the surface as possible and as far away from the discharge as practicable. 11 i What chemical is used to kill algae formation in spray ponds? Potassium permanganate. .' ' ' . .. 12 What is the usual amount of spray iwater delivered to a cooling pond per square foot of area? * -' ' - ` From 0.1 gpm on small sizes to 0.8 gpm on large sizes. 13 t About how much water is lost by evaporation in atmospheric cooling? About 1 gal per 1000 gal for each degree of cooling range... . 14 # How is freezing obviated in cooling pond sprays? ? The pressure and quantity of water is lowered so that the drops become larger in size, and do riot freeze so readily. .' 518 Chapter 26 AIR CLEANING DEVICES ' Air Cleaner Requirements; Classifications, Viscous Type Filters, Unit Filters, Automatic Filters, Dry Air Filters, Air ' Washers, Methods of Installation, Stack Gases, Settling Chambers, Centrifugal Separators, Industrial Filters, . Electrical Precipitators, Exhaust Systems, Air Scrubbers ~ HE removal of impurities from air brought into a building, or from Tair recirculated in a building for ventilating or air- conditioning purposes is the function of any air cleaning or filtering, device. These impurities include carbon (soot) from the incomplete combustion of fuels burned in furnaces and automobile engines, particles of earth, sand, ash, automobile tires, leather, animal excretion, stone, wood, rust and paper, threads of cotton, wool and silk, bits of animal and vegetable matter, bacteria and pollen. Microscopic examination shows that the character of the impurities varies with the locality, but as a rule carbon forms the greater part of them while the total is somewhat proportional to the state of industrial activity and the wind intensity. Additional information on sources of air pollution and the particle sizes of atmospheric impurities will be found in Chapter 4. AIR CLEANER REQUIREMENTS To fulfill the essential requirements of clean air, an air cleaner should; 1. Be efficient in the removal of harmful and objectionable impurities in the air, such as dust, dirt, pollens, bacteria. 2. Be efficient over a considerable range of air velocities. 3. Have a low frictional resistance to air flow; that is, the pressure drop across the filter should be as low as possible. - 4. Have a large dust-holding capacity without excessive increase of resistance, or have ability to operate so as to keep the resistance constant automatically. 5. Be easy to clean and handle, cleans itself automatically, or else be inexpensive enough to replace when dirty. 6. Leave the air free from entrained moisture or charging liquids used in the cleaner. The Society has developed a code1 which explains how such devices are rated by (1) capacity in cubic, feet of air handled per. minute, (2) re sistance in inches of water at rated capacity, (3) dust arrestance,. the 1Ir Standard Code for Testing and Rating Air Cleaning Devices Used-in General Ventilation Work (A.S.H.V.E. Transactions, Vol. 39. 1933, p. 225). . . 519 Heating Venturing Air Conditioning Guide 1938 percentage relationship expressing dust removal efficiency at rated capacity, (4) reconditioning power, the energy necessary to operate the mechanism of an automatic air cleaning device, and (5) dust-holding capacity, the amount by weight of standard dust which a non-automatic air cleaning device will retain before reconditioning is necessary. CLASSIFICATION OF AIR CLEANERS According to the Code, the following four classifications are given the devices: Class A. Automatic Type: In general all air cleaning devices which use power to automatically recondition the filter medium and maintain a non-varying resistance to air flow. Class B. Low Resistance Non-Automatic Type: Air cleaning devices for warm-air furnaces, unit ventilating machines and similar apparatus and installations in which a maximum of not more than 0.18 in. water gage is available to move air through the air cleaning device. Class C. Medium Resistance Non-Automatic Type: Air cleaning devices for systems in which a maximum of not more than 0.5 in. water gage is available to move air through the air cleaning device. Class D. High Resistance Non-Automatic Type: Air cleaning devices for the air intake of compressors, internal combustion engines, and the like, where a pressure of 1.0 in. or more water gage is available to move air through the air cleaning device. Air cleaners may also be classified as follows: 1. According to principle of air cleaning. a. Viscous air filters. (1) Unit type. (2) Automatic type. ' b. Dry air filters. c. Air washers. ' d. Electrical precipitators. - 2. According to application. a. For central fan systems of ventilation and air conditioning. Filters of the automatic or semi-automatic type, as well as the non-automatic viscous unit or dry type are usually recommended and are installed in a central plenum chamber. ' b. For unit ventilators. Filters o[ viscous unit or dry type, installed at inlet of individual units. ,. c. For window installations. Self-contained units consisting of fan and filter, usually dry or viscous type, adapted to be placed in the ordinary window. d. For warm-air furnaces. Unit type viscous or dry filters placed in small plenum chamber of warm-air house heating systems. - e. For compressors and Diesel engines. Unit or automatic type viscous or dry filters, installed at air intake of compressors and Diesel engines. f. For compressed air lines. Unit type viscous or dry filters. g. For stack gases. Settling chambers, dynamic or electrical precipitators. h. For exhaust systems. All types. . Air cleaners may be classified further as follows: 1. For general air conditioning. With the growing congestion of large cities and an industrial growth throughout the entire country, the percentages of foreign material in the air, such as soot or carbon, which are unaffected by an air washer type of air cleaner, have increased. This has brought about the development of 520 Chapter 26. Air Cleaning Devices the viscous and dry type air filters which are part of many ventilating and air conditioning systems. 2. For removal of dusts, smokes and fumes from stack gases. Prevention of atmos pheric pollution from this source is of ever increasing importance, sometimes forced legally and frequently used in order to obtain increased efficiency. 3. For removal and. collection of industrial dusts from the point of their production through exhaust systems. VISCOUS TYPE FILTERS The principle of air cleaning used in viscous filters is that of adhesive impingement. Dust and dirt in the air, especially soot and carbons, are trapped and retained by successive impingements on coated surfaces. While the arrangements of filtering media and the kind of materials used are almost unlimited, there are certain rather definite requirements for a practical commercial filter. Investigations in this country and abroad demonstrate that the first impingement of dust laden air on a viscous coated surface removes about 60 per cent' of the dust, the next impingement takes 60 per cent of what then remains--that is, 24 per cent--and the next impingement removes 9.6 per cent. To secure maximum efficiency, it is necessary to divide the air into innumerable fine streams, as the more intimately and freely the air is brought into_contact with the viscous-coated media the better will be the cleaning. The binding liquid used with viscous filters should have the following properties: . . 1. Its surface tension should be such as to produce a homogeneous.film-like coating on the filter medium. L 2. The viscosity should vary only slightly with normal changes of temperature. 3. It should be germicidal in its action to prevent the development of mold spores and bacteria on the filter media. 4. The liquid should have a high affinity for dust at low temperatures. 5. The liquid should have high capilarity, or ability to wet and retain the dust. 6. Evaporation should not exceed 1 per cent. 7. It should be fireproof. . 8. It should be.odorless. Viscous Unit Filters ' In the unit type viscous filter, the filtering media are arranged in units of convenient size to facilitate installation, maintenance, and cleaning. Each unit consists of an interchangeable cell or replaceable filter pad and a substantial frame which may be bolted to the frames of other like units to form a partition between the source of dusty air and the fan inlet. Where necessary reconditioning equipment should be installed near each group of unit filters, with hot water and sewer connections provided. To secure greater dust holding capacity and a practically constant resistance and .air volume, the filter media are usually placed in the direction of air flow, with progressively finer filter densities determined by the percentage of dust impinged. This arrangement provides relatively large spaces for the collection of dirt in the front of the filter where the bulk of the dust is taken out without undue increase in resistance, while at the back of the filter the openings are smaller to secure high efficiency in the removal of the finer dust particles. ' 521 Heating Ventilating Air Conditioning Guide 1938 The resistance of a well-designed unit filter of the adhesive impinge ment type usually depends upon the velocity at which the air is handled and upon whether the unit is clean or dirty. The cleaning efficiency of the unit is usually highest after it has accumulated a certain portion of its maximum load of dirt because some dust collected in the cell acts as an efficient medium for the further seizing of solids from the air. By periodi cally cleaning a predetermined number of cells, the resistance and capacity : 030 - 0.25 ! 030 E> 0.15 o 2 4 6 8 lo Vi 14 16 QUANTITY OF OUST, OUNCES Fig. 1. Chart Showing Change in Resistance Due to Dust Accumulation . Chapter 26. Air Cleaning Devices localities. Wide variations are also foiind due to different seasons of the year as well as the time of day and the direction of the wind. A chart showing the increase in resistance of a unit filter of the viscous impinge ment type, when tested with the standard test dust described in the code5, is given in Fig. 1. The resistance to air flow of three typical clean viscous impingement type filters having different media densities is shown in Fig. 2. Type A is a dense pack used in bacteria control; Type B is a medium pack used for general ventilation work and Type C is a low resistance unit for use where low resistance is the important factor and maximum cleaning efficiencies are not essential. The operating charac teristics which might be expected under various dust concentrations with air filters having different dust-holding capacities are illustrated in Fig. 3. Filters consisting of inexpensive frames of cardboard or similar material filled with viscous-coated glass wool, steel wool or the like are available. Fig. 2. Resistance to Air-Flow of Typical Unit Air Filters of a built-up filter may be held at any desired figure. The frequency of cleaning any unit filter installation depends upon the dust concentration of air being cleaned, and on the amount of dirt which can be accumulated in the filter medium without causing excessive resistance. (Figs. 1,2 and 3.) It is difficult to satisfactorily compare the cleaning efficiencies of various filter types unless the efficiency ratings are determined under laboratory conditions in accordance with some definite test procedure such as that developed by the Society.2 Efficiency tests made in the field with atmos pheric dust are subject to so many variables that consistent comparisons are difficult. Of- course there is no standard atmospheric dust, as atmos pheric dust varies widely in composition and concentrations in different *Loc. Cit. Note 1. 522 Fig. 3. Maintenance Chart for Unit Type Viscous Filters Because of their construction these units may be discarded when dirty and replaced with new units at relatively little expense. They are used in general ventilation work and with warm-air furnaces find other instal lations where low first cost and low resistance to air flow are essential. The operating characteristics of these units conform in general with those of the rigid frame type. Viscous Automatic Filters The principle of air cleaning used in the viscous automatic filters is the same as in the unit filters. The removal of the accumulated dust, however, is done automatically instead of by hand. The automatic clean ing and recoating of these filters is based on the principle that the viscous fluid itself will perform the cleaning function, thereby eliminating a sepa rate washing agent. The dust collected by the filter thus is deposited finally in the bottom of the viscous fluid reservoir from which it may be Loc. Cit. Note 1. 523 Heating Ventilating Air Conditioning Guide 1938 removed by different methods, depending on the design of the filter. There are three general types of automatic filters. They are differentiated from each other according to the process of self-cleaning and renewing of the viscous coating used by each type, as follows: 1. The filter medium has the form of an endless curtain suspended vertically, with its lower portion submerged in a viscous fluid reservoir. The curtain rotates slowly through this bath, thus performing the cleaning and recoating of the filter medium. 2. The filter screen is arranged in the form of shelves or cylinders, and the viscous fluid is flushed through all parts of the medium in a direction opposite to the air flow. 3. The filter medium is arranged vertically and is stationary. The viscous fluid is flushed from above over the medium, while the air flow is stopped. The washing and renewing process in automatic filters usually is inter mittent. It is accomplished by an electric motor or by other motive power and is controlled by manual or by automatic timing devices. The operating cycle is of a predetermined frequency and should be so timed as to insure a constant static pressure drop across the filter. The customary resistance to air flow is %-in. water gage at an air velocity of 500 fpm, measured at the filter entrance. Automatic viscous filters are made up in units which are delivered either fully assembled or in parts to be assem bled at the point of installation. DRY AIR FILTERS l3ry air filters, in which dust is impinged upon or filtered through screens made of felt, cloth, or cellulose, are available in various types. These filters require no adhesive liquid, but depend on the straining or screening action, of the filtering medium. Because of the close texture of the filtering media used in most of the dry filters, the surface velocity, or velocity of the air entering the media, ranges between 10 and 50 fpm, depending on the nature and texture of the fabric. This necessitates a relatively large screen surface, and the filter media are usually arranged in the form of pockets to bring the frontal area within customary space requirements. As in viscous unit filters, an average constant resistance and air volume may be obtained by periodic reconditioning or renewal of the filter screens. Since some materials suitable for dry filtering media are affectpl considerably by moisture which tends to cause a rapid increase in resis tance, they should be treated or processed to minimize the effect of changes in humidity. Filters using felt and similar materials as filter media usually depend upon vacuum cleaning for reconditioning. A special nozzle, operated from a portable or stationary vacuum cleaner, is shaped to reach all parts of the filter pockets. Permanent filter media should be capable of with standing repeated vacuum cleanings without loss in dust removal efficiency. While most dry filters are cleaned by replacing an inexpensive filter sheet, the useful life of these sheets often may be lengthened by vibrating or vacuum cleaning.'' . AIR WASHERS Air washers have not been used extensively in the past in cleaning air for ventilating purposes because of their inability to remove fine dirt 524 Chapter 26. Air Cleaning Devices particles. However, new types have been developed which appear to have possibilities for applications where the air to be cleaned is extremely dirty or where a higher degree of cleanliness is desired than can be ob tained with a conventionally designed air washer. Information on air washers used in connection with humidifiers will be found in Chapter 25. METHODS OF INSTALLATION The published performance data for all air filters are based on straight through unrestricted air flow. Filters should be installed so that the face area is at right angles to the air flow whenever possible. Eddy currents and dead air spaces should be avoided and air should be distributed uniformly over the entire filter surface, using baffles or diffusers if neces sary. The most important requirements of a satisfactory and efficiently operating air filter installation are: X. The filter must be of ample size for the amount of air it is expected to handle. An overload of 10 to 15 per cent is regarded as the maximum allowable. When air volume is subject to increase, a larger filter should be installed. 2. The filter must be suited to the operating conditions, such as degree of air clean liness required, amount of dust in the entering air, type of duty, allowable pressure drop, operating temperatures, and maintenance facilities. . 3. The filter type should be the,most economical for. the specific application. The first cost of the installation should be balanced against depreciation as well as expense and convenience of maintenance. The following recommendations apply to filters and washers installed with central fan systems: 1. Duct connections to and from the filter should change size or shape gradually to insure even air distribution over the entire filter area. 2. Sufficient space should be provided in front as well as behind the filter to make it accessible for inspection and service. A distance of two feet may be regarded as the minimum. 3. Access doors of convenient size should be provided in the sheet metal connections leading to and from the filters. 4. All doors on the clean air side should be lined with felt to prevent infiltration of unclean air. AH connections and seams of the sheet metal ducts on the clean air side should be as air-tight as possible. , 5. Electric lights should be installed in the chamber in front of and behind the air filter. 6. Air washers should, whenever possible, be installed between the tempering and heating coils to protect them from extreme cold in winter time. 7. Filters installed close to air inlet should be protected from the weather by suit able louvers, in front of which a large mesh wire screen should be provided. . 8. Filters should have permanent indicators to give a warning when the filter re sistance reaches too high a value. STACK GASES Solid particles discharged with stack gases, both domestic and industrial, contribute to the need for air cleaning in general ventilation. The common foreign matter includes the larger fly-ash and unburned carbon particles ranging up to 100 microns and larger, as well as the permanently suspended smokes. Usually it is economical to collect the coarser par- 525 Heating Ventilating Air Conditioning Guide 1938 tides in separators, either gravitational or centrifugal, thus preventing clogging and overloading of the filters or precipitators used for the fines. Air cleaning devices for this purpose must meet the severe conditions of temperature and corrosion while handling large air volumes at low power and labor costs. SEPARATORS In addition to the air cleaning devices previously mentioned, the following are common types available for application to the removal of stack gases. Gravitational Settling Chambers The larger dust and gas particles will settle out from air if time and space are provided. Since the settling rate is constant, the required time of retention of the air in a gravitational settling chamber varies directly with the distance through which the particles must fall before reaching a retaining surface. Horizontal plates placed parallel with the air flow are effective and introduce negligible resistance. Air velocities should be selected so that the settled dust will not be redispersed, and for this reason baffles or constrictions producing increased velocity or turbulence should be avoided. Relations between time of gas passage, distance of fall, and size of particles removed can be calculated from Fig. 1 in Chapter 4. With a forward air velocity of 50 fps passing between horizontal 14 ft shelves placed 3.3 in. apart vertically, particles of 100 microns, which settle at the rate of 59.2 fpm, will all have time to settle through the 3.3 in. vertical distance and reach the shelf while the air is passing along the shelf. Due to redispersion, actual operation would be much less favorable except at low air velocities. Simple settling chambers consist of large spaces through which air velocities are decreased to one or two feet per second and in which dust particles fall into hoppers. In proper design, the inlets and outlets are placed and baffled so as to cause minimum turbulence, and the collected dust is protected from eddy currents. Centrifugal Separators , The force causing settling can be increased^ many times that of gravi tation by giving the air a whirling motion and introducing centrifugal force. The settling rate then becomes dependent upon the peripheral air velocity and the radius of curvature as well as upon the other factors. In centrifugal and cyclone separators, air is introduced tangentially into a vertical cylinder and passes out from the center of the top. The gas velocity and curvature of the cylinder cause whirling which throws the particles to the surface. In the simple centrifugal type, the particles slide down the surface and are removed through a hopper in. the cone bottom. In the cyclone type, they are thrown through slits in the periphery and collect in a second outer cylinder where the air is nearly static and there is little chance for redispersion. .Assumptions regarding streamline flow and turbulence make general calculations of centrifugal settling rate quite involved and rough. Their . 526 Chapter 26. Air Cleaning Devices range of usefulness is indicated in Fig. 1 of Chapter 4. They have wide application in connection with industrial operations such as grinding, screening, combustion, etc., but have little or no effect upon the finer particles. Small diameters give smoother stream lines and larger centrifugal forces for the same power consumption, so that several small units in parallel are to be preferred to one larger one. INDUSTRIAL FILTERS In principle and practice the industrial dry filters are similar to those used for general ventilation, the latter being a development of the former. Bag filters up to 2.5 ft in diameter and 30 ft long, hung vertically, are fed through a header, allowing gas to pass out through the sides of the bag and retaining the dust particles on the inner surface. Depending on the nature of the cloth or mat filtering medium, retention of fines can be very high if gas velocity is low, about 0.5 to 3 cu ft per square foot per minute. The collected dust particles themselves aid in agglomerating and retaining others. Periodic shaking, with the fans off or reversed, at intervals of a few hours drops the excess dust into a lower header or hopper for removal. Readily removed filters built in small sections in which filter media can be replaced are of distinct advantage where deterioration is rapid. Various . styles of construction are available which combine quick interchange ability and large filtering area per square foot cross-sectional area. Use of several independent units in parallel is important for the reconditioning, of each unit separately. Both continuous and intermittent shaking and sweeping devices remove excess dust and maintain a low resistance. . ELECTRICAL PRECIPITATORS For removing fine dust or liquid particles which show no gravitational settling tendency, electrical precipitators are highly effective in air cleaning applications. In this system of air cleaning the particles are first ionized in a region where they acquire an electrostatic charge. The separation of the particles is then accomplished by passing the air be tween parallel plates where the dust particles are attracted to grounded collecting electrodes. The electric field holds them to this electrode unless a high critical redispersing gas velocity is exceeded. Particles are shaken down by either periodic mechanical or hand rapping. The materials of construction for the apparatus may be selected to meet nearly any required conditions of temperature and corrosion. The discharge electrodes are usually of metal in the form of wires or edges placed equidistant between collecting electrodes either in the form of hollow pipes or plates. By properly choosing the type of electrodes the generation of oxides of nitrogen may be practically eliminated. Voltage requirements depend primarily upon the electrode spacing and the gas conditions or particle nature. The maximum field intensity is limited by the arcking voltage for the particular conditions. The discharge electrode should be negative because with this charge higher voltages may be carried without arcking. 527 Heating Ventilating Air Conditioning Guide 1938 EXHAUST SYSTEMS Quick removal of dust particles produced by such operations as grind ing, screening, mixing, etc., is accomplished with exhaust systems. Their applications are numerous and varied, and not only prevent health hazards but eliminate product contamination. Mere discharge to the atmosphere outside of the building without collection is frequently of little effect, for incoming air redistributes the objectionable material. Information on the design of industrial exhaust systems will be found in Chapter 34. Any of the air cleaning devices previously described may be used with them depending upon the severity of the conditions and the nature and size of the material to be collected. ' AIR SCRUBBERS Air scrubbers are used extensively in exhaust systems since they pro vide removal of at least the coarser particles. The choice of scrubbing medium depends upon the character of the particles to be removed. The liquid medium should wet the particles, and the wetting is a surface tension phenomenon specific for each liquid-solid pair. Water effectively wets particles similar to silica, and oil wets particles similar to carbon. Combinations of oil and water, producing a froth, are effective for both and for materials of intermediate nature. Intimate contact between the scrubbing liquid and the particles is essential, and many variations in constructions are available. Fine sprays, baffles, bubble caps, open and packed towers, and splash systems are used. Even the finest sprays are of low efficiency when used in an open chamber. Impact -of the dust particles against a wetted surface is necessary for their retention, and this requires high gas velocities and well placed baffles or packing. Atomization of the liquid and air together is highly effective in removing the finest particles but makes for high power requirements. Corrosion is frequently serious, particularly with high temperature gases containing soluble constituents. The collected material is removed as a thick sludge, and its wetted condition is a factor for consideration if it has possible recovery value. . REFERENCES % An Improved Simple Method of Determining the Efficiency of Air Filters, by H. G. Tufty and E. Mathis (A.S.H.V.E. Transactions, Vol. 33, 1927, p. 57). Design and Application of Oil-Coated Air Filters, by H. C. Murphy (A.S.H.V.E. Transactions, Vol. 33, 1927, p. 73). A Study of Dust Determinators, by F. B. Rowley and John Beal (A.S.H.V.E. Trans actions, Vol. 34, 1928, p. 475). Determining the Quantity of Dust in Air by Impingement, by F. B. Rowley and John Beal (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 483). Smoke and Dust Abatement, by M. D. Engle (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 233). .... .Operation and Maintenance of Air.Filters, by W. G. Frank {Heating, Piping and Air Conditioning, May, 1931, p. 378). Size and Characteristics of Air-Borne Impurities, by W. G. Frank (Healing, Piping and Air Conditioning, January, 1932, p. 35). 528 Chapter 26. Air Cleaning Devices Fundamental Principles in the Design of Dry Air Filters, by Otto Wechsberg (A.S. H.V.E. Journal Section, Heating, Piping and Air Conditioning, April, 1933, p. 217). Operation, Maintenance of Cloth-Screened Dust Collectors, by W. F. Terry (Heating, Piping and Air Conditioning, May, p. 259, June, p. 304, 1933). Testing and Rating of Air Cleaning Devices Used in General Ventilation Work, by Samuel R. Lewis (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 270). The Dust Problem in Air Conditioning, by F. B. Rowley (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, June, 1935, p. 293). An Alternate Meth&d of Comparing Dust Arrestance in Air Cleaning Devices, by Arthur Nutting (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning August, 1937, p. 511). * PROBLEMS IN PRACTICE 1 Assume a fan and duct system which handled 10,000 cfm through clean filters with a system resistance of 0.8 in. of water and that after the filters have become dirty the system resistance increases to 1.0 in. of water, and that the fan speed remains unchanged. Is there any way of predicting the volume of air delivered after the filter becomes flirty? Yes. If the performance curves for the particular make of fan are available, the new volume may be determined from the resistance pressure curve. (Figs. 1,2 3 and 4 Chapter 27.) ' 2 What are the advantages of viscous filters? The principal advantage of the viscous filter is its large dust holding capacity. The dust accumulation is distributed through the depth of the filtering medium rather than upon the surface as in the dry types, which makes it possible for viscous filters to handle heavy dust concentrations without excessive resistance. Since its efficiency and resis tance are based on maximum air velocities of from 300 to 500 fpm through the filter, the viscous filter consumes the minimum amount of space for a given air volume. 3 What are the advantages of.dry filters? Dry filters are more efficient in the removal of fine dust particles from the air, and some types will eliminate even as much as 60 per cent of the smoke particles. Dry filters also are easily and conveniently maintained by vacuum cleaning, vibrating, or renewing the filtering medium. 4* If an air washer is used for cooling arid humidity control in an air con ditioning system, is a filter needed? An air filter is desirable in conjunction with an air washer because of the large amount of soot in the air which, due to its greasy and amorphous nature, is not readily trapped in an air washer. Filters should be placed between the washer and the air intake so that all the dirt will be collected at one point to simplify maintenance and to protect all the equipment in the system. 5 Is an air filter needed with an extended surface type heat exchanger? yUi air filter is essential with an extended surface heat exchanger in order to maintain its efficiency, for without this protection dust particles will adhere to the exposed surfaces, and gradually build up a deposit to the point where the efficiency will be impaired and the resistance increased by restricting the air passage. " 6 What is the proper location of a filter in relation to the fan? A filter will operate equally well whether placed on the suction or discharge side of the fan. It has become standard practice, however, to locate the filter on the fan inlet side because there it has: (1) simpler duct connections, (2) reduced static pressure losses, (3) more even air distribution over the entire filter area. Where an exceptionally high efficiency in dust removal must be maintained, it is often advisable to place the filter on the discharge side of the fan so there can be no infiltration of unclean air. 529 _______ _ Heating Ventilating Air Conditioning Guide 1938 7 What instruments and apparatus are required for determining the pollen concentration in air by means of the settling method? A microscope with a field of known area and a glass slide coated with a viscous material. 8 Describe the procedure for determining the pollen concentration in air by means of the settling method. A glass slide coated with a viscous material is placed for a period of 24 hours in a hori zontal position in the atmosphere to be tested. The slide is then removed and placed under the microscope, and pollen counts are made of approximately 25 fields over the area of the glass slide. Having determined the count over a definite area, as for example, 1 sq cm, and finding the settling rate of the average particles from the chart, Fig. 1 in Chapter 4, the concentration in parts per cubic yard can be calculated. 9 The resistance to air flow of a unit air filter is found to be 0.4 in. of water. The volume of air passing through the filter is 1000 cfm at a velocity of 200 fpm. What would be the filter area required in order to reduce the pressure drop across the filter from 0.4 in. of water to 0.16 in. of water? Referring to Fig. 2: The resistance is substantially proportional to the square of the velocity, or Ri = R, IV 0.4 = 200* 0.16 TV Vj = 126.5 fpm Q = AV 1000 = 126.5 A A 1000 126.5 7.91 sq ft The filter area would be increased from 5 sq ft to 7.91 sq ft. ' 10 A ventilating system complete with filters has a fan which, when operating at 400 rpm and delivering air at 1 in. of water total static pressure, requires an input of 3 horsepower. After the system operates for a time, the pressure drop across the filter caused by the clogging action of the collected dust and dirt increases from 0.1 in. of water to 0.4 in. of water. To maintain the original rate of air delivery with the increased static pressure, at what speed must the fan be run and what horsepower will be required? Static pressure after clogging of filter = 1 + (0.4 -- 0.1) 1.3 in. of water. The static pressure varies as the square of the fan speed. Therefore, if X is the fan speed after the static pressure increases: , T3 _ / X \2 1 V 400 / X = 456 rpm. ' The horsepower varies as the cube of the fan speed. Therefore, if Y is the horsepower after the static pressure increases: _L - ( *56 \3 3 \ 400 / Y = 4.44 horsepower. To maintain the original rate of air delivery with the increased static pressure, the fan speed must be increased from 400 to 456 rpm, and the horsepower from 3 to 4.44. 530 Chapter 27 FANS Classification, Performance, Fan Efficiency, Characteristic Curves, System Characteristics, Selection of Fans, Volume Control, Fan Designations, Motive Power IN heating and ventilating practice, fans are used to produce air flow except where positive displacement is required, in which case com pressors or rotary blowers are used. Fans are classified according to the direction of air flow as (1) axialflow or propeller type if the flow is parallel with the axis, and (2) radial flaw or centrifugal type if the flow is parallel with the radius of rotation. Axial flow fans are made with various numbers of blades of a variety of forms. The. blades may be of uniform thickness (sheet metal), either flat or cambered, or may be of varying thickness of so-called aerofoil section (airplane propeller type). Where an axial flow fan is intended for operation at comparatively high pressures the hub sometimes is enlarged in the form of a disc and the fan is known as a disc fan. Radialflow or centrifugalfans include steel plate fans, pressure blowers, cone fans, and the so-called multiblade fans. All the foregoing types have variations which may be obtained by modification of the proportions or change in the curvature and angularity of the blades. The angularity of the blades determines the operating characteristics of a fan; a forward curved blade is found in a fan having slow speed operating characteristics,, while a backward curved blade is found in a fan having high speed operating characteristics. A wide variation exists in the demands which have to be met by fan installations. A fan may be required to move large quantities of air against little or no resistance or it may be required to move small quanti ties against high resistances. Between these two extremes innumerable specific requirements must be met. In general, fans of all types in each general class can be made to perform the same duty, although mechanical difficulties, noise or lack of efficiency may limit the use to one or another type. The most common field of service for fans of the propeller type is in moving air against moderate resistances, especially where no long ducts or heavy friction must be overcome and where noise is not objectionable, whereas centrifugal fans are commonly employed for operation at the comparatively higher pressures and where extreme quietness is necessary. FAN PERFORMANCE Fans of all types follow certain laws of performance which are useful in determining the effect of changes in the conditions of operation. These 531 Heating Ventilating Air Conditioning Guide 1938 laws apply to installations comprising any type of fan, any given piping system and constant air density, and are as follows: 1. The air capacity varies directly as the fan speed. 2. The pressure (static, velocity, and total) varies as the square of the fan speed. 3. The power demand varies as the cube of the fan speed. Example 1. A certain fan delivers 12,000 elm at a static pressure of 1 in. of water when operating at a speed of 400 rpm and requires an input of 4 hp. If in the same installation 15,000 cfm are desired, what will be the speed, static pressure, and power? Speed = 400 X = 500 rpm Static pressure = 1 X = 1-56 in. . Power = 4 X (= 7.81 hp When the density of the air varies the following laws apply: 4. At constant speed and capacity the pressure and power vary directly as the density. Example S. A certain fan delivers 12,000 cfm at 70 F and normal barometric pressure (density 0.07492 lb per cubic foot) at a static pressure of 1 in. of water when operating at 400 rpm, and requires 4 hp. If the air temperature is increased to 200 F (density 0.06015 lb) and the speed of the fan remains the same, what will be the static pressure and power? : . c, w 0.06015 .... Static pressure = 1 X q 07492 = m' Power 4 w X 0.06015 0.07492 = 3.20 hp 5. At constant pressure the speed, capacity and power vary inversely as the square root of the density. Example S. If the speed of the fan of Example 2 is increased so as to produce a static pressure of 1 in. of water at the 200 F temperature, what will be the speed, capacity, and power? Speed = 400 X^-2||f|-= 446 rpm . VCapacity = 12,000 X 0.07492 = 13,392 cfm (measured at 200 F) 0.06015 w-4xV'S--4*i"> , 6. For a constant weight of air: (o) The speed, capacity, and pressure vary inversely as the density. (b) The horsepower varies inversely as the square of the density. Example 4. If the speed of the fan of the previous examples is increased so as to deliver the same weight of air at 200 F as at 70 F, what will be the speed, capacity, static pressure, and power? Speed = 400 xJSf= 498 rpm Capacity <= 12,000 X 00 0067049125 = 14,945 cfm (measured at 200 F) . 532 Chapter 27. Fans / 0.07492 \2 Power = 4 X 1006015; = 620hp FAN EFFICIENCY The efficiency of a fan may be defined as the ratio of the horsepower output to the horsepower input. The horsepower output is expressed by the formula: Air Horsepower* = cfm X total pressure in inches of water 6356 (1) When the static pressure is used in the computation it is assumed that this represents the useful pressure and that the velocity pressure is lost in the piping system and in the air which leaves the system. Since in most installations a higher velocity exists at the fan outlet than at the point of delivery into the atmosphere, some of the velocity pressure at the fan outlet may be utilized by conversion to static pressure within the system, but owing to the uncertainty of friction losses which occur at the places where changes in velocity take place, the amount of velocity pressure which is actually utilized is seldom known, and the static pressure alone may best represent the useful pressure. The efficiency based upon static pressure is known as the static efficiency and may be expressed as follows: . cfm X static pressure in inches of water Static efficiency1 = 6356 X Horsepower input (2) - Different fans may develop the same capacity against the same static pressure and with the same power input, and therefore operate at the same static efficiency, while maintaining different outlet velocities. Where a high outlet velocity is desirable or can be utilized effectively, the static efficiency fails to be a satisfactory measurement of the performance. In many applications of propeller fans, air is circulated without encountering resistance and no static pressure is developed. The static efficiency is zero and its calculation is meaningless. Because of such situations where the static efficiency fails to indicate the true performance, many engineers prefer to base the calculation of efficiency upon the total or dynamic pressure. This efficiency is variously known as the total, dynamic, or mechanical efficiency, and may be expressed as follows: - Mechanical or TMTotal effic.iency*, = c--/m----X- tota l.7pre,,s-s--u--r-e---in----in--c--h-e:--s--o--f--w---a--t-e--r 6356 X Horsepower input (3) ' CHARACTERISTIC CURVES In the operation of a fan at a fixed speed the static and total efficiencies vary with any change in the resistance which is imposed. With different designs the peak of efficiency occurs when the fans deliver different per-* 533 lSee Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers, Edition of 1932. 533 Heating Ventilating Air Conditioning Guide 1938 centages of their wide-open capacity. Variations in efficiency accompany variations in pressures and power consumption which are characteristic of the individual designs and which are influenced particularly by the shape and angularity of the blades. Such variations in pressure, power, and efficiency are shown by characteristic curves. Characteristic curves of fans are determined by tests performed in accordance with the Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers* as adopted by the American Society of Heating and Ventilating Engineers and the National Association of Fan Manufacturers. The results of tests are plotted in different ways: the Chapter 27. Fans Axial flow fan characteristics are indicated by Figs. 1 and 2. These fans, when properly designed, have a satisfactory efficiency at low resistance, comparing favorably in this respect with centrifugal fans. They are low in cost and economical in operation and occupy relatively little space. Although this type of fan can operate against considerable resistance, the noise often becomes objectionable, so that it does not always compare favorably with centrifugal fans for such service. With most of the designs which employ blades of uniform thickness the power increases rapidly with an increase in resistance. The curves (Fig. 1) show the rapid reduction in capacity and increase in power as the resistance increases. The low efficiency when overcoming Fig. 1. Operating Characteristics of an Axial Flow Fan abscissae may be the ratio of delivery, assuming full open discharge as 100 per cent, and the ordinates may be static pressure, dynamic pressure, horsepower and efficiency. Pressures may be expressed in per cent of the maximum pressure in the manner shown in the illustrations in this chapter, but in engineering calculations they are sometimes expressed in proportion to the pressures due to the peripheral velocity. It should be noted that characteristic curves of fan performance are plotted for a constant speed. Some variation in values of efficiency may occur at different speeds but such variation is usually slight within a wide range of speeds. Fans of similar design but of different size will also show some difference in efficiency. Figs. 1 to 4 show characteristic curves for different types of fans using blades of various shapes, but without reference to the design of housing employed. The efficiency curves are therefore not serviceable for making rigid comparisons of efficiencies obtainable with blades of the various shapes but are intended merely to show reason able values and more particularly to show the manner in which variations occur with changes in fan capacity. *A.S.H.V.E. Transactions, Vol. 29, 1923, p. 407. Amended June. 1931. 534 heavy resistance is due to the low speed of the blades near the hub as compared to the relatively high peripheral or tip speed. The air driven by the blade area near the rim can pass back through the less effective blade area at the hub more easily than it can overcome the duct resistance. Fig. 2 shows the performance of the airplane propeller fan in which the blades are similar in shape to those of an airplane propeller but of varying number according to the pressure to be developed. This fan usually operates at a higher speed than does the former type of propeller fan, and with a different power characteristic, the power remaining fairly constant throughout the range of pressures, being somewhat less at the higher than at the lower pressures. The flatness of the horsepower curve indicates the advantage of this type of fan in preventing overloading of motors where fluctuations in pressure occur. Variations in the diameter, width, pitch, camber, and the thickness of the blades provide a considerable degree of flexibility in design, so that the peak of total efficiency may be made to occur at wide-open volume or at various percentages of that volume. Another advantage of this type of axial flow fan is its low resistance to air passage when standing still. There are some installations in which such a characteristic is desirable. . 535 Heating Ventilating Air Conditioning Guide 1938 The straight blade (paddle-wheel) or partially backward curved blade type of fan is practically obsolete for ventilation. Its use is largely con fined to such applications as conveyors for material, or for gases con taining foreign material, fumes and vapors. The open construction and the few large flat blades of these wheels render them resistant to corrosion and tend to prevent material from collecting on the blades. This type of fail has a good efficiency, but the power steadily increases as the static pressure falls off, which requires that the motor be selected with a moder ate reserve in power to take care of possible error in calculation of duct resistance. Chapter 27. Fans makes it adaptable for direct connected electric motor drives. The high speed may necessitate somewhat heavier construction and more operating attention or service. The dimensional bulk for a given duty often is 150 per cent of that of a forward curve multiblade type fan. Between the extremes of the forward and the full backward curve blade type centrifugal fans a number of modified designs exist, differing in the angularity or in the shape of the blades. Common among these designs are the straight radial blade type, the radial tip type, and the double curve blade type with a forward angle at the heel and a slight backward angle at the tip of the blade. Characteristic curves of these types show Per Cent of Wide Open Volume Fig. 3. Operating Characteristics of a Fan with Blades Curved Forward The forward curved mtdtiblade fan is the type most commonly used in heating and ventilating work, as it has a low peripheral speed, a large capacity, and is quiet in operation. The point of maximum efficiency for this fan occurs near the point of maximum static pressure. The static pressure drops consistently from the point of maximum efficiency to full open operation. The power curve rises continually from low to peak capacity, but if reasonable care is exercised in'figuring resistance there is no danger of overloading the motor. The outstanding characteristics of the full - backward curve multiblade type fan are the steep pressure curves, the non-overloading power curve, and the high speed. (See Fig. .4.) This fan operates at a peripheral speed of- approximately 250 per cent of the forward curve multiblade type for like results. The pressure curves begin to drop at very low capacity and continue to fall rapidly to full outlet opening. The steep pressure curves tend to produce constant capacity under changing pressures. Where wide fluctuations in demand occur, this type of fan is desirable to prevent overloading of motors. The maximum power requirement occurs at about the maximum efficiency. Consequently a motor selected to carry the load at this point will be of sufficient capacity to drive the fan over its full range of capacities at a given speed. The high speed of this type 536 varying degrees of resemblance to the curves of Figs. 3 and 4, according to the degree of similarity to one or the other of the two designs of fan considered. SYSTEM CHARACTERISTICS A given fan performs as determined by the real characteristic of the system to which it is attached. When a different performance of a fan is desired, it is necessary to either change the speed of the fan (as A to B or C to D in Fig. 5), or to change the system (as by moving a damper from A to C in Fig. 5). If the speed of the fan is changed, the new point of opera tion is the intersection of the constant speed static pressure--cubic feet per minute curve for the new speed with the system characteristic. If the system is changed, the new point of operation is the intersection of the constant speed static pressure, cubic feet per minute; curve with the new system characteristic. ' Heating and ventilating systems follow the simple parabolic law quite closely but other types of systems follow some other more or less complex relation. The more complex systems can be separated into their com ponent parts whose individual characteristics are known and the sum mation of the characteristics of the several parts of a system will give the composite characteristic of the system. ` 537 Heating Ventilating Air Conditioning Guide 1938 SELECTION OF FANS The following information is required to select the proper type of fan: . 1. Cubic feet of air per minute to be moved. 2. Static pressure required to move the air through the system. 3. Type of motive power available. 4. Whether fans are to operate singly or in parallel on any one duct. 5. What degree of noise is permissible. 6. Nature of the load, such as variable air quantities or pressures. Fig. 5. Illustration of Operating Points of a Given Fan at Two Speeds on the Same and Different Systems Knowing the requirements of the system,, the main points to be con sidered for fan selection are (1) efficiency, (2) speed, (3) noise, (4) size and weight, and (5) cost. In order to facilitate the choice of apparatus, the various fan manu facturers supply fan tables or curves which usually show the following factors for each size of fan operating against a wide range of static pressures: _ 1. Volume of air in cubic feet per minute (68 F, 50 per cent relative humidity, 0.07488 lb per cubic foot). . 2. Outlet velocity. 3. Revolutions per minute. ' 4. Brake power. . 5. Tip or peripheral speed. ' 6. Static pressure. - 538 Chapter 27. Fans The most efficient operating point of the fan is usually shown by either bold-face or italicized figures in the capacity tables. Fans for Ventilating and Air Conditioning Systems Two important factors in selecting fans for ventilating systems are efficiency (which affects the cost of operation) and noise. First cost and space available are secondary. The fans should be selected to operate at maximum efficiency without noise. Because noise in a ventilating system is irritating and a cause for complaint, fans must be selected of proper size in order to reduce it to a minimum. Noise may be caused by other factors than the fan, namely, high velocity in the duct work, unsatisfactory location of the fan room, improper construction of floors and walls, and poor installation. Where noise is chargeable directly to the fan, it is caused either by excessive peripheral speeds, or the fan is of insufficient size. It should be remembered, however, that the tip speed Table 1. Good Operating Velocities and Tip Speeds for Forward Curved Multiblade Ventilating Fans Static Pressure Inches or Water x- X X H X H l IX m IX 2 . 2K 2^ 3 Outlet Velocity Feet per Minute 1000-1100 1000-1100 1000-1200 1100-1300 1200-1400 1300-1600 1500-1800 1600-1900 1800-2100 1900-2200 2000-2400 2200-2600 2300-2600 2500-2800 To* Speed Feet per Minute 1520-1700 1760-1900 1970-2150 2225-2450 2480-2700 2660-2910 2820-3120 3162-3450 3480-3810 3760-4205 4000-4500 4250-4740 4475-4970 4900-5365 required for a specified capacity and pressure varies with the type of blade, and that a tip speed which may be excessive for the forward curved type is not necessarily so for the backward or slightly backward type. A noisy fan usually is one which is operated at a point considerably beyond maximum efficiency. For a given static pressure there is a corresponding outlet velocity and peripheral speed wherein maximum efficiency is obtained. If a fan is selected to operate at this point, the cost of operation and the noise can be held within control. To aid in selecting fans as near as possible to the point of maximum efficiency, there are listed in Tables 1 and 2 for each static pressure cor responding outlet velocities and tip speeds which will give satisfactory results. The proper tip speed for a given static pressure varies with the design of wheel and with the number of blades or vanes in the wheel. Lower outlet velocities than those listed in Table 1 may be employed, but care must be exercised to avoid selecting a fan for operation below its useful range. The useful range of the fans of Table 2 extends over thefull length of the performance curve. 539 Heating Venturing Air Conditioning Guide 1938 In exhaust ventilating systems where the air column moves toward the fan, noise due to the higher tip speeds and outlet velocities will not be so readily transmitted back through the air column to the building as when the air column is moving toward the rooms. Therefore higher outlet velocities may be used, but this will be at the expense of increased horsepower: Amply large fans should always be used for both exhaust and supply systems, as there may be and usually is leakage despite the most careful workmanship, necessitating the delivery of more air at the fans than is exhausted from or supplied through the openings in the various rooms. Long runs of distributing ducts, heaters, and air washers require definite increments of the total pressure which a supply fan in a venti lating system must overcome. These static pressures should be con sidered when selecting the fan characteristics, speed, and power. ' Table 2. Good Operating Velocities and Tip Speeds for Multiblade Ventilating Fans with Backward Tipped and Double Curved Blades Static Frbssubb .Inches of-Water H Vs 14 y8 % 14 l m 1% 2 1M 214 3 Outlet Vkloott Feet per Minute 800-1100 800-1150 900-1300 1000-1500 1100-1650 1200-1750 1200-1900 1300-2100 1400-2300 1500-2500 1600-2700 1700-2800 1800-2950 2000-3200 Tip Speed Feet per Minute 2600-3100 3000-3500 3400-4000 3800-4500 4200-5000 4500-5300 4800-5750 5300-6350 5750-6950 6200-7550 6650-8050 7050-8550 7450-9000 8200-9850 Fans picked within the limits of Table 1 will operate close to the point of maximum efficiency. No attempt has been made to select these limits for quiet operation, since this is a relative term and varies with the type and location of the installation. ' The connection of a fan to a metallic duct system should be made by canvas or a similar flexible material so as to prevent the transmission of fan vibration or noises. Where noise prevention is a factor the fan and its driver should have floating foundations. ' Fans for Drying Both axial flow and centrifugal types of fans are used for drying work. Propeller fans are well adapted to the removal of moisture-laden air when operating against low resistance and when handling air at low tempera tures. Motors on these fans usually are of the fully-enclosed moistureproof types so that saturated air or air containing foreign material will not injure the motors. Unit heaters employing axial flow fans are widely used in the drying 540 Chapter 27. Fans field. In drying, these fans may be used with unit heaters where not too much duct work is required and where air is to be delivered against pressure, since the noise developed from the high peripheral speed of these fans is not ordinarily objectionable in process work. . Centrifugal fans of the multiblade type generally are selected to supply air for drying, as they are capable of delivering large volumes of air against all pressures likely to be encountered. Belt driven fans usually are to be preferred to direct-connected fans since efficient motor speeds do not usually coincide with efficient fan speeds. Replacement of a standard motor is quick and easy if it is belted. Wherever drying is done throughout the year and where air require ments change as the drying conditions change, the drying can be speeded up or reduced through control of the fan capacity. This may be done by changing the fan speed or by varying the outlet area with dampers. A throttled outlet reduces the volume and reduces the power. Due to the low speeds of forward curved multiblade or paddle-wheel type fans, these can be direct-connected to reciprocating steam engines, and the exhaust steam from the engines may be used in the heating apparatus. In selecting engine driven fans for drying processes, where a large quantity of exhaust steam is used in the heaters, a smaller fan and greater power consumption may be used, because power economy is not essential under this condition. . Where static pressure in a dryer varies, and where several fans must operate in parallel, fans are to be preferred which have a continuously rising pressure characteristic, such as is given by backward-curved or double-curved blades. This type of fan is well adapted for direct-con nected motors of the higher speeds. (See Chapter 35 on Drying Systems.) Fans for Dust Collecting and Conveying ' The application of fans for handling refuse, dust, and fumes generated by machine equipment is covered in Chapter 34. Information is given . regarding the methods for determining air quantities, the velocity required for carrying various materials and the method of determining maintained resistance or total static pressure at which the fan is to operate. The selection of a proper size fan is at times governed by the future require ments of the plant. In many instances, additional future capacity is anticipated and should be provided for. Having determined the necessary volume of air and the maintained resistance or static pressure required, the proper size fan may be selected from the fan manufacturers' performance charts or capacity tables. The fan chosen should be the size that will provide the required ultimate quantities with the minimum power consumption. FAN VOLUME CONTROL Some method of volume control of fans usually is desirable. This may be done by varying the peripheral velocity or by interposing resistance, as by throttling-dampers. Both methods, since they reduce the volume of air, reduce the power required. In many installations adjustments of volume are desirable during varying hours of the day. In others an 541 . Heating Ventilating Air Conditioning Guide 1938 .c fc, o,s5a it f --) -~ \ \ 1 1-- 3 I .*r .5 ./- V ' > o -G =: 542 S*o '& x 2o M Q Z< u. o H z JSS S2 i: C ^5 fii>-S*va vc *c*2 _ I |-uii ^ ISs"^-2gas" < CD a u! Mc 6c0<o~ 'S'C ai ; c.sl 1' T32*Co T83 i SB& BB Chapter 27. Fans increased supply of air in summer over that needed for winter is demanded. Experience is required in deciding whether speed-control or dampercontrol shall be used for specific cases. Where noise is a factor, it may be exceedingly desirable to reduce the speed at times, while on the other hand, any fan which has its normal speed reduced as much as 50 per cent without change in resistance will move only 50 per cent of the air. > FAN DESIGNATIONS Facing the driving side of the fan, blower, or blast wheel, if the proper direction of rotation is clockwise, the fan, blower, or blast wheel will be designated as clockwise. If the proper direction of rotation is counter-clockwise, the designation will be counter clockwise. (The driving side of a single inlet fan is considered to be the side opposite the inlet regardless of the actual location of the drive.)* This method of designation will apply to all centrifugal fans, single or double width, and single or double inlet. Do not use the word "hand," but specify "clockwise" or "counter-clockwise." The discharge of a fan will be determined by the direction of the line of air discharge and its relation to the fan shaft, as follows: Bottom horizontal: If the line of air discharge is horizontal and below the shaft. Top horizontal: If the line of air discharge is horizontal and above the shaft. Up blast: If the line of air discharge is vertically up. . Down blast: If the line of air discharge is vertically down. All intermediate discharges will be indicated as angular discharge as follows: Either top or bottom angular up discharge or top or bottom angular down discharge, the smallest angle made by the line of air discharge with the horizontal being specified. In order to prevent misunderstandings, which cause delays and losses, the arrangements of fan drives adopted by the National Association of Fan Manufacturers and indicated in Fig. 6 are suggested; If double width, double inlet fans are selected, care must be taken that both inlets have the same free area. If one inlet of a fan is obstructed more than the other, the fan will not operate properly, as one half of the wheel will deliver more air than the other half. The backward curved and double curved types with backward tip operate satisfactorily in double or in parallel operation. MOTIVE POWER It is no easy matter to predetermine the exact resistance to be encoun tered by a fan or, having determined this resistance, to insure that no changes in construction or operation shall ensue which may increase air resistance, thus requiring more fan speed and power to deliver the required volume, or which may reduce air resistance, thus causing delivery of more air and a consequent increase of power even at constant speed. It is recommended, therefore, for centrifugal type fans that the rated power to be supplied shall exceed the rated fan power by a liberal margin, when forward curved types are used. When backward or double curved blade types are used, motors with ratings very close to that of the fan horsepower demand can be employed, provided the fan has a limiting horsepower characteristic. *Recommendations adopted by the National Association of Fan Manufacturers. 543 -TT-y Heating Ventilating Air Conditioning Guide 1938 Justification for liberal power provision exists also in the possibility of varying demand due to changes in ventilation requirements, intensity of occupation, and weather conditions. . The motive power of fans should be determined in accordance with the Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers, as.adopted by the American Society of Heating and Venti lating Engineers and the National Association of Fan Manufacturers. Fans may be driven by electric motors, steam engines (either horizontal or vertical), gasoline or oil engines, and turbines, but as previously stated the drive commonly used is the electric motor. REFERENCES Mine Ventilation, by J. J. Walsh (A.S.H.V.E. .Transactions, Vol. 23, 1917, p. 659). Fan Blower Design, by H. F. Hagen (A.S.H.V.E. Transactions,Vol. 28,1922, p. 175). The Specific Characteristics of Fans, by M. C. Stuart and J. B. Lusk (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, September, 1936, p. 507). Non-Dimensional Fan Characteristics, by H. Carlton Moore (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, September, 1937, p. 580). Seetion X, A.S.H.V.E. Code of Minimum Requirements for the Heating and Venti lation of Buildings (Edition of 1929). Coal Miners Pocket Book. , Constructive Mechanism and the Centrifugal Fan, by George D. Beals. Fans, by Theodore Baumeister, Jr. Fan Engineering, Buffalo Forge Company. Heating, Ventilating and Air Conditioning, by Harding and Willard, Revised Edition, 1932. Mechanical Engineers' Handbook, by Kent. Mechanical Engineers' Handbook, by Lionel S. Marks. The Centrifugal Fan, by Frank L. Busey. ' The Fan, by Charles H. Innes. The Theory and Performance of Axial-Flow Fans, by L. S. Marks and J. R. Weske. Theories and Practices of Centrifugal Ventilating Machines, by D. Murgue, trans lated by A. L. Stevenson. . . - PROBLEMS IN PRACTICE 1 0 What information must be supplied to the manufacturer when ordering a centrifugal fan? . a. Sire of fan (catalog number). b. Type of fan. c. Width of fan (single or double). d. Number of inlets (single or double). e. Fan performance and kind of application. /. Direction of rotation (clockwise or counter-clockwise). g. Direction of discharge (top horizontal, down blast, etc.). h. Drive arrangement (see Fig. 6). *. Style of housing (full, three-quarters, etc.). ' 544 Chapter 27. Fans 2 O In selecting fans for quiet operation in public buildings: . a. Should the outlet velocity of the fan be limited? . b. Should the tip speed of the fan be limited? a. Because all commercial fans operating at pressures suitable for this class of work would be considered noisy if the fan were to discharge directly into the room, and because the duct system on the fan discharge is depended upon to absorb a reasonable amount of fan noise, it is desirable to have a moderate run of duct work with some bends and elbows included as sound deadeners. Where this duct is of necessity very short, the outlet velocity must be kept down to the lower limits recommended in this chapter or else an efficient sound absorber, must be used. The experience of the engineer must be his guide in determining the allowable outlet velocity in each individual case. ' b. Tip speed should not ordinarily be limited, because different types of fan blades have entirely different allowable tip speeds for quiet operation. A fan having a backward blade at the tip can run at much higher tip speed than can a forward curved or a straight blade fan, with the same degree of quietness. 3 Is a direct connected or a belted fan preferable in public building work? Where space is at a premium, direct connection is best. Next in space economy is the short V-belt drive. The flat belt drive fan requires the greatest floor space. In this class of work, pressures are usually so low that even with the high speed fans the motor cost is greater for direct connected units than for belt-drive fans. 4 a. What type fans are used in industrial work? b. What outlet velocity is suitable? a. All of the centrifugal types are suitable; the disc and propeller types are suitable for low pressure work, or they are often used as exhausters. b. The outlet velocities on fans for industrial work can be much higher than can those in public building work, where quietness is essential. Fans should be selected with outlet velocities as recommended in this chapter, using the upper limit of velocities. 5 0 Are direct connected or belted fans preferred in industrial work? In industrial applications, fans are often advantageously direct connected to motors. The pressures are usually high enough to use standard motor speeds. The high speed types of fans have limiting horsepower characteristics so that little margin in power must be provided in the driving motor. Belted fans may be used, but where high power is required a special arrangement is often necessary for shaft and bearings on account of the weight of the sheave and the belt pull. 6 A forward curved multiblade fan which requires 5.4 bhp is delivering 22,800 cfm at 70 F against a resistance pressure of 1 in. of water at an outlet velocity of 1440 fpm: a. What is the static efficiency? b. What is the total efficiency? . a. 66.3 per cent-(see Equation 2). b. 74.5 per cent (see Equation 3). . 7 If the above fan has a 54-in. diameter wheel and operates at 193 rpm, will it be suitable for a ventilating installation where a minimum of noise is desirable? Yes. The tip speed will be 2720 fpm and this, together with the 1440 fpm outlet velocity, falls within the limits given in Table 1 for 1-in. resistance pressure. 8 What objectionable feature is inherent in the ordinary propeller fan when it is operating at high resistance pressures? It must operate at a high speed with consequent noise. 545 . Heating Ventilating Air Conditioning Guide 1938 9 At what point should a fan be selected for operation, and why? At its point of maximum efficiency because the cost of operation and the noise produced will be least. 10 # In Fig* 3, a static pressure of 85 per cent of blocked tight pressure cor responds to three different volumes, namely 11 per cent, 30 per cent and 48 per cent of wide open volume* What will determine which volume the fan delivers? The fan can operate only at the intersection of its pressure-volume curve and the system characteristic. The type of system, together with the specification of the volume at a certain static pressure, completely defines the system characteristic. As illustrated in Fig. 5; a given system characteristic will intersect the fan curve in only one point. . . If the 85 per cent value for static pressure is specified for the 48 per cent value of volume, it is at once obvious that the same system wilt not have the same resistance at any other volume. \ 546 Chapter 28 AIR DISTRIBUTION Definitions, Grille Locations, Standards for Satisfactory Con ditions, Factors Affecting Distribution for Cooling and Heat ing, Air Outlet Noises, Selection of Supply Outlets, Balancing System CORRECT airdistribution contributes as much or more to the success of a forced air heating, ventilating, cooling or air conditioning system as does any other single factor. Supplying the proper amount of air is one problem; properly distributing it from the point where it leaves the fan is another. The distribution problem may be further divided into: (a) distribution to the various spaces served by the system, (b) distribution in these spaces. This discussion is primarily limited to division (b), reference being made to the duct system only insofar as it affects the performance of the air distribution outlets. Definitions - In this discussion, the term air outlets or outlets will be used to designate a cover for an opening, whether it is a grille or a register. A register is defined as an outlet with a damper, and a grille is defined as-an outlet without a damper. The perpendicular distance over which the air will satisfactorily carry measured between the face of the outlet and the opposite wall is the throw. In' the case of directional flow outlets, this may be less than the actual carry of -the air. The core area of the outlet is the area of that portion of the grille inside the frame through which the air can flow. The ratio of width to height of the core area is termed the aspect ratio. GRILLE LOCATIONS The location, of supply and exhaust outlets is extremely important if a satisfactory installation is to be secured. Very frequently, however, the room or building is planned and constructed with practically no con sideration of this problem. The engineer of today is more likely than not to have as his problem a building that was constructed long before any consideration whatever was given to air conditioning it. Consequently, the room shapes, the location of columns and beams, and other details of architecture frequently make it difficult to properly locate the outlets. In general, for a cooling installation, the grilles should be located high enough from the floor to prevent the discharge of air directly upon the occupants of the room, and far enough down from the ceiling to minimize 547 V -1 " Heating Ventilating Air Conditioning Guide 1938 Fig. 1. Plan View Long Throw Supply Outlet Fig. 2. Plan View Short Throw . Supply Outlets the possibility of streaking, and to permit induction of air from all sides of the stream. If the stream actually strikes the ceiling, but at a small angle, the throw will be increased somewhat if the ceiling is smooth. If the angle at which the stream hits the ceiling is 20 deg or more, or if the flow along the ceiling is obstructed by panel mouldings or beams, air velocity may be rapidly lost and a decreased throw result. The air stream also should be so directed that it will not strike nearby columns or beams in such a way as to cause misdirection of the air stream or drafts. Where the room is of irregular shape, as an ell, or where it has an alcove in one side, consideration should be given to obtaining satisfactory circulation in these corners. Frequently this cannot be done except by the use of multiple'supply outlets. In using multiple outlets, care must be taken that the several air streams do not interfere with each other, until their velocities, have been reduced to values which will not cause high turbulence and a drafty condition. Beams and offsets in the ceiling will cause little difficulty when substantially parallel to the direction of flow, ' unless they are of considerable depth, but when positioned across the air stream, may cause drafts and failure to secure satisfactory circulation in that portion of the room farthest from the outlet. In the case of a heating installation, down-drafts produced by such obstructions may not be serious, because the air will rapidly lose its downward motion, but the possibility of failure to obtain satisfactory circulation still exists. The location of supply outlets should, if possible, be such as to take advantage of the maximum velocity permissible from a noise standpoint. For instance, the spaces illustrated in Figs. 1 and 2 may be satisfactorily served by either arrangement. However, by taking advantage of the long Fig. 3. Elevation View Ceiling Supply Outlet with Return Wall Outlet Fig. 4. Elevation View Ceiling Supply and Return Outlet 548 Chapter 28. Air Distribution throw, to which the arrangement in Fig. 1 lends itself, fewer outlets are required and additional savings are effected in the sheet metal work. In solving the problem of properly conditioning a room of irregular shape, where multiple wall supply grilles are objectionable, a ceiling out let of the type illustrated in Figs. 3 and 4 may very often be the best solution. . _ In choosing the most desirable location for the return air grille, con sideration should be given to its effect on circulation of the air through the room. It is generally true that the return air grille should be placed on the same wall as the supply and near the floor level. This results in a Fig. 5. Elevation View Correctly Located Return Outlet Fig. 6. Elevation View of Improperly Located Return Outlet U-shaped air path (Fig. 5) which covers the room thoroughly. The arrangement-shown in Fig. 6 should be avoided, because it tends to create a stagnant section below the supply grille. What would otherwise be an unsatisfactory dead spot in a room may in some instances be taken care of by location of the return air grille near that area (Fig. 7). . '' ` STANDARDS FOR SATISFACTORY CONDITIONS The most satisfactory air condition cannot be definitely stated for any particular individual without conducting a series of tests with that individual as subject; some persons are less sensitive than others to variations in temperature, humidity, air velocity and noise. The best 549 Heating Ventilating Air Conditioning Guide 1938 that can be done is to attempt to set limiting conditions leaning toward the values of these variables which produce a condition of comfort for the greatest number of individuals. On a cooling installation, the allowable deviation from average room temperature, that is, the temperature of puffs of air which may strike a person momentarily, is a function of the room temperature as well as the velocity of the air. For instance, in a room controlled at 72 F, a puff of air at 70 F might be uncomfortable to an individual, even at relatively low velocities, whereas if the average room temperature were 80 F, air at 78 F, even at moderate velocities, might be very satisfactory. However, air at 78 F in an average room temperature of 83 F would be cold. In general, other conditions being equal, for the range of temperatures normally encountered in living quarters on cooling installations, the permissible deviation from average room temperature varies from approximately 1 F at the low end of the range to about 3 F at the high end of the range. In this matter, it is important to consider the particular problem in the light of the type of occupancy. For instance, greater deviations from room temperature and higher velocities may be permitted in a garage or a hotel hallway than would be permissible in an office or living room. The velocity which may be considered the permissible maximum differs with the temperature deviation for a given, installation, but an absolute maximum under any conditions might be considered that which would produce a mechanical disturbance, such as the movement of a person's hair or disturbance of papers on a desk. Humidity is an important consideration in the deter mination of one's feeling of comfort; however, if the room generally is assumed to be at a satisfactory value of relative humidity, the designer is justified in neglecting this factor when considering permissible fluctuations in temperature and velocity in the occupancy zone. This is true because the maximum allowable temperature fluctuation results in an unnoticeable humidity change. The standards that might be set up for maximum allowable room temperature deviation and air velocity would not be the same for both heating and cooling installations. In the former case, any appreciable temperature deviation is likely to be above rather than below the average room temperature, whereas the reverse is most likely to be true on a cooling installation. Further, because air movement has a cooling effect in itself, the feeling of warmth due to temperatures above room tem perature is counteracted to a certain extent so that an individual may be subjected to higher velocities of warm air without the feeling of dis comfort occasioned by the same velocities of cool air. In every case, it should be the purpose of the designing engineer to keep the conditions within the zone of occupancy as nearly uniform as possible, securing minimum temperature deviations and low velocities. The air velocity at all points in the room should be at least 25 fpm for good results. It is impractical to measure momentary temperature differences with any degree of accuracy in the field, but in checking a given installation it will generally be found satisfactory to measure velocity only, since on cooling installations high velocities normally occur with low temperatures, and on heating installations high velocities occur with high temperatures. That is, in the former case, the chilled supply air loses its velocity and undergoes an increase in temperature as it settles into the occupancy 550 Chapter 28. Air Distribution zone, whereas in the latter case the heated supply air loses its velocity and undergoes a decrease in temperature during this process. Therefore, if the average velocities within the occupancy zone are not excessive, one is fairly safe in assuming that the temperature difference is also within permissible limits. The subject of sound control is covered in Chapter 30 and it is recom mended for detailed review before consideration of the problem of air outlet noise. An understanding of the relation between sound intensity and loudness level in decibels, as well as the effect of the presence of sound absorbent materials in the room, is particularly necessary. A more detailed discussion of the nature of this problem appears later; whereas the following comments refer to what constitutes a satisfactory noise condition. . . Obviously, the nature of the conditioned space is important when con sidering the allowable outlet noise. In factories, press rooms, and similar . Fig. 7. Plan View Correctly Located Return Outlet Eliminating Stagnant Space ' spaces where the noise level is 65 db or higher, no complaints of grille noise are likely to be made. On the other hand, some homes, offices, hospitals, and, most of all, radio broadcasting and movie sound studios present a real problem which must be intelligently attacked if a satis factory installation is to be made. In this chapter the noise of the air outlets (and returns) only is considered, it being assumed that the noise or sound level of the room without the outlet noise includes that which may be contributed by fans, motors, duct work, and other items of conditioning equipment. The control of noise from these sources is another problem (see Chapter 30). Where sound control is important, the actual room sound level without conditioning equipment should be known. If feasible, the contribution of the conditioning equipment, less outlets, should be estimated to secure the working sound level. If this correction is not made, the use of the first value errs in the direction of safety. It is evident that the point within the room which should concern the designer in this problem is that at which die outlet noise is greatest. A tentative standard listening point relative to the oudet is suggested later in this discussion, and it is assumed that the. outlet noise data are taken 551 Heating Ventilating Air Conditioning Guide 1938 with reference to this point. If it is desired that the outlet noise result in an inaudible addition to the existing noise level, it is safe to assume the total outlet noise to be 5 db below room level. This results in an increase in total noise of slightly over 1 db, which is unnoticeable. If an increase of 3 db is permissible, the outlet noise level may be equal to the room noise level alone. All outlets in the room must be considered, as will appear later, and the returns may be ignored only if they are so sized that the velocity of air through them is much less than through the outlet. DISTRIBUTION FACTORS IN ROOM COOLING In attempting to design a satisfactory air distributing system, it is first necessary to properly locate the grilles in accordance with the recom mendations already stated. Assuming that the best locations have been selected, it then becomes necessary to choose the proper grille for that location. The considerations involved are the amount of air to be handled, the velocity permissible from the standpoint of noise, and the distance the air should carry. The distance it will carry, assuming no obstructions, is affected by a number, of factors which are listed below: 1. The temperature difference between incoming and room air. 2. Height of grille above floor. 3. Face velocity. 4. Core area. 5. Core aspect ratio. 6. Design of grille. The manner in which the above factors affect throw may be generally stated. All other things being constant, a lower temperature of incoming air will result in shorter throw; a greater height above the floor will affect a longer throw; a higher velocity will produce a longer throw; greater area will give longer throw; larger aspect ratio will decrease throw. The variation in throw with type of outlet will, of course, depend upon the design characteristics of the outlet. In consideration of what constitutes the possible throw of an outlet under a given set of conditions, it is important to remember that the throw may be unsatisfactory for any one of several reasons: . 1. It may be so long that it will strike the far side of the room and come down the wall with velocities higher than are permissible, 2. It may be so short that it will fail to carry the full length of the room, and shortcircuit to the return air outlet, or 3. It may spill into the center of the room. . In the first case, the system fails for lack of uniform distribution and the presence of cold areas. In the second case, the standards as to velocity and temperature difference in the zone of occupancy may be satisfactorily met, but air distribution and circulation throughout the entire room is not accomplished, with the result that the end of the room away from the outlet would hot be satisfactorily conditioned. In the third case, the shortcomings of both case one and case two are present. It is evident', therefore, that for a given outlet discharging air at a given velocity, there is a maximum and a minimum length of room which can be satisfactorily 552 Chapter 28: Air Distribution handled. In the latter, the velocity of the air down the far wall is just within the maximum permissible, while in the former, satisfactory circu lation is barely accomplished. . . .. . In general, the higher the outlet is above the floor, the greater may be the difference between room air and incoming air temperatures. Assuming that proper supply outlets for a given installation have been selected, unsatisfactory performance may still result due to the con struction of the duct work immediately back of the outlets. Performance data on the grilles and registers of various manufacturers should be based upion results obtained with the air approaching the grille perpendicularly and at uniform velocity over the entire duct, cross-section. Where this condition does not exist in practice, performance predictions based on published data cannot be expected to be realized. Every precaution should be taken to secure as nearly ideal conditions in the approaching air stream as are possible. . -. Fig. 8. Effects of Expanding Duct Fig. 9. 'Unequal Face Velocities , . Fig. 10.. Effect of _ Turning Member _ In addition to disturbances due to the construction pf.the duct work itself are those which may be created by dampers immediately behind the grille. Where either multiple louvre or single blade, dampers are .used, considerable deflection of the air stream may result, if it is throttled appreciably by these means. This is particularly true when the fins of the register core are perpendicular to the damper blades. If the core has sufficient depth and the fins are parallel to the blades, there is a marked tendency to straighten the air stream, although some deflection may still result. .. - Any attempt to secure a low face velocity and high duct velocity by the construction of any expanding chamber immediately behind the grille is very likely to be unsuccessful. In order to expand from a.small duct to a larger one, and have the air stream fill the duct at the end of the diverg ing section without turbulence, angle A in Fig. 8 should be about 3 deg for four-sided expansion aind about 5 deg for two-sided expansion. From this it is apparent that an attempt to secure equivalent results with a short connection would be futile. What actually happens when this is attempted is illustrated by the arrows in Fig. 8. When localized high velocities through the outlet exist from this cause or any other, the noise produced will naturally exceed that which the outlet area and average face velocity would lead one to expect. This fact should be remembered 553 X Heating Ventilating Air Conditioning Guide 1938 in considering the use of register dampers, particularly in those cases where there must be considerable throttling with the damper to balance a poorly designed system. Where reduction of noise is important, it is recommended that balancing dampers be placed in the duct ahead of the acoustic duct lining. Similar unequal face velocities, aggravated by a deflection of the air stream, are obtained with the arrangement shown in Fig. 9. The latter may be corrected by inserting a turning member in the elbow back of the outlet face as shown in Fig. 10. The importance of straightening the air stream and affecting uniform distribution over the entire face of the outlet cannot be over-emphasized. DISTRIBUTION FACTORS IN ROOM HEATING The problem in the case of a heating installation is substantially the same as in cooling, with a few exceptions. Because the temperature of the incoming air is above that of the room, there is no tendency for it to drop and consequently the throw is not particularly affected by tem perature difference in a low ceiling room. In general, the air should be deflected downward where the grille is above the occupancy zone, and this is particularly desirable where the ceiling is high. For the same reason, that is, to keep the heat in the occupancy zone and to avoid excessive temperature at the ceiling, it is desirable to have the grille comparatively low on the wall, and just slightly above the occupancy zone. If the grille is lower than this, it may create an unsatisfactory condition of very warm air at quite high velocities where it can possibly strike the occupants of the room. Where the velocities are very low, the grilles may even be satisfactorily located below the 6 ft level, although the immediate vicinity of the supply outlets will probably be useless for occupancy because of high temperature. Essentially, the problem is to keep the incoming air up for cooling, and down for heating, until it is thoroughly mixed with the room air. Grilles and registers which are adjustable for deflection upward and downward, either by moving the fins or inverting the grille, are in general use. ' AIR OUTLET NOISES When air is introduced into a room through a grille or register at a constant velocity, sound energy is being introduced into the enclosure at a constant rate. Due to partial reflection at the boundaries of the en closure, the intensity of sound at any point in the space builds up to some maximum value. In a large room at a point remote from the source of sound (the outlet) the intensity can be shown to be substantially pro portional to the rate at which sound energy is generated and inversely proportional to the number of sound absorption units.. (sabins) in the room. It would thus appear that doubling the sound absorption of the room would halve the intensity and result in a noise level decrease of 3 db. However, it is not satisfactory to consider the grille noise on this basis (wherein the sound power received directly from the source is small compared with that received by reflection) since in practice the occupants of the room may be quite dose to the grille. The nearer the listener is to 554 Chapter 28. Air Distribution the sound source, the greater the proportion of the sound intensity which is due to direct transmission. . In the absence of generally accepted standards at this time it is sug gested that the loudness level 5 ft from the lower.edge of the outlet, measured downward at 45. deg in a plane perpendicular to the outlet at its center, represents about the maximum within the zone of occupancy. The cases where persons are nearer to the outlet than this are rare and are ignored in the consideration of this problem. Although the effect of sound absorbent material on the intensity at the 5 ft station is not nearly so great as at more remote points in the room, it should, not be ignored without consideration of the error involved. An average living room may contain 100 sabins (absorption units). If this be decreased to 50 sabins, the diffuse or reflected sound level would be increased 3 db. However, at the 5 ft station the increase would be less than 2 db. If the absorption of the room be increased to 200 sabins, one might expect a reduction in diffuse noise of 3 db; but at the 5 ft station the reduction would be less than 1)4 db. Furthermore, even though the absorption be increased without limit (as in free space) the reduction would still be less than 2 db because of proximity to the source. . In comparing sound ratings of various grilles, the following must be known if the information is to be intelligently applied: 1. The threshold intensity on which the decibel ratings are based. 2. The distance from the grille at which data were taken. 3. If stated as loudness level versus velocity for a given grille, the core area (not nominal area) must be known. 4. The sound absorbing characteristics of the test room. 5. Whether or not corrected for test room loudness level; if not, the room level (without grille noise) must be known. 6. Methods used for recording data. Data mentioned in this chapter are assumed to have been referred to the following: 1. Threshold intensity = 10-" watts per square centimeter1. 2. Microphone location 5 ft from lower edge of outlet on a line downward at 45 deg and in a plane bisecting the outlet perpendicularly. 3. Where data are given as loudness level versus velocity, the rating is per square foot of core area. ' . 4. The room is assumed to have 100 sabins absorption. 5. Plotted data are loudness levels of outlets only, correction having been made for test room level. 6. ' Data taken with a direct reading sound-level meter with frequency weighting network intended to approximate the response of the human ear. If the published ratings are in terms of decibels per square foot, cor rection must be made for area to secure to total sound level of outlets of more or less than one square foot area. This can be done by use of the following fortnula: .. Decibel Addition = 10 logio A (1) lAmerican Tentative Standards for Noise Measurement, American Standards Association. Heating Ventilating . Air Conditioning Guide 1938 where: <4 = tore area, square feet. , . ... . . In practice the allowable total sound and the required air flow are usually known, and it' is desired to determine the, maximum allowable velocity. Since total loudness and air flow are both functions.of velocity arid area, the solution of the problem by use of the previous analysis implies a trial and error method. It has been found possible to present these data with sufficient practical accuracy as a family of uniform curves as illustrated in Fig. 11.. With this chart it is possible to find directly the Velocity in feet per minute which will give a predetermiried total loudness kt a predetermined rkte of flow expressed in cubic: feet per minute. "The Values used ate arbitrarily chosen for the purpose of discussion and do riot necessarily represent data referring ,to any particular make of grille, ` ' - A-- V .. a '> -.7 . . -- ' : ` :v Chapter 28. Air Distribution . - must be made and the maximum velocity corresponding to 27 db total loudness chosen; that is, approximately 550 fpm. : . .. Where more than orie outlet must be considered, the problem is more complicated. If a similar outlet is added in a far corner of a highly absorbent room, the change in noise level at the 5 ft station at the first other sources may be 35 db. As previously stated an outlet having a noise level of 30 db would be substantially, inaudible in such a room, If 1000 cfm are required with a total noise due to outlet of 30 db, a velocity (Fig. 11) of about 675 fpm may be used.- From this velocity and the rate of flow, the core area can be computed. This determination was on the. basis of a room absorption of 100 sabins.. If the, absorption is . greater, the 675 fpm velocity is safe, since the loudness level will go down. However, correction can be made if desired by the use of the chart of Fig. 12, Thus, if the absorption is 200 sabins, a correction of +1.3 db may be made and the permissible velocity becomes that corresponding to a total loudness level of 31.3 decibels or approximately 750 fpm. If the room is highly reflecting and has an absorption of less than 100, correction .is much more important. Forinstance, for 35 sabins a correction of -- 3 db 556 outlet is small; however, if the room is small, or highly reverberant or both, the intensity at the 5 ft station may be almost doubled and the noise level increased nearly 3 db thereby. The simplest method of hand ling this problem, and one which errs in the direction of safety, is to treat the room as though all the air were being supplied by one outlet; Thus, if two outlets, each supplying 1000 cfm are used, the value 2000 cfm 557 Heating Ventilating Air Conditioning Guide 1938 should be used with Fig. 11. Although this method may place an un warranted limit on velocity when used in a large room, it is seldom that such a room has a noise level low enough to make this penalty serious or to justify a more complicated though more exact procedure. In general, return grilles are selected for velocities about half the supply velocity,' and when this is done, they may be neglected in sound computa tions. However, if supply and return grilles are the same size, resulting in the same face velocity, they must be treated as two supply outlets. That is, if 1000 cfm is supplied and exhausted through grilles of the same, area, 2000 cfm must be used in the solution with Fig. 11. SELECTION OF SUPPLY OUTLETS After the heating and cooling load calculations have been made (Chapters 7 and 8), and, or a suitable supply air temperature selected, the volume of air required for each space can be determined. The next step is to determine the velocity at which the air may be introduced into the space quietly and without creating objectionable drafts. Present-day grille design coupled with the introduction of effective acoustical treatment for minimizing fan and duct noises have made grille face velocities in excess of 1500 fpm feasible, and 600 to 1200 fpm is now used in practice. This range of velocities is approximately three times higher than common practice values of a few years ago. Since high velocities make for smaller ducts and outlets, and therefore savings in space as well as greater flexibility in locating the duct work to the best advantage, selection of design velocities is a very important step. The selection of proper velocity requires that the designer have before him reliable data applicable to the particular make of outlet he proposes to use. Even under these circumstances, the problem .is one of cut and try because permissible velocity may be determined by either noise or throw. A method for selecting supply outlets is outlined below in the form of a- sample cooling problem, using numerical values which have no reference to any particular make of outlet. ' 558 Chapter 28. Air Distribution 1. The load calculations have been made; a suitable temperature differential has been selected (it is to be understood that the data referred to from this point on are based on this temperature differential), and the volume of air required determined. Assume that ' Fig. 13 represents a small general office having a noise ievel of 40 db and that 2500 cfm must be supplied for proper conditioning. 2. Select a tentative location for the outlet of outlets, having in mind the type of grille most likely to effect proper distribution. In this particular case, two outlets having a wide spread appears to be a logical choice. 3. Data from which to determine velocity which corresponds to 2500 cfm and a noise rating at least 5 db below the noise level of the office may be presented in a number of forms, one of which is shown in Fig. 11. (Fig. 11 represents assumed values only. In practice similar data should be obtained from the manufacturer whose outlets are being considered. Several similar charts or tables may be necessary to cover any one manu facturer's complete line.) From Fig. 11 it will be noted that for 2500 cfm the type of grille selected may be used at velocities up to 700 fpm without exceeding 35 db; that is, 5 db below the noise level of office. 4. Having determined the velocity, the core area becomes fixed at 3.57 sq ft or 257 sq in. per outlet. In this problem, the two grilles in question are so close together that consideration of their combined area in determining the permissible velocity from the standpoint of noise introduces little error. 5. The type grille selected has thus far been found satisfactory from a noise stand point, provided the face velocity does not exceed 700 fpm. The next consideration is throw, which may be assumed to be 16 ft, and by reference to a manufacturer's catalogue the proper correlative test data may be checked with the throw assumed. It is of course evident that one or more types of grilles may satisfy the requirements, and that in any one type there will be a choice of outlet proportions. It will also be evident that the tentative selection of an outlet having a wide spread may be unsatisfactory from the standpoint of throw, in which event a second choice should be made and the procedure repeated. In the case of a heating problem, the method of solution is the same, but the manufacturer's data must, of course, be based on tests with air above room temperature. TYPES OF SUPPLY OUTLETS Grille, registers or outlet design for attaining uniform distribution and minimum air resistance consists of various fixed and adjustable arrange ments. Some types are designed with directing air blades, fins, bars, louvres, or thin metal strips shaped into a sesies of grooves or tubes, all of which may be set into a suitable round, square or rectangular frame. In order to attain desired long or short air throws, the emergence of air from the outlet may be directed to straight, deflecting, converging or jet air streams depending upon the outlet design. Designs which direct the air stream to produce an ejector effect within the enclosed, space tend to mix the room air with the conditioned air to provide uniform distribution. Centrally located ceiling or wall type outlets arranged for completely diffusing the air consist of several round, hollow, cone-shaped flaring members placed in the proper relationship to each other. The velocity of emergence of the air from the unit can be made practically uniform over the entire surface of the outlet, and the velocity in any direction may be varied to any desired value by adjusting the position of the cones. One or more of the smaller flaring members act as ejectors and injectors which draw a small proportion of the room air into the air spreader where it mixes with the conditioned air before it is discharged. 559 Heating Ventilating Air Conditioning Guide 1938 An idea for producing even distribution of air consists of a perforated ceiling made of a suitable architectural surface and installed a small distance below the normal ceiling level of the room. In the space provided by this suspended ceiling a plenum chamber is formed into which the conditioned air is introduced. From the plenum space the air is permitted to diffuse through the large number of small ceiling openings into the room. Railroad Cars . The early practice of air conditioning railroad passenger cars consisted of a system of bulkhead distribution for the conditioned air. The air was discharged through an inlet opening at each end of 'the car toward the middle with the flow parallel to the long dimension of the car. This type of installation resulted in drafts in the middle of the car and was con sidered unsatisfactory except for small sections that did not require large quantities of air. Later designs incorporated a duct delivery system on each side of the car roof directing the air through numerous inlet openings toward the middle of the car where the two air streams come in contact and deflect downward, gradually filtering into the aisle. At the present time, several center duct air distribution systems are used in railroad car applications. In some instances, square or circular ceiling outlets con nected to a center duct have been used, which distribute the air along the ceiling in widening circles and at right angles to the inlet opening. Another method consists of a continuous slot in the bottom of the duct to which is attached a flat plate so that the air is deflected along the car ceiling. There are also installations in which the ceiling of the car is constructed of perforated metal through which the conditioned air flows through thou sands of openings from a plenum chamber. Extensive tests of all methods .of air distribution indicate that desirable results are obtained from an inside center duct with a large number of openings. Sleeping cars present a special problem in air distribution on account of the berth curtains. In some cars, each lower berth is equipped with an individual fan to draw in cooled air from the aisle. In other cars, small individual ducts with adjustable air outlets deliver air.from the central supply system to each lower berth. Upper berths require no special arrangement. . . BALANCING SYSTEM . .. .\ In designing an air conditioning system, it should be the aim of the engineer to so proportion the duct system that proper distribution of air to every outlet.will be obtained. Since this is almost impossible to accom plish in practice, it . becomes necessary to have means of balancing the system to secure the desired amount of air in each space. There are a number of ways in which this may be accomplished, some of which are listed: 1. Dampers on the supply grilles. 2. Dampers bn the return grilles. . '3. Dampers in the supply ducts. 4. Dampers in the return ducts. 5.: Reducing: the effective area of some.outlets by blank-offs. 6. Combinations of dampers in both supply and return air. 560 Chapter 28. Air Distribution Dampers on the supply grilles themselves are objectionable because of their effect on the air stream. Dampers on the return grilles are frequently helpful in building up a static pressure in the room to prevent infiltration of outside air, and at the same time reduce the volume of incoming air. However, it is frequently impossible to sufficiently reduce the incoming air by this method alone. A damper in the supply duct some distance back of the outlet forms a very satisfactory means of regulating, the flow without disturbing distribution across the outlet face. A damper in the return air duct has the advantage over one immediately behind the grille in that it does not tend to create high localized velocities through the grille as the latter might do if nearly closed. Blank-offs consisting, of pieces of sheet metal covering a portion of the outlet face can frequently be used satisfactorily, although determination of just what is required is a matter of experiment, and the balancing of the system is not nearly so conveniently accomplished as with dampers. Dampers in both supply and return air form the most flexible means of controlling the supply to the room and the static pressure within the room. When feasible, these dampers, particularly those in the supply ducts, should be a substantial distance from the outlet, and ahead of the acoustic duct lining if used. Due consideration should also be given to the use of the several volume control and uniform distribution devices now available.. See Catalog Data Section. ' . ... REFERENCES . ' Methods of Air Distribution, by L. L. Lewis (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 491). Air Supply, Distribution and Exhaust Systems, by S. R. Lewis (A.S.H.V.E. Trans actions, Vol. 39, 1933, p. 139). Characteristics of Registers and Grilles, by J. H. Van Alsburg (A.S.H.V.E. Trans actions, Vol. 41, 1935, p. 245). The Noise Characteristics of Air Supply Outlets, by D. J. Stewart and G. F. Drake (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, January, 1937, p. 65). - PROBLEMS IN PRACTICE 1 9 What important factors are involved in the correct distribution of air to an enclosed space? Not only is it important to distribute the air from the fan to the various spaces served by the system, bdt also the air must be properly distributed within the enclosed space to give complete satisfaction. 2 9 Upon what basis should the selection of supply outlets be based? If possible, the selection should take advantage of the maximum velocity permissible from a noise standpoint. . 3 9 What factors in grille design effect the length of air throw? a. The temperature difference between incoming and room air, b. height of grille above floor, c. face velocity, d. core area, e. core aspect ratio, and /. design of grille. 4 How does the'height of a supply outlet affect the temperature differential within a room? ... - In general, the higher the outlet is above the floor, the greater may be the difference between room air and incoming air temperatures. . 561 Heating Ventilating Air Conditioning Guide 1938 ' 5 Under conditions prevalent in a large room, how does the intensity of sound develop at an air outlet vary? The intensity of sound energy is substantially proportional to the rate at which sound energy is generated and inversely proportional to the number of sound absorption units in the room. 6 # What are the essential differences between a high velocity long throw and short throw grille? Generally, a high velocity long throw grille is used where a large compact mass of air is projected with a reduction in the periphery of the air stream whereas, with a short throw grille design the periphery of the air stream is expanded as much as possible to increase the scrubbing action between the incoming air stream and the stationary air. 7 What type of system is generally used in a large- continuously operated theatre? Most large continuously operated theatres are provided with a complete downward system qf air distribution. With this system a large number of outlet openings are provided each of which discharges air in a thin horizontal stream at high velocity in order that the cool air would be mixed with the area in the theatre before it reaches the patrons.' In this type of system the best distribution is obtained when a sufficient number of exhaust openings are located under the seats. 8 i What means are available for balancing a system to secure the desired amount of air in each space? Ways in which this may be accomplished are by: o. dampers on supply and return grilles, b, dampers in supply and return ducts, c. reduction of the effective area of some outlets by blank-offs, and d. combination of dampers in both supply and return air duct systems. 562 Chapter 29 AIR DUCT DESIGN Pressure Losses, Friction Losses, Friction Loss Chart, Propor tioning the Losses, Sizes of Ducts, General Rules, Procedure for Duct Design, Air Velocities, Proportioning the Size for Friction, Main Trunk Ducts, Equal Friction Method, Duct Construction Details THE flow of air due to large pressure differences is most accurately stated by thermodynamic formulae for air discharge under condi tions of adiabatic flow, but such formulae are complicated, and the error occasioned by the assumption that the gas density remains constant throughout the flow may be considered negligible when only such pressure differences are involved as occur in ordinary heating and ventilating practice. . In the development of the formulae, diagrams, and tables for the flow of air, use is made of the following basic equation for the flow of fluids: If Hv be the velocity head in feet of a fluid, and the velocity, V, be expressed in feet per minute, the fundamental equation is V = 60 ^2g Hv . The factor g is the acceleration due to gravity, or 32.16 ft per second per second. . It is usual to express the head in inches of water for ventilating work and, since the heads are inversely proportional to the densities of the fluids, . ' ' or ` J?l- = 62.4 hy = d 12 - ;: ' f. . ; . ' ` . therefore, - ; (/ . - Hv - 5.2 --a . V = 1096.5 y . . (1) where ' V = velocity in feet per minute. hy - velocity head or pressure in inches of water. d = weight of air in pounds per cubic foot. . . : For standard air (70 F and 29.921 in. barometer) d = 0.07492 lb per cubic foot. Sub stituting this value in Equation 1: .. . . K = 10965 4005 V17 563 > Heating Ventilating Air Conditioning Guide 1938 Chapter 29. Air Duct Design 0.5 times the velocity head. The pressure loss in elbows must also be allowed for in the design. It is customary to express dynamic losses .in .terms of the percentage of the velocity head-; in other words, the per centage of that pressure corresponding to the average velocity in the duct which is expressed in terms of inches of water gage. Figs. 1 and 2 .show the effect of changing the radius of elbows of square and rectangular section1. These charts are based oh tests of pipe elbows of ordinary good sheet metal construction. For example, a five-piece round pipe elbow having a centerline radius of one diameter has a loss of about 25 per cent of the velocity head. At a velocity of 2000 fpm the corresponding head is 0.25 in. water gage, and at this velocity the elbow just referred to would cause a pressure drop of 0.063 in. water gage. Experience has shown that good results may be obtained when the radius to the center of the elbow is times the pipe diameter. The pressure drop will then be approxi mately 17 per cent of the velocity head for round ducts, and 9 per.cefit for square ducts. Very little advantage is gained in making elbows with a radius of more than two diameters2. Fig. 1. Curve Showing Loss of Pressure in Round Elbows 'the drop in pressure.in air distributing systems is due to the dynamic losses and the friction losses. The friction losses are those due to the friction of the air against the sides of the duct. The dynamic losses are those due to the change in the direction or in' the velocity of air flow. . Pressure Losses564 Dynamic losses occur principally at the entrance to the piping, in the elbows, and wherever a change in velocity occurs. The entrance loss is the difference between the actual pressure required to produce flow and the pressure corresponding to the;flow produced; it may vary from 0.1 to i Friction Losses, . " ; ' . Friction losses vary directly as the length of the duct, directly as . the square of the velocity, and inversely , as the diameter. Since length- is a fixed quantity for any system, the factors subject to modification are the area and the velocity, which determine the relation between the first cost of the duct system and the cost of the power for overcoming friction. The friction between the moving air and pipe surface causes a loss of head which is numerically equal to the pressure required -.to maintain a given velocity, and is expressed in the following modification of Fanning's formula: ' - - ". For round pipe and standard air (70 F and 29.921 in. barometer) . ;. . hL hv = 07(4005) - ! . (3) For rectangular ducts , - 1 1 1. O so too __ ISO loo ISO soo Cmren-UNe Radius hi Pczeenr or Pipe Wioth Fig. 2. Curve Showing Loss of Pressure in Square Elbows 564 where ` . hi, -- loss of head, inches of water. V , / V \2 hv = 14005 ) = velocity head, inches of water. V -- velocity of air, feet per minute. .. . ,L = length of jSipe . 1' ; b = diameter of pipe, . | all in feet. . a, b .=. sides of rectangular duct J .`/`= coefficient of frictioni.............. .i '. C ---j- -- length of pipe in'diameters for one head loss. ' . .. . .. . `, .: '. ; . ,i . For all practical purposes C varies only with the nature of the pipe surface:1 C = 60 for perfectly smooth pipe; = 55 for pipers used in planning `Loss of .Pressure Due to Elbows in the Traiismission of Air Through Pipes or Ducts, ^by F. L. Busey (A.S.H.V.E. Transactions. Vol. 19, 1913, p. 366). . Pressure Losses in Rectangular Elbows, by R. D. Madison and J. R. Parker (Heating, Piling and Air Conditioning, July,*p. 365, August,-p.^427? Septerqber,jpy.^83, ,1936).;; 565 . Heating Ventilating Air Conditioning Guide 1938 566 Chapter 29. Air Duct Design mill exhaust systems; = 50 for heating and ventilating ducts; = 45 for smooth and 40 for rough conduits of tile, brick or concrete. However, Fritzsche states (and numerous tests check very closely) that / varies inversely as the 2/7 power of the pipe diameter, and inversely as the 1/7 power of the velocity, or inversely as the 1/7 power of capacity, which is the same thing. Thus Formula 3 may be revised as follows, based upon a loss of one velocity head (at 2000 fpm) in a length equal to 50 diameters of 24-in. galvanized swedged pipe: , fa- = 11 CDL"7 (I4V005\)13/7 (5) The preceding formulae are based on standard air, and for other con ditions the friction varies directly as the air density and inversely (ap proximately) as the absolute temperature. The increase of friction due to increase of air viscosity with increased temperature is small and is generally neglected. Friction Loss Chart Fig. 3 is a convenient chart for determining the friction loss for various air quantities in ducts of different sizes. The general form of this chart is familiar, but it .should be noted that it is corrected for changes in the coefficient of friction based on the rule that the coefficient of friction varies inversely as the 2/7 power of the diameter, and inversely as the 1/7 power of the velocity. Fig. 3 is based on a loss of one velocity head (at a velocity of 2000 fpm)' in a length equal to 50 diameters of 24-in. round galvanized-iron duct of the usual construction. Although this chart is laid out for a value of C equivalent to 50, it may be used for other values of C by varying the friction inversely as this constant. For ex ample, if a rougher pipe is used with 40 as the value of C, the friction loss 50 as read from the chart should be multiplied by Example 1. Assume that it is desired to pass 10,000 cfm of air through 75 ft of 24-in. diameter pipe. Find 10,000 cfm on the.right scale of Fig. 3 and move horizontally left to the diagonal line marked 24 in The other intersecting diagonal shows that the velocity in the pipe is 3200 fpm. Directly below the intersection it is found that the friction per 100 ft is 0:59 in.; then for 75 ft the friction will be 0.75 X 0.59 = 0.44 in. In a like man ner any two variables may be determined by the intersection of the lines representing the other two variables. . . Proportioning the Losses ; Other losses of pressure occur at the entrance to the duct, through the heating units, and at the air washer. In ordinary practice in ventilation work- it is usual to keep the sum of the. duct losses x/z to and the loss through the heating units at less than of the static pressure. The remainder.is. then available for. producing velocity. In the design of an ideal duct, system, all factors should be taken into consideration and the air velocities proportioned so that the resistance will be practically equal in all ducts regardless of length.: SIZES OF DUCTS The sizes of ducts and flues for gravity or mechanical circulation of air are usually based on the losses due to friction, and these losses must be 567 D iam eter..of Branch Pipe ' ' : 30 Heating Ventilating Air Conditioning Guide 1938 XjpBdEO jnao jaj 568 F ig ..4. M a in a n d B r an c h P ip e s fo r 'E q u a l F r ic tio n per F oot of L en g th (1 to 20 Pe r C e n t C a p a c it y ) . "" Chapter 29. Air Duct Design kept within the available pressure difference. This pressure difference in mechanical ventilation is that derived from the fan, while in gravity ventilation the aspirating effect due to the temperature and height of the column of heated air causes the pressure difference. General Rules '. . The general rules to be followed in the design of a duct system are: 1. The air should be conveyed as directly as possible at reasonable velocities to obtain the results desired with greatest economy of power, material and space. 2. Sharp elbows and bends should be avoided. 3. The sides of all ducts or flues should be as nearly equal as possible. (In no case should the ratio between long and short sides be greater than 10 to 1.) Procedure for Duct Design The general procedure for designing a duct system is as follows: 1. Study the plan of the building and draw in roughly the most convenient system of ducts, taking cognizance of the building construction, avoiding all obstructions in steel work and equipment, and at the same time maintaining a simple design. 2. Arrange the positions of duct outlets to insure the proper distribution of heat. 3. Divide the building into zones and proportion the volume of air necessary to supply the heat for.each zone. ' 4. Determine the size of each outlet, based on the volume as obtained in the preceding paragraph, for the proper outlet velocity. 5. Calculate the sizes of all main and branch ducts by either of the following two methods: . a. Velocity Method. Arbitrarily fix the velocity in the various sections, reducing the velocity from the point of leaving the fan to the point of discharge to the room. In this case the pressure loss of each section of the duct is calculated separately and the total loss found by adding together the losses of the various sections. . b. Friction Pressure Loss Method. Proportion the duct for equal friction pressure loss per foot of length. . 6. Calculate the friction for the duct offering the greatest resistance to the flow of air, which resistance represents the static pressure which must be maintained in the fan outlet or in the plenum space to insure distribution of air in the duct system. The duct having the greatest resistance will usually be that having the longest run, although not necessarily so. ' . Air Velocities .- The following velocities of air are considered standard for public buildings: 1. Through the outside air intakes, 1000 fpm. 2. Through connections to and from heating unit, 1000 to 1200 fpm. 3. Through the main discharge duct, from 1200 to 1600 fpm. 4. In branch ducts, 600 to 1000, and in vertical flues, 400 to 800 fpm. 5. In registers or grilles, 200 to 400 fpm depending upon the size and location. diffusers of proper design are used, 25 per cent higher air velocities are permissible. If These duct velocities may safely be increased 20 per cent if first class construction is used to prevent any breathing, buckling, or vibration. High velocities at one point in the system neutralize the effect of proper design at all other points; hence the importance of splitters in elbows and similar precautions. For industrial buildings noise is seldom considered, and main duct velocities as high as 2800 or 3000 fpm may be used where conditions will permit. For department stores and similar buildings, D iam eter of Branch Pipe F ig . 5. . M a in a n d B r an c h Pipes fo r E q u a l F r ic tio n per F oot of L en g th (20 to 100 P er C e n t C a p a c ity ) Heating Ventilating Air Conditioning Guide 1938 o co 570 Chapter 29. Air Duct Design maximum velocities with good construction and design may be as high as 2000 or 2200 fpm in main ducts, with suitable reduction in branches and outlets. With these velocities first-class duct construction is essential. Proportioning the Size ior Friction ' By means of Figs. 4 and 5 the diameter of branch pipes necessary to carry a given percentage of the total air in the main pipe and to maintain equal friction per foot of the length through the entire system may be determined. These charts, as well as Fig. 3, are based on the assumption that the coefficient of friction varies inversely as the 1/7 power of the capacity. Example B. Suppose a 60-in. main pipe is to be used, and it is desired to know the size of branch pipe required to carry 50 per cent of the total air in the main. Find 50 per cent at the left' of the chart, move right to the 60-in. diagonal line and note directly above at the top of the chart that the branch pipe will be 46.5 in. in diameter. Where rectangular ducts are used it is frequently desirable to know the equivalent diameter of round pipe to carry the same capacity and have the same friction per foot of length. Table 1 gives directly the circular equivalents of rectangular ducts for equal friction and capacity, which are based on values determined from Formula 6: d = 1.265 J (a W a+b (6) where a -- one side of rectangular pipe, feet or inches. b = other side of rectangular pipe, feet or inches. d = equivalent diameter of round pipe for equal friction per foot of length to carry the same capacity, feet or inches. To obtain the size of rectangular ducts for different capacities, but of the same friction per foot of length, first obtain the equivalent round pipe for equal friction. Thus, if a branch of sufficient size to carry 30 per cent of a 12 x 36-in. pipe is desired, it is found from Table 1 that the main :is equivalent to a 22.2-in. diameter round pipe. From Fig. 5, 30 per cent Of this is a pipe 14.3 in. in diameter, and referring again to- Table 1, the rectangular equivalent branch is a 12 x 14 in., 10 x 1734 in., or any other desirable combination. .' ` Multiplying or dividing the length of each side of a pipe by a constant is .the same as multiplying or dividing the equivalent round size by the same constant. Thus, if the circular equivalent of an 80 x-24-in. duct is required, it will be twice that of a 40 x 12-in. duct, or 2 X 23.3 = 46.6 in. : Table 1. Circular Equivalents of Rectangular Ducts for Equal Friction Sn>s . Rhctangulab Duct 148 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14.5 15 IS.5 16 3 5.2 5.4 5.5 5.7 5.8 5.9 6.0 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 7.0 3.5 5.7 5.9 6.0 6.2 6.3 6.5 6.6 6.7 6.9 7.0 7.1 7.3 7.4 7.5 7.6 7.7 4 ,, . 6.1 6.3 6.5 6.7 6.8 7.0 7.1 7.2 7.4 7.5 7.7 7.8 7.9 8.1 8.2 8.3 4.5 6.5 6.7 6.9 7.1 7.2 7.4 7.6 7.7 7.9 8.0 8.2 8.4 8.5- 8.6 8.7 8.9 5\ 6.9 7.1 7.3 7.5 7.7 7.8 8.0 8.2 8.3 8.5 8.7 8.8 8.9 9.1 9.2 9.4 5.5 7.3 7.5 7.7 7.8 8.1 8.3 8.5 8.6 8.8 9.0 9.2 9.4 9.5 9.6 9.8 9.9 7.1 7.8 8.4 9.0 9.5 10.1 571 H e a t in g V e n t il a t in g A ir C o n d it io n in g G u id e 1938 Table 1. Circular Equivalents of Rectangular Ducts foil Equal Friction--(Continued) -- -Sira-- Rectangular' ' 'Duct*" 4; . t: ' 9` . .10 . 11 6.1 6.5 1 6.8 ' 7.1 5 6.9 7.3 7.7, 8.0 i2 . '7.4 ' 13 ;, . 7.6 . 14 . . . 7.9 15 . 8.2 8.3 8.7, 8.9 9.2 16 8.4 9.5 17 8.6 9.8 18 8.9 10.0 19 9.1 10.3 ' 20 . 22 -'24 ... 26. ` ... 9.3 9.7 10.0 10.4 10.5 ' 11.0 11.4 11.8 28 ' 10.8 JO ........ 11.0 .. . 32 - - * 11.3 . . .34 ; 11.d* 12.2 12.6 12.9 13.2 36 . c 11.9 38 12.2 40 12.5 . ' 42 ; ' : 12.7 ._ 44 46 48 . . 13.0 . 13.3. 13.5' . 13.7? r 52 : * 54 * ' ' 56 . . " , 58 .. ' , 13.9 14.1 14.3 14.6 13.6. 13.9 14.3 14.5 14.8 15.1 15.4 15.7: 15.9 16.1 16.3 16.6 60 62 64 . 66 14.7 15.0. : 15.1- 15.3 16.8 17.0 17.3 J7.5- 6, ' 7 ' ' 8 9 10 11 12 7.6 8.2 8.8 8.0 8.7 9.3 9.9 8.4 9.2 9.8 10.4' 11.0 8.8 9.6; 10.2 10.9 11.5 12.1 9.2 10.0s 10.7 9.6 10.4 11.1 9.9 10.8 11.5 10.2 11.1 . U.9 10.5 10.8 11.1 11.4 11.4 12.3 11.8. . 12.6 12.1 13.0 12.4 13.3 tl:4 11.8 12.3 12.7 13.1 13.5 13.8 14.2 12.0 12.5 12.9 13.4 12.6 13.1 13.6 14.1 13.8 14.2 14.6 15.0 14.5 15.0 15.4 15.8 13.2 13.7 14.3 14.7 15.2 15.7 16.1 16.5 11.6 12.1 1i32.- <rLj 12.7-' 13.2 13.8 14.3 13.5 13.9 14.3 14.7 14.8 15.2 15.6 16:1 13.6 14.2 14.8 15.4 15.9' 16.4 16.9 17.3 14.5 15.4 15.2 . 16.1 15.8 `16.8 16;4- 17.3 16.2 16.9 17.6 18.3 17.0 17.5 18.0 18.5 18.0 .18.5 - 19.1 19.6 19.0 19:5 20.1 20.7 17.0 17,8 18.5 19.2 191-8 20.5 21:1 21.6 15.1 . 15.4 15.7 16.1, 16.4 16.8,, 17.^ 17.6' 17.7 18.218.6 19.0 19.0 .19.4 19.8 20.3 20.1 . 20.6 21.1 21.6 21.2 21.7 22.2 22.7 22.2 22.8 23.3 23.8 16.4 18.0 19.4 16.7 18.4 19.8 17.0 . 18.7. , 20.1 17.3 i9.o: ' 20.4, . 20!7 `21.1. 21.5 21.9 . 22.0 22.4 22.8 23.2 23.1 - 23.6 24.1 24.5 24.3 24.8 25.2 25.7 17.6 17.9' 18.2' 18.4 19.2 19.6 19.9 20.2 18.7 . 20.4. 19.0 20. z; 19.2 21.0 19.5. 21.2 20.8 21.1 21.5 .21.8.. 22.2 22.6 22.9 23.3, 23.6 24.0 24.4 24.7 24.9 25.3 25.7 26.1 26.2 26.6 27.0 27.4 22.1 ' 23.6 22.4 24.0 22.7. 24 J 23.0 24.6 25.1 25.5 25.9 .26.2 26.5 i 26.9 27.3 27:7 27.8 28.2 28.6 29.0 13 14 15 ' 16 17 18 , 19 . 20 14.3 14.9 15.3 15.4 16.0 16.5. 15.8 16.3 16.8 17.2 16.5 17.1 17.0 17.6 17.4 18.1 17.9 , 18.6 17.6 18.2 18.7 19.2 18.7 19.2 . 19.8 19.8 20.4 20.9 17.6 18.5 19.3 20.0 18.4 19.2 20.0 20.8 19.0 19.9 20.8 21.6 19.7 20.6 21.5 22.3 20.3 21.3 22.2 23.0 20.9 ' 21.5 21.9 22.5 > 22.8 23.5 23.8 24.4 22.0 23.1 24.0 25.1 20.7 21.4 22.0 22.6 21.5 22.2 22.9 23.5 22.4 23.1 23.8 24.4 23.1 23.9 24.6 25.3- 23.9 24.7 25.4 26.2 24.6 25.4 26.2 26.9 25.3 26.2 27.0 27.7 26.0 26.8 27.7 28.5 23.2 23.8 24.4 24.9 24.2 24.8 25.4 25.9 25.1 25.8 26.4 26.9 26.0 26.7 27.3 27.9 26.8 27.5 28.2 28.8 27.7 28.4 29.1 29.8 28.5 29.2 29.9 30.7 29.3 .30.0 30.8 31.4 25.4 25.9 26.4 26.9 26.5 27.0 27.5 28.0 27,5 28.1 28.6 29.2 28.5 29.1 29.6 30.3 29.5 30.1 30.5 31.3 30.3 31.0 31.6 32.2 31.2 31.9 32.5 33.1 32.1 32.8 33.4 34.1 27.4 27.8 28.3 28.7 28.5 29.0 29.5 30.0 29.6 30.1 30.6 31.1 30.7 31.2 31.732.2 31.8 32.3 32.6 , 33.3 32.9 33.4 33.9 34.4 33.8 34.4 34.9 35.4 34.7 35.3 35.9 36.4 29.1 29. S 29.9 30.3, 30.5 30.9 31.3 31.7 31.6 32.1 32.6 33.0, 32.7 33.2 33.7` 34.2 33.8 34.3 34.8 35.3 34.9 35.4 35.9 36.4 36.1 36.6 37.1 37:6, 37.1 37.7 38.2 38.7 21 22 23.6 24.7 25.7 24.2 25.2 26.3 26.6 27.5 28.4 29.2 27.3 28.2 29.1 30.0 30.0 3Q.8 31.6 32.2 30.8 31.5 32.4 33.0 32.9 33.8 34.3 35.0 33.7 34.6 35.2 35.9 35.6. 36.3 36.9 37.4 '36.5 37.2 37.8 38.4 38.1 38.7 39.2 39.8 39.1 39.6 40.2 40.8 24 26;4'~\ 27.5 > 28.5 29.5 ' 30.5 31.3 32.2 33.1 33.9 34.5 35.3 ,36.2 37.0 37.6 38.3 . ' 38.9 . 39.6 40.3 40.9 41.6 42.2 42.8 Additional size.: 4 X 5 - 4.9; 4 X'6 - 5.4;4X 7 - 6.8; 6 X 5 - 6.6; 6 X j? - 6.3; 6 X 7 - 6.6. Table 1. Circular Equivalents of Rectangular Ducts for Equal Friction--(Concluded) C h a p t e r 29. A ir D u c t D e s ig n \ Heating Ventilating Air Conditioning Guide 1938 574 F ig . 6. T y p ic a l L a y o u t of A ir D is t r ib u t io n System Chapter 29. Air Duct Design MAIN TRUNK DUCTS A main duct with branches is generally used to convey tempered air for ventilation purposes only. In place of individual ducts, a compara tively large main duct supplies air by branches to the room or rooms. The velocities vary according to the nature of the installation and the degree of quietness required. At the start of the run a velocity as high as 2000 fpm may be used, but this is considered the maximum for public building work, and is reduced to from 400 to 800 fpm in the risers. This duct system may be designed so that the loss of pressure in the branches is equalized in a manner similar to that previously described. Equal Friction Method Example 8. Fig. 6 shows a typical layout of an air distribution system which is applicable for ventilation of hotel dining rooms and offices. The volume of air in cubic feet per minute for the room is determined on the basis of the number of air changes per hour required. In the example shown, the room ventilated is a hotel dining room 135 ft x 85 ft x 15 ft. A 7 J^-minute air change (8 air changes per hour) is assumed for proper ventilation, giving 22,935 cfm as the air required. . 22 935 The clear area of the fresh air inlet is based on a velocity of 1000 fpm or * = ~ 1000 22.94 sq ft. If the air washer is provided with automatic humidity control, the tempering coil should raise the temperature of the entering air to 32 F. The washer with its auto matic control will then raise the temperature from 32 F to 42 F. If the washer is not provided with automatic humidity control, the tempering coil must raise the temperature of the entering air to at least 55 F to allow for some temperature drop in the washer due to evaporation. The reheating coil is selected to raise the temperature of the air from that leaving the air washer to 70 F. The air washer should have a maximum velocity of 500 fpm through the clear area, which, in this case, is 46 sq ft. For more detailed infor mation on tempering coil and air washer control, see Chapter 37. Since the plan shows a moderately short run of main duct with no risers near the fan outlet, a fan should be selected which will have the required capacity of 22,935 cfm with a maximum velocity through the fan outlet of 1400 fpm. The outlet area, therefore, should be 16J-6 sq ft. -. The main pipe^ size should be selected to give a velocity equal to or less than the velocity at the fan outlet. Choosing a 56-in. pipe with a cross-sectional area of 17.1 sq ft, the velocity inthe main pipe will be 1340 fpm.' Using the friction pressure loss method this 56-iii.' main pipe will be taken as-the basis of calculation. Fig. 6 shows the amount of air to be handled by each section of pipe. Expressing the volume handled, by each section as a percentage of the total volume and using the charts. Figs. 4 and. 5, the pipe sizes are as shown in Table 2. . . ` Table 2. Pipe Sizes for Example 3a Volume or Aib (cm) ' 22,935 12,510 10,425 8,340 6,255 4,170 2,085 Per Cent or Total Volume 100.0 54.6 45.4 . 36.3 27.2 18.2 9.1 .: Diameter or Pipe (Inches) 56 45 42 39 35 29M 23 . Velocity through diffusers (not shown) to be approximately 300 fpm. Equivalent Size or Rectangular Duct (Inches) 60x44 58x30 50 x 30 42 x30 42x24 30 x 24 30 x 15 Heating Ventilating Air Conditioning Guide 1938 The pressure at the outlets nearest the fan will be greater than at the pipes farther along the run so that the former will tend to deliver more than the calculated amount of air. To remedy this condition, volume regulating dampers should be located at the base of each riser and adjusted for proper distribution. At points where branches leave the main it may be advisable, depending upon the nature of the installation, to install adjustable splitters similar to that shown in Fig. 6 where the main duct divides into the 58 in. X 30 in. and 50 in. X 30 in. branches. ., The rectangular equivalents are selected from Table 1; the width to depth proportion will be determined by construction requirements and ease of fabrication. The calcu lation of the friction is as follows: 1 The longest run from the fan outlet to diffuser is 150 ft 0 in.; 150 ft of 56-in. pipe is equivalent to ^------------ ------------------------------------------------------------------- --32.2 dia. Two 45-in., 90-deg elbows (2 X 4g5g X 8.5)..----- --------------- ------ ----- --- 13.7 dia. (Assume each elbow equivalent to 8.5 diameters of duct. Fig. 1.) ( . 23 . Two 23-in., 90-deg elbows (2X|X 8.5)..................... ......... -------------- ---------- 7.0 dia. 23 - - : Two 23-in., 90-deg elbows in riser (2 X X 30) 24.7 dia.gg ...................................................... .............................. (Two bad elbows in riser, each equivalent to 30 diameters of duct). Total diameter of 56-in. pipe. 77.6 1340 \ 2 4005 / = 0-112 in. (Taking 50 diameters as one head loss, then 7g7g6 X 0.112 = 0.174 in. static loss in duct. . Where the connection pieces are made with long easy slopes and the general workc manship is good, a regain in static pressure may be deducted from the foregoing pressure loss. This can be taken as approximately two-thirds the difference in velocity pressures at the fan outlet and the last run of pipe. The velocity in the riser is 667 fpm with a corresponding velocity pressure of 0.027 in. The fan outlet velocity is 1400 fpm with a corresponding velocity pressure of 0.122 in. The regain equals % (0.122 -- 0.027) = 0.063 in. ` ' The net static pressure loss in the duct is: . 0.174 in. - 0.063 in______ __________ J_____ .______________ ___________ ____ --.0.111 in. Other friction losses are as follows: ' : (1) Fresh air intake 1000-fpm velocity (1H heads X 0.0625)---------------.--....0.094 in. (2) Tempering coil loss (from manufacturer's tables)--.i---------------------'-------:--.0.100 in. (3) Air washer loss (from manufacturer's tables)0.250 in. (4) Reheating coil loss (from manufacturer's tables)___________________________ 0.100 in. (6) Allowance for regulating dampers and diffusers........:..0.100 in. Static pressure loss of system---------------------'--------------------------------------------- --.0.755 in. The fan should be selected from the manufacturer's ratings which, according to the Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers1, will deliver 22,935 cfm at a static pressure of 0.755 in. and which has an outlet area of 16H sq ft. The method of design used in Example 3 is the equal friction-method described under the heading Procedure for Duct Design. This involves iSee Chapters 27 and 45. 576 Chapter 29. Air Duct Design Fig. 7. Exhaust System Layout the arbitrary reduction of velocity from the fan outlet to the point of discharge to the room, and the friction is calculated by adding the pressure losses of each section of duct. This method requires dampering in the risers and supply branches in order that equalization of air flow can ,>e attained. Example 4- Fig. 7 shows.an exhaust system layout for exhausting from buildings of the same type as in Example 3. Assume the air requirements based on the number of air changes per hour to be 16,800 cfm. Using a velocity of 1400 fpm in the main duct at the fan inlet, which is an average velocity for this type of system, the area of the main is 12 sq ft, which corresponds to a 47-in. pipe. Referring to Example 3, and using the charts, Figs. 4 and 5, the pipe sizes are as indicated in Table 3 for both round and rec tangular ducts. Table 3. Pipe Sizes foe Example 4a Volume or Am (cm) 16,800 11,550 9,450 5,250 4,200 : 3,150 2,100 Per Cent or Total Volume 100.0 68.8 56.2 31.3 25.0 18.8 12.5 Diameter or Pipe (Inches) 47 41 38 31 28.5 25.3 21.6 - Equivalent Size or Rectangular Duct (Inches) 38 x 48 30x46 30x40 24x34 24x28 16 x 34 16x24 Velocity through-intake grilles (not shown) to be approximately. 400 fpm. Heating Ventilating Air Conditioning Guide 1938 . u S*------- u SECTION "l/Top sheet _ These crossbreaks are --never shown on a plan Reinforced cross seams Side sheet 'Bottom sheet Seams between adjacent panels or plain cross seams Fig. 9. Details of Seams --/ * r eo c 5 c c 5 K" i Fig. 10. Method of Installing Heating Unit \ Fig. 11. Installation of Easement in Duct Around Obstruction 578 Chapter 29. Air Duct Design All risers will require (tampering as in Example 3. The calculation of the friction is as follows: The longest run from the intake grille to fan inlet is 100 ft. (1) Duct friction 100 ft of 47-in. pipe ----------------------------------------- 25.6 dia. Two 28J--in., 90-deg elbows in riser ^ ^ ^ ^---------- ---------------------- 36.4 dia. (Two bad elbows in riser each equivalent to 30 diameters of duct). ` f)Q Ey Q C\ (--J................ .................... 5.2 dia. . Total diameter of 47-in. pipe........ ............. ....... --__________________-- 67.2 dia. Velocity head corresponding to 1400 fpm is I ^ 1 = 0.122 in. Taking 50 diameters as one head loss, then --671--2 XdU0:_1_2_2 ___________- ___ _____ 0.164 in. (2) Intake loss from grille (1J^ heads at a 400 fpm velocity 1} X 0.01) 0.015 in. (3) Static pressure required to produce one velocity head at 1400 fpm0.122 in'. (4) Loss occasioned-by step-up of velocity (0.20 X 0.122).... 0.024 in. (This Iosa varies from 0.05 to 0.40 velocity head depending upon the nature of the change. For average systems 0.20 velocity head is a close approximation.) - Static pressure loss on inlet side: 0.325 in. To this must be added the resistance on the discharge side of the fan. A fan outlet velocity of approximately 1500 to 1600 fpm may be used. Assuming the fan outlet to be equivalent in area to a 45-in. pipe, the velocity is 1525 fpm. ' Loss on discharge (15 ft from fan outlet to discharge): 15 X 12 45 4 diameters of 45-in. pipe. The velocity head corresponding to a velocity of 1525 fpm is 0.145 and the dischargeside loss is 0----14--5 X-----4 = 0.012 in. The total static pressure loss of the system is then: 0.012 + 0.325 = 0.337 in. The fan will'be selected to handle 16,800 cfm at a static pressure of -0.337 in: and to have an outlet velocity of 1525 fpm. Outlet area 11 sq ft. . Where there are one or more ducts with branches, the velocity of air in the ducts may be either chosen arbitrarily or calculated for friction losses. When arbitrary values are assigned; a certain amount of dampering should be provided for; this will be small when the method chosen permits a drop in velocity as the quantity of air is reduced. . After the total air quantity and the size of fan are ascertained, the main duct is usually fixed as being at least equal in area to the fan outlet, or perhaps 10 per cent greater., From this main pipe all others are propor tioned. For example, if the main duct is 30 in. in diameter, a branch to carry 10 per cent of the total capacity should be 12.7 in. in diameter (see Fig. 4) in order to have the same friction per foot of length, while one 579 Heating Ventilating Air Conditioning Guide 1938 carrying one-half the total capacity of a 30-in. main with the same friction loss per foot would be 23.4 in. in diameter. By this method of equalizing friction it is unnecessary to consider the-resistance of each section of pipe independently, but only to know the distance from the fan outlet to the end of the longest run of pipe, the number and size of elbows, and the diameter and velocity in the largest pipe. Example 6. If the greatest length of piping in a system is 130 ft with a 26-in. diameter main pipe and one 20-in. elbow, the piping haying been designed for equal friction per foot of iength, the friction would be the same as for 130 linear feet of 26-in. pipe, or 60 diameters. To this should be added the friction loss in elbows, in this case one 20-in. elbow, whi.ch has a loss equ.ivalent to 8.5 diameters of 2' 0-in. pi.pe. This in turn'.is 20 X 8.5 = 6.6 diameters of 26-in. pipe. The total equivalent length of the system .will then be 60 + 6.6, or 66.6 diameters. Since 50 diameters is equivalent to one velocity 66 6 head, the loss is ^ -- 1.33 times the velocity head. If the velocity is, for example, 2200 fpm, corresponding to 0.3-in. pressure, the friction loss of the system will be 1.33 X 0.3 = 0.399 in. Table 4. Sheet Metal Gages for Rectangular Duct Construction* Gigs Width or Duct - Ssui ' ~ Rkintorced Sbam 26 Up to 12 in. ~ 24 . 13 in. to 30 in. i 22 31 in. to 48 in. i 22 49 in. to 60 in. iM 20 61 in. to 90 in. m % in. x We in. } in. x lJi in. *U panels are not cross-broken two gages heavier material should be used. , Frequently the prevention of sound in a heating or ventilating system imposes more severe restrictions than the prevention of excessive pressure drop. This question is highly involved and requires consideration of many factors. The air velocities to be used will vary with the standard of construction used in the ducts themselves as well as with the nature of the occupancy and the construction of the building. In general, architects and engineers who leave the details of duct construction to the contractor must, of necessity, design for lower velocities than might be required for quiet operation if proper construction details were always followed. The contractor may be expected to build the ducts by the least expensive methods, and the engineer must anticipate this. For further information on noise reduction, see Chapter,30. DUCT CONSTRUCTION DETAILS If panel construction is used with standing seams or similar reinforce . ment, and the panels are cross-broken to give rigidity, there is less like lihood of. vibration due to air flow, or deflection due to air pressure. Elbows made without splitters, and improperly shaped transformation sections produce high local velocities which are the cause of noise in duct work. The use of first-class duct construction with well-designed transr formation sections and splitters in elbows tends tp maintain relatively uniform velocities with decrease in turbulence and in the noise produced. 580 Chapter 29. Air Duct Design ' Figs. 8 to 12 show acceptable construction details for rectangular ducts, elbows, and transformation pieces or connections. Other methods are also acceptable, such as the use of angle iron stiffeners for large ducts. Good construction is essential to the elimination of duct noises and for the prevention of a flimsy installation. Fig. 8 is an isometric view of a duct showing the location of the stiffening seams on the top and side panels. The cross seams should not occur at the same place but should be staggered as indicated.,. Heating units should be installed as shown in Fig. 10 with the duct, connections making an angle of not less than 45 deg, but preferably 60 deg. Fan dis charge connections should have a maximum slope of 1 in 7, as indicated in Fig, 12, Whenever a pipe or other obstruction passes through a duct an easement should be placed around the pipe as indicated in Fig. 11. The recommended gages for rectangular sheet metal duct construction are given in Table 4. REFERENCES Fan Engineering, Buffalo Forge Co. Heat Power Engineering, by Barnard, Ellenwood, and Hirshfeld, Part III. Mechanical Engineers'* Handbook, by Lionel S. Marks, McGraw-Hill Book Co. The Flow of Liquids, by W. H. McAdams (Refrigerating Engineering,.February, 1925, p. 279). A Study of the Data on the Flow .of Fluids in Pipes, by Emory Kemler (A.S.M.E. Transactions, Hydraulics Section, August 31, 1933, p. 7). ., PROBLEMS IN PRACTICE 11 Determine the equivalent number of diameters of straight pipe equivalent to a 90 deg elbow having center line radii of (a) 100 per cent, (b) 150 per cent, abd (c) 200 per cent of the pipe diameter. 1, Assume 1 velocity head lost in 50 diameters. . From Fig..1 the per cent of velocity bead lost: . . . a. For 100 per cent radius is 25.5 per cent X 50 = 12.8 diameters straight pipe. b. For 150 per cent radius is 17.0per cent X 50 = 8.5 diameters straight pipe, c., For 200 per cent radius is 14.5per cent X 50 = 7.3 diameters straight pipe. 2 Why is it desirable to make elbows with a radius equal to one and one-half times the pipe diameter? . Reference to Figs. 1 and 2 will show that while the loss of velocity head, as indicated by the curves, shows considerable variation for elbows between the range of 50 and 150 per cent radius, the line is practically straight after 150 per cent, indicating very little variation in loss of head for elbows of larger radius. . 3 What is the best shape to use for ducts? The shapes to be used in designing ducts, in the order of their preference, are round, square, and rectangular. 4 What'determines which shape to use? Structural and space conditions. Because ducts are as a rule part of the building or structure, it is necessary to proportion their sizes to fit the spaces available. 581 ............ Heating Ventilating Air Conditioning Guide 1938 5 What is meant by "arbitrarily fix the velocity in the various sections?" When using the velocity method as a basis for design, the maximum allowable velocity is fixed for the main supply duct at the fan, and this velocity is gradually decreased as each branch or outlet is taken off the main supply duct. 6 Which system of duct design is to be preferred, the velocity method or the friction pressure loss method? . The friction pressure loss method can be used to advantage where no structural or building conditions limit the shape of the ducts. Where these limiting conditions exist the velocity method is to be preferred. 7 Are the grille sizes figured on the same basis as the outlets? - The. free area through the grilles is. figured the same as the outlets, and this area is increased from 20 to 50 per cent, depending on the design of the grille, to allow for the loss of area caused by the construction of the face of the grille. . 8 t Where it is necessary to provide steel angle braces, how far apart should they be spaced? Angle braces for large ducts should be placed on 3-ft 0-in. centers. 9 # How much air will a 10-in. by 24-in. duct handle if it is part of a system designed on a pressure drop of 0.1 in. per 100 feet of run? -* ' 1450. cfm (Table 1 and Fig. 3). 110 # How does a splitter at a duct junction influence the volume of the air going through each branch? .' A splitter facing the direction of air flow cuts off the air and delivers the desired amount to the branch. 11 0 Why does a wide, shallow duct offer more resistance to the flow of air than does a square duct of equal cross-sectional area? ' The perimeter of the wide, flat duct is greater than that of the square-section duct, so the former has the greater frictional area which increases the resistance and thus reduces the volume at any given pressure. .... 12 What methods are used to keep large ducts from vibrating because of air pulsations, and from sagging because of their own weight? . R-rti=>mal bracing, such as standing seams, or structured shapes, like tees or angles, should be placed across the top and bottom. Exterior braces or cross buckling of metal sheets hrdiagonal panels may be used-for the sides'of large'ducts? 13 What velocities of air flow should be used in the trank ducts of a venti lating system in a public buUding? From 1200 to 1600 fpm. . 14 In a ventilating system in a residence, what is the recommended air velocity through supply registers and grilles?400 400 fpm. 582 Chapter 30 SOUND CONTROL Decibel Defined, Apparatus for Measuring Noise, Problem of Sound Control, Acceptable Noise Levels, Controlling Vibration from Machine Mountings, Controlling Noise through Room Wall Surfaces, Noise Transmitted Through Ducts, Duct Lining Factor IN ventilating and air conditioning a building or a room, the effect of the mechanical system employed must be considered on the acoustics of the space conditioned. It is important to consider also that the use of air conditioning often permits keeping the windows closed, thus giving relief from certain external noises, but at the same time increasing the necessity of providing adequate sound control. It is not assumed that the ventilating and air conditioning engineer will attempt to improve the acoustics of the space that is being con ditioned, but the designer should have at least enough fundamental knowledge of the acoustical effects of the system which is being designed to be sure that no damaging effects occur to the existing acoustical properties. It is assumed that in a given space the architect and acovstical engineer have produced a room or rooms which are satisfactory for speech, music, or other uses. The ventilating engineer's sole function is to ventilate and air condition these rooms properly so that they will be physically comfortable without adding any acoustical hazards. UNIT OF NOISE MEASUREMENT In the United States and England the unit of noise measurement is the decibel (db). In Germany this unit is called the phon. The decibel is defined by the relation N 10 log jr, where N is the number of decibels by which the intensity flux Ii exceeds the intensity flux IQ. The in tensity flux is the measure of the energy contained in a sound wave and is defined in terms of microwatts per square centimeter of wave front in a freely traveling plane wave. It is usually more convenient to select an arbitrary reference intensity for Ia and express all other intensities in terms of decibels above that level. For this purpose the threshold of audibility for the average human ear at a frequency of 1000 cycles per second has been selected. This reference threshold is 10-16 watts per square centimeter or 10~10 microwatts per square centimeter. This reference level also corresponds to a pressure of 0.0002 dynes per square centimeter. ' A stated sound level in decibels, unless otherwise defined, will thus be related to a threshold of 10~16 watts. For example, a level of 60 db above this reference threshold is 10~10 watts. In a similar manner, when sound 583 Heating Ventilating Air Conditioning Guide 1938 measurements sire given in actual intensity or energy units, they can be converted to decibels by this relation. Since the decibel is a ratio, it can only be employed when related to a reference threshold level as given. Noise levels, which vary with fre quency as well as intensity, must not only be related to this reference threshold level, but also to a reference frequency, which is taken as 1000 cycles. These terms and procedures may be found in tentative standards1 published by the American Standards Association. APPARATUS FOR MEASURING NOISE Since the relative loudness to the ear, rather than the actual physical intensity, is the quantity in which engineers are usually interested, it has been found necessary to allow for the varying sensitivity of the ear at different frequencies in designing noise measuring equipment. The most satisfactory method of measuring noise is by means of a sound level meter which usually consists of a microphone, a high gain audio-amplifier, and a rectifying milliammeter which will read directly in decibels. This meter is calibrated to give readings above the threshold of audibility and usually contains a weighing network to make it less sensitive at those frequencies where the ear is less sensitive. For complete specifications relative to the approved type of sound level meters refer to the information2 published by the American Standards Association. . GENERAL PROBLEM OF SOUND CONTROL As previously stated, the function of the ventilating and air con ditioning engineer is to add no acoustical hazard to the conditions already present in the room or building and the problem can be stated as: ' a. To determine the noise level existing without the equipment. , b. To ascertain the noise level which would exist if the equipment were installed without sound control. c. To provide as a part of the installation sufficient sound control appliances to reduce the noise level substantially to that found in (a). ' .' . To accomplish this the engineer should have information of three kinds: 1. A knowledge of the noise levels currently considered acceptable in various rooms in order that he may have a basis on which to proceed. 2. A knowledge of the nature and intensity of the ndise created by the various parts of the equipment. 3. A knowledge of how, when necessary, to vary and control the noise level between the equipment and the conditioned space. In addition, the engineer should have information available to deal with noises which may enter the room due to openings made into.it to accom modate the equipment, such as cross talk between rooms connected with common ducts and noise transmitted to portions of duct system outside the conditioned space and through to its interior. While the general problem may be logically outlined and the items of American Tentative Standards for Noise Measurement, American Standards Association. '. 'American Tentative Standards for Sound Level Meters for Measurement of Noise and Other Sounds, American Standards Association. . 584 Chapter 30. Sound Control knowledge necessary to its solution can be listed, the available infor mation at present is lacking in certain respects. However, attention may be directed to that information which is currently available, and to furthermore outline a solution of the noise problem based on these data: ACCEPTABLE NOISE LEVELS Measurements of noise levels have been observed by several investi gators in various rooms and locations. The information compiled in Table 1 is based on these data, which represent the best opinion on the Table 1. Typical Noise Levels Rooms Sound Film Studios........................................................... Radio Broadcasting Studios.......................................... Planetarium......................................................................... Residence, Apartments, etc.--:........................................ Theatres, Legitimate--..................................................... Theatres, Motion Picture............................................. Auditoriums, Concert Halls, etc..................................... Executive Offices, Acoustically Treated Private Offices Private Offices, Acoustically Untreated. ...................... General Offices.................................................. Hospitals................ ............................................................ Class Rooms................................................. Libraries, Museums, Art Galleries. Public Building, Court Houses, Post Offices, etc........ Small Stores Upper Floors Department Stores .......... Stores, General, Including Main Floor Dept. Stores... Hotel Dining Rooms . , Restaurants and Cafeterias. ................................... Banking Rooms-- .................................. Factories. .................................................... Office Machine Rooms--......................................... Vehicles Railroad Coach.......................................... Pullman Car........................................... Automobile.............................. Vehicular Tunnel............................... Airplane.. NorSB Level in DectBELS to be Anticipate! Min. Representative Max. 10 14 20 10 14 20 15 20 25 25 35 40 25 30 35 30 35 40 25 30 40 25 30 - 35 25 33 40 35 45 50 45 55 60 25 40 55 30 35 45 30 40 45 45 55 60 40 50 ' 60 40 50 55 50 60 70 40 50 60 50 60 70 50 55 60 60 70 80 60 70 80 60a 70 80 55a 65 . 75 50 65 80 75 85 95 80 85 100 .For train standing in station a level of about 45 db is the maxi mum which can ordinarily be tolerated. subject now available. All levels are given in decibels above a reference threshold of 10"16 watts (corresponding to a pressure of 0.0002--dynes per square centimeter). Minimum, representative, and maximum levels are given for each application. These values are intended to indicate the variation which may be expected in different locations of the. same type, but not the time variation which may be expected in each location. The values shown in Table 1 are typical of those found currently in 585 Heating Ventilating Air Conditioning Guide 1938 existing spaces. They are, however, the noise levels of the room and not the noise levels of the ventilating or air conditioning equipment. If the noise level at the room of the equipment is kept at the levels shown in the table the equipment will not add to the acoustical hazard existing without it, provided the equipment noise is heard alone, but if both are heard together the total noise level in the room will be increased about 3 db. This is usually considered an acceptable result. In some cases it is desirable to keep the equipment noise level at the room at such a value that it actually .will not increase the noise level in the room to any measurable degree. . This can usually be accomplished if the equipment noise at .the room can be kept 10 db below the noise level shown in the table. NOISE CREATED BY EQUIPMENT Information concerning the noise levels created by ventilating and air conditioning equipment such as fans, motors, air washers, and similar items is not yet oh a basis which permits tabular presentation although certain manufacturers are prepared to offer such data and do state the noise-producing properties of their products. Absence of this information makes it necessary to resort to indirect means in solving certain problems and also prevents a direct logical solution. " . , KINDS OF NOISE To solve a sound problem of this type it is desirable to consider sepa rately the several means by which noise reaches the room. This avoids to some extent the necessity of knowing the noise level at the source and places the emphasis on ascertaining the level at the point where the sound enters the room rather than on its point of origin. , The noise introduced -into a room or building- by ventilating or air conditioning equipment may be divided into two kinds depending on how it reaches (die room as: t 1. Noise transmitted through the building construction. 2. Noise transmitted through the ducts. . It is convenient to further subdivide these two methods of delivery as: 1. Noise transmitted through the building construction. a. From machine mountings as vibration. b. From equipment through room wall surfaces. . ' 2. Noise transmitted through the ducts. ' a. From equipment such as sprays, fans, etc. b. From outside, and transmitted through duct walls into air stream. c. From air current, including eddying noises. d. Cross talk and cross noises between rooms connected by the same duct system. The next, step in the solution of this problem is to present data and discuss methods whereby solutions to the noise problem can be obtained when the allowable room noise level and the path through which the noise reaches the room are known. ' 586 ; ----^ Chapter 30. Sound Control NOISE THROUGH BUILDING CONSTRUCTION It is impossible to select ventilating equipment which will operate without producing some mechanical noise, and since the equipment must be mounted in a building, it is probable that a part of this noise will be transmitted to the building itself to such a degree as to make noisy con ditions in the rooms which are to be air cohditioned. Much of this noise may be transmitted by the duct if it is rigidly connected to the fan outlet. It is common practice to make the connection between the fan and the duct with a canvas sleeve which effectively restricts noise at this point. Noise may also enter the building through the mounting of the motor and the fan. Flexible mountings should be provided in all installations but these mountings must be carefully designed so that they will actually reduce the contact between the machinery and the supporting floor. If a flexible material is used, it is desirable to investigate the installation so that it is not short-circuited by through bolts which are improperly insulated and by electrical conduit which is not properly broken and is attached both to the equipment and to the building. The flexible mount ing, if it is improperly engineered, may actually increase the contact between the equipment and the floor upon which it is supported. In general, the flexible material should be loaded as heavily as possible without impairing its load-carrying capacity. Controlling Vibration from Machine Mountings The theory of the insulation of vibration was first worked out by Soderberg. If a machine of mass m be supported by an elastic pad the amount of vibratory force communicated by the machine to the floor or foundation upon which it rests will be determined by the elastic and viscous properties of the pad. The ratio of the vibratory force communi cated to the floor or foundation with the machine resting upon the pad, and with the machine resting directly upon the floor, is given by the following equation: where r* + 4ic dy[2TMm - 2 a) c' .= the so-called transmissibUity of the support. . c = the compliance (that is, the reciprocal of the force constant). - , r = the mechanical resistance owing to the viscous forces within the support. . n = the frequency of vibration generated by the machine which is to be insulated, such as the commutation frequency of a motor or the blade frequency of a fan. m = the mass of the machine to be insulated. It should be noted that not only must vibrations within the audible range of fre quencies be considered, but those in the sub-audible range as well, since these may cause objectionable vibrations. All the possible frequencies should be considered in the calcu lation. Sometimes beat effects are introduced by slight irregularities of belts or pulleys that have much lower frequencies than those of the rotating elements.* *C. R. Soderberg, The Electric Journal (January, 1924). and succeeding articles. See also V O. Knudsen, Physical Review, Vol. 32, 1928. p. 324, and A. L. Kimball, Journal Acoustical Society of America, Vol. 2. 1930. p. 297. . . s587 Heating Ventilating Air Conditioning Guide 1938 If r, the mechanical resistance, is very small, formula 1 may be written 1 n,,o* % where n0 is the natural frequency of the machine upon the elastic pad, In most cases of design of resilient machine mounting the effect, of frictional resistance is small, and Equation 2 may be used. In such cases it is only necessary to know the natural frequency of the elastic pad or platform used under the desired loading and the transmissibility for any vibrational frequency of the machine may be obtained. However, this formula gives the theoretical maximum insulation which may be obtained and' should be used with a liberal factor of safety. (A factor of 2 is common practice.) If the pad is to be of any value in the prevention of solid-borne vibra tions, the value of t' must be considerably smaller than unity. If the fundamental frequency of vibration generated by the machine happens to coincide with the natural frequency of the mass of the machine resting on the elastic pad, a condition of resonance will be established, and the machine will exert a greater force upon the foundation than it would if the pad were completely removed. It is necessary, therefore, that the elastic support be sufficiently compliant, and the mass of the machine sufficiently heavy, that the natural frequency of the mass m upon its elastic support will be low in comparison with the frequencies which are generated by the machine. Thus, if the principal vibrations in the machine be of the order of 100 vibrations per second, the natural frequency of the machine mounted on its elastic support should not exceed about 50 vibrations per second, and for best results preferably 20. When the forced frequency is low, it is frequently impossible to insulate for the fundamental forced frequency due to connecting pipe work and other relevant factors. In cases of this kind an effective installation of sound insulation may be obtained with a mounting which functions far above the fundamental forced frequency. \For example, a compressor operating at 500 rpm has a forced frequency of 8.3 vibrations per second. By designing a mounting having a natural frequency of 20 to 25 vibrations per second, it is possible to isolate practically all of the noise. If a slab of insulating material be placed under the entite foundation of a machine, as is often done in practice, it may happen that the natural frequency of the machine on its elastic support will be nearly the same as the frequencies which are to be insulated, in which case the elastic support will be worse than nothing. In general, as Equation 1 shows, both m and c should be as large as possible if the vibrations of the machine are to be effectively insulated from the solid structure of the building. The elastic support under the machine acts as a low-pass filter which passes all frequencies below about two times the natural frequency of the machine mounted on its elastic support, but prevents all frequencies .588* Chapter 30. Sound Control v:above about . from reaching the solid structure of the building. The principal influence of the internal mechanical resistance r is to limit the vibration at the resonant frequency. It is generally advisable, therefore, . to use materials which have an appreciable internal resistance. The values of c and r can be determined for any specimen of flexible material and, when known, can be used to determine the insulation value of any particular set-up. The value of c can be obtained by making static measurements of the amount of displacement of the compressed support for each additional unit of. the compressing force. If this be done for a specimen of the flexible material of a certain thickness and area of cross section, the compliance can be determined for any other thickness or area from the relation that c will be directly proportional to the thickness and inversely proportional to the area of the flexible support. When the internal resistance r is not too large, it can be determined by observing the successive amplitudes of the free vibrations of a mass m which rests upon a specimen of the flexible material, and solving for r by the usual logdecrement method. Or, if the damping be so great that the free motion of m is non-oscillatory, r can be obtained from measurements on the experi mentally-determined resonance curve of the forced vibrations of m, or from measurements of the rate of return of m when it is given an initial displacement. If the resistance of a certain specimen of material, as cork, felt, or rubber, has been determined by any of these methods, the resistance for any other thickness or area of the material can be determined approxi- Table 2. Compliance and Resistance Data for Typical Specimens of Flexible Materials The compliances and resistances given in the table are for specimens 1 in. thick and 1 sq cm in cross-section Materiai Description op Material Approximate Upper Saps Loadino m Pounds per Square Inch Compliance c m Centimetees per Dtnb Resistance r in Absolute Units Corkboard Corkboard Fiber Board Fiber Board Fiber Board Fiber Board Fiber Board Anti-Vibro-Block Sponge Rubber Soft India Rubber 1.10 ib per board foot 0.70 Ib per board foot 1.35 Ib per board foot Carpet lining Insulating board Insulating board Insulating board 25 lb per cubic foot 55 Ib per cubic foot 12 8 4 to 6 10 12 15 15 5 1 to 3 3 to 6 0.25 x 10- 0.50 x 10~* 0.60 x 10- . 0.40 x 10-* 0.18 x 10- 0.16 x 10~` 0.12 x 10- 0.60 x 10" 3.0 x 10- 1.2 x 10- 0.15 x 10* 0.25 x 10s 0.50 x 10s ----------------- .............................. 1.5 x 10* From Architectural Acoustics, by V. O. Knudsen, p. 278. 589 Heating Ventilating Air Conditioning Guide 1938 mately because the resistance will be inversely proportional to the thick ness and directly proportional to the area of cross-section of the flexible support. Thus, if the values of c and r for a flexible material be known, it is possible to calculate, by means of Equation 1, the amount of insu lation that will be obtained from the use of this material as a flexible support for a piece of equipment having a mass m. For the routine calculations in practice, r may be neglected with only a slight sacrifice of accuracy. Table 2 gives the values of c and r for a number of com monly used flexible materials. Example 1. A machine weighing 1000 lb has a base area of 20 sq ft. Assume that the principal vibration of the machine has a frequency of 100 cycles per second (most machinery vibrations are less than ISO vibrations per second, and the assumed frequency of 100 is <]uite representative of typical machines). Suppose that a 1-in. slab of corkboard weighing 1.10 1b per board foot be placed between the machine and the floor. The loading on the cork will then be only 50 lb per square foot, or slightly more than H lb per square inch. (It is assumed that the compliance c in centimeters per dyne for a specimen 1 in. thick and 1 sq cm in cross-section is 0.25 X 10~* and the resistance r in mechanical ohms is 0.15 X 10*.) The transmissibility is calculated in the following manner: Mass of machine in grams = 1000 X 454 = 4.54 X 10s. Area of base in square centimeters = 20 X 144 X 2.54 X 2.54 = 1.86 X 10*. Therefore, the compliance of the entire support, 1 in. thick and 20 sq ft in cross section, is 0.25 X 10-* X ~j-~gg ^ ^ = 0.134 X 10-10 cm per dyne, and the resistance of the entire support is 0.15 X 10s X 1.86 X 10* = 0.28 X 10'mechanical ohms (or absolute units). Therefore, ' V (0.28 X 10s)' + 4%* X 100s X (0.134 X 1(F)7 (0.28 X 10s)7 + ((2x X 100 X 4.54 X 10s) 2ic X 100 X (0.134 X 10-"'' . 4 0.0784 X 10" + 10" 4i* X 10s X 0.018 0.0784 X 10" + ( 2* X 4.54 X 107 - 10s y 2* X 0.134/ = 0.935 Consequently, it is seen that the transmissibility is nearly equal to unity, and that the support therefore is not satisfactory for insulating 100 or fewer vibrations per second. If the amount of cork be reduced so that it is loaded to 10 lb per square inch, the total area of the supporting cork will be only 100 sq in. or 645 sq cm. The compliance, of the entire support will now be 0.25 X lO"* X 0.39 X 10-* cm per dyne, and the resistance will be 0.15 X 10s X 645 = 0.97 X 107 mechanical ohms (or absolute units). Therefore . V (( * 1 (0.97 X 107)7 + 4x* X 100* X (0.39 X 10-*)7 (0.97 X 107)7 + 2 X 100 X 4.54 X 10s) _J_______ V 2* X 100 X (0.39 X 1(H)) V 0.94 X 10" + 4x* 10" X 0.1521 0.94 X 10" + ( 2* X 4.54 X 107 - 10' = 0.0375 y 2x X 0.39 / 590 Chapter 30. Sound Control It is seen, therefore, that with the bearing surface on the cork reduced to 100 sq in. (that is, with the cork loaded to 10 lb per square inch), the transmissibility is reduced to 0.0375, or the amplitude of vibration trans mitted to the floor will be only about 1/27 of what it would be if the machine were mounted directly upon the floor. These two numerical examples will serve to show not only the manner of making the calcu lations, but also the importance of selecting the proper type and design of flexible supports for insulating the vibrations of a machine from the rigid structure of a building. Controlling Noise Through Room Wall Surfaces The ventilating equipment is usually housed in a separate room-.where the noise produced by the mechanical operation of the equipment can-be isolated from the rest of the building. If the vibration of the machinery is absorbed by flexible mounting and is not transmitted to the building, V| 8nch Plaster Insulation Value * 47 db 55l |i ^ 4* Hollow Clay Tile j xl-* 2" Furring Strips g|j ^ Paper and Metal Lath gfi ^2 Plaster Insulation Value - 52 db. -Absorptive Blanket 2 Fibre Board Plaster ^Staggered Wood Studs Insulation Value Greater than 50 db. ^Rough and Finish Flooring Absorptive Blanket Plaster on Lath Insulation Value ~ 50 db. Flooring Resilient Chairs Concrete Slab Resilient Hangers Plaster on Lath Insulation Value " 60 db., or more Fig. 1. Three Wall Sections and Two Floor and Ceiling Sections which are Suitable for the Insulation of Equipment Rooms3 Acoustical Problems in the Heating and Ventilating of Buildings, by V. O. Knudsen (A.S.H.V.E. Transactions, Vol. 37, 1932, p. 211). the only noise to be eliminated by the walls of the room will be the air borne mechanical noise. Acoustical measurements on average brick, tile, lath, and plaster walls indicate that the usual'wall of these types is sufficient to satisfactorily attenuate this air-borne mechanical noise. Three wall sections and two floor and ceiling sections which are satis factory for the wall insulation of the equipment room are shown in Fig. 1. Attention should be given to the equipment room door, since this door may leak badly and allow sound to escape into parts of the building which should be quiet. Where the equipment noise is particularly severe, . double doors should be used and in all cases, the doors of the equipment room should be fitted with tight thresholds and weather-stripping. The door itself may transmit considerable sound if it is thin but it will not transmit a tenth as much as will'be transmitted by a J^-in. crack between the door and the threshold. In cases where the equipment noise is extraordinarily high, it may be 591 Heating Ventilating Air Conditioning Guide 1938 necessary to treat acoustically the walls and ceiling of the equipment room. If the equipment room is not entirely closed, partition walls may be necessary. NOISE TRANSMITTED THROUGH THE DUCTS . After noise reaches the air stream in the ducts it can be controlled by lining the ducts on the inside with a sufficient quantity of sound absorbing material. Lagging material of similar characteristics placed on the out side of ducts serves to prevent noise originating outside the ducts being carried inside the ducts and into the air stream. A case where outside lagging is desirable occurs when ducts originate at the fan in the equipment room and pass through this room on the way to the room being conditioned or ventilated. Unless the ducts are lined some of the mechanical noise from the equipment room air may be trans mitted through the wall of the duct, thus reaching the air stream and be carried into the room. In such cases, that portion of the duct which is exposed to the sounds in the equipment room should be lagged with material such as cork, pipe covering or other sound damping material to prevent the sound from entering the duct at this point. Numerical data are not available to permit a simple and practical calculating procedure to determine thickness of covering which should be used for this purpose. Inside lining material used in the case previously mentioned would serve as an absorber of the sound transmitted through the duct walls, and thus act as a means of preventing the transfer of noise into the air stream. Inside lining may also be used in ducts to absorb noise which reaches the air stream from equipment such as fans, sprays and coils; noise due to eddying currents set up by elbows, dampers and similar obstructions; and noise transmitted from room to room where there is a common duct system. To use the lining effectively it must be properly located, well installed and be applied in sufficient quantity to reduce the noise level of the air stream to the level desired. At present there are no wholly rational or generally recognized methods of calculating the amount of duct lining necessary to accomplish a given reduction of noise level in the air travelling in a duct system; consequently some empirical method has to be used. One empirical method is to use direct trial and error. Another empirical method uses a dilct lining factor evaluated by experience. In the present state of the data on sound control for ducts, the latter method is convenient for making estimates, but attention is specifically called to its empirical nature and to the necessity of exercising judgment in applying it. Use of Duct Lining Factor A duct lining factor (/) giving numerical values for use at various equipment noise levels is shown in Fig. 2. When properly used with Table 1 this chart (Fig. 2) provides a solution which may be both useful and simple. It is important to understand that the levels referred to in this chart are the average noise levels set up in the room by the ventilating or air conditioning equipment. In the case of a piece of equipment which generates a noise level of 95 db, when the noise is measured immediately 592 Chapter 30. Sound Control next to the machine, there might be a reduction of 15 db in passing through the duct, and a further difference of 15 db between the noise at the outlet supply grille and the average level in the room, leaving an effective level of 65 db in the room. Reductions of noise level ranging from 5 to 25 db through duct systems have been encountered without the use of sound absorbing linings and the drop from supply opening to average room level may vary from 5. to 20 db; . Duct lining factorf Noisy Equipment Average Quiet 0 5 10 15 20 25 30 , 75 65 65 55 55 ' 45 45 35 35 25 25 15 15 5 55 45 35 25 15 5-5 . Fig. 2. -Chart for Determining Noise Reduction in Decibels from Duct Lining Factor3 "Values for equipment noise are only general. Wherever possible substitute actual values as supplied by equipment manufacturer or as measured. - To determine whether to use column 1, 2, or 3 in Fig. 2, in forming an estimate of the relative amount of noise generated by the system, ..the length of the untreated duct system and the number of bends or elbow;s or splitters should be considered, since the longer and the more complex the system, the more reduction of noise level will occur before the sound reaches the room grilles. Also the sound absorbing power of the room should be taken into account, since in rooms where there is a great deal of absorptive material; such as rugs, draperies, curtains and furniture, there will be a higher loss, between the outlet grille noise and the average room level. The ventilating engineer will have to judge whether the conditions deviate from the typical. Manufacturers ratings on equipment should-be. considered in con nection with the foregoing discussion. The quantity determined involves . 593 Heating Ventilating Air Conditioning Guide 1938 the noise level which will be produced in the room and the manufacturer s method of rating must be considered before allowances previously mentioned are accepted. To use Fig. 2, proceed by consulting Table 1 and determine the probable noise level already existing in the room, and, as suggested, assume that this level is satisfactory for current practice. This gives a noise level in decibels and with this enter the chart of Fig. 2. Read across the chart and determine the value of the duct lining factor (/) in the column at the left. Then multiply the smallest cross sectional dimension (inches) of the duct by this factor. The result will be the length of duct in inches to be lined to attenuate an average fan noise. If circular ducts are used, the length to be lined will be (f) X diameter of duct. Example 8. A 7 x 30 in, duct is connected to a private office space in a quiet location. Determine the length of lining necessary to attenuate a fan noise satisfactorily. From Table 1 the noise level in this office will be 35 db. Length to be lined for noisy equipment is 22 X 7 = 154 in. Length to be lined for average equipment is 17 X 7 = 119 in. Length to be lined for quiet, equipment is 12 X 7 = 84 in. The sound absorbent properties of duct lining are extremely important and materials which have coefficients as high as possible should be used. This is particularly true of the coefficients at the low frequencies. Fig. 2 is based on materials having a noise quieting coefficient of 0.60 or more. For materials which are less efficient a factor of safety should be added4. Only certain sound absorbent materials among those listed in various publications will be found to be suitable for duct lining. In addition to a high sound absorbent coefficient a duct lining material should haye a low , surface coefficient of friction, high resistance to moisture absorption, and should be fireproof and vermin proof. A number of building codes now specify that any sound absorbent material used for duct lining. shall have no fire hazard. There are no existing specifications on moisture resistance but the manufacturer should be required to show that the material will not absorb sufficient moisture to cause deterioration or to decrease the sound absorbing efficiency. 4p0r coefficients of commercial sound absorbent materials see Bulletin Acoustical Manufacturers As' sociotion, 919 No. Michigan Ave., Chicago, 111. 594 Chapter 30. Sound Control If, as is often the case, the length of duct from the main duct to a grille is shorter than the length of lining indicated by using the factor found, this duct may be sub-divided6 into smaller ducts, so that the value found may be used as shown in Fig. 3. Example 3. Assume a branch duct, as shown in Fig. 3, is 24 in. wide by 12 in. high and 42 in. long. Use a duct lining factor of 10. Case I. (No splitters). Length of lining = / X minimum dimension = 10 X 12 = 120 in. In this case the duct should be lined for 120 in. which is obviously impossible. . Case II. (Two splitters). Results in 3 ducts 24 in. wide and 4 in. high. Length of lining -- f X minimum dimension = 10 X 4 = 40 in. . This length of lining fulfills the space limitations of the branch duct which is 42 in. long. General Suggestions In some instances where high velocity air is used, a considerable amount of whistle is generated at the grille. This noise is obviously produced after the air leaves the duct and there is no treatment which can be installed in . the duct that will reduce this noise. The engineer must take into con sideration the type of grille which he.intends to use and provide sufficient grille area so that the velocity through the grille is reduced to a point where the grille is not too noisy. Ducts serving more than one room permit cross talk between the rooms and should be lined with acoustical material. Where the rooms are close together and the ducts short, the ducts should be sub-divided to provide ample acoustical treatment. Very often in ventilating duct work the engineer feels that it will not be necessary to line ducts if the sound is travelling against the airflow. This, however, is untrue since sound travels so much more rapidly than does the air in even high velocity systems, that it will travel as easily against the airflow as it does with it. . Sounds which are low in pitch are much harder to eliminate from a duct system than sound which is high in pitch, consequently equipment which produces low pitched sounds should be avoided as much as possible. REFERENCES How Sound is Controlled, by V. O. Knudsen (Healing, Piping and Air Conditioning. October 1931, p. 815). s' The Nature of Noise in Ventilating Systems and Methods for Its Elimination, by J. S. Parkinson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning March, 1937, p. 183). . Effect of Humidity upon the Absorption of Sound in a Room, by V. O. Knudsen (Journal, Acoustical Society of America, July 1931). Also see report presented at the May 1933, meeting of A.S. of A. Acoustics and Architecture, by P. E. Sabine. Architectural Acoustics, by V. O: Knudsen. `. Acoustical Engineering, by West. ' Modem Acoustics, by Davis. Patents exist covering the sub-dividing of ducts for installing sound absorbent materials. 595. Heating Ventilating Air Conditioning Guide 1938 PROBLEMS IN PRACTICE 1 Does a soft pad under the ventilating machinery prevent building vibration? It may or it may not. In some cases a soft pad causes more vibration than no pad. A flexible mounting should be carefully designed to be effective. 2 Are especially designed walls necessary in an equipment room to keep noise out of adjoining spaces? Ordinarily good brick, tile, or concrete walls are satisfactory. Window and door openings should be made as tight as possible with weather-stripping, etc. 3 $ How should mechanical noise be eliminated from the duct system? A flexible connection between the fan discharge and the duct should be used. The duct should be lined from the fan end for a certain length, depending on the degree of quietness desired. . . 4 Given the choice of two types of equipment, one generating high-pitched sounds and the other low-pitched sounds, which would you choose? Why? The equipment generating the high-pitched noise should be chosen since high-pitched sounds are more easily absorbed than are low-pitched sounds. ` 5 # In building an acoustic filter in a short duct 32 by 24 in. which direction should the splitters run? The splitters should be installed parallel to the longest dimension, since they will provide more acoustical material per splitter. 6 What should be the characteristics of a good duct-lining material? . High noise reduction. . Physical strength. c. Easy working and installation. d. Fire resistance. e. Cleanliness, absence of loose fibers or pieces. /. Smooth surface to reduce air friction. 7 # Should a ventilating duct be lagged or covered on the outside? Ves, in some locations, and particularly in the equipment room and where the duct runs through noisy rooms to serve a quiet room. This lagging will prevent air-borne sounds from entering the duct through its sides and causing annoying sound in the quiet room. 8 # How Mti cross-talk be eliminated when one duct serves two or more rooms? Install proper filters adjacent to the grilles in each room, using splitters if the duct leads to the rooms are short.9 9 # Space limitations and maximum air velocities for the introduction of air to a broadcasting studio restrict the size of duct to 30-by 16 in. and in addition the length of branch duct which is suitable for lining with, sound absorption material is limited to 22 ft. Determine the length of duct lining necessary to attenuate an-average fan noise and establish a permissable room noise level. Referring to Fig. 2 the noise level for broadcasting studio is 14 db and the corresponding duct lining factor/ is 28. Minimum cross sectional dimension of duct = 16 in. 16 X 28 12 37.3 ft duct lining required. Maximum length of duct is 22 ft, therefore it is necessary to divide the duct with a splitter, resulting in a minimum duct dimension = 8 in: O y OC . ---^-- = 18.7 ft duct lining required to attenuate an average fan noise. 596. Chapter 31 AIR CONDITIONING IN THE TREATMENT OF DISEASE Operating Rooms, Reducing Explosion Hazards, Post-operative Heat Stroke, Nurseries tor Premature Infants, Fever Therapy, Control of Allergic Disorders, Oxygen Therapy, General Hospital Air Conditioning IN the past few years air conditioning has made considerable progress as an adjunct in the treatment of various diseases. Among the im portant applications are those in operating rooms, nurseries for premature infants, maternity and delivery rooms, children's wards, clinics for arthritic patients, in heat therapy, oxygen therapy, X-ray rooms, and in the control of allergic disorders. . AIR CONDITIONING OPERATING ROOMS The most wide application of air conditioning in hospitals is that in operating rooms. Complete air conditioning of operating wards is not only desirable but often necessary for reducing the risk of explosion of modern anesthetic gases in dry winter atmospheres, and for the pro tection of the patient and operating personnel against excessive summer heat. Reducing Explosion Hazard Explosion hazards in operating rooms have begun with the introduction of modern anesthetic gases and anesthesia apparatus. Ether adminis tered by the old drop method is still regarded as comparatively safe; but when mixed with pure oxygen or with nitrous oxide in certain concen trations (see Table 1) the explosion hazard may be as great as with ethylene-oxygen mixtures. During the course of ethylene anesthesia the mixture, usually 80 per cent ethylene and 20 per cent oxygen, is so rich that the danger of ex plosion is slight, confined to an area in the immediate vicinity of the face mask, where leakage of ethylene into the air may accumulate to the lower explosion concentration (see Table 1). The most dangerous period is at the end of the operation when the patients' lungs and apparatus are customarily washed out with oxygen with or without the addition of carbon dioxide. Even when this procedure is omitted, it is difficult in practice to avoid dilution of the anesthetic gas with air during the normal course of breathing following the administration of anesthesia. In either case the mixture would pass through the explosion range and extra- 597 Heating Ventilating Air Conditioning Guide 1938 ordinary precaution is necessary for the safety of the patient and opera ting personnel. Copious ventilation, from 6 to 12 air changes per hour, is necessary to preclude accumulation of explosive mixtures and to reduce the concen tration of anesthetics to below the physiologic threshold so that the surgeon and his personnel will not be affected. The most important cause of accidents is probably static sparks which may result from accumulation of frictional charges on the rubber surfaces of die anesthesia apparatus, on woolen blankets, and on the bodies of the operators as they walk on insulated floors, when the humidity is quite low. Grounding the various parts of the anesthesia apparatus is not entirely effective, so long as rubber remains in use in the conventional equipment. To prevent accumulation of static charges within the. apparatus or on persons coming near to it, the measures proposed1 are humidification of air to between 55 and 60 per cent relative humidity, grounding the Table 1. Approximate Limits of Inflammability of Ethylene and Ether2 Ethtxsnx Mooed With Air _...................L................. Oxygen............ ..................... Nitrous Oxide........... ......... Lower limit Per Cent 3.0 3.0 -- Upper limit Per Celt 30 ** 80- Lower Limit Per Cent 1.7 1.7 3.8 Upper limit Per Cent 5040=*= . 26 = ^Limits of Inflammability of Gases and Vapors, H. F. Coward and G. W. Jones, XJ. S. Department of Commerce. Bulletin No. 279, 1931. .. apparatus and operating table, and using conducting floors and shoes so that the operating staff and attendants will be always grounded as they move about. The significant factor is the absolute humidity, rather than the relative humidity, because upon it depends the electrical conductivity of the atmosphere. The principal objection to artificial humidification is the necessity of constant supervision to make sure that the apparatus is functioning properly. Artificial humidification in operating rooms during cold weather may also prove beneficial in reducing evaporation from exposed tissues and from the wet skin of the patient, and by allowing a lower room tempera ture. Operating Room Conditions Little is known about optimum air conditions that are necessary to maintain a normal body temperature during the course of anesthesia and in the immediate post-operative period. Under the influence of anesthesia a patient is.at a very low ebb. All anesthetics, as a rule, produce dilation of the vessels in the skin and much sweating, particularly in the case of ether anesthesia. The loss of body heat is increased considerably, while the general metabolism may be *The Hazard of Explosion of Anesthetics, by Y. Henderson. Report of the Committee on Anesthesia (Journal American Medical Association. 94:1491, 1930). 598 Chapter 31. Air Conditioning in the Treatment of Disease depressed. The organism loses ability to regulate its own body tem perature and becomes unusually sensitive to chilling and post-operative complications. In order to maintain a normal body temperature, a high. air temperature is necessary, as high as 90 F or higher in the case of ether anesthesia, judging from experiments on animals*. . Such high temperatures are obviously uncomfortable for the operating personnel, and in order to alleviate the condition the room temperature is usually kept between 72 and 80 F in cold weather with the patient carefully guarded with blankets and hot water bottles during and for some time after the operation. . Post-operative Heat Stroke: It would seem that surgeons have learned to fear so much the occurrence of post-operative pneumonia and shock that even in hot summer weather patients are sometimes needlessly bundled up with detrimental consequences. In 1916 several deaths were reported3 of heat stroke following surgical operations, and a number of cases suffering from a mild isolation, often recognized as post-operative reaction or shock. From these observations it was concluded that all operating room activities should cease during ' summer heat waves with the exception of urgent operations, when every effort should be made to keep the patient cool and comfortable. . In cases of exophthalmic goitre, one investigator4 warns most em phatically against the performance of operations in extremely warm weather, for under such conditions the risk in spite of all precautions (prior to the introduction of summer cooling in operating rooms) is too . great. An analysis of seyeral cases over a 10-year period shows a striking rise of post-operative deaths in June, July, and August, resulting unex pectedly from extreme post-operative reaction passing onto acute hyperthyroidism. . More recently four cases were reported5 of post-operative heat stroke admitted 24 hours preceding operation and sheltered from direct sun rays. All four were not ill and apparently were good risks. There occurred, however, at the time of operation and for several days preceding it, a heat wave with a moderately high temperature, a high relative humidity, and no wind. In addition to warm weather, excessive loss of body fluids is believed to have been a factor in the production of heat stroke in those four cases. . Aside from the possibility of post-operative heat stroke in warm and sultry weather, the surgeon is also concerned with the lowered recupera tive power of the patients, and with his own discomfort as well as the discomfort of his team, which impairs the efficiency of the technic to the disadvantage of the patient. .. In view of this experience it is customary: to defer major operations as much as possible until the passing of heatwaves, in hospitals not equipped with cooling facilities. But there are exceptional cases, like acute appen- Heat Regulation and Water Exchange. The Influence of Ether in Dogs, by H. G. Barbour and W. Bourne (American Journal Physiology, 67:399, 1924). Post-operative Heat Stroke, by A. V. Moschcowitz (Surgery, Gynecology and Obstetrics, 23:443, 1916). *The Effect of Heat Upon Operations for Exophthalmic Goitre, by A. J. Walton (British Medical Journal, 1:1045, 1923). Post-operative Heat Stroke, by T. M. Martin (Journal Missouri Medical Association. July, 1928. Abstract Anesthesia and Analgesia, 8:23, 1929). 599 'Heating Ventilating Air Conditioning Guide 1938 dicitis for instance, which sometimes come with summer heat waves, and develop dangerously unless promptly operated upon. Complete air con ditioning of operating rooms would therefore seem to be a necessity in many sections of the United States. Satisfactory Air Conditions: Although the comfortable air conditions for the operatives are not identical with those of the patient, a compro mise is as a rule not difficult; with a relative humidity of 55 to 60 per cent, a temperature of 80 F in warm weather and between 72 and 75 F in cold weather will probably prove satisfactory. Additional heat may be furnished to the patient locally or by suitable covering according to body temperature in individual cases. ` Central station air conditioning plants and individual unit air con ditioners proved satisfactory in operating rooms when producing between 8 and 15 air changes per hour of filtered and properly humidified air, with full provision for summer cooling and dehumidification and without recirculation during the course of anesthesia. A separate exhaust fan system is as a rule necessary in order to confine and remove the gases and odors. Double windows are desirable and often necessary to prevent condensation and frosting on the glass in cold weather and to minimize drafts. The high air flow of 8 to 15 air changes in operating rooms is desirable for three reasons: (a) to reduce the concentration of the anes thetic to. well below the physiologic threshold -in the vicinity of the operating personnel, (b).to remove excessive amounts of heat and some times moisture from sterilizing equipment if inside the operating room, from the powerful surgical lights, solar heat, and from the bodies of the operatives, and (c) to provide extra capacity for quickly preparing the room for emergency operations. Much can be gained by careful insu lation of sterilizing equipment and by thorough exhaust ventilation of sterilizing rooms adjoining the operating rooms. . It is generally believed that in addition to operating rooms, an adjoining ward should also be conditioned to provide for the treatment of post operative fever. Such a post-operative ward may also prove valuable in treating patients with heat stroke, fevers, summer diarrhea and other cases affected by high temperature, when the room is not used for-any thing else. Sterilization of Air in Operating Rooms: Of considerable significance to operating rooms and contagious wards is'{he use of ultra-violet radi ation for sterlizing the air.6 Results reported7 would seem to indicate that the post-operative temperature rise of patients during the first few days is in most instances caused more by bacterial contamination of the operative wound than by the absorption of blood and traumatized tissues. Operating room infections, which were quite frequent before the instal lation of special ultra-violet lamps, are said to have practically disappeared. NURSERIES FOR PREMATURE INFANTS One of the most important requirements in the care of premature infants is the stabilization of body temperature. This is necessary because Air-Bome Infection and Sanitary Air Control, by W. F. Wells (Journal Industrial Hygiene, 17:253, 1925). .; . . 'Sterilization of the Air in the Operating Room by Special Bactericidal Radiant Energy, by Deryl. Hart (Journal Thoracic Surgery, 6:45, 1936). . ` 600 Chapter 31. Air Conditioning in the Treatment of Disease their heat-regulating system is not fully developed; the metabolism is low and the infants generally exhibit marked inability to maintain a normal body temperature by their own efforts. The resistance to infec tion is low and the mortality rate, very high. Air Conditioning Requirements The optimum air conditions for the growth and development of these infants were determined by extensive research at the Infants Hospital, Boston, Mass.,8 using four'valid criteria, namely, stability of body tem perature, gain in weight, incidence of digestive syndromes, and mortality. . Wide variations were found in individual requirements for temperatures from 72 to 100 F, according to the constitutional state of the infants and body weights. The optimum relative humidity was about 65 per cent, and the air movement less than 20 fpm. A single nursery conditioned to 77 F temperature and 65 per cent relative humidity was found to satisfactorily fulfill the requirements of the majority of premature infants. Additional heat for weak or debili tated infants may be furnished in the cribs or by means of electric incu bators placed inside the conditioned nursery and the temperature adjusted according to individual requirements. In this" way multiplicity of chambers and of air; conditioning apparatus is obviated; the infants in the heated beds derive the benefit of breathing cool humid air, and the nurses and doctors need not expose themselves to extreme conditions. Importance of Humidity: Although external heat is an important factor in the maintenance of normal body temperature, humidity appears to be of equal or greater importance. When the premature nurseries at the Infants Hospital were kept at relative humidity between 25 and 50 per cent for two weeks or longer, the body temperature became unstable, gains in weight diminished, the incidence of gastro-intestinal disturbances increased, and the mortality rose. On the other hand, continuous ex posure to air conditions with 55 to 65 per cent relative humidity gave satisfactory results over a period of years. . The initial physiologic loss of body weight (loss occurring within first four_ days of life) was found to vary inversely with the humidity. In the old nurseries with natural humidity it averaged 12.4 per cent of , the birth weight; in the conditioned nurseries it was 8.9 per cent with 25 to 49 per cent relative humidity, and 6.0 per cent with 50 to 75 per cent relative humidity. The number of days required to regain the birth weight was correspondingly maximum in the old nursery, mini mum in the conditioned nurseries under high, humidity, and inter mediate in the conditioned nurseries with low humidity. Maximum gains in body weight occurred in the conditioned nurseries under high humidity (55 to 65 per cent) in infants weighing less than 5 lb. The gains were less under low humidity (25 to 50 per cent) in the same nurseries, and in the old nurseries prior to the installation of air condi tioning apparatus. . The incidence and severity of digestive syndromes, with diarrhea, 8The Premature Infant: A Study of the Effects of Atmospheric Conditions on Growth and on Develop ment, by K. D. Blackfan, C. P. Yaglou and K. McKenzie (American Journal Disease of Children, 46:1175. 1933). 601 Heating Ventilating Air Conditioning Guide 1938 persistent vomiting, diminishing gains or loss of body weight, and other symptoms, were generally from two to three times as high under low than under high humidity. . c Finally, the mortality of premature infants was found to be greatly affected by humidity. In Table 2 is given the net mortality according to the humidity in which the derangement of body function began. In the old nurseries, prior to the installation of the air conditioning system, the death rate from acute and chronic infections was 26.5 per cent as com pared with 9.7 per cent in the conditioned nurseries under low humidity and 0.0 per cent under high humidity. Summarizing the conclusions of these studies, the best chances for life in premature infants are created by maintaining a relative humidity of Table 2. . Net Mortality of Premature Infants According to Humidity3 Infants Hospital, Boston, Mass. Unconditioned Nurseries (1923-1925) Conditioned Nurseries (1926-1929) . Cause or Death ' Unclassified...... ........... ............. Natural Huumrrr Per Cent Mortality 26.5 1.2 1.2 Relative Humiditt 2549 Per Cent . 50-75 " Per Cent Per Cent Mortality Per Cent Mortality 9.7 0.0 0.0 0.7 4.8 . 0.0 28.9 14.5 0.7 Excluding cases with multiple congenital anomalies incompatible with life, and also deaths occurring within 48_hours after admission to the hospital. 65 per cent in the nursery and by providing a uniform environmental temperature just sufficiently high to keep the body temperature within normal limits. Medical and nursing care are, of course, factors of equal and sometimes of greater importance. Air Conditioning Equipment: Most of the installations now in use are of the central station type providing for filtration, for humidification and heating in cold weather, and for cooling and dehumidification in hot weather. A high ventilation rate, between 15 and 25 air changes, is desirable to remove odors and maintain uniformity of temperatures in extremes of weather. Recirculation is not used extensively in these wards. owing to odors and the possibility of infection. - AIR CONDITIONING IN FEVER THERAPY Artificial production of fever in man is an imitation of nature's way of overcoming invading pathogenic organisms. The action may be direct and specific by obliteration or destruction of the invading organism within the safe limit of human fever temperature; or an indirect one in case of heat resistant organisms, through general mobilization of the defensive 602 Chapter 31. Air Conditioning in the Treatment or Disease mechanisms of the body, by means of which the activity of pathogenic bacteria and their toxins may be retarded or neutralized. . The limits of induced systemic fever are usually between 104 and 107 F (rectal), and the duration from 3 to 6 hours at a time. The total period of fever treatment varies with the type of the organism involved from a few hours to 50 hours or more. The diseases reported to respond favorably to artificial fever are: gonorrhea, neurosyphilis, chorea, asthma, peripheral vascular diseases, occular gonorrhea and syphilis. There are a number of other conditions in which the usefulness of artificial fever is not yet settled. The most striking results are seen in gonorrhea in which various strains of organism can be killed by artificial fever within the limits of tolerance of man. Equipment for the Production of Systemic Fever Various means have been tried for producing artificial fever, including injections of various crystalloid or colloid substances; a number of physical methods, such as hot baths, radiant heat, diathermy, radiothermy, and, in the last few years, an air conditioned chamber. The relative ad vantages and disadvantages of these various methods were discussed in recent papers.9' The results by the use of air conditioned cabinets have not been fully explored, and it is therefore difficult to determine the ad vantages and disadvantages of the value of air conditioning at this time. Under certain conditions a combination of systemic fever and additional local heating by diathermy or other means is claimed to yield better results than systemic fever alone by reducing considerably the killing time of the organism and rendering the treatment less trying to both patient and attendants.10 The air conditioned chamber11 consists of an insulated cabinet approxi mately 6 ft long, 3 ft wide, and 2.5 ft high, containing in a small rear compartment, electric air heaters, a water pan for humidification, a centrifugal fan, and controls. The nude patient lies on an air mattress inside the front compartment with his head protruding outside the front end through a rubber collar. Warmed air at 130 to 150 F and 30 to 50 per cent relative humidity is blown upon the body of the patient, and the. rectal temperature rises to 105 F usually in from 40 to 60 min. The heat is then turned low and adjusted so as to maintain the desired body tem perature in each individual case. More recently a heat cabinet was described12 in which saturated air between 100 and 120 F in temperature is used for elevating the pa tient's body temperature. This gives a rapid rise of body temperature with a relatively low air temperature; it eliminates skin burns, and the room in which the heat box is located is not overheated unduly. Fever Therapy for Gonococcic Infections, by A. U. Desjardins, L. G. Stuhler and W. C. Popp (Journal . American Medical Association, 106:690, 1936). Artificial Fever Therapy as a Therapeutic Agent, by H. P. Doub (Radiology, 25:360, 1935). The Treatment of Gonorrheal Arthritis by Means of Systemic and Additional Focal Heating, by W. Bierman and C. Levenson (American Journal Medical Science, 191:55. 1936). Artificial Fever Therapy of Syphilis, by W. M. Simpson (Journal American Medical Association, 105:2132, 1935). "Fever Therapy Induced by Conditioned Air, by F. C. Houghten, M. B. Ferderber and Carl Gutberlet (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, February; 1937, p. 115). 603 Heating Ventilating Air Conditioning Guide 1938 Extensive research is now in progress to determine the usefulness and limitations of fever therapy on a wide variety of pathogenic conditions. While this form of therapy is rapidly gaining wide recognition, its appli cation, according to the American Medical Association, should be strictly a hospital procedure surrounded with the safeguards commonly employed in a major operation and under the direction of skilled physicians. CONTROL OF ALLERGIC DISORDERS Although there is some division of opinion over the ultimate cause of allergy, the prevailing belief is that it is due to an inherited or acquired hypersensitiveness to foreign or pollen proteins in certain individuals who react abnormally to the offending substance. The reaction may be induced by inhalation, eating, or absorption of the allergens through the skin. The clinical manifestations are hay fever, asthma, eczema, hives, contact dermatitis, etc. . Symptoms oi Hay Fever and Asthma The respiratory tract is probably the most usual site of allergic mani festations, the so-called hay fevers and asthma. In hay fevers, the nose and eyes are red and itchy, and there is considerable discharge. Nasal obstruction is the most common and most distressing symptom. The severity of the symptoms varies widely from day to day depending chiefly on the amount of pollen in the air. Seasonal asthma comes in attacks. The most popular theory con cerning the mechanism of action is that the offending substance irritates the nerve endings in mucous membranes of the respiratory tract, causing spasmodic contraction of the small bronchioles of the lungs, which interferes with breathing, particularly with expiration. Non-seasonal allergic disturbances are. sometimes attributed to house or street dusts, fungi, odors and irritating gases, and heat or cold, particularly sudden temperature changes. It is often stated in the literature that heat'reg ulation in asthmatic individuals is likely to be unstable, with a tendency to subnormal body temperature. Many allergic cases who are apparently well, develop their attacks when cold weather appears, or upon changing from warm to cool outdoor air. Air Conditioning Apparatus \ . In recent years considerable effort has been directed toward the elimi nation of the principal cause of allergy from' the air of enclosures by filtration or other air conditioning processes capable of removing pollens, in the hope of providing relief to individuals who failed to respond to. medical treatment (desensitization or immunization). Paper or cloth filters, mounted in inexpensive window or floor units, proved quite satisfactory in removing all but traces of pollen. Allergens may also be removed by passing the air through a water spray, or over cooling coils kept at a temperature low enough to cause condensation of atmospheric moisture on the surface of the coils. Although the chief remedial factor in the treatment by conditioned air is the filtration of pollen, a certain amount of cooling and dehumidification 604 Chapter 31. Air Conditioning in the Treatment or Disease appears to be desirable. A comfortable temperature between 75 and 82 F in warm weather and a relative humidity well below 50 per cent proved satisfactory.13 Direct drafts, overcooling or overheating are apt to initiate or aggrevate the symptoms. Limitations oi Air Conditioning Methods The results obtained with air filtration or other air conditioning pro cesses in the control of allergic conditions are fairly comparable to those obtained by desensitization treatment so long as the patients remain in the pollen free atmosphere. But while specific desensitization is preven tive and in a few instances curative for all practical purposes, filtration gives only temporary relief. With rare exceptions, the symptoms recur on exposure to pollen laden air. Moreover the usefulness of air condi tioning methods is limited because all cases are not caused by air-borne substances. Cases of bacterial asthma do not respond at all to the treat ment with filtered air. Despite these limitations air conditioning methods possess definite advantages in the simplicity of treatment, convenience, and under certain conditions almost immediate relief. Hay fever cases are usually relieved of most of their symptoms within an hour or so after exposure to properly filtered air. In pollen asthma cases relief comes more slowly, usually after an exposure of from 1 to 12 days depending upon the severity of asthma. A pollen free atmosphere is especially valuable for patients in whom desensitization has given little or no relief, and in instances in which desensitization is not advisable owing to intercurrent illness. On the whole, conditioning methods are considered to be a valuable adjunct in medical diagnosis and treatment of allergic disorders. AIR CONDITIONING IN OXYGEN THERAPY Oxygen therapy is the principal measure employed for preventing and relieving the distressing symptoms of anoxemia, which is a deficiency in the oxygen content of the blood. Some of the more important conditions in which' oxygen treatment is believed to be beneficial are pneumonias, anemia, heart affections, post-operative pulmonary disturbances, certain mental disturbances, asphyxia, asthma and atelectasis in new-born infants. The necessity of air conditioning in oxygen therapy arises from the fact that oxygen is too expensive a gas to waste in the ventilation of oxygen tents and oxygen chambers. The oxygen rich atmosphere in these enclo sures is therefore reconditioned in a closed circuit by removal of excess heat, moisture, and carbon dioxide given off from the occupants. Oxygen Tents: In oxygen tents the air enriched with oxygen is usually circulated by means of a small motor blower which sends the air over soda lime to remove'carbon dioxide and then over ice to remove excess heat and moisture. The concentration of oxygen in the tent is regulated by means of a pressure reducing valve and flow meter. In an inadequately `The Effect of Low Relative Humidity at Constant Temperature on Pollen Asthma, by B. Z. Rappaport. T. Nelson and W. H. Welker (Journal Allergy, 6:111, 1935). 605 Heating Ventilating Air Conditioning Guide 1938 cooled oxygen tent, high temperatures and humidities are inevitable, increasing the discomfort of the patient and imposing an added strain on an already overburdened heart. Oxygen therapy under such conditions may do more harm than good14. An ice melting rate of about 10 lb per hour gives satisfactory results in patients with fever in a medium size tent. Oxygen tents are somewhat confining to the patient; the restless type of person is difficult to control, and the delirious impossible to control. Medical and nursing care is complicated, as the tent must be opened or removed with attendant loss of oxygen. Oxygen concentrations of 50 per cent or more are difficult to maintain, and it is a problem to keep the temperature and humidity low enough in hot weather. The direct advantages are portability and low cost. Oxygen Chambers: The conventional oxygen chamber is an air-tight sheet metal enclosure of fire-proof construction, large enough to accom modate one or two patients. Trap doors or curtains are provided for the personnel, food and service to avoid loss of oxygen. Glass windows in the ceiling and walls admit light from electric fixtures outside the chamber. The air conditioning system may be of the gravity type, or of the fan type using mechanical refrigeration or silica gel for drying the air. The gravity system includes a bank of brine coils controlled thermostatically, which dehumidify and cool the air. The cool air falls over trays at the bottom of the coils, containing soda lime to remove the carbon dioxide given off by the occupants. A heater at the base of the opposite wall warms the air to the desired temperature. Ordinary industrial oxygen is introduced from storage tanks outside the chamber and the concentration is regulated according to the prescription of the physician. The only change of air in the chamber is that taking place by leakage through trap doors. The chief objections to the gravity circulation system are stratification of cold air near the floor and accumulation of odors, which may require the use of activated charcoal or an excess of oxygen for deliberate aeriation. The fan circulation systems include compact extended surface coolers, heaters, and sometimes silica gel beds installed outside the chamber for the removal of moisture. A spray dehumidifier is not suitable for this purpose because it is often desired to cool the ,air below 32 F in order to obtain low relative humidities. The temperature and humidity requirements in oxygen therapy depend primarily upon the physical condition of the patient, and secondarily upon the type of disease. In pneumonias, the range of satisfactory conditions is placed between 60 and 75 F with 20 to 50 per cent relative humidity, depending on the condition of the patient. Oxygen chambers are unquestionably more comfortable than oxygen tents. The patients receive unhampered medical and nursing care, and the oxygen concentration, the temperature and humidity can be ade quately controlled at any desired level. The chief disadvantage is high initial and operating costs in comparison with oxygen tents or with the nasal catheter method of oxygen administration. The nasal catheter "General Measures Employed in the Treatment of the Pneumonias, by J. G. M. Bollowa (Health Examiner 5:12.1936). 606 -- : - - = ~~ ' - r;;jV . ^ Chapter 31. Air Conditioning in the Treatment or Disease method is the simplest and most inexpensive of all but it may cause con siderable discomfort to the patient and it is not satisfactory for continuous administration and in restless or delirious patients. Moreover, oxygen concentrations greater than 40 per cent in the inspired air are difficult to obtain. The chamber method is of value in large hospitals and for research and experimental purposes, but for routine oxygen therapy alone it may prove a liability rather than an asset in many hospitals. GENERAL HOSPITAL AIR CONDITIONING Complete conditioning of large hospitals involves a capital investment, depreciation and running expense which may not be justified. In clean and quiet districts, the requirements of almost all general and private wards during the cool season of the year can be satisfactorily fulfilled by the use of rational heating in conjunction with window air supply and gravity or mechanical exhaust. Insulation against heat and sound is much more important than humidification in winter; it will also help considerably in keeping the building cool in warm weather. Exces sive outside noise and dust may require the use of silencers and air filters in the window openings. Cooling and dehumidification in warm weather are important. In new hospitals particularly, the desirability of cooling certain sections of the building should be given serious consideration. Financial reasons may preclude the cooling of the entire hospital, but the needs of the average hospital can be met by the use of built-in room coolers and a few portable units which can be wheeled from ward to ward when needed. In the North and certain sections of the Pacific Coast, cooling is needed on but a few days during summer, while in the South, built-in room coolers can be used to advantage from May to October, and in tropical climates almost continuously throughout the year. Objectionable noise is an important drawback to the use of self-contained units, but the difficulty is gradually being overcome by improvements in design. Aside, from comfort and recuperative power of the patients, cooling is 'of great assistance in the treatment of pyrexias in the new-born and in post-operative cases, in enteric disorders, fevers, heat stroke, heart failure, and in a variety of other ailments which often accompany summer heat waves. Considerable research is now in progress on the influence of air con ditioning upon a wide variety of diseases such as pneumonia, upper respiratory diseases, tuberculosis, arthritis, nervous instability, hyper thyroidism, essential hypertension, skin diseases, vascular disorders, and others. The field is a fruitful one having many possibilities. PROBLEMS IN PRACTICE 1 Where has air conditioning in hospital wards proved itselfof sufficient value to justify the expense? In nurseries for premature infants, anesthesia and operating rooms, oxygen therapy chambers, heat therapy rooms or cabinets and allergic wards. ' 607 ^ Heating Ventilating Air Conditioning Guide 1938 2 What is the major problem in conditioning hospitals? For general hospital wards, the major problem seems to be one of providing adequate amounts of ventilation rather than air conditioning, with some provision for cooling over-heated wards on unusually warm summer days. 3 i What are the usual requirements for ventilation of operating rooms? To preclude the accumulation of explosive mixtures and to reduce the concentration of anesthetics below the physiologic threshold, it is desirable that ventilation to the extent of 6 to 12 air changes be provided. 4 What are the optimum air conditions for premature infants? The best chances for life in premature infants are created by maintaining a relative humidity of 65 per cent and an environmental temperature sufficiently high to keep the body temperature within normal limits. 5 How does air conditioning assist in the treatment-of allergic disorders? In cases in which the individual fails to respond to medical treatment, air conditioning may provide a valuable adjunct in relieving the symptoms. Although the chief remedial factor in the treatment by conditioned air is the filtration of pollen, it has been found that in warm weather temperatures between 75 and 82 F and relative humidities well below 50 per cent are more conducive to comfort. 608 Chapter 32 RAILWAY AIR CONDITIONING Passenger Car Ventilation, Quantity of Outside Air, Method of Air Distribution, Air Cleaning, Steam or Vapor Heating Equipment, Cooling Equipment, Humidity and Temperature Control, Power Supply, Installation and Operating Costs . THE general principles of air conditioning as applied to buildings also apply to railway passenger cars, but due to space and weight limi tations and the severity of the service, equipment designed for stationary work is seldom suitable for car installations. Equipment for railway use must be safe, reliable, compact, light in weight, accessible for inspection and repairs, automatic in operation and in addition, have low initial, operating, and maintenance costs. To air condition a passenger car properly, ventilating, filtering, heating, cooling, humidifying, and control equipment must be provided together with an adequate power supply. Air from the interior of the car is mixed with air from the outside and passed through the air conditioning unit where it is heated or cooled, _____-------^ humidified or dehumidified and delivered to the interior of the car through ""==~------- suitable ducts and grilles. PASSENGER CAR VENTILATION One of the important problems in connection with air conditioning of cars is that of ventilation. In non air-conditioned cars, ventilation is accomplished by exhaust fans, roof ventilators and open doors and windows. This practice provides an ample supply of outside air but does not prevent the entrance of smoke, cinders, and dirt. Quantity of Outside Air An average passenger car contains approximately 5000 cu ft of air and may seat as many as 80 passengers. The occupants are continually liberating heat, carbon dioxide, moisture, odors, and some organic matter from their breath, skin and clothing. The heat and moisture can be removed by cooling and dehumidification, but the other constituents can be successfully handled only by proper ventilation and air cleansing. In the average car from 2000 to 2500 cfm should be circulated by the air conditioning unit. Some of this air may be recirculated, but a portion of it should always be brought in from the outside. The amount of outside air required depends upon the type of car, number of passengers, air temperature, humidity, odors, and whether or not occupants are smoking, and will vary from 15 to 90 per cent of the total air circulated. The per- 609 ' Heating Ventilating Air Conditioning Guide 1938 centage of outside air should be kept as low as possible to maintain the air in the proper condition in order to minimize the heat or cooling load. For normal conditions, 10 cfm of outside air per passenger is sufficient. When smoking is permitted, 12 to 15 cfm per passenger should be ad mitted. Under exacting demands and adverse condition, it may be necessary to increase the quantity to 20 cfm per passenger. Method of Air Distribution . Various methods may be used to distribute the air delivered to the interior of the car by the circulating fan or blower. The methods commonly used are: 1. A duct lengthwise along the center of the car. 2. One or two side ducts built on the outside of monitor-roofed cars, or on the inside of turtle-backed or arched-roofed.cars. . 3. Free discharge at the end bulkheads, or by free discharge from a unit placed overhead in the center of the car, discharging toward the ends. For details of air distribution and duct design, see Chapters 28 and 29. Smoking rooms present a special problem. The cloud of smoke that usually hangs near the ceiling can be broken up by having the incoming air directed along the ceiling in all directions at a velocity somewhat higher than that used for the rest of the car. The air should be exhausted from the room by a fan or through a grille to the washroom or lavatory, and then outside by a fan in a ventilator. . For compartments an adjustable supply duct outlet grille-of suitable size and design should be provided and provisions made in the door or partition for the removal of the air to be recirculated. The grille used for this purpose should be designed and arranged so as . to obstruct the vision of passengers, but still allow the air to pass from the room to the recirculating grille at the air conditioning unit. Lower berths in sleeping cars and office cars should be provided with an adjustable air outlet which will discharge the amount of air desired at low velocity in any direction so that the occupant can regulate the ventilation to meet his own requirements. . In cars containing but one or two rooms or compartments, satisfactory results may be obtained by discharging the air directly from the con ditioning unit into the upper part of the car. Care must be taken to have a proper discharge velocity. If the velocity is too low, the air will drop before reaching the end of the car and if too high it will discharge against the end bulkhead and be reflected back. Care must be exercised to secure proper circulation, otherwise objectionable drafts will be experienced. The recirculating air grilles are usually of the straight flow type, and should be located so that objectionable drafts will not be created by the return air. The outside air intakes, located in the car vestibule, on the side of the car, or on the roof of the car, depending upon the location of the. cooling coils, should be of ample size to permit the entrance of suf ficient outside air. On many of the recently air-conditioned cars, there are no dampers or shutters at the outside air intakes, the percentage of outside air being controlled by blocking the flow through the recircu lating grille. 610 Chapter 32. Railway Air Conditioning Air Cleaning . All of the air circulated by the blower is filtered before passing over the cooling coils. In some cars the outside and recirculated air are filtered separately before mixing, while on others the air from the two sources is . mixed before passing through a common filter. Filters in use are made of metal, wool, cloth, spun glass, hemp, paper, hair, and wire screen. Most filters have a viscous coating of oil for greater cleaning efficiency. Some types may be cleaned, retreated, and returned to service while other types are discarded when dirty. STEAM OR VAPOR HEATING EQUIPMENT The majority of cars in service are heated by circulating low pressure steam or vapor through pipes located along the side walls near the floor. When an air conditioning unit, using air from the outside, is installed it is necessary to provide a heating coil to warm the air during cold weather. Usually from 30 to 40 per cent of the heat required is supplied from the air conditioning unit and the balance from the floor heating system. It is necessary to have sufficient floor radiation to keep water lines in the car from freezing while standing in the yard with the air conditioning unit shut off. In new and some rebuilt cars, finned pipes are used for the floor heat to provide greater radiation surface. A few cars have the heating pipes enclosed in a duct, through which air is forced by a fan, the warmed air discharging through numerous openings along the floor. The amount of heat required depends upon the type and construction of the car, especially the amount and kind of insulation, outside temperature, wind velocity and direction, train speed, number of passengers, and inside temperature desired. In severe weather, with temperatures from --10 to -- 20 F, an average of approximately 200 lb of steam per car per hour is required. Pullmans require approximately 250 lb per hour, coaches 150 to 175 lb per hour and baggage cars 150 lb per hour. COOLING EQUIPMENT . Three general types of cooling or refrigerating equipment are being used with satisfactory results: These are the ice-activated, the steam-ejector and the mechanical compression systems. These systems when arranged for car use, function the same as in stationary service, but must be more compact and lighter in weight. See Chapter 24 for description of the .general principles of the various systems. The mechanical compression systems are divided into three general classes depending upon the type of drive for the compressor, namely, the electro mechanical, the direct mechanical, and the internal combustion engine mechanical. The compressor of an electro mechanical compression system is driven by an electric motor, the power for which is supplied by a generator and a storage battery. The generator is driven from the car axle by a gear, belt, or other type of mechanical drive. The compressor of a direct mechanical compression system is driven directly from the car axle by means of a mechanical drive, the speed of the compressor being regulated by an electric speed control which permits slippage at high train speeds. The compressor of the third type of mechanical compression 611 Heating--Ventilating--Air-Cont>itioning~Guide~1938 system is driven by an internal combustion engine operating on propane. Sufficient fuel for several days' operation is carried in drums mounted in a rack under the car. The refrigerant frequently used in the mechanical compression systems is dichlorodifluoromethane. The condensers are cooled by blowing a large quantity of outside air over the dry condenser coils, or over the coils wet by a spray of water to obtain the benefits of evaporative cooling. The latter method gives lower discharge pressures which is a distinct advantage when operating at high outside temperatures. A device gaining in popularity is a liquid subcooler by means of which the liquid refrigerant is subcooled by evaporative cooling, producing more available refrigeration at the air conditioning unit. Another type of system which has been tried for railway passenger car air conditioning uses dry ice as the refrigerant, the equipment being essentially the same as for the water ice-activated system. Until an adequate supply of dry ice can be assured at a stable and reasonable price, this system .will not be a serious competitor to the other three types now in use. The capacity required in the refrigerating system depends upon a number of factors such as size and type of construction of car, thickness and kind of insulation used, the amount of heat produced within the car by motors, lights, and other appliances, the amount of outside air, the intensity of solar radiation, the number of occupants, and the inside temperature desired. The sun load on a bright day is about 1.2 tons. For average cars on sunny days, with high outside temperatures and humidities, from 65,000 to 80,000 Btu per hour will have to be removed from the interior of the car to maintain an inside effective temperature within the comfort zone. This means that a refrigerating capacity of from 5.5 to 7.0 tons will be required. HUMIDITY CONTROL The temperature to be maintained in a car depends upon the outside temperature and the humidity desired inside the car. With a low hu midity it is necessary to maintain a higher temperature to establish a desirable comfort condition. Little humidity control has been attempted : on cars up to the present time. A certain degree of automatic humidity control is secured with cooling, but the relative humidity obtained depends largely on the temperature of the evaporator, which should be below th,e dew-point temperature of the air. With certain outside atmospheric conditions it may not be possible to operate the conventional equipment with a sufficiently low evaporator temperature to reduce the humidity without dropping the temperature too low. One method has been developed whereby the evaporator temperature is carried below the dew point a sufficient amount to insure dehumidification and then the cold air is heated to the proper temperature by passing it over coils through which part of the high temperature liquid from the condenser is by-passed. Such a system is costly and has not been generally applied. During the heating season humidification is desirable from a comfort standpoint, but unless properly controlled, condensation will appear on 612 Chapter 32. Railway Air Conditioning the windows. A steam or water spray controlled by a humidistat will provide the necessary moisture for humidification. There are several cars with this feature now in use. TEMPERATURE CONTROL The control of the air conditioning equipment should be simple and automatic in order to eliminate the human element for the selection of the control point. The use of a centralized panel for all switches, fuses, relay, etc., will simplify the installation and operation. Generally, separate thermostats are used for heating and cooling control. The best location for the thermostats depends upon the car layout and method of air distribution and can best be determined for any particular type of car and equipment by careful consideration of the several factors involved. The floor heat thermostats are usually located near the floor. The over head heat and cooling thermostats are placed in the upper part of the car, sometimes in the air ducts or at the recirculating grille. All thermostats should be located so that the air can circulate freely around them. Maintenance of uniform comfort conditions for cooling, floor and over head heating, has been satisfactory with provisions for a high, a medium, and a low thermostat setting and in some cases two settings have been satisfactory for cooling. In many cars the following points have been found to be satisfactory: 72, 74, and 76 F for cooling, and 60, 71 and 74 F for floor and overhead heating. A few cars are in operation in which the inside temperature is varied dependent upon the outside temperature in order to prevent too high a differential between inside and outside temperatures. The maximum inside dry-bulb temperature permitted by these controls is usually 80F. The heating and refrigerating equipment should be interlocked so that they cannot both operate at the same time. While heating, the control should be so arranged that in case of a steam failure the blower fan will stop or the outside air intake should be closed to prevent cold outside air from being introduced into the conditioned space. POWER SUPPLY One of the most important problems to be solved in connection with railway car air-conditioning is that of power supply. The majority of non air-conditioned cars now in service are electrically lighted and equipped with fans. Power is furnished by storage batteries and axle generators of from 2 to 5 kw capacity. Electric Power Requirements When air conditioning is installed the electrical load is increased, according to the type of system as indicated in Table 1. To furnish this additional electric power, the capacity of. the axle generators must be increased to 4 to 20 kw, and the storage battery capacity increased, in addition to'that required by the car lighting system by 400 to 700 amp-hr for the electro-mechanical system, by 150 to 300 amp-hr for the steamejector and direct drive mechanical systems, and by 50 to 200 amp-hr for the ice-activated and internal combustion engine mechanical systems. 613 Heating Ventilating Air Conditioning Guide 1938 Table 1. Electric Power Required to Operate System System Kilowatts 10.50 1.00 1.25 3.35 1.20 Total Power Requirements In addition to the electric power requirements, for continuous operation at average temperatures, the direct drive mechanical system requires 10.24 hp from the car axle and the steam-ejector system requires 230 lb steam per hour from the locomotive boiler for a 6-ton unit. The iceactivated system requires 463 lb of ice per hour and the internal com bustion engine drive mechanical requires 7.3 lb propane per hour. This power, with the exception of the ice and propane, as well as the power required to move the extra weight of the equipment and the power required to overcome the axle bearing friction, must be supplied by the locomotive en route, and if a number of cars in the train are air condi tioned, the effect on train performance should not be overlooked. The demand for power for cooling comes, however, at the time of the year when steam for heating is not required, and the demand for lighting is at a minimum. The total power required by the air conditioning systems will vary with the speed of train operation because of the effect of speed upon the drive efficiency and upon the resistance due to the added weight of the equip ment. Fig. 1 shows the effect of speed upon the efficiency of the direct drive used with the direct mechanical system, and upon the average efficiency of four mechanical drives and generators used for electric power generation. The total increase in weight of passenger cars because of air conditioning is approximately 9,600 lb for the. electro-mechanical, 8,600 lb for the direct mechanical, 8,600 lb for the internal combustion engine drive mechanical, 11,300 lb for the steam, and 8,500 lb for the ice-activated system. The average refrigeration load has been found to be 3.3 tons, and the average capacity of air conditioning systems is about 5.92 tons. The relation of load to capacity, 3.3 -=- 5.92 = 0.56 or 56 per cent, is that percentage of the time during the cooling season that the cooling equip ment will be in operation. The average drawbar horsepower demand upon a locomotive, accordingly, consists of 56 per cent of the horsepower required for continuous operation and 44 per cent of the horsepower required for non-operation. Table 2 shows the drawbar horsepower that must be supplied by the locomotive for each air-conditioned car for continuous operation of the air conditioning system, for non-operation of the equipment, and for an average condition when the air conditioning equipment is operating continuously 56 per cent of the time and is not operating 44 per cent of the time. It is important not to overlook the horsepower demand on the locomotive when the air conditioning equip ment is not operating, which includes the horsepower required to operate 614 Chapter 32. Railway Air Conditioning the blower fan, to haul the weight of the equipment, to overcome drive and generator friction, and to replace the losses occasioned by the re moval of current from the storage battery. Fig. 2 shows the tractive resistance of a 75-ton passenger car with six wheel trucks without an axle generator, with a 4 kw generator load, and, for the same car with an increase in weight of 5 tons and a 20 kw axle Fig. 1. Efficiencies of Drive Mechanisms for Railway Air Conditioning Systems Fig. 2. Tractive Resistance of 75 Ton Passenger Car with Six Wheel Trucks generator load. The curve with the 4 kw generator is representative of a car before air conditioning, and the curve with the 20 kw generator and 5 tons added weight is representative of a car after air conditioning. At 50 mph, the tractive resistances of these two cars are 520 lb and 745 lb respectively, or a difference of 2251b. Then: 5 = 29.7 hp f4 uU X uoOOO is required due to a 16 kw load and 5 tons added weight. Ten cars with a similar load would require 297 horsepower or roughly 10 per cent of the capacity of a 3,000 hp passenger locomotive. . 615 Tt Heating Ventilating Air Conditioning Guide 1938 Consideration must also be given to the power requirements for refrigeration while the car is standing or running at slow speeds. The electrical energy required for the ice-activated, steam, and internal combustion engine drive mechanical systems is easily supplied from the storage battery. Steam for the steam system can be supplied from the locomotive or. from a stationary plant. The majority of the electro mechanical systems are equipped with A. C.--D. C. motors. While standing in the yards and stations the A. C. motor is connected , to a 220-volt, 3-phase circuit. The majority of these equipments are so ar- Table 2. Locomotive Power Demands for Different Air Conditioning Systems System Drawbar Horsepower per Car Required ' at Train Speeds . 30 MPH | 50 MPH | 70 MPH | 90 MPH For Continuous Operation Electro-Mechanical................................................. Direct Mechanical.................................................. Internal Combustion Engine Mechanical....... Steam-Ejectora...................................... :................. Ice-Activated.-......................................................... 20.9 16.8 3.4 7.6 3.2 22.2 19.5 4.6 9.3 4.5 25.4 29.5 7.0 12.5 6.8 31.6 42.6 11.9 19.0 11.6 For Non-Operation Electro-Mechanical.................................... -........... 5.0 6.4 9.0 14.4 Direct Mechanical.................................................. 5.2 6.3 8.7 13.5 Internal Combustion Engine Mechanical........ 2.2 3.5 5.8 10.6 Steam-Ejector.......................................................... 3.7 5.4 8.4 14.8 Ice-Activated. ........................................:............... 1.9 3.2 5.5 10.2 For Average Condition of 56 Per cent Continuous Operation and 44 Per cent Non-Operation Electro-MechanicaL .................................. ......... Direct Mechanical..........,............................ .......... Internal Combustion Engine Mechanical Steam-Ejectora....................................... :................ Ice-Activated.... ....................................................... 13.9 11.7 2.8 . 5.9 2.6 15.2 13.7 4.1 7.6 3.9 18.2 20.3 6.5 10.7 6.2 24.0 29.6 11.4 17.5 11.0 aIn addition, steam is required from the locomotive to the extent of 230 lb per hour during the time the equipment is in operation. ' ' ranged that, while operating on A. C. power, the D. C. motor may be used as a generator for battery charging.-; If an auxiliary circuit is not available the D. C. compressor motor may be operated from the storage battery for short periods of time. The direct drive mechanical compres sion systems are, also, equipped with A. C. motors for operation from' auxiliary circuits. As these equipments can only be operated when con nected to the auxiliary circuit or while the train is running above the cut in speed of the drive, many cars are equipped with an auxiliary hold-over system by which reserve cooling is available. Due to the. characteristics of the direct drive, the air conditioning system operates at reduced capac ity when the car is moving at speeds below 42 mph. 616 Chapter 32. Railway Air Conditioning COST OF RAILWAY AIR CONDITIONING The cost of railway air conditioning is usually expressed in terms of 1000 car-miles. The actual costs for the different systems, however, are dependent upon a number of variables. Based upon a survey of the most prominent railroads in air conditioning, and upon extensive tests, the values given in Table 3 are indicative of the present costs-of air-con ditioning to the railroads. Table 3. Air Conditioning Costs for Railway Air Conditioning System Gross Installation Cost Electro-Mechanical................. Direct Mechanical................... Internal Combustion Engine Mechanical_____ Steam-Ejector........................... Ice-Activated.......... .................. $6,484.00 8,515.00 5,750.00 8,475.00 3,982.00 Fixed Charges $ 8.65 11.35 7.67 11.30 5.31 Costs per 1000 cab-miles* Maintenance Cost Operation Cost $3.33 2.33 $0.99 0.93 3.30 2.15 0.97 1.99 1.02 5.29 Total $12.97 14.61 12.96 14.47 11.57 For an average cooling season of 5 months, an average train speed of 50 mph and an average car mileage of 150,000 miles per year. Gross Installation Cost The gross installation cost, from which the fixed charges are derived, may be amortized on this basis: 1. Depreciation, at the rate of 12.5 per cent. 2. Interest, at the rate of 6 per cent. 3. Taxes and insurance at the rate of 1.5 per cent. . The fixed charges per 1000 car-miles for any type of system are: FC = ^(020A) (1) where . FC = fixed charges, dollars per 1000 car-miles. A = gross installation cost, dollars. m = total number of car-miles traveled in one year. . Maintenance Cost The average maintenance cost is based upon the experience of the railroads in maintaining several hundred air conditioning units. The maintenance cost per 1000 car-miles is: ' where MC 1000 B m (2) MC = maintenance cost, dollars per 1000 car-miles. B = total annual maintenance cost, dollars. rn = total number of car-miles traveled in one year.- 617 Heating Ventilating Air Conditioning Guide 1938 Operation Cost The cost of operation is influenced by: . 1. Speed of train operation. ' 2. Average drawbar horsepower required to operate air conditioning system. 3. Length of the cooling season. 4. Cost of power produced by the locomotive at $0.00493 per horsepower-hour. 5. Proportion of time the cooling equipment is operated during the cooling season considered as 56 per cent. 6. Cost of additional necessities as: a. Ice in bunker, at $4.42 per ton, i. Propane on the car, at $0,039 per pound, c. Steam at $0,021 per 100 pound. Fig. 3. Comparative Total Costs for Railway Passenger Cars The operation cost in dollars per 1000 car-miles is: ' 00 = (p x E + 0 56 f x g) + 1000 K) (H x E) (3) where . OC = operation cost, dollars per 1000 car-miles. D =^average drawbar, horsepower demand on a locomotive at speed S. E -- cost per horsepower-hour, dollars. ' F .= additional necessities such as ice, steam or propane, pounds per hour. G = cost of additional necessities, dollars per pound. H = drawbar horsepower required when system is not operating. S = speed of train operation, miles per hour. K -- length of cooling season, months. ' 0.56 = Proportion of operation time to total time during the cooling season. - Chapter 32. Railway Air Conditioning Total Cost of Air Conditioning When the fixed charges, maintenance cost, and operation cost are each. expressed in terms of 1000 car-miles, addition of the three elements will give the total cost of air conditioning on that basis. Comparisons of the total cost per 1000 car-miles for the five methods of air conditioning are shown in Fig. 3, representing costs for an average ' condition, namely a cooling season of five months and an average speed of 50 mph. COOLING LOAD CALCULATIONS The calculated heat gain for a railway passenger car is dependent on several variables which may be determined from the basic data given in Chapters 5, 6 and 8. REFERENCES Summary Report on Air Conditioning of Railroad Passenger Cars, by Division of Equipment Research, Association of American Railroads, November 24, 1936. . Engineering Report on Air Conditioning of Railroad. Passenger Cars, by Division of Equipment Research, Association of American Railroads, April 15, 1937. . Report on Performance and Cost of Operation of 1937 Internal Combustion Engine Mechanical Compression Equipment for Air Conditioning Railroad Passenger Cars, by Division of Equipment Research, Association of American Railroads, May 1, 1937. PROBLEMS IN PRACTICE 1 What item is the greatest among the cooling loads figured in the design of a summer air conditioning system for a passenger car? The heat from passengers. 2 # To what extent does bright sunshine increase the cooling .requirements of a passenger car? About 1.2 tons of refrigeration. 3 What is the total refrigerating capacity generally required in a passenger car? ' 5.5 to 7 tons per car. 4 `'What is the effect of train speed upon the cooling requirements of a car? Requirements are slightly increased because of increased heat transmission. 5 What is the fan capacity of the air conditioning unit in the average car? 2000 to 2500 cfm. 6 When is it economical to take all air for car cooling from outdoors? When the outdoor wet-bulb temperature is lower than that in the car. 7 What various arrangements are used for distributing cooled air into cars? Bulkhead delivery at center or ends of car, center duct, and side duct on one or both sides. 8 What types of cooling systems are used? Ice-activated, steam-ejector, and mechanical compression systems. 619 . Heating Ventilating Air Conditioning Guide 1938 9 What cooling medium is used for condensing the refrigerant in a railroad * air conditioning system? Outdoor air, sometimes with the aid of evaporative cooling. 10 f How may adequate cooling of condensers be provided in hot desert regions? By evaporative cooling with water sprays. ' 11 How is the temperature controlled in railroad cooling systems? By intermittent operation of the compressor, the steam jet or the ice water circulating pump. 12 How much steam is required* for car heating on the coldest days? Pullmans 250 lb per hour, coaches 150 to 175 lb per hour, baggage cars 150 lb per hour. 13 # At present costs which is likely to be the greater, fixed charges or operating costs? The fixed charges for steam and mechanical compression systems, and operating costs for ice systems. 14 # What would be the annual operating cost for a car equipped with an ice- activated system under the following conditions: a total mileage of 150,000 car-miles per year, a cooling season of 5 months, and an average train speed of 50 mph? . $1,705.00. ' . \ 620 Chapter 33 INDUSTRIAL AIR CONDITIONING Atmospheric Conditions Required, General Requirements, Classification of Problems, Control of Regain, Moisture Con tent and Regain, Conditioning and Drying, Control of Rate of Chemical Reaction, Control of Rate of Biochemical Re actions, Control Rate of Crystallization IN the application of air conditioning to industrial processes, too much stress cannot be laid upon a thorough understanding by the air con ditioning engineer of the problems involved. A complete knowledge of these problems is necessary before a satisfactory design can be made. Individual processes and machines are changing rapidly and air con ditions must be constantly revised to meet the new conditions. ATMOSPHERIC CONDITIONS REQUIRED The most desirable relative humidity during processing depends upon the product and the nature of the process. As far as the behavior of the material itself and its desired final condition are concerned, each material and process presents a different problem. The best relative humidity may range up to 100 per cent. Similarly the most desirable temperature may range between wide limits for different materials and treatments. Ex tremes in either relative humidity or temperature require relatively expensive equipment for maintaining these conditions automatically. In departments where people are working, their health, comfort, and productive efficiency must be considered and often a compromise between the optimum conditions for processing and those required for the comfort of the worker is desirable. ' It is generally considered that relative humidities below 40 per cent are on the dry side, conducive to low regains, a brittle condition of fibrous materials, prevalence of static electricity, and a tendency toward dryness of the skin and membranes of human beings. At the other end of the scale, humidities above 80 per cent are relatively damp, conducive to high regains, extreme softness, and pliability. Table 1 lists desirable temperatures and humidities for industrial pro cessing. In using this table, care must be taken in qualifying the process. In preparing many materials, conditions are not maintained constantly, but different temperatures and humidities are held for varying lengths of time. * 621 Heating Ventilating Air Conditioning Guide 1938 Table 1. Desirable Temperatures and Humidities for Industrial Processing Ihdustht Process Temperature Degress Fahrenheit Rkiattvb Humxditt Per Cent Automobile. 65 40 Baking... Dough fermentation room................................. Make-up room............... . .................... .............. Paraffin paper wrapping...................................... 70 75 80 70 75 to 80 75 to 80 80 80 to 90 70 to 80 28 to 40 50 65 76 to 80 60 to 70 55 to 70 55 to 70 55 80 to 95 60 60 to 75 Biological . Products.__ below 32 38 to 42 Fermentation in vat room................................. Brewing.................. 44 to 50 60 50 30 to 45 Ceramic__________ Drying of auger machine brick....................... Drying of refractory shapes.............................. 180 to 200 110 to 150 80 60. 50 to 60 60 35 Chemical General storage......... ..................................:........... 60 to 80 35 to 50 Confectionery.. Chewing gum rolling. ..................;.................... Chewing gum wrapping....................................... Chocolate covering.................................................. 75 70 62 to 65 70 to 80 65 75 to 85 60 to 68 .50 45 50 to 55 30 to 50 50 50 50 to 65 Distillery. General manufacture Storage of grains................................................... 60 45 60 30 to-45 Drug______ Storage of powders and tablets...................... 70 to 80 30 to 35 . Electrical_______ Insulation winding____________1.......................... Manufacture of cotton covered wire.......... Manufacture of electrical windings._______ Storage of electrical goods................................. 104 60 to 80 60 to 80 60 to 80 5 60 to 70 35 to 50 . 35 to 50 Food... Fur.. Butter making........................................................... Dairy chill room........ Preparation of cereals.................................... Ripening of meats........................................... Slicing of bacon....................... ...................... Storage of apples........................................... Storage of citrus fruit.................................... Storage of eggs in shell.................................. Storage of meats........................... ;................. Storage of sugar. ................. ....... Drying of fiirs.. Storage of furs........ ........................................ 60 40 60 to 70 70 to 80 40 60 31 to 34 32 . 30 Oto 10 80 . 60 60 . 38 38 80 45 75 to 85 80 80 50 35 . 110 28 to 40 25 to 40 622 7T Chapter 33. Industrial Air Conditioning Table 1. Desirable Temperatures and Humidities for Industrial Processing (Continued) ' Irddbtbt Process Temperature Degrees Fahrenheit Relative Humiditt Peb Cent Incubators.--. 99 to 102 55 to 75 Laboratory. General analytical and physical....... ........ .` 60 to 70 Storage of materials______ 60 to 70 60 to 70 35 to 50 Leather._________ Drying of hides__________________________ 90 Library. Book storage (see discussion inthischapter) 65 to 70 38 to 50 Linoleum_________ 80 40 Matches.... ...... -- 72 to 74 60 50 Munitions._______ 70 55 Paint. 70 to 90 180 to 300 Air drying of oil paints................................. . 60 to 90 25 to 50 25 to 50 Paper. Binding, cutting, drying, folding, gluing.. 60'to 80 60 to 80 25 to 50 35 to 45 Photographic.... Development of film...................................... Printing............................ ................................. 70 to 75 75 to 80 70 72 60 50 70 65 Printing__________ Press room (general). .................................. Press room (lithographic)........ .................... 70 77 75 60 to 75 60 to 80 45 65 60 to 78 20 to 60 35 to 45 Rubber.... ................ Dipping of surgical rubber articles............ 90 75 to 80 80 to 84 .. 25 to 30 42 to 48 Soap. 110 70 Cotton-- carding_______________ ;............... combing.......................................... spinning.. ..................................... Rayon-- spinning.......................................... Textile.... ............... spinning.... ............................... ...... throwing......................................... Wool-- carding. .. ................................... weaving. . 1: 75 to 80 75 to 80 75 to 80 60 to 80 68 to 75 70 70 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 50 60 to 65 50 to 60 60 to 70 70 to 80 85 65 60 to 65 65 to 70 65 to 70 60 to 70 65 to 70 55 to 60 50 to 55 Tobacco.________ Cigar and cigarette making.......!........ ........ Stemming or stripping....... :.... ................... .. 70 to 75 90 75 to 85 56 to 65 85 70 623 Heating--Ventilating--Air-Conditioning Guide 1938 GENERAL REQUIREMENTS In general, air conditioning apparatus for industrial purposes must be capable of absorbing heat from various sources such as machinery power, electric lights, people, sunlight and chemical reaction; of warming or cooling to any desired temperature, and of providing ample air supply at all times. Refrigeration may of may not be required, depending upon natural conditions, the required relative humidity and the maximuni permissible temperature. Washing, purifying and recirculating of the air may be desirable. Good distribution is essential for the control of air motion and for the prevention of uneven conditions. Accurate, sensitive and reliable automatic control of humidity or temperature, or both, is", vital in most cases. . Ordinarily, outside weather conditions and the ventilation required for workers are of secondary importance in relation to the total work to be done by the air conditioning system. In extreme cases of high concentra tion of industrial heat from machinery and ovens the error of entirely omitting the heat gain through the building structure would not be serious. At the other extreme, where low temperatures must be produced with refrigeration and where comparatively little power is used for driving the machinery, the heat gain through the building structure will become the major factor in determining the size of equipment and in this case the ventilation requirement assumes a normal degree of importance. Buildings which are to be air conditioned should therefore be designed with careful consideration of over-all cost and efficiency. Condensation resulting from high humidities must be prevented by suitable materials and construction, or else collected and drained to prevent loss of product or quick deterioration of the structure. Air leakage or filtration may add greatly to operating costs or make the maintenance of low humidities (relative or absolute) wholly impossible. Low temperatures require good, insulation. . It is apparent that the subject of air conditioning for industrial processes .is extensive and greatly involved, and that a detailed treatment is there fore beyond the scope of this book. A few of the salient points of the general subject are covered in this chapter. CLASSIFICATION OF PROBLEMS In general, any industrial air conditioning problem may be listed under one or more of the following four classes: `/ 1. Control of Regain. 1 2. Control of Rate of Chemical Reactions. 3. Control of Rate of Biochemical Reactions. 4. Control of Rate of Crystallization. CONTROL OF REGAIN . In the manufacture or processing of hygroscopic materials such as textiles, paper, wood, leather, tobacco and foodstuffs, the temperature and relative humidity of the air have a marked influence upon the fate of production and upon the weight, strength, appearance and general 624 Chapter 33. Industrial Air Conditioning quality of the product. This influence is due to the fact that the moisture content of materials having a vegetable or animal origin, and to a lesser extent minerals in certain forms, come to equilibrium with the moisture of the surrounding air. In industries where the physical properties of a product affect its value, the percentage of moisture is of special importance. With increase in moisture content, hygroscopic materials ordinarily become softer and more pliable. Standards of regain are firmly fixed in trade with fair penalties for excesses. Deficiencies result in loss of revenue to seller and loss of desirable quality to buyer. Manufacturing economy therefore requires that the moisture content be maintained at a percentage favorable to rapid and satisfactory manipu lation and to a minimum loss of material through breakage. A uniform condition is desirable in order that high speed machinery may be adjusted permanently for the desired production with a minimum loss from delays, wastage of raw material and defective product. In the processing of hygroscopic materials, it is usually necessary to secure a final moisture content suitable for the goods as shipped. Where the goods are sold by weight, it is proper that they contain a normal or standard moisture content. MOISTURE CONTENT AND REGAIN The terms moisture content and regain refer to the amount of ihoisture in hygroscopic materials. Moisture content is the more general term and refers either to free moisture (as in a sponge) or to hygroscopic moisture (which varies with atmospheric conditions). It is usually expressed as a percentage of the total weight of material. Regain is more specific and refers only to hygroscopic moisture. It is expressed as a percentage of the. hone-dry weight of material. For example, if a sample of cloth weighing 100.0 grains is dried to a constant weight of 93.0 grains, the loss in weight, or 7.0 grains, represents the weight of moisture originally contained. This expressed as a percentage of the total weight (100.0 grains) gives the moisture content or 7 per cent. The regain, which is expressed as a per- 70 centage of the bone-dry weight, is or 7.5 per cent. The use of the term regain does not imply that the material as a whole has been completely dried out and has re-absorbed moisture. During the processing of certain textiles, for instance, complete drying during manu facturing is avoided as it might appreciably reduce the ability of the material to re-absorb moisture. A basis for calculating the regain of textiles is obtained by drying under standard conditions a sample from the lot and the dry weight thus obtained is used as a basis in the calcu lations to determine the regain. The moisture content of an hygroscopic material at any time depends upon the nature of the material and upon the temperature and especially the relative humidity of the air to which it has been exposed. Not only; do different materials acquire different percentages of moisture after prolonged exposure to a given atmosphere, but the rate of absorption or drying out varies with the nature of the material, its thickness and density. 625 f- Heating Ventilating Air Conditioning Guide'1938 Table 2. Regain of Hygroscopic Materials Moisture Content Expressed in Per Cent of Dry Weight of the Substance at Various Relative Humidities--Temperature, 75 F Classi fication Material Description Relative Humidrrr--Per Cent Authority 10 20 30 40 50 60 70 80 90 Cotton * Sea island--roving 23 3.7 4.6 5.5 6.6 7.9 93 115 14.1 HafhilvnfiiA Cotton American-- cloth 2.6 3.7 4.4 S3 5.9 6.8 8.1 10.0 14.3 Schloering Cotton Absorbent 4.8 9.0 115 15.7 115 20.8 22.8 243 25.8 Fuwa Natural Textile Fibres Wool Silk Tinpn . . Australian merino--skein 4.7 .7.0 8.9 10.8 12.8 14.9 17.2 19.9 23.4 Hartshorns Raw chevennea--skein 3.2 5.5 6.9 8.0 8.9 10.2 11.9 14-3 18.8 Schloesing Table cloth . 1.9 2.9 3.6 43 5.1 6.1 7.0 8.4. 10.2 Atkinson . linen Dry spun--yarn 3.6 5.4 6.5 73 8.1 8.9 9.8 11.2 13.8 Sommer Jute ' Average of several grades 3.1 5.2 &9 83 10.2 12.2 14.4 17.1 20.2 5torch Hemp " Manila and sisal--rope 2.7 4.7 6.0 7.2 83 9.9 11.6 13.6 15.7 Fuwa Rayons Viscose Nitrocellu lose Cupramonhun Average skein Cellulose Acetate Fibre . 4.0 5.7 6.8 7.9 9.2 10.8 114 14.2 16.0 Robertson 0.8 1.1 1.4 1.9 14 3.0 3.6 43 5.3 Robertson M. F. Newsprint Wood pulp--24% ash 2.1 3.2 4.0 4.7 5.3 6.1 7.2 8.7 10.6 O. 8. B. of S. H. M: F. Writing Wood pulp--3% ash 3.0 4.2 5.2 6.2 7.2 83 9.9 11.9 14.2 D. aB.ofS. Paper White Bond Com. Ledge Kraft Wrapping Rag--1% ash 75% rag--1% ash Coniferous . 2.4 3.7 4.7 5.5 6.5 73 8.8 10.8 13.2 D.&B.ofS. 3.2 4.2 5.0 5.6 6.2 6.9 8.1 10.3 13.9 u. a B. of S. 3.2 4.6 5.7 6.6 7.6 8.9 10.5 116 14.9 u. a b. of a Leather . Sole oak--tanned . 5.0 8.5 11.2 13.6 16.0 18.3 20.6 24.0 29.2 Phelps Catgut Racquet strings 4.6 7.2 8.6 10.2 12.0 14.3 17.3 19.8 21.7 Fuwa Ghie Mine. Organic Rubber Materials Wood Hide SoEd tire Timber (average) 3.4 4.8 5.8 6.6 7.6 9.0 10.7 11.8 123 Fuwa 0.11 0.21 0.32 0.44 0.54 0.66 0.76 038 0.99 Fuwa 3.0 4.4 5.9 7.6 9.3 1U 14.0 17.5 22.0 Forest P. Lab. Soap White 1.9 3.8 5.7 7.6 10.0 119 16.1 19.8 23.8 Fuwa Tobacco Cigarette 5.4 8l6 11.0 133 16.0 19.5 25.0 33.5 50.0 Ford White Bread . - 03 1.7 3.1 43- 6.2 83 11.1 14.5 19.0 Atkinson Crackers ' 2.1 2.8 3.3 3.9 5.0 6.5 83 10.9 14.9 Atkinson Food stuffs Macaroni Flour 5.1 7.4 8.8 10.2 11.7 13.7 16.2 19.0 22.1 Atkinson . 2.6 4.1 5.3 63 8.0 9.9 114 15.4 19.1 Bailey Starch 2.2 3.8 5.2 6.4 7.4 8.3 9.2 10.6 12.7 Atkinson Gelatin .. 0.7 1.6 2.8 3.8 4.9 .6.1 7.6 9.3 11.4 Atkinson Asbestos Fibre Finely divided 0.16 0.24 0.26 0.32 0.41 0.51 0.62 0.73 0.84 Fuwa Silica Gel - Mlsc. Inorganic' Domestic Coke Materials Activated Charcoal Steam activated 5.7 9.8 12.7 15.2 17.2 18.8 20.2 21.5 22.6 Fuwa 0.20 0.40 0.61 0.81 1.03 1.24 1.46 1.67 139 Selvig 7.1 14J 22.8 26.2 28.3 29.2 30.0 31.1 32.7 Fuwa Sulphuric Arid ff*S04 33.0 41.0 17.5 52.5 57.0 61.5 67.0 73.5 82.5 Mason 626 y. Chapter 33. Industrial Air Conditioning Table 2 shows the regain or hygroscopic moisture content of several organic and inorganic materials when in equilibrium at a dry-bulb tem perature of 75 F and various relative humidities. The effect of relative humidity on regain of hygroscopic substances is clearly indicated. The effect of temperature is comparatively unimportant. In the case of cotton, for instance, an increase in temperature of 10 deg has the same effect on regain as a decrease in relative humidity of one per cent. Changes in temperature do, however, affect the rate of absorption or drying. Sudden changes in temperature cause temporary fluctuations in regain even when the relative humidity remains stationary. The regain or moisture content affects the physical properties of textiles to a marked degree, changing the strength, pliability and elasticity. The fact that the regain of textiles will come into equilibrium with the conditions of the surrounding air and' vary with its temperature and relative humidity is the fundamental basis for the control of physical qualities during manufacture. During the preparation processes in a cotton mill, the cotton fibers should be in a condition to be easily carded. These preliminary processes are carried out best in a relative humidity of 50 to 55 per cent. As the cotton fiber comes to the spinning operation, more flexibility is needed and the relative humidity is increased in this department. For many years, 65 per cent relative humidity was con sidered the optimum. To offset the extra work performed on the fiber as the spindle speed is increased, many cotton mills now carry 70 per cent relative humidity in the spinning rooms.1 Winding, warping and weaving are all processes calling for great flexibility and a consequent need for higher humidity. Other textile fibers, due to their different natural characteristics, are processed under relative humidities and temperatures applicable to each. Rayons, on account of great loss of strength with the higher regains, should be processed in a relative humidity of 57 per cent. Acetate silk, another chemical fiber, with approximately 50 per cent of the regain of rayon, may be processed between 60 and 65 per cent relative humidity. All hygroscopic materials release sensible'heat equivalent to the latent heat of the moisture absorbed by the material, all of which may account for a large percentage of the total heat load. . CONDITIONING AND DRYING In gerteral, the exposure of materials to desirable conditions for treat ment may be coincidental with the manufacture or processing of the materials, or they may be treated separately in special enclosures. This latter treatment may be classified as conditioning or drying. The purpose of conditioning or drying is usually to establish a desired condition of moisture content and to regulate the physical properties of the material. When the final moisture content is lower than the initial one, the term drying is applied. If the final moisture content is to be higher, the process is termed conditioning. In the case of some textile products and tobacco, *The Present Status of Textile Regain 'Data, by A. E. Stacey, Jr. (National Association of Cotton Manufacturers, 1927). . .... .` 627 Heating Ventilating Air Conditioning Guide 1938 for example, drying and conditioning may be combined in one process for the dual purpose of removing undesirable moisture and accurately regu lating the final moisture content. Either conditioning or drying are frequently made continuous processes in which the material is conveyed through an elongated compartment by suitable means and subjected to controlled atmospheric conditions. CONTROL OF RATE OF CHEMICAL REACTION A typical example of the second general classification, that is, the control of the rate of. chemical reactions, occurs in the manufacture of rayon. The pulp sheets are conditioned, cut to size, and passed through a mercerizing process. . It is essential that during this process close con trol of both temperature and relative humidity should be maintained. Temperature controls the rate of reaction directly, while the relative humidity maintains a constant rate of evaporation from the surface of the solution and gives a solution of known strength throughout the mercerizing period. . Another well-known example of this class is the drying of varnish which is an oxidizing process dependent upon temperature. High relative humidities have a retarding action on the rate of oxidization at the surface and allow the gases to escape as the chemical oxidizers cure the varnish film from the bottom. This produces a surface free from bubbles and a film homogeneous throughout. . Desirable temperatures for drying varnish vary with the quality. A relative humidity of 65 per cent is beneficial for obtaining the best processing results.- . . . - . CONTROL OF RATE OF BIOCHEMICAL REACTIONS In. the field of biochemical control, industrial air conditioning has been applied to many different and well-known products. All problems involving fermentation are classed under this heading. As biochemistry is a subdivision of chemistry, subject to the same laws, the rate of reaction may be controlled by temperature. An example of this is the dough room of the modern bakery. Yeast develops best at a temperature of 80 F. A relative humidity of 65 per cent is maintained so as to hold the surface of the dough open to allow the COi gases formed by the fermentation to pass through and produce a loaf of bread, when baked, of even, fine texture without large voids: Another example of' a similar process is found in the curing of maca roni. The flour aind water mixture is fermented and dried; As it is necessary to have a definite amount of water present to carry on a fer mentation process, the moisture must be removed in a relatively short period to stop fermentation and prevent souring and in such a manner as to avoid setting up internal strains in the mixture. Best results are obtained with the correct cycles of both temperature and humidity.- The curing of fruits, siich as bananas and lemons, also come under this classification. Bananas are treated somewhat differently and to accom plish the required results, a cycle of temperatures and relative humidities is used. The starches in the pulp of the fruit must be changed and the 628 Chapter 33. Industrial Air Conditioning skin cured and colored, after which the fruit is cooled to maintain as slow a rate of metabolism as possible. Ideal conditions range between 55 to 57 F and in no case should the temperature go below 49 F, as the starches then become fixed and are indigestible. The curing of lemons is an entirely different problem. Bananas are cured for a quick market, while lemons are held for a future market. The process, therefore, varies in the temperature used. Temperatures from 54 to 59 F have been found to be best suited for this process. A high relative humidity of 88 to 90 per cent is necessary to hold shrinkage to a minimum and, at the same time, develop the rind so it will be sufficiently tough to permit handling. Tobacco from the field to the finished cigar, cigarette, plug or pipe tobacco, offers another interesting example of what may be done by industrial air conditioning in the control of color, texture and flavor. In the processing of tobacco, the first three classifications of air con ditioning are involved, and only through close atmospheric control can the best quality of the.leaf be developed. CONTROL RATE OF CRYSTALLIZATION The rate of cooling of a saturated solution determines the size of the crystals formed. Both temperature and relative humidity are of im portance, as the one controls the rate of cooling, while the other, through evaporation, changes the density of the solution. - . In the coating pans for pills, gum and nuts, a heavy sugar solution is added to the tumbling mass. As the water evaporates, each separate piece is covered with crystals of sugar. A smooth, opaque coating is only accomplished by blowing into the kettle the proper amount of air at the right temperature and relative humidity. If the cooling and drying is too slow, the coating will be rough and semi-translucent, and tie ap pearance unsightly; if too fast, the coating will chip through to the interior. Only by balancing temperature, relative humidity, and volume of air to the sugar solution, can tie proper rate be obtained and a perfect coating assured. The foregoing is presented as typical of a few of the problems met with in applying air conditioning to various industrial processes. They are far from complete but with the help of a few natural laws may assist in solving others where similar basic principles are involved. CALCULATIONS The methods for determining the proper heating and cooling loads for the various industrial processes are similar to those outlined in Chapters 7 and 8. Because of the large number of motors and heat processing units usually prevalent in an industrial application, it is particularly important that operating allowances for the latent and sensible heat loads be' definitely ascertained and used in the calculations to determine the total equivalent design load. 629' r Heating Ventilating Air Conditioning Guide 1938 REFERENCES Effect of Air Conditioning upon Munitions, by J. I. Lyle (A.S.H.V.E. Transactions, Vol. 23, 1917, p. 383). Air Conditioning for Sausage Manufacturing Plants, by M. G. Harbuia (A.S.H.V.E. Transactions, Vol. 28, 1922, p. 343). Air Conditioning and Refrigerating Large Bakeries, by W. L. Fleisher {Heating, Piping and' Air Conditioning, December, 1929, p. 621; January, 1930, p. 24). ' Air Conditioning for Textile Plants Making and Using Synthetic Yarns, by L. L. Lewis {Rayon Textile Monthly, July, August, September, 1930). . Air Conditioning in the Bakery, by W. L. Fleisher {Heating, Piping and Air Con ditioning, February, 1931, p. 158). Air Conditioning in Industrial Processes (Match Factory), by W. L. Fleisher {Heating, Piping and Air Conditioning, March, 1931, p. 196). Air Conditioning of Press Rooms, by I. C. Baker {Heating, Piping and Air Con ditioning, July, 1931, p. 553). . Pre-Cooling Fruits and Vegetables with Circulating Air, by C. E. Baker {Heating, Piping and Air Conditioning, January, 1932, p. 42). Air Conditioning Maintains Quality of Fruits and Vegetables, by C. E. Baker {Heat ing, Piping and Air Conditioning, August, 1935, p. 369). Air Condition the Bakery Throughout, by W. W. Reece {Heating, Piping and Air Conditioning, August, 1936, p. 149). . Air Conditioning as Applied in Theatres and Film Laboratories, by D. C. Lindsay {Transactions Society of Motion Picture Engineers, April, 1927, Vol. XI, No. 30, p. 335 365). . Air Conditioning Requirements of Multicolor Offset Printing, by C. G. Weber (Refrigerating Engineering, December, 1936, p. 6). Banana Ripening Manual, Circular No. 14, Equipment Department, Fruit Dispatch Co., New York, N. Y. The Commercial Storage of Fruits, Vegetables and Florists' Stocks, by D. H. Rose, R. C. .Wright and T. M. Whiteman {U. 5. Department of Agriculture, Circular No. 278). ; Reactions of Lithographic Papers to Variations in Humidity and Temperature, by C. G. Weber and L. W. Snyder (7. 5. Bureau Standards Journal Research, January, 1934) Relation of Air Conditions to Tobacco Curing, by J. Johnson and W. B. Ogden {Wisconsin Agricultural Research Bureau 110: 1-48, 1931). Temperature Studies of Some Tomato Pathogens, by Alice A. Nightingale and G. W. Ramsey {U. S. Department of Agriculture Technical Bulletin No. 520, August, 1936). The Treatment of Offset Papers for Optimum Register, by C. G. Weber and M. N. V. Geib {U. S. Bureau Standards Journal Research, February, 1936). Summary Report of National Bureau of Standards Research on Preservation of Records, by A. E. Kimberly and B. W. Scribner {U. S. Bureau of Standards Miscel laneous Publication, 154, March 16, 1937). PROBLEMS IN PRACTICE . 1 Why is air conditioning required for some industrial processes? To control the physical properties of the materials being processed. Example. In the manufacture of chewing gum, it is rolled into slabs and scored. The scored slab must then be broken at the score marks to form the sticks. If the slab is too warm, breaking is impossible, if the slab is too cold or too dry, it becomes brittle and shatters, thereby producing much material to be reworked. . 630 Chapter 33. Industrial Air Conditioning 2 Why is it necessary to control the physical properties of the material being processed? >., To permit permanent adjustment of machinery. ' Example. In the manufacture of cigarettes, the amount of tobacco fed upon the piaper tape is determined by pressure against springs. When the tobacco is over-moist and, therefore, over-soft, a great excess will go into the finished cigarette; when the tobacco is too dry and, therefore, harsh, too little goes into'the finished cigarette. ft A condition of 75 F dry-bulb temperature and 55 per cent relative humidity is being maintained in a cigarette manufacturing department. . What will be the regain and moisture codtent of the tobacco? ' "' ' The regain, from Table 2 = ' ' 17.75 per cent. ^The moisture conAten.t = 17.75 X 100 = 15.1 per cen.t. 10U ~r l/./O 4 A 1-lb sample taken from a 100-lb batch of material is found to have a bonedry weight of 0.89 lb. This material is to be processed under atmospheric conditions which should produce a regain of 15 per cent. Compute the finished weight for each original 100-lb batch. Let W equal the number of pounds of moisture in a finished batch. 8W9 = rega-in = 15 per ce- nt = 15 jqq . W - 13.35 89 + 13.35 -- 102.35 lb finished weight. 5 A bundle of sea island cotton is found to have a bone-dry weight of 9.26 lb. What is the proper relative humidity at 75 F to produce a weight of 10 lb at equilibrium? Desired conditioned weight = 10.00 lb Bone-dry weight = 9.26 lb Weight of moisture required = 0.74 1b . " Regain = X 100 = 7.9 per cent. From Table 2, the proper relative humidity required is 60 per cent. * 6 t Compute the bone-dry weight of 1000 lb of manila rope which has been stored for a considerable period of time in a conditioned room at 75 F dry-bulb temperature and 50 per cent relative humidity. Assuming that this material has come to equilibrium under the atmQspheric conditions given. Table 2 shows a regain of 8.5 per cent. Let W equal the total weight of moisture in pounds. 1000 -- W = bone-dry weight in pounds. W oc . 8.5 iooo -- w = regain =85 perceat = ido W = 78.3 lb moisture 1000 -- 78.3 = 921.7 lb bone-dry weight. . 7 An egg evaporating plant wishes to dry 2000 lb of egg whites (85 per cent water) to crystalline form each 24 hours. The maximum permissible air de livery temperature in the dryer-is 140 F. What air volume will be required, assuming that outside air is at 95 F dry-bulb and 78 F wet-bulb and that air leaves the dryer 70 per cent saturated? Moisture to be removed = 2000 X 0.85 = 1700 lb. Using psychrometric chart and starting at the intersection of the vertical 95 F dry-bulb temperature line and the 46 per 631 Heating Ventilating Air Conditioning Guide 1938 cent humidity line, move horizontally to the right to the intersection with the 140 F vertical temperature line at 13 per cent relative humidity; then move along the constant heat (or wet-bulb line) to its intersection with the 70 per cent relative humidity curve and read 97.5 F dry-bulb, which will be the temperature of the air leaving the dryer. Moisture per cubic foot at 97.5 F and 70 per cent relative humidity = 13.2 grains Moisture per cubic foot at 95 F and 78 F wet-bulb = 8.3 grains Moisture added per cubic foot of air handled 1700 X 7000 24 X 60 X 4.9 1685 cfm. 4.9 grains No allowance is made for heat lost in .the transmission to and from the dryer or for the heat required to raise the product from its entering temperature to that maintained in the dryer. This would necessitate a trial and error solution common to all drying problems. ,\ 632 Chapter 34 INDUSTRIAL EXHAUST SYSTEMS Classification of Systems, Design Procedure, Requirements for Suction and Velocity; Hoods, Design of Duct Systems, Col lectors, Resistance of Systems, Efficiency of Exhaust Systems, Selection of Fans and Motors, Corrosion IN almost every industry some type of exhaust or collecting system is essential to achieve efficient and economical control of dusts and fumes. General design information is included in this chapter which is intended to relate primarily to factory exhaust systems. CLASSIFICATION OF SYSTEMS There are two general arrangements, the central and the group systems. In the central system a single or double fan is located near the center of the shop with a piping system radiating to the various machines to be served. In the group system, which is sometimes employed where the machines to be served are widely scattered, small individual exhaust fans are located at the center of the machine groups. The group arrangement has the advantage of flexibility. Exhaust systems are also classified by the means employed to collect dust or other material handled. The dust or refuse may be collected and controlled by enclosing hoods, open hoods, inward air leakage, or by exhausting the general air of the room. With some classes of machinery it is not feasible to closely hood the machines and in these cases open hoods over or adjacent to the machines are provided to collect as much as possible of the dust and fumes. This class includes such machines as rubber mills, package filling machinery, sand blast, crushers, forges, pickling tanks, melting furnaces, and the unloading points of various types of conveyors. The open hoods should be placed as close to the source of dust or fumes as possible, with due regard to the movements of the operator. When the hood must be placed at some distance above the machine it should be large enough to encompass an area of considerable extent as diffusion is usually quite rapid. Consideration must also be given to the natural movement of the fumes.. For those that are lighter than air the hood should be over or above the machine and where a heavy vapor or dust-laden air at ordinary temperature is to be removed, horizontal or floor connections are required. If it is attempted to remove heavy dust such as lead oxides by an over head hood the conditions may be worse than if no exhaust were used at all, owing to the rising air current carrying the dust up through, the 633 ' Heating Ventilating Air Conditioning Guide 1938 breathing zones. The objective to keep in mind in all cases is to take advantage of the natural tendency of the material to move upward or downward. In another class of operation the main objective is to prevent the escape of dust into the surrounding atmosphere, the removal of some dust from the machine or enclosure being merely incidental. The dust-creating apparatus is enclosed within a housing which is made as tight as prac ticable, and sufficient suction is applied to the enclosure to.maintain an inward air leakage, thus preventing escape of the dust. While the exhaust system is required to handle only the air which leaks in through the crevices and openings in the enclosure, yet in many installations leakages are very high and great care is required to obtain satisfactory results with a system of this kind. The inward-leakage principle is utilized for controlling dust in the operating of tumbling barrels, grinding, screening, elevating, and similar processes. .. . Certain dust and fume producing operations are best carried on by isolating the process in a separate compartment or room and then apply ing general ventilation to this space. The compartment or room in which the work is performed should be as small as is consistent with convenience in handling the work. The ventilating system should be designed so that a strong current of clean air is drawn across the operator, and away from him toward the work, where the dust is picked up and carried from the room. DESIGN PROCEDURE The first step in the design of an exhaust system is to determine the number and size of the hoods and their connections. No general rules, however, can be given since hood and duct dimensions are determined by the characteristics of the operations to which they are applied. When a tentative decision regarding the set-up has been made, it is then necessary to obtain the suction and air velocities required to effect control. At this point the designer must rely upon the prevailing practice and on such physical data relating to hoods, duct systems and collectors as are avail able. Finally, in choosing the fan, the area of the intake, should be equal to or greater than the sum of the areas of the branch ducts. The speed, of course, must be sufficient to maintain the estimated suction and air velocities in the system. In general, the most important requirements of an efficient exhaust and collecting system, are as follows1. ' 1. Hoods, ducts, fans and collectors should be of adequate size.: . . 2. The air velocities should be sufficient to control and convey the materials collected. 3. The hoods and ducts should not interfere with the operation of a machine or any working part. ..... 4. The system should do the required work with a minimum power consumption. 5. When inflammable dusts and fumes are conveyed, the piping should be provided with an automatic damper in passing through a fire-wall. 6. Ducts and all metal parts should be grounded to reduce the danger of dust ex plosions by static electricity. 7. The design of an exhaust system should afford easy access to parts for inspection and care. ' iFor more detailed requirements see Safe Practice Pamphlets Nos. 32 and 37, published by the National Safety Council. Chicago. ,- 634 .Chapter 34. Industrial Exhaust Systems REQUIREMENTS FOR SUCTION AND VELOCITY The removal of dust or waste by means of an exhaust hood requires a movement of air 'at the point of origin sufficient to carry it to a col lecting-system. The air velocities necessary to accomplish this depend upon the physical properties of the material to be eliminated and the Table 1. Size- of Connections foe Wood-Working Machinery Type op Machine Circular saws, 12-in. diam--------------------------- --------------Circular saws, 12-24-in. diam--------------------------- --------Circular saws, 24-40-in. diam-------------------------------------Band saws, blade under 2 in. wide.,----------------------------Band saws, blade 2-3 in. wide. Band saws, blade 3-4 in. wide-------------------------------------Band saws, blade 4-5 in. wide------------------------------------Band saws, blade 5-6 in. wide.------------------------------------Small mortisers----------------------------------'------------------------Single end tenoners----- -----------------------------------------------Double end tenoners-------------- ------------------------------------Double end, double head tenoners------ _..-------------------Planers, matchers, 'moulders, stickers, jointers, etc.-- With knives, 6-10 in With knives, 10-20 in________________________ ___ With knives, 20-30 in---- ----------------------------- ------Shapers, light work--------------- -------- -------------------:---------Shapers, heavy work...------------------ ---------------------------Belt sander, belt less than 6 in. wide....---------------- ------Belt sander, belt 6-10 in. wide. Belt sander, belt 10-14 in. wide.------------------ :--------------Drum sander, 24 in...-------------------------------------------------Drum sander, 30 in-------------- -------------------------------------Drum sander, 36 in Drum sander, 48 in____:_______________________________ Drum sander, over 48 in..... ................................................ Disc sander, 24 in. diam.__________________ .___________ Disc sander, 26-36 in. diam____ ____ __________________ Disc sander, 36-48 in. diam______ ...---------- '___________ Arm sander . Diameter of Connections in . , Inches . 4 5 6 4 5 6 7 8 6 6 7 10 5-6 6-8 6-10 4-5 8 5 6 7 5 6 7 8 10 5 6 7 4 direction and speed with which it is thrown off. If the dust to be removed is already in motion, as is the case with high-speed grinding wheels, the hood should be installed in the path of the particles so that a minimum air volume may be used effectively. It is always desirable to design and locate a hood so that the volume of air necessary to produce results is as small as possible. . The static suction at the throat of a hood is frequently used in practice, as a measure of the effectiveness of control. This is of considerable value where exhaust, systems adapted to particular operations have been standardized by practice. Tables 1 and 2 present the duct sizes usually ' employed for standard wood-working machinery and for grinding and buffing wheels. Static pressures which in practice have been found necessary to control and convey various materials, are given in Table 3. It must be remembered, however, that the suction is merely a rough . 635 X Heating Ventilating Air Conditioning Guide 1938 Table 2. Size of Connections for Grinding and Buffing Wheels Diameter of Wheels Grinding^ 6 in. or less, not over 1 in. thick. 7 in. to 9 in., inclusive, not over 114 in. thick--------- 10 in. to 16 in., " " " 2 in. u 17 in. to 19 in., ` " " 3 in. a 20 in. to 24 in., " " "4 in. a 25 in. to 30 in., " " ` 5 in. a Bulling-- 6 in. or less, not over 1 in. thick. -------- 7 in. to 12 in., inclusive, not over 1)4 in. thick___ 13 in. to 16 in., " " ` 2 in. 0 17 in. to 20 in., " " " 3 in. 0 - 21 in. to 27 in., " " " 4 in. 0 27 in. to 33 in., " " "5 in. 0 Max. Grinding Surface Sq In. 19 43 101 180 302 472 19 57 101 189 338 518 . Min. Diam. of Branch Pipes in Inches 3 . 3H 4 4H 5 6 3H 4 5 6 7 measure of the air volume handled and consequently of the air velocity at the opening of the hood. The elimination of any dusty condition requires added information concerning the shape, size and location of the hood used with regard to the operation in question. In some states grinding, polishing and buffing wheels are subject to regulation by codes. The static suction requirements, which range from lp2 to 5 in. water displacement in a 17-tube, should be followed although in several instances they may appear to be excessive. Frequently, in these operations, a large part of the wheel must be exposed and the_dust laden air within the hood is thrown outward by the centrifugal action of the wheel, thus counteracting useful inward draft. This tendency may be diminished by locating the connecting duct so as to create an air flow of not less than 200 fpm about the lower rim of the wheel. Exact determinations of hood control velocities are not available, but it is safe to assume that for most dusty operations they should not be less Table 3. Suction Pressures Required at Hoods ' Ttpe or Installation ` \ Static Suction in Inches op Water Exhausting from pottery processes-----------------------1........ .............................. Fur and felt machinery exhaust......................................................................... 636 134-5 2 '2 2-4 2-3 2 2 2 2-4 2-3 2-3 2 3-5 Chapter 34. Industrial Exhaust Systems than 200 fpm at the point of origin. For granite dust generated by pneumatic devices, Hatch et al2 give velocities from 150 to 200 fpm, depending on the type of hood used, as sufficient for safe control. Con sidering the character of the industry, air velocities of this order may be extended to similar dusty operations. The method for approximately determining these velocities in terms of the velocity at the hood opening is given below. . HOODS No set rule can be given regarding the shape of a hood for a particular . operation, but it is well to remember that its essential function is to create an adequate velocity distribution. The fact that the zone of greatest effectiveness does not extend laterally from the edges of the opening may frequently be utilized in estimating the size of hood required. Where complete enclosure of a dusty operation is contemplated, it is desirable to leave enough free space to equal the area of the connecting duct. Hoods for grinding, polishing and buffing should fit closely, but at the same time should provide an easy means for changing the wheels. It is advisable to design these hoods with a removable hopper at the base to capture the heavy dusts and articles dropped by the operator. Such provisions are of assistance in keeping the ducts clear. Air volumes used to control many dust discharges may often be reduced by effective baffling or partial enclosure of an operation. This procedure is strongly urged where dusts are directed beyond the zone of influence of the hood. . Axial Velocity Formula for Hoods When the normal flow of air into a hood is unobstructed, the following formula may be used to determine the air velocity at any point along the axis3: V - 0-1 Q ** + 0.1 A (1) where V = velocity at point, feet per minute. A = area of opening, square feet. * = distance along axis, feet. Q = volume of air handled, cubic feet per minute. . . . Velocity Contours It is possible by use of a specially constructed pitot-tube4 to map contours of equal velocity in any axial plane located in the field of in fluence. It has been found that the positions of these contours for any hood can be expressed as percentages of the velocity at the hood opening and are purely functions of the shape of the hood6. _ ^Control of the Silicosis Hazard in the Hard Rock Industries. I. A Laboratory Study of the Design of Dust Control Systems for Use with Pneumatic Granite Cutting Tools, by Theodore Hatch. Philip Drinker and Sarah P. Choate. (Journal of Industrial Hygiene, Vol. XII. No. 3. March. 1930). 1933)^e ^'on^ro^ Industrial Dust, by J. M. DallaValle (Mechanical Engineering, Vol. 55, No. 10. October `Studies in the Design of Local Exhaust Hoods, by J. M. DallaValle and Theodore Hatch (A.S.M.E. Transactions, Vol. 54, 1932). . .. .. . Vo]>V^<l932C^a387)riStiCS f Hoods under Suction- J- M. DallaValle (A.S.H.V.E. Transactions, 637 Heating Ventilating Air Conditioning Guide 1938 Further, the velocity contours are identical for similar hood shapes when the hoods are reduced to the same basis of comparison. These facts are applicable to all hood problems so that when the velocity contour distribution is known, the air flow required can be determined.. Fig. 1 shows the contour distribution in two axial planes perpendicular to the sides of a rectangular hood with a side ratio of one-half. The distribu tion shown is identical for all openings with a similar side ratio provided the mapping is as shown in the figure. The contours, of course, are expressed as percentages of the velocity at the opening. Fig. 1. Velocity Contours for a Rectangular Opening with a Side Ratio of One-Half. Contours are Expressed as Percentages of the Velocity at the Opening . Air Flow from Static Readings The volume of air flow through any hood may be determined from the following equation: . Q = 4005 f A V~ht (2) where ' Q -- volume of air flow, cubic feet per minute. A area of connecting duct, square feet. ht = static suction at throat of hood, inches of water. / = orifice or restriction coefficient which varies from 0.6 to 0.9 depending on the shape of the hood. - 638 Chapter 34. Industrial Exhaust Systems An average value of/is 0.71, although for a well-shaped opening a value of 0.8 may be.used. The factor/is determined from the equation: where b, is the velocity head in the connecting duct. The term static suction is not a good measure of the effectiveness of a hood unless the area of the opening and the location of the operation with respect to the hood are known. This is clearly indicated by Equation 1 which shows that the velocity at any point along the axis varies inversely as the area of the opening and the square of the distance. However, this formula coupled with Equation 2 should serve to indicate the velocity conditions to be expected when operations are conducted external to the hood opening. ' Large Open Hoods ... . Large hoods, such as are used for electroplating and pickling tanks, should be subdivided so the area of the connecting duct is not less than one-fifteenth of the open area of the hood. Frequently, it will be found necessary to branch the main duct in order to obtain a uniform distri bution of flow. Canopy hoods should extend 6 in. laterally from the tank for every 12-in. elevation, and wherever possible they should have side and rear aprons so as to prevent short circuiting of air- from spaces not directly over the vats or tanks. In most cases, hoods of this type take advantage of the natural tendency of the vapors to rise, and air velocities may be kept low. Cross drafts from open doors or windows disturb the rise of the vapors and therefore provision must be made for them. The air velocities required also depend upon the character of the vapors given off, cyanide fumes, for example, requiring an air velocity of approxi mately 75 fpm on the surface of- the tank and. acid and steam vapors requiring velocities as low as 25 to 50 fpm. The total volume of air flow necessary to obtain these velocities may be approximately determined from the following simple formula: where Q = 1.4PDV (4) .... Q = total volume of air handled by hood, cubic feet per minute.. ' P -- perimeter of the tank, feet. . . ' D -- distance between tank and hood opening, feet. V = air velocity desired along edges and surface of tank, feet per minute. . Lateral Exhaust Systems The lateral exhaust method, as developed. for chromium plating, is applicable in many instances in preference to the canopy type hoods. The method makes use of drawing air and fumes laterally across the top of vats or tanks into slotted ducts at the top and extending fully along one or more sides of the tanks. The slots are 2 in. wide and for effective `Health Hazards in Chromium Plating, by J. J. Bloomfield and Wm. Blum ((/. S. Public Health Report, Vol. 43, No. 26, September 7, 1928). .' .` 639 Heating Ventilating Air Conditioning Guide 1938 ventilation a 2,000 fpm exhaust air velocity at the slot face is advisable. In addition, the duct should not be required to draw the air laterally for a distance of more than 18 in. and the level of the solution should be kept 6 to 8 in. below the top of the tanks. - Flexible Exhaust Systems The flexible exhaust tube method may be advantageously used for removing dust or fumes. Flexible tubes having one end connected to an exhaust system and a slotted hood attached to the other end may be shaped at will to fit in with industrial processes without affecting the ease of operation. Efficient dust or fume removal may be had with use of relatively small exhaust volumes. This type of system may be used on swing grinders, portable grinding wheels, soldering operations, stone .cutting, rock drilling, etc. Spray Booths In the design of an efficient spray booth, it is essential to maintain an even distribution of air flow through the opening and about the object being sprayed. While in many instances spraying operations can be performed mechanically in wholly enclosed booths, the volatile vapors may reach injurious or explosive concentrations. At all times the con centrations of these vapors,' and particularly those containing benzol, should be kept below 100 parts per million. Spray booth vapors are dangerous to the health of the worker and care should be taken to mini mize exposure to them. . It is recommended in the design of spray booths that the exhaust duct be located in a horizontal position slightly below the object sprayed. Stagnant regions within the booth should be carefully avoided or should be provided with exhaust. The air volume should be sufficient to main tain a velocity of 150 to 200 fpm over the open area of the booth, and the vapors may be discharged through a suitable stack to permit dilution, but it is better practice to pass the fumes or vapors through baffle type washers or scrubbers designed for efficient spray fume removal7. Hoods for Chemical Laboratories . Hoods used in chemical laboratories are generally provided with sliding windows which permit positive control of the fumes and vapors evolved by the apparatus. Their design should offer easy access for the installation of chemical equipment and should be well lighted. Air velocities should exceed 50 fpm when the window is opened to its, maxi mum height. - DUCT SYSTEM DESIGN The duct system should be large enough to transport the fumes or material without causing serious obstruction to the air flow. It is good practice to proportion the ducts to obtain , the desired velocities and suction pressures at the hoods, although in many cases only an approxi mation to an ideal design is possible. Many exhaust hoods, and par- 'For a discussion of spray booths, see Special Bulletin No. 16, Spray Painting in Pennsylvania, Depart ment of Labor and Industry, 1926, Harrisburg, Pa. " 640 Chapter 34. Industrial Exhaust Systems ticularly those used in buffing and polishing, are connected by short branch pipes to the main duct which renders proportioning impractical. Construction The ducts leading from the hoods to the exhaust fan should be con structed of sheet metal not lighter than is shown in Table 4. The piping should be free from dents, fins and projections on which refuse might catch. . All permanent circular joints should be lap-jointed, riveted and sol dered, and all longitudinal joints either grooved and locked or riveted and soldered. Circular laps should be in the direction of the flow, and piping installed out-of-doors should not have the longitudinal laps at the bottom. Every change in pipe size should be made with an eccentric taper flat on the bottom, the taper to be at least 5 in. long for each inch change in diameter. All pipes passing through roofs should be equipped with collars so arranged as to prevent water leaking into the building. The main trunks and branch pipes should be as short and straight as possible, strongly supported, and with the dead ends capped to permit inspection and cleaning. All branch pipes should join the main at an Table 4. Gage of Sheet Metal to be Used for Various Duct Diameters . '. DLAMETER of I>UCT . Gagb or Metal 9 to 18 in._ . .............. 19 to 25 In.. ............... .................................................... 26 in. or more.......... ................... 24 22 20 .18 acute angle, the junction being at the side or top and never at the bottom of the main. Branch pipes should not join the main pipes at points where the material from one branch would tend to enter the branch on the opposite side of the main. . Cleanout openings having suitable covers should be placed in the main and branch pipes so that every part of the system can be easily reached in case the system clogs. Either a large cleanout door should be placed in the main suction pipe near the fan inlet, or a detachable section of pipe, held in place by lug bands, may be provided. Elbows should be made at least two gages heavier than straight pipe of the same diameter, the better to enable them to withstand the addi tional wear caused by changing the direction of flow. They should pref erably have a throat radius of at least one and one-half times the diameter of the pipe. Every pipe should be kept open arid unobstructed throughout its entire length, and no fixed screen should be placed in it, although the use of a trap at the junction of the hood and branch pipe is permissible, provided it is not allowed to fill up completely. The passing of pipes through fire-walls should be avoided wherever possible, and sweep-up connections should be so arranged that foreign material cannot be easily introduced into them. 641 Heating Ventilating Air Conditioning Guide 1938 Table 5. Air Speeds in Ducts Necessary to Convey Various Materials Material . Air Velocities (mi) 2000 3000 2000 2000 2000 1500 ` 2200 5000 4000 4000 At the point of entrance of a branch pipe with the main duct, there should be an increase in the latter equal to their sum. Some state codes specify that the combined area be increased by 25 per cent. While this is not always necessary and is frequently done at the expense of a reduced air velocity, it is none the less advisable where future expansion of the exhaust system is contemplated. Air Velocities in Ducts . When the static suction has been fixed for a given hood, the air velocity in the duct may be determined from Equation 2. Air velocities for conveying a material should be moderate. Table 5 gives the velocities generally employed for conveying various substances. Equations 5a and 5b may be used as tests to determine the conveying efficiency of a system8. Velocities determined from these formulae should be increased by at least 25 per cent since they represent the minimum at which a stated size and density of material can be transported. . . - For vertical ducts: . V = 13,300 --f-r <f>- (5a) For horizontal ducts: _ where V = 6000 --f-p d" . r+1 (Sb) V = air velocity in duct, feet per minute. \ s -- specific gravity of particles. . i = average diameter of largest particles conveyed, inches. . Examples. Granular material, the largest size of which is approximately 0.37 in.in diameter, with a specific gravity of 1.40 is to be conveyed in a vertical pipe the velocity, of the air in which is 4100 fpm; find whether the material can be transported at this velocity. Substitute data in Equation 5a and multiply by 1.25: - V = 1.25 X 13,300 X ^ X 0.370-" Antilog (0.57 X log 0.37) = 0.568; the required velocity is, therefore, 5500 fpm.. 'Determining Minimum Air Velocities for Exhaust Systems, by J. M. DallaVaUe (A.S.H.V.E. Journal Section. Heating, Piping and Air Conditioning, September, 1932, p. 639). 642 1 Chapter 34. Industrial Exhaust Systems Table 6. Loss Through 90-Dbg Elbows Elbow Center Line Radius in Per Cent or Pipe Diameter 50 . 100 150 200 to 300 . Loss in Per Cent or Velocitt Bead 75 26 17 14 Hence, the duct velocity must be increased either by speeding up the fan or decreasing the diameter of the duct, or both. . Duct Resistance The resistance to flow in any galvanized duct riveted and soldered at the joints may be obtained from Fig. 3, Chapter 29. The pressure drop through elbows depends upon the radius of the bend. For elbows whose centerline radii vary from 50 to 300 per cent of pipe diameter, the loss may be estimated from Table 6. It is sometimes convenient to express the resistance of an elbow in terms of an equivalent length of duct of the same diameter. Thus with a throat radius equal to the pipe diameter the resistance is equivalent to a section of straight pipe approximately 10 diameters long, while with a throat diameter radius 1J^ times the dia meter, the resistance is about the same as that of seven diameters of straight pipe. COLLECTORS The most common method of separating the dust and . other materials from the air is to pass the mixture through a centrifugal or cyclone collector. In this type of collector the mixture of the air' and material is introduced on a tangent, near the cylindrical top of the collector., and the whirling motion sets up a centrifugal action causing the compara- tively heavy materials suspended in the air to be thrown against the side of the separator, from which position they spiral down to the tail piece, while the air escapes through the stack at the center of the collector. The diameter of the cyclone should be at least 3j^ times the diameter of the fan discharge duct. When two or more separate. ducts enter a cyclone, gates should be provided to prevent any back draft through a system which may not be operating. Cyclones working in conjunction with two or more fans should be designed to operate efficiently at twothirds capacity rating. The following formula is useful in computing the loss through a cyclone when the velocity of the air in the fan discharge duct is known: *-(*) <6> ; ______ __ ------ B where . he = the pressure drop through the cyclone, inches of water. V = the air velocity in the fan discharge duct, feet per minute. If a cyclone is used to collect light dusts such as buffing wheel dusts; 643 X Heating Ventilating Air Conditioning Guide 1938 feathers and lint, the exhaust vent should be large enough to permit an air velocity of 200 to 500 fpm. This will, of course, require a cyclone of larger dimensions than given for the foregoing general case. When a high collection efficiency is desired, or the material is very fine, multicyclones may be used. These are merely small cyclones arranged in parallel which utilize the principle of high centrifugal velocity to attain separation. The capacities and characteristics of this type of separator should be obtained from the manufacturers. Cloth Filters Filters are used when the material collected by an exhaust system is valuable or cannot be separated efficiently from the air with an ordinary cyclone. They are also employed when it is desirable to recirculate the air drawn from a room by the exhaust system, which otherwise might entail considerable loss in heat. Bag filters which are properly housed may be operated under suction. Bag houses used in the manufacture of zinc oxide and other chemical products are operated on the positive side of the fan. Wool, cotton' and asbestos cloths are commonly used as filtering mediums. When woolen cloths are employed, the filtering capacities vary from 34 to 10 cfm per square foot of filtering surface, depending on the character of the material collected. The rates for cotton and asbestos cloths are lower. The type of filter cloth and the rates of filtration depend, of course, on the material to be collected and the fan capacity. The time increase of resistance varies with the amount of material per mitted to build up on the surface of the filter and can be determined only by experiment. The limits of the increase may be regulated by adjust ment of the shaking or cleaning mechanism. These limits may be regulated further according to the capacity of the fan and the effective performance of the hoods and the duct system. For additional information on Dust and Cinders, see Chapter 26, Air Cleaning Devices. RESISTANCE OF SYSTEM The maintained resistance of the exhaust system is composed of three factors: (1) loss through the hoods, (2) collector drop, and (3) friction drop in the pipes. . .. The loss through the hoods is usually assumed to be equal to the suction maintained at the hoods. The collector drop in inches of water is given approximately by Equation 6, but where possible the resistance of the particular collector to be used should be ascertained from the manu facturer. Friction drop in the pipes must be computed for each section where there is a change in area or in velocity. Find the velocities in each section of pipe starting with the branch most remote from the fan. The friction drop for these sections can be determined by reference to Table 6. Total friction loss in the piping system is the friction drop in the most remote branch plus the drop in the various sections of the main, plus the drop in the discharge pipe.. . 644 Chapter 34. Industrial Exhaust Systems EFFICIENCY OF EXHAUST SYSTEMS The efficiency of an exhaust system depends upon its effectiveness in reducing the concentration of dusts, fumes, vapors and gases below the safe or threshold limits9. Too much emphasis cannot be placed on the necessity of testing exhaust systems frequently by determining the concentration of atmospheric con tamination at the worker's breathing level. Commonly accepted values of threshold limits for the usual gases and vapors are given in Table 7. SELECTION OF FANS AND MOTORS Manufacturers generally provide special fans for the collection of various industrial wastes. These are available for the collection of coal dust, wood shavings, wool, cotton and many other substances. For Table 7. Threshold Limits of Common Vapors and Gases* Substance Chlorine................................ Ozone.................................... Hydrogen chloride...... ...... Sulphur dioxide-- ............. Carbon monoxide.............. Hydrogen sulphide............ Benzene................................ Methanol........................... Carbon tetrachloride..___ Spec. Gray, op Gas ob Vapor (Air 1) 2.486 5.5 1.2678 2.2638 0.9671 1.190 2.73 1.1 5.3 Inflammable Limits .(%> non-inflamm. do do do 12.5-74 4.3-46 1.4-7.0 7.5-26.5 non-inflamm. Physiological Action irritant do do do asphyxiant do anesthetic do do Maximum Allowable Concentration (ppm) 0.35 0.80 10.0 10.0 100.0 85-130 ' 100.0 100.0 100.0 The Prevention of Occupational Diseases, by R. R. Sayers and J. M. DaliaValle (Mechanical Engi neering, Vol. 57, No. 4, April, 1935). . particular features concerning special fans, consult the Catalog Data Section of The Guide and manufacturers' data, When, substances having an abrasive character are conveyed, the fan blades and housing should be protected from wear. This may be accomplished by placing a collector on the negative side of the fan or by lining the housing and blades with rubber. If no future expansion of an exhaust system is contemplated, the fan motor should be chosen to provide the calculated air volume. Should, however, the exhaust system be required to handle more air in the future, the motor should be adequate for the maximum load anticipated. Further information regarding the choice of fans and motors is given in Chapters 27 and 38. PROTECTION AGAINST CORROSION The removal of gases and fumes in many chemical plants requires that metals used in the construction of the exhaust system be resistant to Criteria for Industrial Exhaust Systems, by J. J. Bloomfield (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 353). . 645 Heating Ventilating Air Conditioning Guide 1938 Table 8. Materials to be Used for the Protection of Exhaust Systems Against Corrosion3 Ttpb or Fume Conteted Protective Material to be Used ' Rubber lining or chrome-nickel alloys Aluminum coated iron, aluminum, high chrome-nickel alloys High chrome-nickel alloys Hydrochloric acid_________ Rubber lining, chrome-nickel alloys Nitrous gases_________ ____ Nickel-chrome alloys Condensed from data given by Chilton and Huey (Industrial and Engineering Chemistry, Vol. 24,1932). chemical corrosion. A list of the materials which may be used to resist the action of certain fumes is given in Table 8. Hoods and ducts when short, may frequently be constructed of wood and be quite effective. Rubberized paints are available and may be applied as protective coatings in handling such gases and fumes as chlorine and hydrochloric acid. PROBLEMS IN PRACTICE 1 What is the most common method of reducing total air volumes handled in cases employing large hoods over apparatus covering a large area? The use of the petticoats on large hoods which permits a comparatively high air velocity at the rim of the hood and controllably small velocities in the center. 2 Why is it not permissible to connect up emery wheels and buffing wheels to the same exhaust system? . Emery wheels and buffing wheels should be handled by separate systems because of the fire hazard, as it is possible for sparks from the emery wheels to ignite the lint and dust from the buffing wheels when both are carried through the same system. 3 A tank, 4 ft by 8 ft, contains a fluid which gives off injurious, vapors. A large hood is located 30 in. above the top of the tank and extends slightly over its edges. Assuming that a velocity of 60 fpm is required to adequately control the vapors near the edges of the tank, calculate the air flow, required. Using Equation 4, P = 2 X 4 + 2 X 8 = 24 ft; 0 = 30 in. = 2.5 ft; V = 60 fpm. Hence, Q = 1.4 X 24 X 2.5 X -60 = 5040 cfin. 4 Silica dust with a specific gravity of 2.65 is being conveyed in a duct system. The velocity measured in a vertical portion of the system is found to be 2700 fpm. What is the mHomnm diameter particle 'transported at this velocity? 2 65 '- Using Equation 5a, 2700 = 13,300 X X <?>" - - : from which d = (0.281k = 0.11 in. ' 5 . What special materials may be used to resist chemical corrosion .in a system exhausting gases and fumes? ' Various protective materials are available for exhaust systems depending largely upon the type of fumes conveyed. Nickel-chrome alloys, aluminum coated metals and rubber linings are extensively used. Also protective rubberized paints are available which may be applied for conveying chlorine and hydrochloric acid fumes. 646 ^ Chapter 35 DRYING SYSTEMS Drying Methods, Driers, Mechanism of Drying, Moisture, General Rules for Drying, Equipment, Humidity Chart, ' Combustion, Design, Estimating Methods DRYING, in its broader sense, refers to the removal of water, or other volatile liquid from either a gaseous, liquid, of solid material. In practice, the process of direct drying gaseous material is referred to generally as dehumidifying, or condensing, and in some cases chemicals are used in the adsorption or absorption of moisture. Drying a liquid is called evaporation or distillation. The common usage of the word drying refers to the removal of water or other liquid, such as a solvent, by evapo ration from a solid material. ' i When the solid to be dried contains large amounts of free water, the actual drying process is frequently preceded by the removal of part of the water by some mechanical means, such as filtration, settling, pressing or centrifuging.' Removal of as much water as possible by such methods is usually advisable, as the cost of these operations, per pound of water removed, is generally much less than by evaporation. DRYING METHODS Drying may be accomplished in any one or combination of the following methods: , , '. 1. Radiation. 2. Conduction, or direct contact. 3. Convection. ! - -' - '. * . Radiation , The source of heat for radiation may be either the sun, or heated surfaces. Sun drying is practiced where danger from rain is slight, and where sufficient time can be allowed. Where a strict adherence to a schedule is necessary, or where dusty atmosphere, is present, this method is not in favor. Fruits are often dried in the sun. Radiation from hot surfaces (heated by steam, electricity, or other means) furnishes generally, from one-third to one-half the total heat required for evaporation. Convection currents set up by these hot surfaces and the cooler materials carry the balance of the heat. Heating Ventilating Air Conditioning Guide 1938 Chapter 35. Drying Systems Conduction or Direct Contact Drying This method of drying is advantageous where the material can be flowed on to the drying surface and the dried material scraped off, or where the material to be dried can be handled in a sheet, and where there is no danger of subjecting the product to the full temperature of the heating medium. The source of heat for this method may be steam, electricity, hot oil or hot water. Convection The circulation of heated air or other gases about the material to be dried is generally termed convection drying. The convection may be either natural or forced. With forced circulation, the temperature of the T a b l e 1. D r ie r s fo r E v a p o r a t io n o f W a t e r Fig. 1. Relation Between Useful and Total Heat Supplied Fig. 2. Rate of Drying of Whiting Slab drier is more uniform and the rate of drying is much higher than with natural circulation. Where humidity is used, the control is much easier, and more accurate. The source of heat for a convection drier may be steam, electricity, hot water, oil-fired heater, gas-fired heater, or coal furnace. Where either oil, gas or coal is used, the type of heater may be direct or indirect; i.e., the products of combustion may be used (direct), or the circulated air may be heated through an interchanger (indirect). Where the direct type is used, there is naturally a higher thermal efficiency, but it can only be used where the odor, soot, or the chemical elements of the products of combustion do not affect the material being dried. When heat economy is an important consideration this method (Fig. 1) may be used, permitting a small amount of air to be circulated, if a sacrifice of accurate control of temperature and humidity can be justified. DRIERS The term adiabatic drier is applied to a drier in which all the heat is supplied by air externally heated. The temperature of the air in the 648 649 Heating Ventilating Air Conditioning Guide 1938 drier decreases as a transfer of heat to the material being dried takes place. Where part or all of the heat is supplied by steam coils or other means, within the drier itself, the drier is known as a constant temperature drier. Driers using little air for heating medium with a high temperature drop, are difficult to hold at uniform temperatures; the more air used, the easier it is to secure accurate control of temperature and humidity. Driers may be classified as shown in Table 1. ' ' MECHANISM OF DRYING : The modem theory-of drying may be summed up as follows: Assuming uniform velocity and distribution of air at a constant temperature and humidity over the surface to be dried, the drying cycle will be divided into two distinct stages: 1. Constant rate period. . 2. Falling rate period. ! The constant rate period occurs while the material being dried is still very wet, and continues as long as the water in the material comes to the surface so rapidly that the surface remains thoroughly wet, and evapora tion proceeds at a constant rate, precisely as from a free water surface. The material assumes a temperature corresponding to the wet-bulb temperature of the surrounding air, or slightly higher, due to radiation and conduction from dry surfaces adjoining the material. The constant rate period continues until a time when the moisture no longer comes to the surface as fast as it is evaporated. This point is called the critical moisture content. As the drying proceeds, a period of uniform falling rate is entered. During this period, the surface of the material is gradually drying out, and the rate of drying falls as the remaining wet surface decreases in area. This period is also known as unsaturated surface drying. ' ' As drying continues, the surface is completely dry and the water from the. interior evaporates and comes through the surface as vapor. As the plane of water recedes, the diffusion of the vapor becomes more difficult and hence the period is known as varying falling rate period, or sub-surface drying. " ; As drying progresses another point called equilibrium moisture content is'reached, where the vapor pressure of the moisture in the air, and the' vapor pressure of the moisture ;in the material are equal,' and drying1 ceases. The drying of a slab of whiting is shown in Fig. 2 and illustrates' the principles pointed out above. The factors affecting the variations of drying rates during the above periods are pointed out in Table-2. ' Omissions in the Cycle ... . Many solids, such as lumber, are so dry at the beginning of the drying operation that the constant rate period of-free surface evaporation, does not occur. Frequently the surface of the material is dry enough so that no surface drying can take place, in. which case only the final stage of sub surface drying is involved. In other instances, the critical moisture con tent of a wet solid.is sufficiently1low that sub-surface drying starts almost immediately.after the conclusion^ the constant.rate period. Thus the 650 . Chapcer 35. Drying Systems intermediate state of urisaturated surface drying does not occur and the drying is of the sub-surface type during practically the whole of the falling rate period. With other lands of material, particularly thin sheets, such as newsprint paper, sub-surface drying may occur at such a. low moisture content that it is not encountered in commercial work, the Table 2. Factors Influencing Drying Factor Temperature Drying Period . Constant Rate, Unsaturated Surface . Sab-Surface - Increase in temperature increases drying rate Increase in temperature in* creases drying rate, because with decreased viscosity, dif fusion increases Humidity Drying rate increases as humidity is decreased No effect until equilibrium con tent is reached; drying then ceases Air Velocity Drying rate varies approximately as the 0.6 power of the velocity No effect Air direction Drying rate increases the more nearly the air blows perpendicular to surface; for dead air film becomes thinner No effect Thickness of Material Drying rate is not affected by the Drying rate varies inversely as thickness the square of the thickness falling rate period being confined solely in practice, to unsatiirated surface drying. MOISTURE Moisture in the solid may be in either of two forms: .: . ' 1. Capillary or free. 2. Hygroscopic or chemically combined. . . Free moisture is contained in the capillary spaces between the particles or fibers of the materials. The loss of this moisture changes only the weight of the material. Chemically combined or hygroscopic moisture is intimately associated with the physical nature of the material and its removal changes both the physical characteristics as well as the chemical properties. The amount of hygroscopic moisture a material can contain is limited. This limit is called the fiber saturation point. When material is dried below this point, care must be exercised to avoid physical changes in the material, such as shrinkage, hardening, etc. All hygroscopic materials have definite equilibrium: moisture contents dependent; on temperature and humidity. Materials are frequently dried, to a -lower moisture content than those of equilibrium conditions in use, and.allowed to regain, the necessary moisture, after leaving the drier, to equalize the ' moisture in the material. Fig. 31 shows the equilibrium moisture content of wood. ' .... '.* 651 lU. S. Department of Agriculture Bulletin, No. 1136; 651 Heating Venturing Air Conditioning Guide 1938 Temperature GENERAL RULES FOR DRYING The highest temperature possible should be used because of faster drying and smaller requirements for ventilation. The amount of moisture that can be carried by a pound of air increases rapidly with rise in tem perature as shown in the humidity chart of Fig. 4. Too high a tempera ture may cause spoilage of materials; many materials calcine or change their chemical properties if heated too hot; gypsum and glauber salts lose some of the chemically combined water, fall apart, and change their chemical properties. Too high or rapid rise in temperatures in drying lumber or ceramics may create a liquid vapor tension within the material so high that the cells explode, causing permanent injury to the fiber. If too high a temperature is used on some chemicals, they begin to react RELATIVE HUMIDITY IN ATMOSPHERE, PER CENT Fig. 3. Relation of Equilibrium Moisture Content in Wood to the Relative Humidity of Surrounding Air . exothermally; a temperature rise and chemical action from within will burn the materials, e.g., bakelite products, gunpowder, etc. During the constant rate period of drying, the material heats only to the wet-bulb temperature of the surrounding air, consequently high temperatures will not injure the material in this stage. Humidity Moisture in the drying air may be very important. Many materials tend to case-harden, dry on the outside, forming a skin which retards the . moisture flow from the inside to the surface, or stops it completely; and so increases the drying time very much or causes a change of the physical properties of the material. It is often necessary to add humidity to the air in the initial stage of drying. Lumber case-hardens, cracks, and warps if the outside is dried too fast. Ceramics crack if not heated through before drying commences. Elastic materials warp while others crack if not evenly dried. Many paints case-harden if not dried under high . humidity. ' On the other hand, in the case of those materials whose physical or chemical properties require that they be dried at relatively low tem peratures high humidity tends to retard drying in the first stage and may even stop it altogether in the final stage. Where drying temperatures 652 Chapter 35. Drying Systems below 120 to 140 F are used the drying rate may be highly dependent on atmospheric humidity conditions. In such instances it is often desirable to dehumidify the air entering the drier during periods of high atmos pheric humidity; where a high degree of uniformity is required it is often possible to secure complete independence of atmospheric conditions by recirculating the air in a closed system which includes a suitable dehu midifier. For this purpose absorptive dehumidifying systems have the advantage of accomplishing the desired: reduction of humidity without appreciably elevating or lowering the dry-bulb temperature of the air; for this reason after-cooling is not required, and reheating is reduced to a minimum. Complete descriptions of such dehumidifying systems are given in Chapter 24 on Cooling and Dehumidification Methods. Air Circulation As noted under Mechanism of Drying, air velocity is more important in the first two stages of drying than in the last, and for this reason zone drying in continuous driers is frequently considered. It permits accurate regulation of temperature; humidity, and velocity in the different zones. High velocity results in more rapid drying, more even distribution of temperature and consequently more even drying in the first period. Too high a velocity may be detrimental because of excessive power needed for creating it, or because the material may blow away if it is light and fluffy. In the drying of paints, varnishes, arid enamels, high velocity or improper distribution of the air even with the use of filters, may cause dust already in the drier, to be blown against the material, ruining the finish. Table 3 presents data on drying of various materials. EQUIPMENT FOR DRYING Equipment for drying may be divided into the following classes: 1. Heat and humidity supply. 2. Methods of handling. 3. Ovens. The heat arid humidity supply for low temperature work up to 250 F is often steam; steam coils either in the oven or outside, heat the air used for drying. Circulation of heated oil is used to a limited extent, but the danger of leaks is serious, for if the oil is hotter than the flash point, a fire may start if the oil is released to the atmosphere. In many cases where steam is not available, direct or indirect fired heaters are used with gas or oil as fuel. Indirect heaters should be carefully selected from a standpoint of long life and efficiency. The heat exchange surface should be adequate in area and easily accessible for cleaning and removal. For extremely high temperatures, alloy surface may be used. With direct-fired equip ment care must be used in the selection of burners and sufficient com bustion space allowed to insure complete combustion of fuel. Humidity can be obtained in driers by the use of steam spray, humidifiers, or recirculation. Methods of handling of material have been indicated in Table 1. For low temperature work up to 200 F ovens and driers are commonly built of two thicknesses of insulating board (fireproof preferred), with air space between. As the temperature increases materials better able to 653 Heating Ventilating Air Conditioning Guide 1938 Chapter 35. Drying Systems withstand the heat must be used. Metal lined ovens are easy to keep clean, and many high temperature driers up to 1000 F are made of metal panels with insulation between. Care should be taken to avoid through metal (metal extending through the oven from inside to out). Batch type ovens are entirely closed while in use and control of air leakage is easily taken care of. In the continuous drier where the ends are open, heat and air leakage becomes important. Warm air leaking oiit of the ends of ovens means a heat loss, and often the temperature and humidity outside the oven becomes unbearable. For this reason, inclined or bottom entry ovens are' used, as the-warm air leakage can be more easily controlled. See Figs. 5 and 6. HUMID HEAT, B tu PER.DEG F PER LB DRY AIR TEMPERATURE, DEG F F ig . 4. H u m id ity Chart 8o O CM tGiVM an 83d na o a Fig. 5. Small Part Multiple Pass Oven Fig. 6. Inclined End Enameling Oven HUMIDITY CHART FOR DRYING WORK In drying problems the chemical engineer uses different psychrometric values than those used by the heating, ventilating and air conditioning engineer., The humidity chart illustrated in Fig. 4 is based upon values determined from the following explanations: Humidity {II) is the number of pounds of water-vapor carried by one pound of dry air. Percentage Humidity (%H) is the number of pounds of water vapor carried by one pound of dry air at a definite temperature, divided by the number of. pounds of vapor that one pound of-dry air would carry if .it were completely saturated at the same temperature. Per Cent Relative Humidity (3>) is the ratio of weight of water vapor contained in any given volume of air, to the weight of water vapor present in the same volume of saturated air, all values referring to the same temperature. . -. To convert from one relation to the other, ., .. . >> where .' - pa -- vapor pressure of water,. inches mercury; at dry-bulb temperature, degrees Fahrenheit. . .: P = 4> Pa- .................... . COMBUSTION : Where products of combustion are used directly in the oven, a know ledge of their formation and heat values is important,', The, properties of 655 . Heating Ventilating Air Conditioning Guide 1938 Table 3. Drying Time and Conditions for Representative Materials3 Material Temperature Deg F Per Cent Relative Humiditt DaTING Time 140-180 200 140 300 140 150-190 120 325 350 to 90 1100 150 165 180 110-150 150 95-100 170-210 150-200 160-180 400 Max Cores, Oil sand for molding.34"--1 in. thick Black sand with goulic binder 3 in. thick 8 in. thick 300 480 480 16 in. thick 700 Cores, Crank case (in continuous over Cores, Radiator (in continuous ovens] 525-600 275-450 150 180 70 to 20 6 Hrs 2.5 Hrs 4-6 Hrs 15 Min 18 Hrs 40 Min 12 Min 24 Hrs, 108 Min 4.5 Hrs 2 Hrs 5 Hrs 24 Hrs 10 Hrs 4--6 Hrs 24 Hrs 2 Hrs 30 Min 2.5 Hrs 4.5 Hrs 10 Hrs 2-3 Hrs 1.5 Hrs 2 Hrs 225 290-425 225 2 Hrs + Air Dry 1 Hr 3 Hrs 200 90-95 450 225-300 250 150-180 85-110 \ 140 110 110 704)0 70-90 130 Gut..................................................................... Gypsum board % in. thick..................... / \ Start Wet Finish 150 350 97 ft 350-190 180-200 150-190 120 140-180 90 70-90 40-50 1 Hr 18-36 Hrs 1 Hr 30-350 Min 1.5 Hrs 20-30 Min 2-6 6-9 Days 2 Days ^ 4 Hrs 60 Min 8-16 Hrs 1 Hr 2 Hrs 2-4 Hrs 4-6 Days See references at end of chapter. 6S6 Chapter 35. Drying Systems Table 3. Drying Time and Conditions for Representative Materials3--Con. Material Temperature DegF Per Cent Relative Humiditt DaTING Time 120-180 70-300 300 1.5-2 Hrs 300-450 1.5 Hrs 200 30 Min 140-180 78-95 85 90 70 4 Days Leather uppers............................................................ 80 2-3 Days 110-145 10-30 6-10 Hrs Lithographing on tin color work. ............... 250-270 Lithographing on tin Japan....................................... 350 18-25 Min Lumber green hardwood......................................... 100-180 3-180 Days 160-220 2-14 Days 90-110 7.5-8 Hrs 140-180 350 15 Min Milk and other liquid foods spray dried.................. 135-300 Millboard sheets 95 Instantaneous 10 Hrs Moulds green sand C.I. flasks (onef 8 in. thick 600 6 Hr4 surface only exposed). ................ \ 13 in. thick 700 13 Hrs Motors, field coils......................... ............. 180 Motors, stators............................. 250 6.5 Hrs 90-95 75-140 24 Hrs Oil cloth............................................. ........ 150 Paint, wood wheels. ............... .... 150 35 8-24 Hrs Paint, on sheet metaL................................... ........... 350-140 22-30 2.5 Hrs Paper, machine dried.. ......................................... 180 Paper, air dried........................... ........ 90-200 Paper wall, ground coat........... .... 140 3 Min Paper wall, varnished............................................... 140-160 45 Paper cardboard, spirit varnish................................. Ppaoti**? 150 135 1-2 Min Pears............................................ Peas........... ................................ 140 24 Hrs 150 6 Hrs Potatoes sliced. ............. 85 4 Hrs Potatoes steamed.................. Prunes.- .............. Rags....................................... Ramie fiber. ....... ... . 170 140 180 140 6.5 Hrs 10 Hrs Rice........ ......................... . 150 Rock wool insulation .. Rubber.................. 300 . 85-90 8 Hrs,. . 6-12 Hrs Rubber reclaimed............ 140-200 1-2 Hrs Rugs...................... . 190 4--8 Hrs Salt................ 350 Rotary Drier Sand loose 1 in. deep . 300 Sausaee casinvs.... 110 Shade cloth. . .... Shirts. .......... Soap. ................ 240 120 100-125 1-2 Hrs 20 Min 12-72 Hrs Starch........... 180-200 Stock feed mixed.... 180-220 20-30 Min Storage battery plates 100-110 90 for 24 Hrs Sugar. ........... 250 Low for 6 Hrs " 150-200 20-30 Min *See references at end of chapter. 657 7 Heating Ventilating Air Conditioning Guide 1938 Table 3. Drying Time and Conditions for Representative Materials3--Con. Material Temperature Deg F Pee Cent Relative Huuiditt DaTING Time Tanin and other chemicals (spray dried)............... - 250-300 Terra Cotta (air drying in conditioned room)......... 150-200 85-130 180-200 Varnish refrigerator boxes................................................ . .110 110-140 120-130 120-130 . 120-130 Waliboard fiber insulating, roller type drier......--. Wallboard fiber insulating, truck type drier...:--J \JVnnl ` "* ............................................................ 170 300 300-385 300-385 100 180 200 105 35 25-35 35-40 35-40 35-40 Instantaneous 12-96. Hrs 12 Hrs 12 Hrs 5-7 Hrs Overnight 6-8 Hrs + 2 Hrs acclima tion -16-18 Hrs + 4 Hrs acclima tion 20-24 Hrs + 4 Hrs acclima tion . 15-20 Min 2H-3 Hrs 24-48 Hrs 24 Hrs 20 Min oSee references at end of chapter. the common constituents of fuel are shown in Table 4. The heating values of oils are shown in Fig. 7. The sensible heat in Btu contained in the products of combustion of an average fuel oil and various gases is given in Fig; 8. The problem of securing complete combustion in a heater is important, in order to secure efficiency and the absence of soot formation, but unlike the ordinary power or heating boiler, excess air need not be maintained at a minimum in most cases. Excess air is generally admitted either in the heater or before the products go into the drier. DESIGN, In all drying problems, data regarding temperatures, time, and hu midity must be obtained by experiment or previous experience. Experi ments are best performed at the temperatures, humidities, and velocities to be actually used in the full sized drier, and with full size samples. The following nomenclature and explanation of terms will be used in the discussion of drying calculations: H = humidity of air, pounds of water vapor per pound of dry air. G = pounds of dry air supplied to the drier per unit of time. 5 = pounds of stock dried per unit of time in a continuous drier. 5' = pounds of stock charged per batch to a discontinuous drier. 0 - time. Q = total heat supplied to the drier. ' ' 658 Chapter 35. Drying Systems t = air temperature, . . . f = stock temperature. --' ; t = average stock temperature over short time interval, in a batch drier. I?, = wet-bulb temperature. , s' = specific heat of the stock: B = total radiation and conduction losses per unit time. .. v> = pounds of water per pound of dry stock. r = heat of evaporation of water. s = humid heat of air, IF. heat necessary to raise 1 lb of dry air + H lb of steam Subscript (1) designates conditions at the point where the material in question (air. or stock) enters and (2) where it leaves the drier. . Air driers may be divided into two classes, those in which all moisture evaporated from the stock leaves the drier as vapor in the effluent air, and those in which part or all of the moisture is condensed from the air in the drying equipment itself. In any continuously operating drier of the first type the relation between moisture content of the stock and quantity of air required for the drying operation is given by the equation: G (Ht -- Hi) -- S(u>i -- to,) (2) Table 4. Gas Combustion Constants3 Gas Carbon Hydrogen Oxygen Heat op Combustion las peb La op Combustible a Cu Ft 3S | o per Lb Btu per Lb 5o 2u Gross Net Required for Combustion 0. Nt Air Flue Products COi BA Hi c 12.000 14.140 14,140 2.667 8.873 11.540 3.667 8.873 Hi 2.015 187.723 61.100 51.643 7.939 26.414 34.353 -- 8.939 26.414 0, 32.000 11.819 Nitrogen Nt 28.016 13.443 Carbon Monoxide CO 28.000 13.506 4,369 4.369 0.571 Carbon Dioxide COi 44.000 8.548 1.900 2.471 1.571 1.900 Methane Ethane Propane Sulphur Dioxide CHt 16.031 23.565 23.912 21,533 3.992 13.282 17.274 2.745 2.248 13.282 CtH, 30.046 12.455 22.215 20,312 3.728 12.404 16.132 2.929 1.799 12,404 CiHg 44.062 8.365 21,564 19,834 3.631 12.081 15.712: 2.996 ,1.635 : 12.081: 50i 64.060 ' 5.770 Water Vapor ff*0 18.015 21.017 Air -- 28.900 13.063 j - ; All gas volumes corrected to 60 E and 30 in.-mercury barometric pressure dry; - ; : 659 Heating Ventilating Air Conditioning Guide 1938 In discontinuous driers, e.g., compartment driers, the drying operation is given by the equation: G (Hi - Hi) = S'~ (2a) In the continuous drier, the heat consumption per unit time is: = Gsi(ti - h) + G(r, + h- t',) (H, - Hi) + 5(1', - t'i)(s' +wi)+B (3) Equation (3) assumes continuity of operation. For charge or batch operations, the total time of the drying cycle may be broken up into a number of periods, sufficiently short so that over each period average Chapter 35. Drying Systems into contact with the stock with sufficient intimacy so that the air leaving the drier is saturated, or nearly, so. Counter-current as against parallel flow of air and stock gives rise to optimum operating conditions, resulting in a minimum quantity of air required (G), and a corresponding minimum loss, as sensible heat, in the exit air. Similarly, continuous operation is superior to intermittent operation.. .. Despite the fact that the sensible heat loss increases with the rise in temperature of the air, the percentage of heat lost from this source decreases, provided the increase in moisture carrying capacity of the air, TEMPERATURE, DEG FAHR Fig. 7. Heating Values of Fuel Oil, Btu Gross values of t, t' and H may be employed provided the third term of the right hand member of the equation is modified to read: S' - I",) (s' - Wi) and in the second term f', be replaced by . . i'i + t", 2' . Theoretically these periods should be very short and the equation integrated. Practically the error introduced by using a small number of long periods and employing average values of the variables over each, rarely introduces serious error. The evaluation of equation (2a) may be approximated in a similar manner. The first term of the right hand member of equation (3) represents heat lost as sensible heat in the effluent air. In many drying operations this becomes excessive. Each pound of air supplied should remove the maxi mum amount of moisture. This is best accomplished by bringing the air 660 Fig. 8. Heat Content of Gases Above 32 F in Btu per Pound due to high temperature, is actually utilized. To secure maximum thermal efficiency in drying, a high drying temperature and high satura tion of the outlet air is imperative. Ventilation Phase . The technique of attack of the ventilation phase of a drying problem is best made clear by an illustration. Assume that a material containing 40 per cent moisture is to be dried until this quantity of moisture is reduced to 5 per cent by weight. The material will stand an air tempera ture of 150 F and it is possible to provide sufficiently good contact between the material and the drying air so that the effluent air can be 661 TT Heating Ventilating Air Conditioning Guide 1938 brought up to 50 per cent humidity at 150 F. The drier is to use room " air, die temperature and humidity of which may be assumed to average 70 F and 50 per cent. A counter-current drier will be employed and the air in this drier will be kept at a substantially constant temperature of 150 F by heaters thermostatically controlled. The stock enters at 70. F, rises quickly to the wet-bulb temperature of .the air; with which it is in H=0.0234, 0.008 H) ' W-0.150 W2-0.6687 W2-0.0527 W-P0UNDS OF WATER PER POUND DRY STOCK Fig. 9. Temperature-Humidity Relations in a Drier Fig. 10. Core Drying Time Temperature Relations Vent 33$ per cent St 422 F / Recirculation 66$ per cent I at 422 F"Y tb --ji 15 tb product of perfect comnibustion per pound fuel T> . Fig.11. Excess air for combustion X (bat 70 F Core Drying Diagram op Combustion Products and Air contact, and is found experimentally to maintain wet-bulb temperature until the moisture content has fallen to 20 per cent. From this point its temperature rises progressively as it dries. In this range the difference in temperature between stock and air, divided by the wet-bulb depression, ifiky be .assumed proportional, to the moisture content. . ' The" moisture content of the entering stock, in the units here employed. is. ' ... '' 40 per cent water 60 per cent dry stock .. ,, , ' ' 5 per cent water 95 per cent dry stock 662 0.0527 Chapter 35. Drying Systems - m, = i = 0.614 lb water evaporated per pound of dry stock: Since the air leaving the drier is 50 per cent saturated at 150 F from Fig. 4, Ht = 0.105.: Similarly, Hi = 0.008, corresponding to 50 per cent humidity at 70 F. Consequently Ht --.Hi -- AH = 0.097 lb water evaporated per pound dry air. . Inspection of equation (2) shows that (H) is linear in w. Hence,- one can construct on Fig. 9, the line marked (H) being drawn connecting the initial and final points just computed. ................... : Since the air leaving the drier has a temperature of 150 F and a humidity of 0.105, Fig. 4 shows that its wet-bulb temperature is 129 F. This is plotted at the right hand side of Fig. 9. Since the stock maintains a wet-bulb temperature down to 20 per cent moisture, where w = 0.25, the corresponding humidity can be computed by the use of equation (2) or by reading directly from the diagram, the value being 0.0392. Fig. 4 shows that the corresponding wet-bulb temperature is 105 F. Any intermediate point on the wet-bulb temperature curve can be calculated similarly. The points for w - 0.5 are shown in Fig. 9. . Below the point, w. = 0.25, the temperature of the stock begins to rise appreciably above the wet-bulb temperature. Its temperature at any given point in this range, for example at w = 0.15, may be computed as follows: At this point, H = 0.0234 (from equation (2)) and from Fig. 4, tw = 95 F. Hence the wet-bulb depression, t -- = 150 -- 95 = 55 F. The assumption made regarding the relation between stock temperature and moisture content in this range may be formulated: A I1 _ v> t -- tw ~ 0.25 At the point w = 0.1.5, At' = 33 F, t' = 117 F. The temperature of the stock leaving the drier, similarly computed, is 136 F. ' " . Fig. 9 thus computed gives in graphical form the information as to the temperature humidity relationships in the drier. The air requirements can be computed by equation (2). Thus, per 100 lb of dry stock, it is necessary to supply 633 lb of dry air. Furthermore, since from Fig. 4 it is seen that the volume of 50 per cent saturated air at 70 F, is 13.55 cu ft per pound; 8580 cu ft of room air must be supplied per 100 lb dry stock. Similarly, since the volume of 50 per cent saturated air at 150 F is 18.0 cu ft per pound, the volume of hot wet air discharged from the drier, is 11,400 cu ft per 100 lb of dry stock. Finally, the heat necessary to supply to the drier, as a whole, or to any section of it, may be computed from equation (3). ' - High Temperature Drier In the design of a high temperature drier unit a method of approach to the necessary calculations involved are outlined as follows: Example 1. Cores 4 and 5 in. thick are to be dried by heating to a temperature at 400 F. An intermittent type box oven is to be used, size 12 x 14 x 10 ft with 856 sq ft surface having an average heat transfer of 0.3 Btu per square foot per degree per hour. Drying time as determined by test is 2 hr (Fig. 10). Cores weighing 6 tons, and 15-ton steel plates, trucks etc. are delivered to the drier at 70 F. The oven is heated by an external heater; the products of combustion and 66^ per cent recirculated air will be delivered to the oven at 825 F. Fuel oil of 19,980 Btu gross and 18,830 Btu per pound net heating value, weighing 6.75 lb per gallon and having 15 lb .product per pound fuel 663 , Heating Ventilating Air Conditioning Guide 1938 for perfect combustion. Cores consist of 91 per cent sand, 3 per cent oil binder, and 6 per cent water. Solution. Heat required per ton of cores: Lb Material X Temp. Rise X Sp. Ht. = Btu Sand_____________ ________ ____ 0.91 X 2,000 X (400 - 70) X 0.2 = 120,120 Binder_____________________ :.... 0.03 X 2,000 X (400 - 70) X 0.4 = 7,920 Water heating_____,__________ 0.06 X 2,000 X (212 - 70) X 1.0 = 17,040 Water evaporation.............. ,__ 0.06 X 2,000 X 970 (Fig. 4) = 116,520 Water superheating (approx. 50 per cent reaches 575 F) Total Heat..... ....... ............................ ............................................ j....... 271,400 Btu Heating Load First Hour Heated to 212 F Water. ............................ ...... Evaporation............................ 212 F 212 F 66.7% 66.7% 14.9 X 120,120 7'920 0.667 X 116,520 0.667 X 9,800 Btu = 51,688 = 3-408 = 17,040 = 77,680 = 6,530 TotaL. _______ 390 F 422 F Avg. 6 X 156,346 320 X 30,000 X 0.12 352 X 856 X 0.30 = 938,076 = 1,152,000 = 90,394 ........................................................................ ............ 2,180,470 Heating Load Second Hour 400 F Water... ___ ______ _ Superheat................................ 400 F 33.3% . 33.3% !H X 120,120 ! X 7,920 0.333 X 116,520 0.333 X 9,800 == 68,432 = 4,512 = 38,840 = 3,270 Total Per Ton__ . 115,054 Fnr fi ton 6 X 115,054 = 690,324 460 70 X 30,000 X 0.12 = 252,000 575 505 X 856 X 0.30 = 129,684 Total 1,072,008 ' ^Binder oxidizes and liberates heat, which is neglected in this calculation. bAverage value of coefficient is less than 0.3 because oven is not up to 575 F. This is neglected. 422 F is arrived at by taking,area under curve as compared to area under 575 F ordinate. 664 Chapter 35. Drying Systems Heat in 1 lb fuel oil = Heater Loss (10 per cent) = 1883 Duct Loss (5 per cent) = 942 18,830 Btu 2,825 Btu 16,005 Btu available to heat oven. Heat content of gases in 1 lb fuel oil at 825 F is 205 Btu (Fig. 8) 15 lb X 205 = 3,075 Btusensible heat in products of perfect combustion. 12,930 Btu to heat air X and Y . . (Fig. 11). Y (Sat Sm) -f- X (S&s -- S70) = 12930 (4) Y = 2 (X + 15) for 66.7 per cent recirculation. where 5 = heat content of air at temperature noted taken from Fig. 8 (Recirculation and exhaust contains water vapor, products of combustion, and a greater portion of air. Heat capacities of all vary so little that they have all been assumed to be air). Ssa - Sm = 190 - 91 = 99 . Sea -Sn = 190 - 8.6 = 181.4 Substituting values of Y, H, etc. in Equation 4, (2 X + 30) 99 + 181.4 X = 12,930 X = 26.3 lb excess air. . Y = 82.6 lb recirculating air. Total = 26.3 + 82.6 -f- 15 = 123.9 lb air and products of combustion circulated per pound fuel burned. Heat in air exhausted from oven at 422 F per pound fuel burned = 0.333 X 123.9 X (Sz - S,,,) = 41.3 (91 - 8.6) = 3,400 Btu. Btu available for heating material = 16,005 -- 3,400 = 12,605 Btu per pound fuel. Fuel used in first hour = 2,180,470 4- 12,605 = 173 lb = 25.6 gal. During the second hour the heater capacity will be much greater than required. If an automatic oven temperature control operates on the oil supply, the delivery tem perature of the air entering the oven and the quantity of oil burned will decrease, the air supply being constant. Heat in air exhausted = 41.3 (SBi -- SK) = 41.3 (127 -- 8.6) = 4880 Btu per pound fuel. Heat available for heating material = 16,005 -- 4880 = 11,125 Btu. Fuel used in second hour = 1,072,008 -4- 11,125 = 96.5 lb oil = 14.3 gal. Total oil used per load = 25.6 + 14.3 = 39.9 gal. i ESTIMATING METHODS Values based on practical experience are available for rough estimating of drying problems. The temperature will drop approximately 8.5 F per grain of water evaporated per cubic foot of air (measured at 70 F) or approximately 0.62 F per pound of air at any temperature; Air will drop 55 F per cubic foot for each Btu extracted. Generally air will absorb from 2 grains to 5 grains per cubic foot of air in one passage through an air drier, depending on the temperature and the degree of contact with the material. The amount of steam required to evaporate a pound of water will vary from 1.5 lb to a more usual figure of from 2.5 to 3 lb of steam per pound of water evaporated., . 665 7 ?.Y: Heating Ventilating Air Conditioning Guide 1938 REFERENCES Commercial Drying Apparatus, by L. P. Dwyer (A.S.H.V.E. Transactions, Vol. 22, 1916, p.479). . . . ' Artificial Drying with Special Reference to the Use of Gas, by G. C. Shadwell (A.S.H. V.E. Transactions, Vol. 23, 1917, p. 231). Drying by Evaporation, by F. R. Still (A.S.H.V.E. Transactions, Vol. 23, 1917, p. 255). . High Temperature Drying, by Burt S. Harrison (A.S.H.V.E. Transactions, Vol. 24, 1918, p. 7). The Temperature of Evaporation, by W. H. Carrier (A.S.H.V.E. Transactions, Vol. 24, 1918, p. 25). . . Commercial Dehydration, by J. E. Whitley (A.S.H.V.E. Transactions, Vol. 26, 1920, p. 551). . Drying as an Air Conditioning Problem, by A. W. Lissauer (A.S.H.V.E. Trans* actions, Vol. 27, 1921, p. 251). A Chronological Survey of Drying and Driers, by J. E. Bolling (A.S.H.V.E. Journal, Section, October, 1921, p. 715). . -. Calculations for Drying Design, by Grosvenor (Transactions, American Institute Chemical Engineering, 1908, p. 184). . The Rate of Drying Solid Materials, by J. Lewis (Industrial Engineering Chemistry, 1921, p.427). . .. Adiabatic Drying of Hygroscopic Solids, by A. M. McCready, and W. L. McCale (Transactions, American Institute Chemical Engineers, 1933)1 ` ; Lignite Drier, by Lavine & Sutherland (Chemical and Metallurgical Engineering, July, 1929). . .. Enameling Oven Economy, by B. S. Harrison (Fuels & Furnaces, February, 1931). Powdered Yeast Prepared by Spray Drying, by A, W. Farrell (Food Industry, December; 1931). . Factors that Influence Drier Performance, by A. Weisselberg (Chemical and Metallur gical Engineering, August, 1932). .. Principles of Drying Lumber and. Humidity Diagram, by H. D. Tiemann (Forest Service Bulletin 104, 1912). .. Symposium on Drying. Articles by W. K. Lewis, W. H. Carrier, A. E. Stacey and Fleming, R. G. Metz, G. B. Ridley, C. O. Lavett, D. J. Van Marie (Journal Industrial Engineering Chemistry, May, 1921). The Drying of Solids, by T. K. Sherwood (Bulletin Massachusetts Institute Technology, Nos. 237, 247 and 258). Air Conditioning and Engineering, American Blower Co. Combustion (American Gas Association, 3rd edition, 1932). Die Trockentechnik, by M. Hirsch (Julius Springer, Berlin, 1932). Drying (Kent's, Mechanical Engineers Handbook, 10th edition, 1923; 11th edition, 1936). x ' Drying, by W. H. Carrier (Marks', Mechanical Engineers Handbook, 3rd edition, 1930). Drying, by Perry (Chemical Engineers Handbook, 1934). Drying by Means of Air and Steam, by E. Hausbrand (D. Van Nostrand Sf Co., 1901). Drying in Industrial Plants, by J. O. Ross. ' Elements of Chemical Engineering, by Badger and McCabe (McGrow HiU Co., 1931). Fan Engineering, Buffalo Forge Co. Fuels and Their Combustion, by Haslam and Russell (McGrow Hill Co., 1926). Heat Transmission, by W. H. McAdams (McGrow Hill Co., 1933). Modern Drying Machinery, by H. B. Grenshaw, London, 1926. Principles of Chemical Engineering, by Walker, Lewis, McAdams (Chapters on Evaporation, Humidity and Drying, 2nd edition, McGrow HiU Co.). The Kiln Drying of Lumber, by A. Koehler and R. Thelen, New York, 1926.. The Kiln Drying of Lumber, by H. D. Tiemann (Lippincott, 1920). *s 666 Chapter 35. Drying Systems PROBLEMS IN PRACTICE 1 What makes a commercial adiabatic drier differ from a theoretical one? The word adiabatic means no heat lost to the outside and that the sensible heat lost by the air is equal to the latent heat of the water evaporated. In an actual drier, the solid containing the water, and the water itself must be heated to the temperature of evapora tion, before evaporation can begin. Radiation losses from the drier enclosure is the other factor causing deviation from the theoretical adiabatic process. 2 What is a zone drier? This term refers to a continuous drier where the drying medium is divided into two or more sections, in order to have better control of the temperature and humidity gradients through the drier, and often different velocities. 3 If a material enters a drier containing 70 per cent water and. 30 per cent solids, and leaves the drier with 10 per cent water and 90 per cent solids, (a) What is the evaporation per pound of dried product? (b) What is the evapora tion per pound of bone dry material? . . a. 90 -- 1 = 2 lb water per pound dried product. . - 70 , b. Water entenng -- = 233 per cent on bone dry basis. Water leaving -- ^ = 11 per cent on bone dry basis. Water evaporated 222 per cent on bone dry basis. Evaporation = 2.22 lb water per pound bone dry material. ` .` 4 What items must be included in a calculation of the drier heat require ments? a. Heating water to be evaporated from the entering temperature to the temperature of evaporation. b. Evaporating water to be removed. c. Superheating, evaporated water from the temperature of evaporation to the exit temperature of the air. d. Heating material from entering to leaving temperatures. e. Heating residual water from the entering to the leaving temperatures. f. Heating conveyor or other supporting materials. g. Radiation losses through the enclosure. .. h. Sensible heat in the exit air. . 5 The following conditions prevail in a drier; 250 lb water evaporated per hour. Air enters heater at 80 F dry-bulb and 65 F wet-bulb. Air exhausted from drier at 130 F dry-bulb and 100 F wet-bulb. Stock enters drier at 70 F. Heat required for warming stock and radiation losses are not considered. Fan is located ahead of heater. Find conditions of air entering and leaving drier, volume handled by fan, and temperature of air entering drier to supply the necessary heat, using Humidity Chart in Fig. 4. Entering Air: Humidity, H = 0.01 lb water vapor per pound dry air. Dew-point = 57 F Per Cent Humidity, % H = 46 - 667 X Heating Ventilating Air Conditioning Guide 1938 Leaving Air: Humidity, H = 0.0355 lb water vapor per pound dry air. Per Cent Humidity, % H = 32 Water pick up = 0.0355 -- 0.01 = 0.0255 lb per pound bone dry air. Bone dry air circulated per hour = 250 -s- 0.0255 = 9800 lb. Volume of air circulated at 80 F dry-bulb, and 46 per cent humidity . 14.1 -- 13.6 = 0.5 cu.ft vapor (Fig. 4). Volume = 13.6 H- (0.46 X 0.5) = 13.87 cu ft = 1 lb dry air + vapor. . Volume handled by fan at 80 F = = 2260 cfm. Btu received by water = (130 -- 70) X 1.0 = 60 Latent heat of steam at 130 F (Fig, 4) -- 1019 Total = 1079 Btu per pound. Heat used for evaporation per pound dry air = 1079 X 0.0255 = 27.43 Btu. For entering air: Humidity, H = 0.01, Humid Heat = 0.2425 Btu per pound (Fig. 4) (ti -- h) X S = Btu for evaporation (<, - 130) X 0.2425 = 27.43 f, = 247 F 6 Given the following conditions, air 160 F dry-bulb, 49.6 per cent relative humidity ($), 29.92 in. Hg, barometric pressure, find the per cent H, absolute humidity. For 160 F, ps -- 9.65 in. Hg (From Table 6, Chapter 1) p = 4>ps = 0.496 X 9.65 = 4.78 OQ QO __ QfiC on`no-----Tro X 0.496 = 0.40 or 40 per cent absolute ljumidity. 4./o ' 668 Chapter 36 NATURAL VENTILATION Wind Forces, Stack Effect, Openings, Windows, Doors, Sky lights, Roof Ventilators, Stacks, Principles of Control, General Rules, Measurements, Dairy Barn Ventilation, Garage Ven tilation VENTILATION by natural forces, supplemented in certain cases with mechanical forces, finds extensive application in industrial plants, public buildings, schools, dwellings, garages, and in farm buildings. The natural forces available for the displacement of air in buildings are the wind and the difference in temperature of the air inside and outside the building. The arrangement and control of ventilating openings should be such that the two forces act cooperatively and not in opposition. Wind Forces In considering the use of natural wind forces for the operation of a ventilating system, account must be taken .of (1) average and minimum wind velocities, (2) wind direction, (3) seasonal, daily and hourly varia tions in wind velocity and direction, and (4) local wind interference by buildings and trees. . Table 1, Chapter 8, gives values for the average summer wind velocities and the prevailing wind directions in various localities throughout the United States, while Table 2, Chapter 7, lists similar values for the winter. In almost all localities the summer wind velocities are lower than those in the winter, and in about two-thirds of the localities the prevailing direc tion is different during the summer and winter. While average wind velocities are seldom below 5 mph, there are many hours in each month during which the wind velocity is from 3 to 5 mph, even in localities where the seasonal average is considerably above 5 mph. There are relatively few places where the hourly wind velocity falls much below 3 mph for more than 10 daylight hours per month. Usually a natural ventilating system should be designed to operate satisfactorily with a wind velocity of 3 to 6 mph, depending on locality. The following formula may be used for calculating the quantity of air forced through ventilation openings by the wind, or for determining the proper Size of such openings: where Q = BA V (1) Q = air flow in cubic-feet per minute. A = free area of inlet (or outlet) openings in square feet. V = wind velocity in feet per minute, = miles per hour X 88. E = effectiveness of openings. (E should be taken at from 50 to 60 per cent if the inlet openings face the wind and from 25 to 35 per cent if the inlet openings receive the wind at an angle.) . 669 Heating Ventilating Air Conditioning Guide 1938 If outlet openings, where air. leaves a building, are smaller than inlet openings, where air enters a building, the air will be less effective than indicated by the constant E. . The accuracy of the results obtained by the use of Formula 1 depends upon the placing of the openings, as the formula assumes that ventilating openings have a flow coefficient slightly greater than that of a square-edge orifice. If the openings are not advantageously placed with respect, to the wind, the flow per unit area of the openings will be less, and if unusually well placed, the flow will be slightly more than that given by the formula. Inlets should be placed to face directly into the prevailing wind, while ' outlets should be placed in one of the following four places: 1. On the side of the building directly opposite the direction of the prevailing wind. 2. On the roof in the low pressure area caused by the jump of the wind (see Fig. 1). 3. In a monitor on the side opposite from the wind. 4. In roof ventilators or stacks exposed to the full'force of the wind1. ' Forces Due to Stack Effect2 ' . The stack effect produced within a building is due to the difference in weight of the warm column of air within the building and the cooler air outside. The flow due to stack effect is proportional to the square root of the draft head, or approximately: . where Q = 9.4 A V H{t - t0) (2) air flow in cubic feet per minute. free area of inlets or outlets (assumed equal) in square feet. = height from inlets to outlets, in feet. average temperature of indoor air in height H, in degrees Fahrenheit, temperature of outdoor air, in degrees Fahrenheit. constant of proportionality, including a value of 65 per cent for effectiveness of openings. This should be reduced to 50 per cent (constant = 7.2) if conditions are not favorable. . The height between inlets and outlets should be the maximum which the building construction will allow. .. In some cases the necessary air flow will be known from the require ments of the building occupancy, and the area necessary for certain assumed temperature differences may be calculated. Or the areas may be'fixed by the building construction, and the maximum air flow for various differences between indoor and outdoor temperatures may be calculated. In any case, the conditions which give the minimum air flow are those which control the design, as the system must have ample capacity even under the most unfavorable conditions which are.those of mild or warm weather. . TYPES OF OPENINGS The engineering problems of a natural ventilation system consist of the design, location, and control of ventilating openings to best utilize the* *Airation of Industrial Buildings, by W. C. Randall (A.S.H.V.E. Transactions, VoL 34, 1928, p. 159). Neutral Zone in Ventilation, by J. E, Emswiler (A.S.H.V.E. Transactions, Vol. 32. 1926. p. 59). Predetermining Airation of Industrial Buildings, by W. C. Randall and E. W. Conover (A.S.H.V.E. Transactions, Vol. 37. 1931, p. 605). 670 Chapter 36. Natural Ventilation natural ventilation forces, in accordance with the requirements of build ing occupancy. The types of openings may be classified as: . 1. Windows, doors, monitor openings, and skylights. 2. Roof ventilators. 3. Stacks connecting to registers. 4. Specially designed inlet or outlet openings. Windows, Doors and Skylights .. : Windows have the advantage of transmitting light, as well as providing ventilating area when open. Their movable parts are arranged to open in Fig. 1. The Jump of Wind from Windward Face of Building. (A--Length of Suction Area; B--Point of Maximum Intensity of Suction; C--Point of Maximum Pressure) various ways; they may open by sliding as in the ordinary double-hung windows, by tilting on horizontal pivots at or near the center, or by swinging on pivots at the top or bottom. .Whatever the form and type of window used, the amount of. clear area that can be made available is the factor of greatest importance in ventilation. All types of sash (double-hung, top, center or bottom horizontal pivoted, or vertical pivoted) have about the same air flow capacity for the same clear area. Air leakage through closed windows is important during high. winds (Chapter 6). . 671 r Heating Ventilating Air Conditioning Guide 1938 The proper distribution of air in occupied spaces is an element almost as important as that of sufficient air quantity. Advantageous pivoting of sash is very useful for securing good air distribution. Deflectors are some times used for the same purpose, and these devices should be considered a part of the ventilation system. Door openings are seldom included in the ventilation calculations, though they may be of great value for extreme summer conditions, and should be considered in this connection as well as in garage design. Skylight and monitor openings are of importance as these and the roof ventilators are outlets, while the lower windows are usually inlets on the windward side and outlets on the leeward side. In general the areas of inlets and outlets should be about equal. It is important to make a check on this ratio in any installation, as any great excess of area of one set of openings over another means waste opening area. The operating devices used for sash, monitors, skylights and roof ventilators should be well selected as poor operating devices may defeat the entire design. Roof Ventilators The function of a roof ventilator is to provide a storm and weather proof air outlet, which is sensitive to wind action for producing additional flow capacity, and at the same time is subject to manual or automatic control by suitable dampers. The capacity of a ventilator at a constant wind velocity and temperature difference, depends upon four things: (1) its location on the roof, (2) the resistance it offers to air flow, (3) the area and location of openings provided for air inflow at a lower level, and (4) the ability of the ventilator head to utilize the kinetic energy of the wind for inducing flow by centrifugal or ejector action. Frequently one or more of these capacity factors is overlooked in a ventilator installation. For maximum flow induction, a ventilator should be located on that part of the roof which receives the full wind without interference. (See Fig. 1.) This does not mean that no ventilators are to be installed within the suction region created by the wind jumping over the building, or in a light court, or on a low building between two high buildings. Ventilators are highly effective in such low-pressure areas, but their ejector action, caused by wind velocity, is of little importance in these locations, and hence their size should be increased proportionally. Ventilator resistance depends on (1) type'of inlet, (2) area of openings and passages, and (3) number of turns or changes of direction of the air flow. The inlet grille, if any, should have ample free area, and the venti lator should always be provided with a taper-cone inlet in order to produce the effect of a bell-mouth nozzle (flow coefficient 0.97) rather than that of a square-entrance orifice (flow coefficient 0.60). In other words, the grilles should be oversize as compared with the ventilator, and-they should be connected by tapering collars. If the ventilator head construction produces changes in the direction of air flow, the area of the flow passages should be increased accordingly. Air inlet openings at lower levels in the building are of course necessary for the economical use of ventilator capacity. The inlet openings should be at least equal to, and preferably twice as great as the combined throat areas of all roof ventilators. The air discharged by a roof ventilator 672 Chapter 36. Natural Ventilation depends on wind velocity and temperature difference, but due to the four capacity factors already mentioned, no simple formula can be devised-for expressing ventilator capacity. Several types of roof ventilators are shown in Figs. 2 to 11. These may be classified as stationary, Figs. 2 to 6, pivoted or oscillating, Figs. 7 to 9, or rotating, Figs. 10 and 11. When selecting roof ventilators, some attention should be paid to ruggedness of construction, storm-proofing features, dampers and damper operating mechanisms, possibilities of noise from dampers or other moving parts, and possible maintenance costs. . It should be kept in mind that a suitable combination of roof venti lators with mechanical ventilation frequently offers the best solution of a ventilating problem. The natural ventilation units may be used to sup plement power driven supply fans, and finder favorable weather con ditions it may be possible to shut down the power driven units. Where .low operating costs are very important, such a combination has great advantages. Roof ventilators with built-in electric fans are attracting increased attention because they combine the advantages of low instal lation and operating cost with those of continuous service. Controls In connection with any combination between natural and fan venti lation, the controls are of importance. Both the fans and the ventilator dampers may be controlled by some combination of three methods: (1) hand operation, (2) thermostat operation, and (3) control by wind velocity. The thermostat station may be located anywhere in the building, or it may be located within the ventilator itself. The purpose of wind velocity control is to obtain a definite volume of exhaust regardless of the natural forces, the fan motor being energized when the natural exhaust capacity falls below a certain minimum, and again shut off when the wind velocity rises to the point where this minimum volume can be supplied by natural forces. Stacks Stacks are really chimneys and utilize both the inductive effect of the wind and the force of temperature difference (the so-called gravity action). While their openings projecting above the roof are not provided with any special construction for developing suction by the action of the wind, the plain vertical opening is also effective in this respect. Like the roof ventilator, the stack outlet should be located so that the wind may act upon it from any direction. Stacks are applicable particularly in the case of schools, apartments, residences and small office buildings. Partitions interfere with general air circulation, and some type of outlet from each room is necessary. If the building is not too tall, and the requirements of occupancy are moder ate, a system of stacks with registers in each room may be more eco nomical than a system of mechanical ventilation employing fans. In making the comparison, however, the building space occupied by the stacks should be considered. With little or no wind, chimney effect or temperature difference will produce outflow through the stacks and an equal inflow through windows 673 Heating Ventilating Air Conditioning Guide 1938 --. Chapter 36. - Natural Ventilation in all sides of the building. With wind, the inductive force at the top of ventilating shafts is more powerful than that on the leeward side'of the building, so that air is drawn in through leeward openings by a combina tion of the forces of wind and temperature difference. On' the windward side, the direct forcing pressure of the wind is of course added to- the temperature difference effect. Thus forces are available for causing in flow at practically every window of such a building. Adequacy of stack size must, of course, be provided. PRINCIPLES OF AIR FLOW CONTROL The air flow through a ventilation opening depends on the two factors already discussed, namely, (1) the natural forces available, (2) the open ings available, and the resistance to flow offered by these openings. The design problem includes, of course, a . determination of the desired air Five Common Types of Stationary Ventilators , Three Typical Oscillating Ventilators 674 Fig. 10. quantity and distribution in order that the openings may be properly placed. The purpose of ventilation is to carry off either excess heat or air , impurities, and the desired air quantities depend upon the amount of heat or of impurities present. The amount of heat can be determined, in the------ -- case of forge shops for example, from the amount of fuel burned, which in turn is based upon the production capacity for which the building is being designed. In the case of foundries, the heat given off by the metal in cooling from the molten state can be used. In some instances, not all of the heat may be dissipated to the air, but a fair estimate of the amount to be removed by the air can usually be made. ' The next step is to select the temperature difference to be maintained. Knowing the amount of heat to be removed and having selected a desirable, temperature difference, the amount of air to be passed through the building per minute to maintain this temperature difference can be . determined by means of the following equation: ' : ff = c60Q(t-to) (3) where ' c 0.24 specific heat of air. . . .' V = specific volufne of the air, cubic feet per pound, about 13.5. (See Chapter 1.) . 675 ' Heating Ventilating Air Conditioning Guide 1938 H = heat to be carried off, in Btu per hour. Q = air flow in cubic feet per minute. t = inside temperature, degrees Fahrenheit. to = outside temperature, degrees Fahrenheit. For disposing of air impurities, the required air flow must be such that the outside air will dilute the impurities to a degree that they are no longer objectionable. For human occupancy, such as in auditoriums and classrooms, 10 cfm per person is usually taken as the minimum of outside air necessary for ventilation (see Chapter 3). For garage ventilation, sufficient air must be admitted to dilute the carbon monoxide content of the indoor air to 1 in 10,000 (see Garage Ventilation in this Chapter). Air quantity and quality are not the only requirements. For human occuparicy, air distribution is important. In ventilation the air distribu tion is almost entirely a matter of the number, the design, and the location of inlets and outlets. In locating openings, special precautions should be taken against the formation of dead air spaces or pockets within the zone of occupancy (see Chapter 28). Suggested. methods for estimating the air flow due to temperature difference alone and to wind alone have already been given. It must be remembered that when both forces are acting together, even without interference, the resulting air flow is not equal to the sum of the two' estimated quantities. The same openings have been assumed in both cases, and since the resistance to flow through the openings varies ap proximately with the square of the velocity3, this resistance becomes a limiting factor as the flow through the openings is increased. Recent investigations4 show that the total flow is only 10 per cent above the flow caused by the greater force when the two forces are nearly equal, and this percentage decreases rapidly as one force increases above the other. Tests on roof ventilators indicate that this is too conservative in the direction of low total flow quantities, but there is in any case a large judgment factor involved. The wind velocity and direction, the outdoor temperature, or the indoor activities cannot be predicted with certainty, and great refinement in calculations is therefore not justified. When designing for winter conditions, an added variable is the heat lost by direct flow through walls and windows and by infiltration. Example 1. Assume a drop forge shop, 200 ft long, 100 ft wide, and 30 ft high. The cubical content is 600,000 cu ft, and the height of the air outlet over that of the inlet is 30 ft. Oil fuel of 18,000 Btu per lb is used in this shop at the rate of 15 gal per hour (7.75 lb per gal). Temperature differences are 10 F in summer and 30 F in winter, and the wind velocity is 5 mph in summer and 8 mph in winter. What is the necessary area for the inlets and outlets, and what is the rate of air flow through the building? Solution. The system must be designed for the summer conditions as these are the more severe. The heat to be removed per hour is: , fiT = 15 X 7.75 X 18,000 = 2,092,500 Btu. By Equation 3, the air flow required to remove this heat with a temperature difference of 10 deg is: ,, VH 13.5 X 2,092,500 ,na r Q = --c 6n0 --(t -- <, o') = n0.o2--4 <Xs m60 "Xvi1n0 = 196,172 cfm. *Loc. Cit. Notes 1 and 2. 4This is true for turbulent flow only. It would be more correct to state that the resistance varies approxi mately with V* for high to moderate velocities, with V1*8* for moderate to low velocities, and with the first power of the velocity for very low velocities through small openings. . 676 Chapter 36. Natural Ventilation This is equal to 19.6 air changes per hour. The assumption is made that the average temperature difference between indoors and outdoors is the same as the temperature rise of the air from the inlet opening to the outlet opening. Actually, the latter difference is larger and so the value of 19.6 air changes per hour is conservative as it allows for more cooling than is necessary for an average temperature difference of 10 deg. If 196,172 cfm are to be circulated by the force of the temperature difference alone, the area of opening would be, by Equation 2: 4 = 9.4 Q 196,172 = 9.4 vW = 11205 sqft- . If this area of openings were provided, a wind velocity of 5 mph, acting alone, would produce a flow according to Equation 1, of: Q = EAV = 0.50 X 1,205 X 5 X 88 = 265,100 cfm. If the inlet openings do not face the wind, but are at an angle with it, about half this amount may be considered to flow. ' A factor of judgment must now be exercised in making the selection of the area of openings to be specified. Apparently 1205 sq ft are a very generous allowance because either a direct wind of 5 mph or an average temperature difference of 10 deg acting alone will more than suffice to ' carry away the heat, and when the two forces are acting together, the system may have an excess capacity of 25 per cent to 50 per cent, especially if the outlets are made up partially of roof ventilators which employ the force of the wind for producing a suction effect. On the other hand, the wind may at times come from an unfavorable direction, or its velocity may fall below 5 mph or the building construction may not permit a full 2400 sq ft of inlet window area and an equal amount of monitor or roof ventilator outlet area. In case the two sets of openings are not equal, their effectiveness is reduced. From this example, it must be apparent that while formulas may furnish a reliable guide, the final solution of a problem of natural venti lation requires a common sense analysis of local conditions to supplement and to modify the dictates of the formulas. GENERAL RULES A few of the important requirements in addition to those already outlined are: 1. Inlet openings should be well distributed, and should be located on the windward side near the bottom, while outlet openings are located on the leeward side near the top. Outside air will then be supplied to the zone of occupancy. ' 2. Direct short circuits between openings on two sides at a high level may clear the air at that level without producing any appreciable ventilation at the level of occupancy. 3. Roof ventilators should be located 20 to 40 ft apart each way and preferably on the ridge of the roof. The closer spacings are used when ventilating rooms with low ceilings. 4. _ Greatest flow per square foot of total opening is obtained by using inlet and outlet openings of nearly equal areas. . 5. In an industrial building where furnaces, that give off heat and fumes, are to be installed, it is better to locate them in the end of the building exposed ito the prevailing wind. The strong suction effect of the wind at the roof near the windward end will then cooperate with temperature difference, to provide for the most active and satisfactory removal of the heat and gas laden air. 677 Heating Ventilating Air Conditioning Guide 1938 6. In case it is impossible to locate furnaces in the windward end, that part of the building in which they are to be located should be built higher than the. rest, so that the wind, in splashing therefrom will create a suction. The additional height also increases the effect of temperature difference to cooperate with the wind. 7. In the use of monitors, windows on the windward side should usually be kept closed, since, if they are open, the inflow tendency of the wind counteracts the outflow tendency of temperature difference. Openings on the leeward side of the monitor result in cooperation of wind and temperature difference. 8. In order that the force of temperature difference may operate to maximum advan tage, the vertical distance between inlet and outlet openings should be as great as possible. Openings in the vicinity of the neutral zone are less effective for ventilation. 9. In order that temperature difference may produce a motive force, there must be vertical distance between openings. That is, if there are a number of openings available in a building, but all are at the same level, there will be no motive head produced by temperature difference, no matter how great that difference might be. , 10. In the design of window ventilated buildings, where the direction of the wind is quite constant and dependable, the orientation of the building together with amount and grouping of ventilation openings can be readily arranged to take full advantage of the force of the wind. On the other hand, where the direction of the wind is quite variable, it may be stated as a general principle that windows should be arranged in sidewalls and monitors so that there will be approximately equal area on all sides. Thus, no matter what the wind's direction, there will always be some openings directly exposed to the pressure force of the wind, and others opposed to a suction force, and effective movement through the building will be assured. 11. The intensity of suction or the vacuum produced by the jump of the wind is greatest just back of the building face. The area of suction does not vary with the wind velocity, but the flow due to suction is directly proportional to wind velocity. 12. Openings much larger than the calculated areas are sometimes desirable, especially when changes in occupancy are possible, or to provide for extremely hot days. In the former case, free openings should.be located at the level of occupancy for psychological reasons. 13. Special consideration should be given to the possibility of sidewall or monitor windows being closed on account of weather conditions. Such possibilities favor roof ventilators and specially designed stormproof inlets. MEASUREMENT OF NATURAL AIR FLOW The determination of the performance of any ventilating system involves measurements which are not easy to make. The difficulties are increased in the case of natural ventilation, since the motive forces and the air velocities are very small. The measurements necessary for giving the capacity of a system are (1) velocity of the wind, (2) velocity of the air through inlet and outlet openings, (3)\outdoor air temperature, and (4) average indoor air temperature. Measuring Wind Velocity. The cup-type of anemometer as used for Weather Bureau observations is sufficiently accurate for this measure ment. Some more accurate instruments as well as direct-reading types have been developed for airport service, but for ventilation work it is the average wind velocity over a long period which determines the capacity of the system. Hence the use of the Weather Bureau instrument, with an observation period of one hour or more, is satisfactory. If observations of wind direction are required, these should be taken by observing a sensitive weather vane at frequent intervals (about every 5 minutes) during the same period. Velocity of Air Through Openings. The vane type anemometer is the most practical instrument for this measurement. 678 Chapter 36. Natural Ventilation Use a small (4 in.) low-speed anemometer, and correct all readings according to a recent calibration. Mount the anemometer in a strap iron clamp with a long handle for convenience. Divide each opening into 5 in. squares (by string or wire) and hold the anemometer in the center of each square for a definite period of from 15 to 30 seconds. Record the result of the traverse as soon as completed and start another one im mediately. A series of traverses over a period of one hour, or the full period covered by the wind velocity observations with a fairly steady wind, may be considered a satisfactory test for that wind velocity. It is preferable, to have an anemometer observer at each opening. If the. opening is covered by a grille or register, use the proper correction factors, (see Chapter 44). Outdoor Temperature. It is easy to make an error of 1 to 5 deg in observing the outdoor air temperature. An accurate thermometer, calibrated in 1 deg divisions should be used. The thermometer should be mounted in the shade at about mid-height of the building and not too near the building wall or adjacent to an air outlet. The heat from a wall or roof which has been exposed to the sun is easily transmitted to a thermometer, with resulting high readings. ' Average Indoor Temperature. ' It is important to note that the capacity of an opening (such as roof ventilator) does not depend on the difference in the temperatures measured adjacent to the opening. It depends rather on the difference between the average temperature of the column of air inside the building and that outside. Indoor temperatures should therefore be observed at various heights to secure a good average. DAIRY BARN VENTILATION5 A successful barn ventilating system is one which continuously supplies the proper amount of air required by the stock, with proper distribution and without drafts, and one which removes the excessive heat, moisture, and odors, and maintains the air at a proper temperature, relative humidity, and degree of cleanliness. . Bam temperatures below freezing and above 80 F affect milk produc tion. Milk producing stock should be kept in a bam temperature be tween 45 arid 50 F. Dry stock, at reduced feeding, may be kept in a barn 5 to 10 deg higher. Calf bams are generally kept at 60 F, while hospital and maternity bams usually have a temperature of 60 F or somewhat higher.. The heat produced by a cow of an average weight of 1000 lb may be taken as 3000 Btu per hour. The average rate of moisture production by a cow giving 20 lb of milk per day is 15 lb of water per day, or 4375 grains per. hour. To set a standard of permissible relative humidity for cow; bams is difficult. For 45 F an average relative humidity of 80 per cent is satisfactory, with 85 per cent as a limit. " ` Where the bam volume is within the limit that can be heated by the stabled animals, the air supply need not be heated. The air should be *Dajry Barn Ventilation,'by F. L. Fairbanks (A.S.H.V.E. Transactions, Vol. 34, 1923, p. 181). Cow Barn Ventilation, by Alfred J. Offner (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 149). " ` For additional information on this subject refer to Technical Bulletin, U. S. Department of Agriculture (1930), by M. A. R. Kelley. ' 679 Heating Ventilating Air Conditioning Guide 1938 supplied through or near the ceiling. It is better to have the exhaust openings near the floor as larger volumes of warm air are then held in the bam and there is better temperature control with less likelihood of sudden change in barn temperature. If a cow weighs 1000 lb and produces 3000 Btu of heat per hour, and if a barn for the cow has 600 cu ft of air space with 130 sq ft of building exposure, one cow will require 2600 to 3550 cfh of ventilation, depending on the temperature zone in which the barn is located. The permissible heat losses through the structure, based on one cow and depending on the temperature zone, vary between 0.043 and 0.066 Btu per hour per cu ft of bam space, and 0.197 to 0.305 Btu per hour per sq ft of barn exposure. GARAGE VENTILATION6 On account of the hazards resulting from carbon monoxide and other physiologically harmful or combustible gases or vapors in garages, the importance of proper ventilation of these buildings cannot be over emphasized. During the warm months of the year, garages are usually ventilated adequately because the doors and windows are kept open. As cold weather sets in, more and more of the ventilation openings are closed and consequently on extremely cold days the carbon monoxide concentra tion runs high. Many garages can be satisfactorily ventilated by natural means par ticularly during the mild weather when doors and windows can be kept open. However, the A.S.H.V.E. Code for Heating and Ventilating. Garages, adopted in 1929 and revised in 1935, states that natural venti lation may be employed for the ventilation of storage sections where it is practical to maintain open windows or other openings at all times. The code specifies that such openings shall be distributed as uniformly as pos sible in at least two outside walls, and that the total area of such openings shall be equivalent to at least 5 per cent of the floor area. The code further states that where it is impractical to operate such a system of natural ventilation, a mechanical system shall be used which shall provide for either the supply of 1 cu ft of air per minute from out-of-doors for each square foot of floor area, or for removing the same amount and discharging it to the outside as a means of flushing the garage. Research \ Research on garage ventilation undertaken by the A.S.H.V.E. Com mittee on Research at Washington University, St. Louis, Mo., and at the Code for Heating and Ventilating Garages (A.S.H.V.E. Transactions, VoI. 35, 1929, p. 355), (A.S. H.V.E. Reprint, January, 1935). Airation Study of Garages by W. C. Randall and L. W. Leonhard (A.S.H.V.E. Transactions, Vol. 36, 1930. p. 233). Carbon Monoxide Concentration in Garages, by A. S. Langsdorf and R. R. Tucker (A.S.H.V.E. Trans actions. Vol. 36, 1930, p. 511). Carbon Monoxide Distribution in Relation to the Ventilation of an Underground Ramp Garage, by F. C. Houghten and Paul McDermott (A.S.H.V.E. Transactions, VoL 38, 1932, p. 439). Carbon Monoxide Distribution in Relation to the Ventilation of a One-Floor Garage, by F. C. Houghten and Paul McDermott (A.S.H.V.E. Transactions, Vol. 38, 1932. p. 424). Carbon Monoxide Distribution in Relation to the Heating and Ventilation of a One-Floor Garage by F. C. Houghten and Paul McDermott (A.S.H.V.E. Transactions, Voi. 39, 1933, p. 395). Carbon Monoxide Surveys of Two Garages, by A. H. Sluss, E. K. Campbell and Louis M. Farber (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 263). 680 Chapter 36. Natural Ventilation University of Kansas, Lawrence, Kans., in cooperation with the A.S.H. V.E. Research Laboratory, and at the A.S.H.V.E. Research Laboratory has resulted in authoritative papers on the subject. Some of the conclusions from work at the Laboratory are listed below: 1. Upward ventilation results in a lower concentration of carbon, monoxide at the breathing line and a lower temperature above the breathing line than does downward ventilation, for the same rate of carbon monoxide production, air'change and the same temperature at the 30-in. level. 2. A lower rate of air change and a smaller heating load are required with upward than with downward ventilation. .. 3. In the average case upward ventilation results in a lower concentration of carbon monoxide in the occupied portion of a garage than is had with complete mixing of the exhaust gases and the air supplied. However, the variations in concentration from point to point, together with the possible failure of the advantages of upward ventilation to accrue, suggest the basing of garage ventilation on complete mixing and an air change sufficient' to dilute the exhaust gases to the allowable concentration of carbon monoxide. ` 4. The rate of carbon monoxide production by an idling car is shown to vary from 25 to 50 cfh, with an average rate of 35 cfh. 5. An air change of 350,000 cfh per idling car is required to keep the carbon monoxide concentration down to one part in 10,000 parts of air. . PROBLEMS IN PRACTICE 1 What, factors may make the adoption of a system of ventilation depending upon wind movement inadvisable in new construction? a. Variation in direction of wind. . b. Variation in wind velocity. c. Inability to clean incoming air. d. Inability to control location, size and shape of buildings on adjacent property. e. ' Unsatisfactory warming of incoming air during cold weather. 2 a. What factors are important in the location and control of ventilating openings? b. What types of ventilating openings are best suited to a proper distribu tion of the air supplied? a. The proper distribution of air as required by the occupants, and the best utilization of natural ventilating forces. The general rules referred to in this chapter apply par ticularly to these factors. . b. Windows with swinging sash and openings with deflectors may be used to direct air to the points desired. - 3 6 a. What is the best location for ventilating openings? b. How are the sizes of ventilating openings determined for proper air supply? 1 a. Inlet openings should be low and facing the prevailing winds where possible. openings should be high and on the side opposite the prevailing winds. b. For simple openings use Formula 1: . Q = EAV Outlet and for stacks use Formula 2: Q = 9.4 A V H (i - t,,) The use of these formulae is illustrated in Example 1 of the text of this chapter. Inlet and outlet areas should be approximately the same for best results. 681 Heating Ventilating Air Conditioning Guide 1938 , 1 . II | ! ; i ; I i ! f | - I . 4 a. What are the advantages of roof ventilators? . b. How are proper sizes determined for roof ventilators? . - a. Roof ventilators offer the best utilization of the inductive force of the wind, and they may be very economically fitted with built-in fans to supply the necessary circulation when the force of the wind is not sufficient. b. Because of the many factors affecting the flow through roof ventilators no accurate formula can be given. It is usual practice to make the combined throat area of all roof ventilators between one-half area and full area of the air inlets as determined by Formula 1. . 5 # What methods of control are used in ventilating systems? Hand-control, control by a thermostat located in the. ventilated space or in the ventilator, or wind velocity controldesigned to keep the air discharge constant regardless of wind velocity. 6 How is the quantity of air required for a building determined? Sufficient air must be supplied to carry away the heat and impurities generated within a building. The temperature rise and concentration of impurities in the exhaust air must be held within specified limits. (See Example 1 in the text of this chapter). - 7 # What measurements are necessary to determine the capacity of a ventilating system? . Wind velocity and air velocities through openings, determined by suitable anemometers; outdoor air temperatures, measured by a shaded thermometer not near objects heated by the sun or near exhaust air openings; indoor air temperatures, measured at various heights tosecure a .good average.. 8 0 How much air must be supplied for dissipating the heat generated in a dairy barn housing 100 cows if the outside temperature is 20 F and the inside temperature is to be maintained at 45 F? The total, heat generated is 100 X 3000 = 300,000 Btu per hour. Then from Formula 3, . 0 =____ ^____ , v c 60 (< - to) .. 13.5 X 300,000 0.24 X 60 (45 - 20) = 11,250 cfm. This amount of air should also keep down humidity and odors. 9 0 a. What precaution is necessary in the ventilation of garages using natural ventilation? ' b. How much window area is required for a garage with 50 x 100 sq ft floor . area if natural ventilation is used? a. The carbon monoxide content of the air should be kept below 1 part in 10.000 and windows should be kept open at all times. . b. The window area should aggregate 5 per cent of the floor area. I 0.05 X 50 X 100 = 250 sq ft of window area. This area should be evenly distributed along two sides of the building. 682 Chapter 37 AUTOMATIC CONTROL Purpose of Automatic Control, Definitions of Control Units and Terms, Types of Control, Central Fan Systems, Unit Systems, Control of Automatic Fuel Appliances, Residential Control Systems, Control of Refrigeration Equipment, Indus trial Processes THIS chapter is prepared with the purpose of acquainting the engi neer with the principles underlying the use of automatic control, the general types and varieties of control equipment available and their application. Automatic control, properly applied to heating, ventilating and air conditioning systems, makes possible the maintenance of desired con ditions with maximum operating economy. A properly designed and complete control system has the ability to interlock and coordinate the various functions of heating, ventilating and air conditioning in a manner impossible to accomplish with manual regulation. Automatic control is an integral and essential part of a heating, venti- . lating or air conditioning installation and cannot be regarded as an acces sory. In order to insure satisfactory results, the control should be designed with and incorporated in the heating, ventilating or air conditioning system. The control equipment should be given careful consideration in the planning of any installation in order that the entire system may operate together with satisfactory results. . In order that proper selection and application of controlling devices may be made it is important that a broad understanding exist as to the types of control available and their principles of operation. Improper selection and application of control equipment will result in unsatis factory and inefficient operation. Specific control devices and systems are described in the Catalog Data Section. PUHPOSE OF AUTOMATIC CONTROL Automatic control is normally applied to heating, ventilating or air conditioning systems: . 1. To insure the maintenance of certain desired or required conditions of temperature, pressure, humidity, air motion or air distribution. 2. To serve a safety function, limiting pressures or temperatures within predetermined points, or preventing the operation of mechanical equipment unless it may function without hazard. 3. To produce economical results and thereby insure operation of the system at a minimum of expense. 683 Heating Ventilating Air Conditioning Guide 1938 DEFINITIONS OF CONTROL UNITS AND TERMS Controlling devices and terms commonly used in the automatic control of heating, ventilating and air conditioning systems are: Thermostats: Thermostats are defined as temperature sensitive devices reacting to temperature changes. There are four major types of thermostats. A Room Thermostat is normally installed on the wall of the room whose temperature it is to control, and in reacting to rising or falling tem peratures, the thermostat causes the operation of heating or cooling equipment so that desired temperatures will be maintained. The temperature sensitive element will usually consist of a bi-metal strip or coil, Or a vapor-filled bellows as illustrated in Fig. 1. ' Bi-Metallic straight strip type curved strip type Fig. 1. Typical Thermostatic Elements Immersion Thermostats are used for controlling liquid temperatures. The.sensitive element will normally be encased in a protective well which is inserted in the liquid, the temperature of which is being controlled. The temperature sensitive element will usually consist of a bi-metal coil, thermal expansion rod, or a vapor-filled system. If the latter is used the temperature sensitive bulb may be connected to the case of the instrument by either a flexible or rigid tube. Insertion Thermostats are similar to immersion thermostats except that they are for use in controlling the temperature of a gas such as air. The sensitive element will often be encased in a protective well which prevents mechanical damage, but which permits the gas to come in direct contact with the element. . Surface Thermostats include those devices which measure surface temperatures. These surface temperatures will often be an indirect measure of the temperature of a gas or fluid as in the case of a pipe within which water is flowing. The sensitive element will usually be placed in direct contact with the surface of the object whose temperature it is to measure and may consist of a bi-metal spiral or vapor-filled bellows. 684 Chapter 37. Automatic Control Humidity Controls: . Humidity controls are defined as automatic devices reacting to changes in relative humidity. Within this group, the devices which operate in controlling humidity supplying equipment are regulating devices and when operating only to prevent relative humidity from exceeding a predetermined maximum are a'form of limit control. The humidity sensitive element may consist of hair, paper! wood, skin or any other material which changes its dimensions with changes in humidity. . . . Controls.are available provided with both temperature and humidity, sensitive elements, which operate, .to maintain definite relations between dry-bulb temperature and relative humidity. Pressure Controllers: Pressure controllers are defined as devices reacting to pressure and pressure changes. Examples of such devices are the pressure controls governing, the operation of refrigeration equipment from either head or.suction pressure, devices reacting to steam or water pressure or the pressure of air in the distribution systems. Damper Motors: Damper motors are defined as specialized power units, the purpose of which is to position outdoor air, face, by-pass or. distribution dampers, regulating the flow of air through the system. Connected by suitable linkages, these damper motors react at the com mand of thermostats, humidity controllers and pressure controllers to adjust the air flow to the needs of the system. .. Control Valves: Control valves are defined as steam valves, water valves or air valves which may be adjusted at the command of con trollers to regulate the flow of the medium passing through them to the needs of the system. Such control valves are usually constructed with an electric or pneumatic power unit connected to the valve stem-so that the movement of the power unit will react to position the valve as con ditions demand. . Self-contained valves are also included under this classification. Their, application is principally limited to the regulation of the steam supply to individual radiators in two-pipe low pressure steam heating systems, and the temperature of hot water supply tanks. Solenoid Valves: Solenoid valves are, as their name implies, valves actuated by the magnetic effect of an electric solenoid built within them. While normally these valves are opened when the solenoid is energized, they are sometimes built in a reverse acting manner and closed when- energized. In heating, ventilating and air conditioning systems, they are normally adapted to the control of oil or gas burners as fuel valves, as water valves on humidifiers, or as refrigerant valves in refrigeration systems. . Relays: A relay is defined as a unit installed between a controller and the device under control, for purposes of amplifying the capacity of the controller or performing an auxiliary control function. For example, a thermostat, in order to preserve its sensitivity may be constructed so that it is not capable of handling the power required of a motor. A relay is, therefore, installed between the two. The thermostat actuates the relay and the relay, in turn, actuates the motor. Motor driven switching devices are also often used as relays. . 685 r Heating Ventilating Air Conditioning Guide 1938 TYPES OF AUTOMATIC CONTROL Operating Media or Source oi Power Supply Automatic control systems may be classified in three broad groups based upon their primary operating media or source of power, as follows: 1. Electric Control Systems. In such control systems the primary medium utilized to provide for the operation is electricity, and the basic function of these controls consists of switching or otherwise adjusting electric circuits to govern electric motors, relays or solenoids. The individual units of this type of system are interconnected by line voltage or low voltage wiring, and this wiring serves to complete the circuits carrying the commands of the controllers to the controlled valves or damper motors. 2. Pneumatic Control Systems. In the pneumatic control systems, the primary source of operation is obtained through a medium of compressed air, the pressure of which is varied by the controlling devices. In these systems one or more centrally located air compressors furnish a supply of compressed air which is distributed in special piping to the various con trolling and controlled devices. By means of leak ports or orifices, the pressure of the air is varied in the branch lines and the changing pressures are utilized in air operated damper motors or valves to obtain the move ment necessary to the operation of valves and dampers. 3. Self-Contained, Control Systems. Self-contained control systems have, in general, been restricted to such operations as could be effectively handled by a power unit with integrally mounted or direct-connected controller. Such applications consist of valves utilized to admit steam or other media into coils to regulate the temperature of tanks or to regulate the admission of steam into heating coils or radiators as determined by the controller element. Motion of Controlled Equipment Automatic control: equipment can also be classified into two general types with respect to the characteristics of the motion imparted by the controls to the controlled equipment, such as two position or positive acting control and modulating or graduated action control. In any control system it is necessary to'choose the type of equipment whose characteristics permit the type of control operation desired and in many cases both types of control are used in the same system to best meet various requirements. . 1. Two Position or Positive:-acting Control. This type of control operates positively between two positions such as on and off or open and closed with no intermediate positions or degrees of motion between the two extremes of operation. A simple thermostat which starts and stops an oil burner or a unit heater motor is an example of this type. As applied to a valve or a damper, the action of the controlling device would serve to fully open or fully close the valve or damper. In some applications of this type of control, artificial heat is applied to the sensitive element of the room thermostat at the same time that heat is being added to the space under the control of the thermostat in order to 686 "r" Chapter 37. Automatic Control increase its sensitivity. This usually results in more accurate control and more frequent operation of the heat source. 2. Modulating or Graduated-acting Control. This type of control causes motion in the controlled device in proportion to motion caused in the controller by fractional degree variations in the medium to which the controller is responsive. After a fractional change has been measured at the controller and has effected a new position of the valve or damper in proportion to the amount of such change, the' system stands by awaiting further change at the controller before any additional motion occurs. The extent of the motion is limited only by the limits of the controller and by the intensity of the change of conditions as measured. With this type of control, the damper or control valve may be operated in intermediate positions between its extreme limits in order to properly modulate or proportion the flow of air, steam or water, reacting with changes of con ditions at the controller. Various modifications of this type of control are available, designed to meet special requirements and conditions, all based on operation of the controlled equipment in intermediate positions. This type of control motion cannot be used on valves of one-pipe steam , systems as the partial opening of the valves will not permit the condensate to escape against the flow of incoming steam. This type of control should not be used to control, the flow of steam to a heater coil of a fan system which is in the direct path of untempered outdoor air at temperatures below freezing, because of the possibilities of freezing condensate in the bottom of the coil. Division oi Space under Control Control systems vary considerably with the type and size of the building, occupancy of the building, and with the heating or cooling system, humidity supplying equipment and ventilating means available for control. In the following paragraphs the general requirements of various phases of these different buildings will be discussed. 1. Individual Room Control. The most accurate and flexible form of control for any structure is that calling for the regulation of each indi vidual room by control equipment reacting to conditions in that room only. Such control necessitates a thermostat in each room, located to properly measure the conditions of the room, controlling the radiator, unit heater, unit ventilator or other heating source supplying heat to that room only in which the thermostat is located. This arrangement permits the maintenance of any desired conditions in any room, entirely inde pendent of any other room. In the case of large rooms, where one ther mostat location will not serve to properly measure the conditions through out the room, and where two or more sources of heat supply are provided in the room, additional thermostats may be used, each controlling its respective section of the heating source. This form of control, due primarily to the number of control devices required over the entire building, normally is the most expensive type of control system. How ever, where maximum flexibility and the most accurate control is desired, individual room control can be depended on to furnish the desired results. 2. Single Thermostat Control. Probably more widely used than any other form of control is the type of automatic system regulated entirely 687 . Heating Ventilating Air Conditioning Guide 1938 from a single room thermostat. The wide use of this particular means of control is primarily due to the fact that it is the form of regulation best adapted to residences and small buildings, which far out-number the larger structures. In larger buildings, this form of control has definite short comings. In the small buildings and average size residences it is possible to select a location and install a thermostat of suitable characteristics which, in controlling from the surrounding air temperature, will hold the temperature of the entire building within entirely satisfactory limits. It must be recognized that the thermostat reacts to and controls from the temperatures to which it is subjected and that, therefore, the position selected for the thermostat must be representative of general conditions throughout the structure. It must further be recognized that if certain areas or rooms of a structure are not properly balanced as regards heating or cooling capacity and distribution, the control as dictated by the ther mostat will not produce satisfactory results in these unbalanced areas. 3. Zone Control. As the size of buildings increases, it becomes in creasingly difficult to provide proper regulation for the entire structure from a single thermostat control. In such instances, where the advantages of individual room control are not obtainable by reason of its cost, an intermediate form of control system is available, commonly described as zone control'. In this form of control system a building is divided into areas or zones such that the general requirements and the general con ditions through the areas are relatively constant as to exposure and occupancy, and then each zone is provided with control equipment which functions to regulate the conditions in that particular zone. As in the case of individual room control, each zone may be regulated to its own needs which may vary from the needs of other zones within the same structure. Variations of the usual zone control methods by the use of recently developed special devices have been quite successful in obtaining greater economy from heating systems. Frequently these use an outside ther mostat or group of thermostats which adjust the operation of the controls to conform to variations in weather conditions. ' CENTRAL FAN SYSTEMS A central fan system includes any conditioning system by which either outdoor air, return air, or combinations of outdoor and return air, are conditioned at a central point and then distributed through duct work to the various sections of the space being conditioned. . Heating Cycle Central fan ventilating systems may be sub-divided, first into split systems, by which air is supplied for ventilating purposes only and heat is supplied in winter from another source such as direct radiation; and second, into combined systems, in which the functions of ventilation and heating are both performed by the central fan system. . A control system for a central fan ventilating system using all outdoor air and discharging air at a predetermined temperature is illustrated in Fig. 2. Thermostat Tj located in the outdoor air intake is set just above freezing, and controls valve Vi on the first heating coil. This valve must 688 Chapter 37. Automatic Control be completely open or completely closed to avoid danger of freezing. The by-pass damper around the heaters and the other two valves V2 and V3 are controlled by thermostat 7* located in the discharge duct from the fan. If the temperature of the discharge air increases, through the action of Tt the damper is moved automatically to admit more cold air. Should this not reduce the temperature sufficiently, the valves V% and Vs on the heating coils will be closed gradually and in sequence until the correct temperature is reached; The control of the damper and valves Vs and Vs must be gradual or there will be a wide fluctuation in temperature. In ventilating systems it is customary to supply air to the ventilated spaces at an inlet temperature approximately equal to the temperature maintained in the rooms. The radiators therefore are designed to take care of all the heat losses from the room and in order to maintain con trolled room temperatures it is necessary to control the radiators in dependently of the ventilation control. Insertion thermostat Fig. 2. Control of a Split System of Ventilation In some installations, such as theatres and auditoriums, it is difficult to install.sufficient direct heating surface to offset the heat losses from the room. There are also installations where a short heating-up period is allowed before occupancy of the room, and in these cases it is necessary to use the entire heating capacity of the ventilating system for this purpose. An additional thermostat may be installed in the room which will take the control away from the fan discharge thermostat (T, in Fig. 2) and utilize the full heating capacity when the room is below normal temperature. In central fan systems, air washers are often used and in such cases, due to the effect of temperatures on humidity, additional control is required. An arrangement with control of the second tempering heating coil from the air washer temperature and with the usual control of the first tempering heating .coil from the outside temperature is shown in Fig. 3. This permits the air to be kept cool while passing through the washer so that too much moisture will not be absorbed. Control of the reheating units and by-pass damper by an insertion thermostat in the fan discharge, and the application of a pilot thermostat to a system of this sort is illustrated in Fig. 3. :. 689 Heating Ventilating Air Conditioning Guide 1938 Where a number of rooms are to be heated and ventilated through one central fan. system it is customary to provide tempering heating units, automatically controlled to provide a minimum temperature for venti lation only and additional heating units to supply the heating require ments. These reheating units may be located in the various branch ducts to the different rooms, each under control of its individual room ther mostat, or individual ducts may be run to the various rooms from the central unit. In this case reheater coils are provided to maintain a. predetermined temperature in a warm air chamber. Each room duct is connected to this warm air chamber and to the tempered air supply, and through the action of a room thermostat on a gradual-acting double mixing damper the proper proportions of warm and tempered air are secured to maintain desired conditions in the room. In all types of central fan systems, the outdoor air damper is usually opened and closed by a damper motor controlled from a manual switch Pilot room n thermostat ""V I Fig. 3. Control of Ventilating System with Air Washer Using Pilot Thermostat or by a relay in the fan motor circuit, so arranged that when the fan motor is started,, the relay causes the damper motor to open the outdoor air damper. Recirculating and vent dampers may also be opened and closed by means of damper motors controlled from remote locations. Generally these damper motors are positive acting and are either completely open or closed. However, in some cases, where part outdoor air and part recirculated air is desired, it is advantageous to control the dampers so that definite proportions of damper opening area exist. In some instal lations the control of outdoor air and recirculating dampers is under the command of a thermostat at the intake to the conditioner, in which case the proportions of outdoor and recirculated air are fixed by the resultant temperature of their mixture. This arrangement tends to reduce the amount of outdoor air used as the outside temperature is lowered. . . The operation of a central fan system during the heating cycle often results in unfavorably low relative humidity and the provision and control of-humidity becomes an important factor of the system. If water spray humidification is used, control may be effected by a humidity con- . 690 Chapter 37. Automatic Control trailer actuating a control valve in the water supply to the sprays. ' If steam humidification is used, either of the steam jet type or of the steam heated evaporating type, the flow of steam may be controlled from the humidity controller in the ventilated space. Where an air washer is used, approximate control of humidity may be obtained by maintaining the air temperature in the air washer at a predetermined desired dew-point temperature. For example, the dew-point temperature at 70 F and 40 per cent relative humidity is 45 F. Therefore, if the air temperature is maintained at 45 F as it leaves an air washer (assuming it is fully saturated) and. then is heated to 70 F, it will have a relative humidity of 40 per cent. If it is desired to maintain these conditions in a given space, the air temperature can be raised to any necessary point, say 120 F (at which the relative humidity will be only 9 per cent). When the heat in the air has been dissipated, the space temperature being maintained at 70 F, the relative humidity will be 40 per cent. Whenever moisture is being added to the air during the heating cycle by the use of a spray or any other means, a considerable amount of care must be used in order to prevent frost from collecting on the windows due to the air being reduced below its dew-point at the inside surface of the windows. - Cooling Cycle Central fan cooling systems are divided into two general groups based upon the methods employed to control the temperature and humidity of the treated space. Cooling normally involves the removal of moisture from the air, and to accomplish this end the temperature of the air must be lowered below the dew-point. The air at this low temperature must then be treated or introduced into the room in such manner as to avoid uncomfortable cold drafts. In the first group the air is supplied from the conditioner after being cooled and dehumidified to a fixed temperature and humidity and then before entering the treated space is reheated. This is accomplished either by passing the air through coils heated with steam, hot water, or other heating medium, or the air from the conditioner is mixed with recirculated air before entering the conditioned space. In the second group are those systems which use the treated space as a mixing chamber, the air being supplied to it at the temperature and humidity leaving the conditioner and depending upon diffusion in the conditioned space to give ultimately the correct conditions. In these systems the temperature and humidity of the treated space are measured and govern, through control of the cooling means, the temperature and the humidity of the air leaving the conditioner. .: In Fig. 4 is represented one of the most simple central fan types of cooling system. Thermostat T measures the temperature within the treated space and operates to start and stop the refrigeration compressor or to control the supply of refrigerant to the cooling unit as required 'to maintain a fixed temperature in the space. <; There are three general methods for the control of relative huniiditry in central fan cooling systems, which are: J 691 Heating Ventilating Air Conditioning Guide 1938 1.. By provision for limiting the relative,humidity in addition to the temperature at a definite point. When this method is used; either temperature or humidity may demand operation of the cooling source regardless of whether or not the other factor has been exceeded. The use of a high limit humidity control in this manner is desirable during conditions of high relative, humidity but its operation may^cause excessive cooling unless some method of reheating is employed. , . >:[ 2. By the maintenance of a fixed effective temperature. .By this method, a definite relation is maintained between temperature and humidity, ana sensible cooling is done whenever possible instead of the removal of latent heat in the form of moisture. 3. By the maintenance of a fixed dew-point in the air discharge. This method usually provides for the control of relative humidity within the space being conditioned between reasonable limits, but does not take into consideration any change in the latent heat load, as compared to the sensible heat load. , .f The necessity for varying inside temperature conditions in accordance with changes in outdoor conditions on many types of installations is important. A control system is shown in Fig. 5 where the temperature of the treated space is adjusted according to the outdoor temperature. Room thermostat . Air intake Cooling coil 1 1 ! Fig. 4. c_> Compressor Diagram of Simple Cooling System Control Thermostat Ti measures the outdoor temperature and thereby auto matically determines the inside dry-bulb temperature control point. Thermostat 7, in the conditioned space measures the temperature of that space and controls the refrigerant to the cooling coil so as to maintain the temperature in the space being conditioned at the point which has been set up by thermostat 7\. - It is usually found desirable to adjust the indoor temperature between available limits with the outdoor temperature all of which is fully described in Chapter 3. Various combinations of control may be applied to cooling systems to secure desired relationship between outdoor temperature and resultant indoor temperature and humidity. - All Year Systems An all year central fan conditioning system consists of the combination of a ventilating system and a cooling system. During certain seasons of the year, it is sometimes possible to control 692 Chapter 37. Automatic Control the dew-point of the air discharged from an air washer by regulating the relative quantities of outdoor and return air. The use of this method for controlling the outdoor and return air dampers may also provide for automatic change-over from the heating to cooling cycles, providing thereby for the maintenance of a fixed dew-point temperature in the airdjscharge during both cycles. Complete automatic control of all year systems incorporates an auto matic change-over between the cooling and heating cycles. If the instab lation necessitates operation of manual switch or other device to change over between the heating and cooling cycles, then the control System is semi-automatic. The full automatic change-over between cycles becomes particularly desirable in the early and late portions of the cooling and heating seasons when heating is required during the early and late portion of the day and cooling may be required during the middle of the day. A system for the control of an all year conditioning system providing for automatic change-over from the cooling to heating cycles is illustrated in Fig. 6. Fig. 5. Diagram of Compensated Cooling System Control During the heating cycle, thermostat Ti in the return air or room measures the temperature of the conditioned space and modulates control valve Vi which, in turn, modulates the flow of steam to the heating coil so as to maintain a fixed temperature in the space. Humidity control Hi measures the relative humidity in the space being conditioned and opens control valve F, so as to admit water to the sprays whenever moisture is required in the air. ' During the cooling cycle, thermostat T, in the return air measures the temperature in the space being conditioned and modulates control valve: V3 which, in turn, modulates the flow of water to the cooling coil so as to maintain a fixed temperature in the space. Humidity control H3 measures the relative humidity in the space being conditioned and then assumes command of control valve V3 whenever the relative humidity exceeds a predetermined amount. . During the heating cycle thermostat T3 acts as a low limit. It assumes command of control valve Fi whenever it is necessary to prevent the air 693 Heating Ventilating Air Conditioning Guide 1938 discharge temperature from falling below a minimum point. Thermostat Tt may also be arranged to act as a low limit during the cooling cycle if the conditions of the installation make it desirable. Thermostat Tt installed in the inlet to the conditioner controls damper motor Mi which in turn regulates the relative quantity of outdoor and return air admitted to the system. This damper action may be provided with a minimum setting of the outdoor air damper so that a minimum fixed requirement of outdoor air will be insured for ventilating purposes. Humidity control H, measures the outdoor air relative humidity and prevents the outdoor air damper from opening beyond its minimum Fig. 6. Diagram of Complete Automatic Control All Year Air Conditioning System position whenever the outdoor air relative humidity exceeds a pre determined point. When the fan is stopped, relay R positions damper motor Mi so as to close the outdoor air damper. N . .' Thermostat 7\ must be set at a lower temperature than thermostat Tt in order that each may assume command upon the fall or rise respectively of the temperature of the return air. As an example, Ti might be set at 72 F and Tt at 76 F. When the temperature of the return air approaches 72 F, it would indicate that a change had taken place from the cooling to the heating cycle and when the return air approaches 76 F, it would indicate that a change has taken place from the heating to the cooling cycle. UNIT SYSTEMS A unit system provides for the same functions as a centra! fan system except that the actual conditioning is usually done within the space being conditioned instead of at some central location outside of the space. The 694 Chapter 37. Automatic Control automatic control problems, therefore, become exactly the same as for central fan conditioning systems except that compactness, ease of instal lation and control cost often assume somewhat more importance. Because of the usual segregated location of unit equipment throughout a building and its consequent lack of competent supervision, complete automatic control is essential to its satisfactory operation. Unit Heaters In its simplest form, unit heater control consists of a room thermostat the function of which is to start the unit heater motor when heat is required and shut it off when the demand is satisfied. With this limited control, it is possible in some instances that, with no steam available at the heater, the operation of the fan at the command of the thermostat would cause objectionable drafts. To prevent this occurrence, limit controls are available which will prevent the operation of the fan at the command of the room thermostat except when steam is available, as determined by the temperature of the steam or return pipe or the pressure of the steam supply. ' In some cases it is desirable to operate the unitheaters continuously for circulation of air where, due to the type of installation, cold drafts will not result therefrom. In such instances the room thermostat regulates the supply of steam to the unit through a control valve in the steam supply line and the unit heater motor operation is manually controlled. Where several unit heaters serve a limited area, they may be grouped for purposes of automatic control, and several heaters placed in operation at the command of one thermostat. By properly grouping the units which will operate together, the benefit of zone control can often be obtained with a minimum of control equipment. Where such group operation is utilized, the thermostat and limit control usually function through a relay, as the combined load of the several motors may exceed the current capacity of the thermostatic control device. Cooling Units ' The recommended form of temperature control for the cooling unit contemplates the continuous operation of the cooling unit fan with auto matic two position regulation of the compressor or cooling coil as deter mined by a room thermostat or by a temperature controller measuring the temperature of the return air as it is taken into the cooling unit. Such operation insures continuous circulation of the air in the room served by the cooling unit, and in addition to providing the cooling effect due to the moving air, this circulation overcomes the tendency of air to stratify. Thus, as this temperature tends to rise, the temperature controller will open the valve supplying either refrigerant or cold water to the cooling unit coil or start the compressor. . Cooling units may also be controlled by arranging the room thermostat to start and stop the fan motor or by a combination of motor and refrig erant control. ' . A humidity controller may be used in conjunction with the thermostat as a high limit control to permit the cooling and dehumidifying of the air 695 Heating Ventilating Air Conditioning Guide 1938 whenever the relative humidity rises above some predetermined point such as 60 per cent even though the thermostat is satisfied. This control is desirable on damp days or in conditions where the humidity load may become excessive, but its operation will result in excessive cooling unless some means of reheating is provided. Unit Ventilators - There are various types of unit ventilators available but in general all types are designed to draw air from the outside or to mix outside and recirculated air, heat it and introduce it into the room under control of a thermostat. In the application of control to unit ventilators the essential require ment is that the action be graduated to prevent sudden changes in the temperature of the discharged air and where direct radiation is used in conjunction with the unit that the cycle of control be so arranged that steam will be admitted to the direct radiation only when the unit is unable to carry the heating load. This arrangement prevents the unit from delivering air at low temperatures to offset the overheating effect of the direct radiation and results in the delivery of a higher percentage of tempered air. There are two general types of control applied to unit ventilators as follows: .- 1. The mixing or by-pass damper type of unit is provided with a damper, equipped with a damper motor, which, under control of the thermostat, passes air through and around the heating element in such proportion as to maintain a uniform room tempera ture, the two streams of cold and tempered air being mixed and diffused at the ceiling. A control valve may also be used on the steam supply to the heating element of the unit and should be arranged to throttle the steam supply when the damper approaches a position to by-pass all of the air. . The outside air damper of this type of unit is usually provided with a damper motor and controlled by a remote manual switch to assume either a fully open or fully closed position. 2. The recirculating type of unit ventilator is equipped with a control valve on the steam supply to the heating element of the unit and with a damper motor on the outside air-recirculating air damper, both under the control of the room thermostat. Some units are so arranged that a mixture of outside air and recirculated air passes through the heating element and others so that only the recirculated air is heated. The fundamental requirements of control as applied to this type of unit is that the steam supply to the direct radiation, the steam supply to the unit ventilator and the mixing of outside and recirculated air be accomplished in a definite cycle or sequence to meet the requirements of the particular unit used and differs from the mixing damper type of unit in that the percentage of outside air and recirculated air delivered by the unit is determined by room temperature. The damper motor is sometimes arranged so that a fixed minimum quantity of outside air is delivered continuously as soon as the room has reached a predetermined temperature. A limit thermostat, either in the mixing chamber or in the discharge of the unit, is sometimes used in conjunction with the room ther mostat, so arranged that the action on either the control valve or the dampers, or both, is stopped when a predetermined minimum temperature has been reached in the unit discharge, to prevent delivery of air at a lower temperature. For additional information on the control of unit ventilators when installed and operated under various types of applications refer to Chapter 23. . 696 Chapter 37. Automatic Control All Year Conditioning Units It is desirable to provide for automatic change-over between the cooling and heating cycles in the control system for all year conditioning units because of the probable necessity of changing over a large number of units if done manually. A control system for an all year conditioning unit providing for the automatic change-over is shown in Fig. 7. Operation of the control equipment is as follows: 1. During the Heating Cycle. Combination controller T\ measures the temperature in the space being conditioned and opens control valve Vi so as to admit steam to the heating coil whenever heat is required so as to maintain a fixed temperature in the space. Combination controller Ti also measures the relative humidity in the conditioned space and opens Fig. 7. All Year Air Conditioning Unit with Complete Automatic Control control valve Vi so as to admit water to the sprays whenever moisture is required in the space. 2. During the Cooling Cycle. Combination controller Tt measures the temperature and humidity in the conditioned space and opens refrigerant -- control valve Vs, thereby admitting refrigerant to the cooling coil when ever cooling is required to maintain the temperature or relative humidity within predetermined maximum limits. The temperature control point of controller Ti must be set at a lower point than that of controller Ts in order to provide for the automatic change-over between the cooling and heating cycles. As an example, controller Tx might be set at 72 F and controller Ti at 76 F. As the temperature in the space approaches 72 F, it would indicate a change from . the cooling to the heating cycle and when the temperature in the space approaches 76 F, it would indicate a change from the heating to the cooling cycle, and the corresponding controllers would assume command. In the same way, the relative humidity control point of controller T\ would be set at a lower point than that of controller 7V As an example-, Ti might be set at 35 per cent and Ts at 60 per cent. 697 Heating Ventilating Air Conditioning Guide 1938 CONTROL OF AUTOMATIC FUEL APPLIANCES It is essential that automatic controls be used with oil burners, gas burners, and stokers in order to maintain even temperatures and provide safe and economical operation of the heating plant. There are many types of burners and many types of automatic control, and it is essential that the proper type of control equipment be selected to fulfill the require ments of the burner equipment and its application. Combustion regulation equipment should be used on the larger com mercial and industrial applications to control the secondary air supply and thereby provide for economical operation. This type of control will usually consist of a pressure regulator which measures and controls the pressure over the fire and which thereby indirectly regulates the carbon dioxide percentage in the flue gas. On all automatically-fired steam boilers it is advisable to provide control equipment which will stop the burner operation in case the boiler water line falls below a predetermined level of safety. Thermostats used to control automatic fuel appliances may be provided with clock mechanisms which will operate to maintain lower temperatures during night hours for economy of fuel. Oil Burner Controls In the normal oil burner installation as encountered in residential and small commercial installations, the burner operation is frequently regu lated by electric controls and primarily governed by a room thermostat. It is essential that a limiting control be incorporated in the control system to prevent the temperature of the heating medium from exceeding any predetermined safe maximum. The type of limit control selected will depend on the type of the heating system. In a warm air furnace instal lation, a limit control would be used, reacting to the temperature of the heated air in the bonnet of the furnace; in a hot water system a control reacting to the temperature of the water in the boiler; and in a steam ' system a control reacting to the pressure of the steam in the boiler. In addition to the normal control of the burner from the room ther mostat and limit control, it is necessary that a combustion safety device be used to prevent operation of the burner under hazardous conditions. The oil fire is automatically ignited by means of gas, electric spark or incandescent element and the combustion safety control acting through a sequence device permits the burner operation only when the fire is prop erly established as the burner starts up. A further function of the com bustion safety control is to react to any major disturbance in the flame during the running operation, shutting down the burner arid preventing the discharge of unburned fuel.if for any reason the flame is extinguished. Gas Burner Controls In the case of the domestic burner, full automatic operation is the normal requirement and the burner is started and stopped at the com mand of a room thermostat which, in turn, opens and closes a control valve in the gas supply line. For purposes of. preventing abnormally high temperatures in the bonnet of gas-fired furnaces or in the temperature of 698 Chapter 37. Automatic Control the water in gas-fired hot water heating boilers or excessive pressures in gas-fired steam boilers, temperature and pressure limit controls are used. Ignition is normally secured through the use of a gas pilot flame and a safety device is provided, utilizing the heat of the pilot flame in such a manner that if the pilot light is extinguished for any reason, the main gas valve cannot be opened. For satisfactory and economical operation, all automatically fired gas burners should be equipped with pressure regu lators on the gas supply line. Stoker Controls Domestic stokers are normally placed under command of a room thermostat for primary operation subject also to the command of a limit control to prevent their operation when conditions in the boiler or furnace exceed predetermined safe maximums. Utilizing coal as fuel, automatic ignition is not provided and the stokers, once ignited, maintain their fire, merely changing the rate of combustion by changing the draft and the rate at which the coal is fed. Thus, at the command of the room ther mostat the stoker motor is started, driving a forced draft fan and fuel feeding mechariism. The rate of combustion is thus increased and this ' operation continues until the thermostat has been satisfied when the . motor is stopped, and the fuel in the combustion chamber continues to burn at a slow rate with reduced draft. At certain seasons of the year, the operation of the stoker under the requirements of the thermostat may be so infrequent that there is a possibility of the fuel in the combustion chamber burning out or the fire going out between operations. To prevent this occurrence, automatic controls may be utilized to operate the stoker independently of ther mostat requirements, sufficiently to sustain the fire either through a timing device functioning for short periods at predetermined intervals or through a temperature control device reacting to minimum stack or boiler temperatures. Control may also be utilized to prevent stoker operation and the delivery of coal into the combustion chamber in the event that the fire has gone completely out. This control is governed normally byjhe stack temperature and shuts down the stoker after a predetermined minimum stack temperature is reached. . RESIDENTIAL CONTROL SYSTEMS The control installation in a residence may vary from the simple regulation of a coal-fired heating plant to the completely automatic all year air conditioning system. Residential installations with automatic fuel burning appliances, such as oil burners, gas burners or stokers, are normally equipped with single room thermostat, limit and safety controls as outlined above under Control of Automatic Fuel Appliances. Coal-Fired Heating Plant Control in the normal coal-fired' domestic heating plant consists of regulating the combustion rate in accordance with requirements. This function is accomplished by a spring or electric-driven damper motor which under the command of a room thermostat and through chain linkage, operates the draft and check dampers of a boiler or warm air 699 Heating Ventilating Air Conditioning Guide 1938 furnace. Such installation should be protected against excessive tern- . perature or pressure by means of a limit control serving to check the fire when temperature or pressure conditions at the boiler or furnace reach a predetermined maximum. '. All Year Domestic Hot Water Supply Hot water of steam heating boilers with automatic'fuel burning ap pliances can be used for all year heating of domestic water supply. The fuel burning appliance in this case is controlled from the temperature of water or pressure of steam in the boiler to maintain uniform boiler con ditions and domestic hot water is heated by means of an indirect heater. The heating of the residence is normally governed by means of a ther mostat which operates a control valve in the flow line of a gravity hot water or a steam system, or controls the operation of a circulating pump in a forced circulation hot water system.' `' ' Air Conditioning Systems Residential air conditioning systems are of various types normally including a heating source and a motor-driven fan for circulating air. In addition, such installations may involve spray-head equipment, the purpose of which may be only to supply humidity, or which, in some instances, are of greater capacity and serve not only to humidify but to wash the air passing through them. It is also common practice to include dry filters to aid in air cleaning. Such installations distribute suitably heated and humidified air during the heating cycle, and during the summer or cooling cycle may be used effectively as conditioners if the washer unit is supplied with water at suitable temperature or if such an installation is equipped with other refrigeration means. During the heating cycle the regulation of temperatures is normally one or the other of the problems previously discussed in connection with . the various types of heating sources described, such as the oil burner, gas burner, stoker or the coal-fired heating plant under automatic control. Regulation of: the humidity during the heating cycle is normally accom plished by opening and closing a solenoid water valve supplying water to the spray-heads, the solenoid valve being under control of a room type humidity control. In the average installation the fan is permitted to run only during such intervals as the thermostat is calling for heat or at the command of a limit control to prevent the overheating of the bonnet of a warm air furnace. The limit control should also prevent the operation of the fan at the command of the thermostat until the circulating air ternperature has increased to a predetermined point. When cooling equipment is provided in such installations, control during the cooling cycle will be an adaptation of the control principles described for central fan systems selected for the type of cooling equip ment utilized. The selection of automatic control equipment for residential air con ditioning systems is just as important as for commercial installations. Fewer controls are generally used and systems are usually less com plicated except in the case of a very large residence, installation when the control system may become as complete as the commercial installation. 700 -.Chapter 37. Automatic Control CONTROL OF REFRIGERATION EQUIPMENT The most common means of providing cooling for air conditioning may be divided into four general classifications as follows: - . Compressor. Type Refrigeration .. .. . Refrigeration compressors may furnish refrigerant to direct expansion cooling coils through which air is being passed, or to coils in cooling tanks through which water is passed which is then pumped to air washers or cooling coils through which the air is passed. . In either case the compressor motor may be started and stopped in order to meet the demand for refrigeration or a pressure controller may be used to regulate the low side or suction pressure of the compressor. When the latter method is used, the flow of refrigerant to codling coils may be regulated by the opening and closing of a solenoid refrigerant valve at the command of a temperature controller or thermostat. A high pressure cutout as an individual unit or in combination with either a temperature or pressure controller provides a safety feature against the development of excessive pressures on the high side of the compressor. - .` ' Refrigeration by Ice When ice is used for the cooling or dehumidification of air, it is usually placed in bunkers and water is sprayed over it. This water, after being cooled, may be used in air washers or surface cooling coils and is usually returned to the bunker for additional cooling after being used. Control of the water temperature leaving the cold water tank may be maintained by a temperature controller, which measures the temperature of the water in the tank and modulates a control valve in a by-pass which permits a portion of the return water to return directly to the tank instead of passing through the sprays. Vacuum Refrigeration A vacuum refrigerating system consists of an evaporator, compressor, condenser and auxiliaries. The refrigerant used is water, and water vapor (steam) is the power medium. Water which has been passed through an air washer or cooling coil is sprayed directly into the evaporator or water cooler where it is cooled by its own evaporation. A condenser is attached directly to the compressor discharge and its function is to recondense the water vapor drawn from the evaporator, plus the steam which supplies the energy for compression. The temperature of the cold water leaving the flash chamber should be measured 6y a temperature controller which will in turn operate a two position or positive control valve installed in the steam line to the jet so as to permit steam to flow only when cooling is required. If city water is used in the condenser, the amount of water should be modulated according to the demand as measured at the condenser outlet by means of a temT perature controller and control valve. .. Heating Ventilating Air Conditioning Guide 1938 Refrigeration by Well Water When well water is available in sufficient quantities at low temperatures during the cooling season, it may be pumped directly to air washers or cooling coils. Control is usually effected through control valves on the water supply to the cooling unit actuated by temperature or humidity controllers, or both, located either at the outlet of the conditioner or in the conditioned space. INDUSTRIAL PROCESSES There are many industrial processes requiring automatic temperature and humidity regulation.' The control equipment operates on the same principles that have been described, but it is often especially designed for each particular process. Each installation, or the installation for each process, is likely to be a problem peculiar to that process. PROBLEMS IN PRACTICE 1 What important functions of heating, ventilating, and air conditioning systems do automatic controls fulfill? Controls are applied to maintain adequate requirements for human comfort and efficiency; to maintain requirements for industrial processes; to obtain economy in operation; and to provide necessary safety measures. .. . 2 How may temperature control be obtained in a room heated by a unit heater? . With constant steam supply, the unit heater motor may be started or stopped by a thermostat, either directly or through a relay. With intermittent steam supply, opera tion of the motor by thermostat can be limited to the time that steam is available, by using a reverse-acting temperature or pressure limit switch. 3 How may temperature control be obtained in a room cooled by a selfcontained mechanical unit? - - The fan operation may be controlled by a manual switch, while a room thermostat in con junction with a solenoid valve may regulate the flow of the refrigerant to the coil. The thermostatic circuit might be operative only when the fans are running; and the com pressor might be controlled by refrigerant pressure. - 4 How may temperature control be obtained in a room heated by an auto matically-fired warm air furnace? A room thermostat might control the combustion unit; and a limit switch in the top of the furnace unit, when at a low setting of its control might operate the fan whenever there is a rise of temperature, and when at a high setting of its control it might shut off the combustion unit. A room humidity control operating a solenoid valve on the water supply to the humidifier, or operating a relay on the recirculating pump motor to the humidifier, may be connected in parallel with the fan motor. Humidification may be supplied only when heat is supplied and when the humidity control acts in conjunction with a time switch. 5 How may humidity be controlled in a unit humidifier for a steam or hot water heating plant? Since heat is required for evaporation, a temperature limit switch, preferably of the immersion type, may be placed in the heating supply riser to cause the unit to be in operative when heat is not available. A room humidity control will operate a solenoid valve on the water supply to the sprays. Both the solenoid valve and the humidity control may be electrically wired in parallel with a fan motor, and be subject to the temperature limit switch. 702 Chapter 38 MOTORS AND CONTROLS Direct Current Motors, Alternating Current Motors for Single Phase and Polyphase, Special Applications, Classification of Motors, Manual Control, Automatic Control, Pilot Controls, Direct Current Motor Control, Squirrel Cage Motor Control, Multispeed Motor Control, Slip Ring Motor Control, Single . Phase Motor Control THE electric motor, available in many different types suitable for various services, is now the most widely used form of prime mover. The equipment for starting, controlling and protecting these motors varies with the type and with the functions it is desired to attain. Motors used for heating, ventilating and air conditioning applications may be divided into two general classifications as.follows: 1. For use with direct current. 2. For use with alternating current. . DIRECT CURRENT MOTORS There are three types of direct current motors available: 1. Shunt. Wound. 2. Compound Wound. 3. Series Wound. Shunt Wound motors being suitable for application to fans, centrifugal pumps, or similar equipment where the amount of starting torque required is relatively small, are used for the majority of applications in the field of heating, ventilating and air conditioning. They may be used on reciproeating pumps and compressors, if started under unloaded conditions. Compound Wound motors are required for application to compressors, stokers, reciprocating pumps when started under loaded conditions, and also when applied to similar equipment where high starting torque is required. Whenever frequent starting makes high starting and accelerat ing torque desirable, or where sudden changes of load are encountered, compound wound motors are used. Series Wound motors find only limited application in a few special cases and are available in only a limited range of sizes. 703 Heating Ventilating Air Conditioning Guide 1938 Speed Characteristics Direct current motors are available with speed, characteristics of four types: 1. Constant speed. 2. Adjustable speed. 3. Adjustable varying speed. 4. Varying speed. Constant Speed motors may be shunt wound or compound wound. Shunt wound motors have a nearly flat speed-load characteristic, with a regulation of 15 per cent for up to % hp,.12 per cent for one to 5 hp and 10 per cent for 1]/q, hp and larger, based on full load speed. Compound wound motors have a speed regulation over the range from full load to no load of not more than 25 per cent, based on full load speed. Adjustable Speed motors are usually shunt wound since it is impractical to maintain the proper relation between the shunt and series fields of compound wound motors when wide variations of the field strength are required to obtain the speed adjustment. Adjustment of the speed of shunt wound motors is obtained by field control on motors rated at % hp and larger, with the minimum or base speed at full field strength and higher speeds at reduced field strength- (obtained by adding resistance in the field circuit). The speed regulation from no load to full load will not exceed 22 per cent for 2 to 5 hp; nor 15 per cent for hp and larger. Below 2 hp, the regulation may exceed 22 per cent. If closer speed regulation is required, specifically wound motors must be obtained. - Practically constant horsepower output is obtained at all speeds up to a ratio of 2 to 1. For higher speed ratios, the horsepower rating at the minimum speed is less than at the maximum speed, this difference varying with the speed ratio. High efficiency is maintained over the entire speed range. Most listed constant speed motors are suitable for operation up to a speed ratio of 2 to 1 by the use of proper control equipment. Adjustable Varying Speed motors may be either shunt or. compound wound and speed adjustment is obtained by adding resistance in series with the armature. The speed thus obtained is always below the rated full-field speed. Any standard shunt or compound wound constant speed motor may be used in conjunction with the proper armature resistor. The usual range of speed reduction is 50 per cent. The speed obtained for any setting of the resistor depends on the load of the motor and will vary with this load. . The speed regulation at high speed is comparable to a constant speed motor, but becomes poorer as the speed is decreased. . When operating at reduced speed, an increased torque requirement which the motor could easily handle at rated speed is easily sufficient to stall the motor; for example, a motor operating at two-thirds speed would be stalled by a torque about 50 per cent in excess of the normal requirement. The efficiency of the motor is reduced as the speed is reduced, since the 704 Chapter 38. Motors and Controls loss in the resistor is greater at lower speeds. Speed reduction by armature control is usually selected where: 1. A wide speed range is not required. 2. Close speed regulation is not necessary. 3. Operating time at reduced speed is short. 4. Operating load at reduced speed is small so that the reduced efficiency can be ignored. 5. The rating is less than 1 hp. Varying Speed motors are series wound and the speed varies with the load on the motor. They should be used where: 1. The load is practically constant or increases with speed. 2. The motor can easily be controlled by hand. They should not be used where there is a possibility of operation without load or at a reduced load, as the speed of the motor may become dangerously high. For shunt wound motors with full field strength, the starting torque varies almost directly with the starting current, which is dependent on the ' resistance in the armature circuit. With varying positions of the starting . rheostat, it is possible to obtain a wide range of starting torque, within the limits of starting current permitted by the power company. A compound wound motor requires somewhat less current for the same starting torque. The maximum torque of shunt, series, and compound wound motors is limited by commutation. ALTERNATING CURRENT MOTORS Alternating current motors may be divided into two main groups, namely, (1) those operating on single phase current, and (2) those oper ating on polyphase current. 1. Single phase motors are available in four common types: a. Capacitor motors. 1. Full capacitor. ' 2. Capacitor start-induction run. . ' b. Repulsion induction motors. c. Repulsion start, induction run motors. d. Split phase motors. . 2. Polyphase (2 or 3 phase) motors are available in four common types: a. Squirrel cage induction motor. b. Automatic start induction motor. c'. Slip ring, wound rotor induction motor. d. Synchronous motor. . Where the public utility supplying the current determines that a particular installation should be served with polyphase current, it is generally understood that the major portion of the motors will be for polyphase current, although it is commonly acceptable for the smaller motors to be single phase.' This will limit the use of single phase current to the smaller motor- ratings and the polyphase to the larger motors. Domestic and semi-commercial installations will invariably be single phase. 705 Heating Ventilating Air Conditioning Guide 1938 Single Phase Motors .' Capacitor type motors are available in ratings up to 10 or 15 hp for general purposes. These motors are recommended for pumps, compressors and fan duty including housed centrifugal fans and propeller fans. The general purpose motor is commonly known as a high torque capacitor motor having approximately 300 per cent starting torque with normal current and having a different value of capacitance for starting and running which is automatically changed over by a mechanical or electrical means. Capacitor motors for fan duty are usually divided into the open high torque type for belted fans and the totally inclosed non-ventilated low torque type for propeller fans mounted directly on the motor shaft. The open low torque capacitor motor may be used with small centrifugal fans mounted on the motor shaft. . Although the motors for belted fans are called high torque, the available starting torque is somewhat less than the torque of the general purpose motor and the slip at full load is approximately 8 per cent. With this larger amount of slip, adjustable speed down to 60 or 70 per cent of rated speed may be obtained by line voltage variation. Motors for propeller fan drive may be supplied with sleeve bearings to obtain greater quietness in the smaller sizes where the fan thrust does not exceed approximately 25 lb. For larger fans, thrust ball bearing motors should be used. Low torque capacitor motors have approximately 50 per cent starting torque and do not change the value of capacitance from start to run. Capacitor motors with high slip may have taps brought out from the main winding which when connected to the line, give a second speed of from 65 to 70 per cent of the normal speed. This type of motor must be specially designed for the individual fan, otherwise the correct low speed will not be obtained. Care should be exercised in applying it to centrifugal fans where restriction to the air flow through the use of adjustable dampers changes the motor load and consequently the speed. This same effect is also found in transformer speed controllers,, however, a series of trans former taps allow for a selection which partially overcomes the effect of change in motor load. Capacitor start-induction run motors are usually confined to the smaller horsepower ratings and differ from the capacitor motors by having no running capacitor. The value of starting capacitance used may vary with the different types of applications involved. These motors may be used for practically any of the applications met in air conditioning. However, consideration should be given to the fact that they are not as quiet as a capacitor motor. Repulsion induction motors start as repulsion motors and operate under full speed as combined repulsion and induction motors through the in herent characteristics of the motor which has, in addition to the wire . winding with commutator, a buried squirrel cage winding. No additional switching devices are required to change over from start to run. This andthe repulsion motor described below may be used for constant speed drives where high starting torque is required and where commutator and brush noise is not a factor. 706 Chapter 38. Motors and Controls The repulsion start-induction run motor starts as a repulsion motor, has a switching means for transferring from start to run which short circuits the commutator and permits operation under full speed as a wound induction motor. This motor is suitable for applications similar to those for which the repulsion induction motor is used. The split phase motor has a high resistance auxiliary winding in the circuit during starting which is disconnected through the action of a centrifugal switch as the motor comes up to speed. Under running con ditions, it operates as a single phase induction motor with one winding in the circuit. These units are available for the lower horsepower ratings and when equipped with a high slip rotor may be used for adjustable varying speed through line voltage control. - Polyphase Motors . Squirrel cage induction motors are available in three types and a full range of sizes:- ' 1. The normal torque, nonnal starting current squirrel cage motor has close speed regulation, high efficiency, high power factor, medium starting torque, high pull-out torque, and is suitable for general purpose applications. This motor has a large current inrush and a low starting current power factor. It operates with these characteristics only when started directly across the line on full voltage. When central stations require current limiting starting equipment on such motors, the starting torque is less. Current limiting hand operated starters are standard equipment. ' 2. The normal torque, low starting current squirrel cage motor has approximately the same torque as the normal current motor, but the starting current is about 20 per cent less than the normal torque motor on full voltage and ordinarily within the National Electric Light Association locked rotor current limits on sizes up to 30 hp. This motor lends itself toautQmatic or remote control because no current limiting starting equipment is necessary up to and including 30 hp. A magnetic starter with low voltage and thermal relay overload protection gives the most satisfactory service. 3. The high torque, low current squirrel cage motor has a starting torque approxi mately 25 to 50 per cent greater than the normal torque motor on full voltage with starting current approximately 10 per cent less than the normal torque motor started on full voltage, but within the required limits on 30 hp sizes and smaller. These motors are also started directly across the line on full voltage through a magnetic starter or other approved starting device. , These three types of motors are also available in two, three, or four speed designs with variable torque, or constant torque characteristics. Two speed motors may be either single, or two winding; three speed motors are single, two, or three winding; and four speed motors are two, three, or four winding. When a motor is wound with a winding for each speed, better operating characteristics may be obtained because no sacrifice is made for the other speed and operating characteristics ap proaching single winding motors may be expected. Frequently, multispeed motors lend flexibility to an installation that cannot be obtained in any other way. Multispeed motors are started directly across the line through magnetic starting equipment with overload and low voltage protection and com pelling relays to insure starting on low speed regardless of the ultimate running speed. Starting on low speed limits the starting current to the starting current of the low speed winding and consequently lowers the maximum demand, c 707 Heating Ventilating Air Conditioning Guide 1938 CUBBENT Table 1. Classification of Motors Speed Charac teristics Full Voltage Starting Torque Starting Current Hp Range Ttpb OP ' See Footnote* ' 1. Shunt Direct 2. Compound 3. Series Constant Speed Drives Constant Medium Medium All Constant High or Variable Variable High Medium All Medium Small (a) Fans and (c) Centrifugal Pumps' . (b) (c) (e) Recipprocating Pumps and frequent or hand starting (d) Fans direct `. connected : Poly phase 4. Squirrel Cage Constant Normal High All General Purpose 6-8 Times (a) Fans-and (c) Centrifugal Pumps 5. Squirrel Cage Constant Normal Medium Medium (a) Fans and Medium Torque 5-6 Times Small Centrifugal Pumps 6. Squirrel Cage High Torque Constant High Medium Medium 5-6 Times Small (6) Reciprocating; Pumps (e) and Compressors started loaded 7. Automatic Start Constant High High Torque . Low 3 Times Medium (b) Reciprocating Pumps , (e) and Compressors started loaded 8. Slip Ring Wound Rotor Constant High Low All 1-3 Times with sec ondary control (a) and Hoists (b) Reciprocating Pumps (ic) and Frequent (ie) or Hand Start 9. Synchronous High Speed Constant Medium Medium Medium (a) Fans and Cen S-T'Times Large trifugal Pumps 10. Synchronous Low Speed Constant Low Low Medium (a) Reciprocating 3-4 Times Large Compressors Start ing Unloaded Single phase 11. Capacitor Constant High Normal Medium (6) Pumps and Small Compressors 'Applications: a. Drives having medium or low starting torque and inertia (WR*) such as fans and centrifugal pumps or reciprocating pumps and compressors started unloaded. . b. Drives having high starting torques, such as reciprocating pumps and compressors started loaded.' c. Similar to (a) except where frequent or hand starting (large WR*) requires a higher starting and accelerating torque. . d. Fans direct connected. e. Stoker drives. 708 Chapter 38. Motors and Controls Cubbent . Table 1. Classification of Motors--(Continued) TYPE Speed Charac teristics Full Voltage Starting Torque Starting Cubbent Hp Range . Ttpe op Application See Footnote* Single phase - 12' Capacitor Fan Constant High Medium Medium (a).Fans--belted Small 13. Capacitor Fan Constant Low Medium Medium (d) Fans--direct Small 14. Capacitor Start Constant Any Induction Run Medium Medium (u) Fans Small . (b) Pumps and Compressors 15. Repulsion Induction Constant High Medium Medium () Fans Small () Pumps and Compressors 16. Repulsion Start Constant High Induction Run Medium Medium () Fans Small () Pumps and Compressors 17. Split Phase Constant Medium and Adjusttable Medium Frac tional (a) Fans (b) Pumps and Compressors Adjustable Speed Drives 18. Shunt Field Adjustment Constant Medium Medium All Direct 19. Shunt Armature Variable Medium Medium All Resistor . (a) Fans and (e). Centrifugal Pumps (a) Fans and (e) Centrifugal Pumps 20. Squirrel Cage Variable Medium Medium Medium (a) Fans High Slip, . Small Tapped Winding Poly phase . 21. Squirrel Cage Variable High Slip, Trans former Adjust- ' ment Medium Medium Medium Small. (a) Fans 22; Squirrel Cage Constant Medium Separate Wind Multi or High ing or Regrouped Speed Poles Low All (a) Fans (b) Pumps and (c) Compressors Heating Ventilating Air Conditioning Guide 1938 CURRENT Table 1. Classification of Motors--(Continued) TYPE . Speed Charac teristics Full Voltage Starting Torque Starting Current Hp Range Ttpb op Application 8eb Footnote* Poly phase Single PHASE 23. Wound Rotor, Variable Slip, Ring, Ex ternal Secondary Resistance High Low All (a) Fans and (b) Centrifugal Pumps 24. Capacitor High Variable High Torque Tapped Winding Normal Medium (a) Fans, belt Low 25. Capacitor Low Variable Low Torque Tapped Winding Medium Medium (d) Fans, direct Low 26. Capacitor High Torque Trans former Adjust ment Variable Low Low Frac tional (d) Fans 27. Capacitor Low Torque Trans former Adjust ment Variable Low Low Frac tional (d) Fans 28. Split Phase Constant Normal Normal Frac Regrouped Poles tional (d) Fans Often where the central station requires current limiting starting equipment for the normal torque, normal starting current motor, it is advisable to use the normal torque low starting current multispeed motor. High slip polyphase motors may be used for adjustable varying speed drives in a manner similar to that described for capacitor motors, with either a transformer speed regulator or tapped motor windings. It is apparent from these motor characteristics that a squirrel cage motor may be selected for operating any air conditioning and allied equipment. Automatic start induction motors are constructed with two windings on the rotor, one of which is a high resistance, squirrel cage winding used in starting and gives a high starting torque approximately the same as the high torque, squirrel cage. A centrifugal mechanism within the motor switches to the second low resistance winding when the motor comes up to speed, thus obtaining running characteristics equal to the normal torque, normal current squirrel cage motor. The powet factor of the starting current is high. . Slip ring wound rotor motors are built for two classes of service, con stant speed and adjustable variable speed. The motors are identical in- each case and use the same primary control, the only difference being in the secondary control. 710 Chapter 38. Motors and Controls Slip ring motors for constant speed service are used where high starting torque with low starting current is required for bringing heavy loads up to speed. The resistance is in the secondary or rotor circuit, only when starting, and is short circuited when the motor is up to speed. For adjustable varying speed service, part or all of the secondary controller resistance is in the circuit whenever the motor is operating below full speed. The speed obtained with a given resistance in the secondary circuit is dependent on, and changes with the load on the motor. The horsepower developed by the motor is approximately pro portional to the speed, whereas the power required by the motor is practically the same at reduced speed as at full speed, hence the efficiency at reduced speeds is much lower than at full speed. ' Synchronous motors are ordinarily used only where there is a need for, or advantage in, obtaining power factor correction. It is necessary to consider each application as a special case which must be individually engineered, since for satisfactory operation, the combined moment of inertia of the compressor fly wheel and motor rotor must be correctly established. The general classification of motors used for heating, ventilation and air conditioning is shown in Table 1. SPECIAL APPLICATIONS A few applications of motors may require special constructions such as splash proof, explosion proof, fully enclosed, and self-ventilated to meet hazardous or special duty conditions. These requirements are frequently encountered in certain industrial applications, in which cases it is neces sary to select the motors from the viewpoint of service conditions, as well as the required operating characteristics to meet the demands of the machines being driven. CONTROL EQUIPMENT FOR MOTORS In selecting control for alternating and direct current motors it is necessary to determine whether the installation is to be operated by manual or.automatic control. The available controls and the function of each group of apparatus may be outlined as follows: X. Manual Control: a. To establish current. ' (1) Snap switch. (2) Knife switch. (3) Manually operated contactor. (4) Drum switch. . . b. Establish current and add overload protective device. (1) Snap switch with overload element. (2) Knife switch with fuse or thermal cutout. (3) Manual contactor with overload protective device; also reduced voltage starting compensator. (4) Drum switch with overload protection. e. Establish current and add overload and low voltage protective devices. (1) Not used. (2) Not used. 7X1 Heating Ventilating Air Conditioning Guide 1938 (3) Manual contactor or reduced voltage compensator with overload and low voltage release. (4) Drum switch equipped with latch coil to give low voltage release. 2. Automatic Control: a. To start on full voltage. (1) Without overload device. (2) With overload device. (3) With combination overload device and knife switch. b. Reduced voltage starting. (1) Primary resistance type starter. (2) Auto compensator type. (3) Reactance type. .. PILOT CONTROLS In selecting pilot control devices to operate in conjunction with either manual or automatic motor control, it is necessary that they be classified as follows: 1. Two Wire Control. Most thermostats, float switches, and pressure regulators, provide two wire control which gives low voltage release. A three position pilot switch can be used in connection with this method and thus provide manual control. With a low voltage (12 or 20 volt) control circuit it is desirable to use a low voltage thennostat. When this type of thermostat is used it will be found that a saving in the wiring cost results. When using the low voltage thermostat on a control circuit a relay and trans former panel should be used instead of the low voltage coil on the starter. 2. Three Wire Control. Momentary contact start and stop push button stations are usually furnished as standard accessories with automatic starters, which gives low voltage protection. This control cannot be used in combination with two wire pilot devices. In selecting manual control for an alternating or a direct current motor, the common practice is to locate the control near the motor. When the control is installed at the motor, an operator must be present to start and stop or change the speed of the motor by operating the control mechanism. Frequently manual control is employed only as a device to give overload protection and another device is employed to start and stop the. motor. Manual control is used particularly on small motors which operate unit heaters, small blowers, and room coolers in an air conditioning system In other cases manual control in the form of drums, when used with multispeed motors, is only used as a speed setting device with the starting and stopping functions operated automatically through thermostats, and pressure switches. .. Because of the increasing complexity, of air conditioning systems, heating, ventilating and air conditioning equipment is being operated on automatic control with less dependence on manual operation and regu lation. Automatic control of motor starters may be accomplished by the use of remote push button stations, by a thermostat, float switch, pressure regu lator or other similar* pilot devices. An added advantage of automatic control is that the main wiring for the starter may be installed near the motor, while the starter may be operated by a control device located else where. In the majority of air conditioning installations, requiring motors 1 hp and larger, two or three phase alternating current is usually supplied. 712 Chapter 38. Motors and Controls DIRECT CURRENT MOTOR CONTROLS Air conditioning installations using direct current power are now only' used where alternating current is not available. Direct current motors are always started through starters, which are devices using a resistance to be put in series with the armature circuit during starting only, the resistance being gradually cut out as the motor comes up to speed: The starting current is held within safe limits by the use of the resistance. The speed of a direct current motor may be regulated by the following methods: 1. Speed regulation by field control--by using a device with resistance to be put in series with the field winding. After the motor has been started to be used to increase the speed of the motor above full field speed. . 2. Speed regulation by armature control--by using devices with resistance to be put in series with the armature circuit to be used to reduce the speed of the motor below full field or normal speed. 3. Combinations of field and armature control, so that the starting, field control, or armature control may be combined in a single unit. *, , Field control is usually preferred, depending on the size of the instal lation. For example, if a direct current motor were required with speed regulation between 1200 and 600 rpm, a choice of supplying a 1200 rpm motor with armature control or a 600 rpm motor with field control, both giving the same speed variation would be possible. While the 1200 rpm motor with armature control is lower in first cost than the 600 rpm motor with field control, the cost of operating the 600 rpm motor with field control is less and will save the difference in first cost over a period of time depending on the size of installation. A wide speed variation can be easily obtained in a direct current motor by using a combination of field and armature control. SQUIRREL CAGE MOTOR CONTROL To meet the requirements of various drives of an air conditioning system, three-types of squirrel cage, two or three phase motors may be used: ' ' . 1. Normal torque, normal starting current. 2. Normal torque, low starting current. 3. High torque, low starting current. Because of the large current inrush of the normal torque, normal starting current motor, central stations usually require current limiting starting equipment on such motors above 5 hp. To meet the starting current requirements, manual or automatic current limiting starting com pensators are used. These compensators are equipped with '50, 65 and 80 per cent voltage taps, the 65 per cent tap being regularly furnished when the compensator leaves the factory. Motors 5 hp and smaller have starting currents within the requirements of central stations and manual or magnetic, full voltage control may be used. The normal torque, low starting current motor has a starting current which is approximately 20 per cent less than the normal current motor on 713 Heating Ventilating Air Conditioning Guide 1938 full voltage and well within the required current limits on 30 hp sizes and smaller. This motor, therefore, lends itself to across-the-line control because no current limiting equipment is necessary. In selecting motors for fans, pumps, or blowers, it should be noted that while the cost of the normal starting torque, low starting current motor is higher, the cost of full voltage control is lower, so that the total cost of low starting current motors with across-the-line control is lower. A magnetic starter with low voltage and thermal overload protection gives the most satisfactory service. These switches may be controlled by remote push button stations, thermostats, or pressure switches to meet the requirements of any particular installation. The high torque, low starting current motor has a starting current approximately 10 per cent less than the normal torque, low starting cur rent motor when started on full voltage. These motors, most commonly used on compressor drive, can be started directly across-the-line with manual or magnetic starters. Adjustable varying speed motor control by terminal voltage regulation requires a tap-changing switch manually or magnetically operated. Such a control switch operates to alter the voltage applied to the motor by contacting different auto-transformer voltage-ratio taps or by changing the amount of resistance inserted in the primary or line circuit. . ' MULTISPEED MOTOR CONTROL To make an installation more flexible, multispeed motors are available with two, three or four speed designs, with variable torque, constant torque or constant horsepower. characteristics. Multispeed may be' started by means of manual or magnetic starting equipment. When using automatic magnetic control with two, -three, and four speed separate winding or consequent pole motors, control is obtained from a remote point by means of a push button master switch. The various speeds of the motor are obtained from the master switch by simply depressing the correct push button, which is known as selective speed control. It is commonly used in the smaller theatre installations where the fan and motor is located backstage and the speed control is located in the lobby. .. Magnetic multispeed motor controllersv may also be provided with a compelling relay which makes it necessary that the operator press the first speed button before regulating the motor to the desired speed. This assures the operator that the motor is always started at low speed before the motor is adjusted to one of the higher speeds. Starting on low speed limits the starting current to the starting current of the low speed winding, and therefore, permits the use of motors in sizes larger than ordinarily permitted by central stations for full voltage starting. Timing relays, which provide for automatic acceleration, may be used for control. With the automatic acceleration feature, it is only necessary to press the button for the desired speed. The motor will always start in low speed and automatically step up to the desired speed. Where the change of speeds does not occur at regular intervals, and where it is only necessary to. change from one speed to another to take . 714 Chapter 38. Motors and Controls care of seasonal requirements, a manual drum speed selector may be used. This drum is used to select the proper motor speed while an automatic starter is used to start and stop the motor. . The smaller size speed selector drums rated 10 hp at 220 volts and smaller may also be used as a motor starter to make and break the current, as well as, serving as a speed selector device. Reversible or non-reversible drums may be supplied depending on the requirements of the installation. In the large size drums, a separate contactor must be provided to make and break the current. The contactor may be any approved starter. Overload and low voltage'protection may be accomplished by using a magnetic starter. No push button station is required, the handle switch on the drum having the same characteristics as a three wire push button station. In selecting two speed motors for fan, pump, blower, or compressor drive it will be found that the two winding motors are more expensive than the single winding. The control for two speed, two winding motors is more economical and the combined price of the motor and contactor is only slighdy higher. Because of the better performance of the two speed motor and the factor of safety in having two independent motor windings, the increased cost is considered worth the difference. . SLIP RING MOTOR CONTROL When close speed regulation and low starting current is required slip ring or wound rotor motors are used. Slip ring motors are built for two classes of service, constant speed and adjustable varying speed. The motors for the two classes of service are identical, the only difference being in the secondary control used with the motors. Control for both , primary and secondary of a slip ring motor is required. The primary control for a constant or adjustable speed is the same type as used with squirrel cage motors. Manual or magnetic starters, acrossthe-line type, may be used depending on the installation. The starting'current and starting torque of a slip ring motor are almost entirely dependent on the amount of resistance in the secondary control and in the manner in which the secondary control is operated. The National Electric Manufacturers Association has adopted service classi fications which allow a selection of resistors permitting a starting current on the first contact of resistance varying from approximately 25 per cent of full load current to approximately 200 per cent of full load current or more, and permitting the resistor to remain in the secondary circuit of the motor for a period varying from not more than 15 seconds during an interval of operation from 4 minutes to continuous. . Speed regulation of a slip ring motor is obtained by inserting resistance in the secondary circuit and usually provides for a 50 per cent speed reduction when the motor takes its full rated current at normal speed. As resistors are.supplied for both fan duty and constant torque duty, care should be taken in selecting the proper resistors. Slip ring motors when used with centrifugal pumps and fans should have fan duty resistors. Because of the low current inrush of the fan and pump 715 Heating Ventilating Air Conditioning Guide 1938 load a starting resistor NEMA classification No. 15 may be used. For speed regulation resistor, classification No. 93 should be selected. On a compressor drive using an unloader, a constant torque resistor classi fication No. 15 should be used. If the compressor is started under load, NEMA classification No. 56 or 76 are used. For constant torque speed regulation, resistor No. 95 is used. SINGLE PHASE MOTOR CONTROL Where three phase current is not available or where single phase opera tion is preferred, then single phase repulsion induction, capacitor type or multispeed single phase motors may be used. Since the starting currents of all single phase motors are required to be within the starting-current limits established by the local power-supply company, a suitable type of starter may be chosen from the following selection: 1. Enclosed two pole manually operated motor starters with thermal overload protection. ...... 2. Enclosed two pole automatic motor starter operated by a push button, thermostat or similar device, with thermal overload relay and low voltage protection. . 3. A manual or magnetic resistance type starter with low voltage protection. 4. A manual or magnetic control for pole changing motors and for adjustable varying speed motors using an auto-transformer or resistance in the primary circuit to obtain line (or terminal) voltage drop. _ .............. In selecting across-the-line control for single phase capacitor type motors it is usually very desirable to use three pole across-the-line starters. Control for multispeed, single phase capacitor motors may be selected from tables on three phase rating when Consideration is given to the increased current and the necessary switching of connections. PROBLEMS IN PRACTICE 1 When motors are being considered as prime movers,'what are some of the basic considerations that determine the final selection of the correct unit? a. The kind of current available for driving the necessary motors is a primary con sideration. There are two groups of motors available for driving the equipment on any job, which are the direct current type or alternating current type. The proper group selection depends entirely on the current available. b. It is also necessary to decide whether constant speed or variable speed operation is desired. .: c. Consideration must also be given to the type of service required. 1. Whether variable torque or constant torque motors will be required. 2. Whether a high starting torque is required or whether a relatively small starting torque is required. . d. It is important to take into consideration the atmospheric conditions surrounding the motor location. .. 2 t When using direct current motors: a. What three types are available as regards their windings; 6. What four types are available with reference to their speed characteristics?. ,. :, 'i a. Shunt wound; compound wound, and series wound.. : b. Constant speed, adjustable speed, adjustable varying speed, and varying speed. 716 Chapter 38. Motors and Controls 3 With direct current motors as prime movers what type would you use: a. For driving a fan; b. For driving a compressor? " a. A fan requires a relatively small starting torque, therefore, a shunt wound motor would be ideal for this type service. . .. ... b. A compressor has a constant torque, therefore, a compound wound motor would be the proper selection for this duty. '. - . 4 # What is one of the important factors that should be taken into account when a series wound direct current motor is being considered? With a series wound motor the speed varies with the load, therefore this type should never be used where there is a possibility of the motor operating without being loaded. The resultant high speed may prove to be dangerous. . 5 With the use of alternating current motors what two groups are generally considered? - Motors using single and polyphase power supply. * .: ' 6# Under the alternating current group of motors what common types are available: a.. For single phase duty; b. For polyphase duty? . a. Capacitor high torque, capacitor fan--(1) high torque, (2)- iow torque, capacitor start-induction run, repulsion induction, and split phase. b. Squirrel cage--(1) general purpose, (2) medium torque, (3) high`torque, automatic . start high torque, normal torque normal current, normal torque low current, high torque low current, slip ring wound rotor, synchronous high speed, synchronous low speed. 7 t What is the most commonly used of the polyphase motors? . . - The squirrel cage induction motor is the type most generally used for ordinary applica tion. - ; :.. . ' ... 8 # With the use of squirrel cage motors what speed characteristic is available and what construction is used to make these more-flexible? The squirrel cage motor is basically a constant speed motor. However both single phase and polyphase high slip motors are used for adjustable varying speed drive through the use of line voltage control. When using an adjustable varying speed motor, particularly with a centrifugal fan and to a somewhat lesser extent, with a propeller fan, special care should be taken to assure that the fan is closely motored adequately loads the motor) in order to obtain the desired speeds under reduced speed operation. To make the squirrel cage motor more flexible, multispeed units are used quite frequently. These units may be single winding for the two speed unit or for different number of windings depending upon the number and combination of speeds required. For two speed single winding units the second speed is always one-half of top speed. 9 Differentiate between synchronous speed and full load speed of a motor. Synchronous speed is the theoretical or no load speed. With the induction motor there is a certain amount of slip depending upon the load. As a rule, at full load, the speed is approximately 96 per cent of synchronous speed, however, motor manufacturers generally list full load speeds on their motor name plates. The synchronous type of motor has a full load speed which is the same as the synchronous. 10 What are the general requirements usually recommended by the power company, with reference to connecting polyphase motors to the power line? For motors up to and including 5 hp, normal torque, normal starting current type of units can be connected directly to the line. For motors from 5 to 30 hp, both high torque and normal torque, low starting current types of units can be used with across-the-line type of control. Above these sizes, it is necessary to furnish current limiting starting equipment. It is always advisable to check with local power companies as thgre are no standards for V Heating Ventilating Air Conditioning Guide 1938 connecting of loads on the power line and they are likely to vary with different power companies. XI In controlling direct current motors what two methods are used, what speed ranges are obtained, and what is the relative efficiency of each method? In controlling direct current motors, resistance is placed in either the armature circuit or the field circuit. For armature control, the speed is reduced with the increase of re sistance. With the field control, the speed is increased with the addition of resistance in the field circuit. For most listed direct current motors, it is possible to obtain operation up to a speed ratio of two to one with field control equipment. This type of control is used in con nection with shunt wound motors for best results. For speed adjustment by resistance in series with the armature circuit, a reduction of 50 per cent in speed can generally be obtained. This control can be used with either shunt or compound wound motors. The field control method of changing speeds on direct current motors is the most ef ficient. Due to the large current in the armature circuit, this method results in a high loss when the speed is reduced any. appreciable amount. It is well to remember that with field control only constant horsepower output is obtained, therefore, care should be taken that the motor at normal speed is large enough to care for any increase m load as a result of speeding up the unit. 121 What reduction in speed is possible and how is it obtained when alter nating current slip ring motors are used? Speed variation in slip ring motors is obtained by inserting resistance in the secondary circuit. This generally allows for a 50 per cent speed reduction when it is fully loaded at normal speed. From 20 to 30 per cent speed reduction can be obtained through the use of line voltage control of an adjustable varying speed motor with a fan closely motored the fan approximately fully loads the motor). V 718 1 Chapter 39 PIPING AND DUCT INSULATION Heat Losses from Bare and Insulated Pipes, Heat Losses from Ducts, Low Temperature Insulation, Insulation of Pipes to Prevent Freezing, Economical Thickness of Pipe Insulation, Underground Pipe Insulation INSULATION reduces the flow of heat where it is desired to maintain a temperature higher or lower than that of the surroundings. Its use . contributes to the most economical operation of heating and refrigerating systems. * HEAT LOSSES FROM BARE PIPE - Heat losses from horizontal bare iron pipes, based on data obtained from tests conducted at the Mellon Institute, are given in Table 1. The Table 1. Heat Losses from Horizontal Bare Iron Pipes Expressed in Blu per linear foot per degree Fahrenheit difference in temperature between the pipe and surrounding still air at 70 F Nominal Pipe (Inches),..-- 120 F Hot Water 150 F 180 F 210 F 227.1 F (5 Lb) Temperature Difference Steam 297.7 F (SO Lb) 337.9 F : (100 Lb) Vi Vs 1 114 1 Vi 2 2Vi 3 iVi 4 4J4 5 6 8 10 12 S0F 0.543 0.660 0.791 0.979 1.09 1.34 1.58 1.88 2.13 2.36 2.60 2.87 3.39 4.32 5.32 6.25 80 F 0.573 0.690 0.829 1.02 1.15 1.40 1.67 1.99 2.24 2.50 2.75 3.02 3.56 4.55 5.61 6.62 no F 0.605 0.729 0.878 1.087 1.220 1.491 1.778 2.100 2.380 2.650 2.920 3.200 3.775 4.830 5.925 6.995 140 F 0.638 0.762 0.920 1.15 1.29 1.58 1.87 2.22 2.51 2.78 3.08 3.38 4.01 5.14 6.34 7.46 ISM F 0.656 0.781 0.953 1.184 1.335 1.637 1.937 2.301 2.585 2.873 3.170 3.493 4.115 5.270 6.551 7.670 227.7 F 0.742 0.886 1.084 1.345 I..520 1.866 2.215 2.641 2.972 3.312 3.655 4.030 4.755 6.120 7.592 8.900 267.9 F 0.796 0.955 1.166 1.450 1.640 2.015 2.388 2.853 3.215 3.582 3.956 4.368 5.153 6.635 8.245 9.670 719 Heating Ventilating Air Conditioning Guide 1938 . Fig. 1. Chart for Estimating Dollar Value of Heat Loss . from Bare Iron Pipes. (See Table l)a This chart is based on 100 linear feet per 1000 hoars. For fractions or multiples of these factors, multiply by proper percentage. . monetary value of the loss of heat given in Table 1 may be obtained by means of Fig. 1 for various heating system efficiencies, temperature differ ences, and calorific values and costs of coal. To solve a problem, select the proper heat loss coefficient from Table 1 and locate this value on the upper left hand margin of the chart. Then draw lines in the order indi cated by the dotted lines, the dollar value of the heat loss per 100. linear feet, of pipe per 1000 hours being given on the upper right hand scale. In using this chart, the cost of coal should also include the labor for hand ling it, boiler room expense, etc. 720 Chapter 39. Piping and Duct Insulation Table 2. Heat Loss from Horizontal Bare Bright Copper Pipe Expressed in Btu per linear foot per degree Fahrenheit bet-wee', the pipe and surrounding still air at 70 F ' Nominal . Pipe (Inches) Hot Water (Type K Copper Tube) Steam (Standard Pipe Sue Pipe) 120 F ISO F 180 F 210 F 227.1 F (5 Lb) Temperature Difference 297.7 F 1 337i>F (50 Lb) 1 (100 Lb) 50 F A 0.180 M . 0.236 l 0.290 1M 0.340 lK v2 0.390 0.490 2'A 0.580 3 0.680 3A ' 4. 0.760 0.940 4A 5 L020 6 1.160 8 1.460 80 F 0.210 0.275 0.338 0.400 0.463 0.525 0.675 0.788 0.888 1.000 1.200 1.375 1.725 110 F 0.218 0.291 0.354 0.418 0.473 0.600 0.709 0.848 0.946 1.045 i .255 1.410 1.820 HOF 0.229 0.307 0.373 0.443. 0.507 0.628 0.750 0.871 1.000 1.107 1.320 1.500 1.890 157.1 F 0.299 0.357 0.440 0.510 0.598 . 0.719 0.840 0.987 1.114 1.210 1.335 1.465. 1.685 2.100. 227.7 F 0.338 0.408 0.492 0.571 0.671 0.813 0.953 1.107 1.235 1.361 1.495 1.670 1.890 2.373 267.9 F 0.355 0.418 0.523 0.598 0.710 0.851 1.008 1.165 1.307 1.456 1.488 1.755 1.942 2.510 ------------------- A AWJtt uftiuui vurroA i ifn. Vjl VC.IN UNt Thin Coat of Clear Lacquer Expressed in. Btu per linear foot per degree Fahrenheit between the nnd surrnurrd-itsir c/77 /> rt t 7/1 E* Nominal Fife , ' (Inches) . Hot Water (Type E Copper Tube) Steam (Standard Pipe Sue Pipe) 120 F 150. F . 180 E. 227.1 F 297.7 F 337.9 F (5 LW--- : (50 Lb) " -.(100 Lb).-'' ' Temperature Difference A % 1 -~ lK iA. 2 IA 3 aA 4 4A 5 6. 8 - 50 F 0.240 ,0.320 0.390 0.470 0.540 0.690 0.840 0.960 1.100 1.241 1.480 1.700 2.200 80 F . 0.265 0.356 0.437 0.537 0.612 0.762 0.937 1.025 1.250 1.400 1.685 1.936 2.500 , 110 F 0.282' 0.373 0.463 0.554 0.645 0.818 0.991 1.135 1.318 1.480 1.790 2.052 . 2.630 ; 140 F . 157.1 F . 0.307 0.414 0.507 0.614 0.714 0.892 1.085 1.270 1.442 1.556 1.965 2.272- 2.854 0.401 0.477 0.598 0.700 1.208. 1.005 1.178 1.400 1.580 1.750 1.910 2.130 2.450 3.120 227.7 F 0.461 0.571 0.681 0.812 0.966 1.164 1.361 1.625 1.845 2.040 2.240 2.415 2.810 3.425 267.9 F 0.478 0.578 0.710 0.840 0.990 1.201 1.420 1.700 1.905 2.130 2.350 2.610 . 2.990 3.730 Heat losses from horizontal copper tubes and pipes with bright, bright lacquered and tarnished surfaces are given in Tables. 2, 3 and 4'. : In order to determine heat losses per linear foot of pipe from known losses per square foot, it is necessary to know the area in square feet per ^rm Copper Fiping, by R. H. Heilman (Healing Piping and Air Conditioning. September. 721 X Heating Ventilating Air Conditioning Guide 1938 Table 4. Heat Loss from Horizontal Tarnished Copper Pipe Expressed in Btu per linear foot per degree Fahrenheit between the pipe and surrounding still air at 70 F Nominal Peps Size (Inches) Al M l lK 1V2 '2 . 2A 3 3H '4 4H 5 6 8 Hot Water (Type K Copper Tube) Steam (Standard Pipe Sue Pipe) 120 F 150 F 180 F 210 F 1 227.1 F (5 Lb) 297.7 F (50 Lb) 337.9 F (100 Lb) Temperature Difference 50 F' 0.250 0.340 0.440 0.500 ' 0.580 0.730 0.880 1.040 1.180 1.460 80 F 0.287 0.381 0.475 0.559 0.656 0.825 1.000 1.175 1.350 1.500 1.600 1.840 2.400 1.812 2.125 2.685 110 F 0.300 0.409 0.509 0.618 0.710 0.890 1.091 1.272 1.454 1.635 1.980 2.270 2.910 140 F 0.321 0.429 0.536 0.622 0.750 0.957 1.143 1.343 1.535 1.715 2.071 2.430 3.110 157.1 F 0.433 0.533 0.636 0.764 0.904 1.101 1.305 1.560 1.750 1.941 2.131 2.387 2.740 3.310 227.7 F 0.500 0.543 0.746 0.878 1.053 1.273 1.490 1.800 2.020 2.240 2.465 2.770 3.210 4.050 267.9 F 0.530 0.654 0.803 0.934 1.120 - 1.364 1.605 1.940 2.170 2.430 2.650 2.990 3.440 4.370 linear foot of pipe. Table 5 gives these areas for various standard pipe sizes, and Table 6 for copper tubing, while Table 7 gives the area in square feet for flanges and fittings for various standard pipe sizes. Very often, when pipes are insulated, flanges and fittings are left bare due to the belief that the losses from these parts are not large. However, the fact that a pair of 8 in, standard flanges having an area of 2.41 sq ft Table 5. Radiating. Surface per Linear Foot of Pipe Nominal , Pipe Size (Inches) " Yi Vt, l Wi m Surface ` Area (Sq Ft) 0.22 0.275 0.344: 0.435. 0.498 Y Nominal Pipe Size . (Inches) 2 2K 3 3^ 4 . Surface Area (Sq Ft) . 0.622 0-.J53 0.917 1.047 1.178 Nominal Pipe Size (Inches) 5 6 8 10 12 Surface Area (Sq Ft) 1.456 1.734 2.257 2.817 3.338 Table 6 : Radiating Surface per Linear Foot of Copper Tubing (Inches) ' Vi l .. m m (Sq Ft) 0.164 0.229 0.295 .. .0.360. 0.426 Tube Size (Inches) 2 m `3 4 Surface Area (Sq Ft) 0.556 0.687 0.818 0.949 1.080 : Tube Size (Inches) 5 6. 8 Surface Area (S Ft) 1.342 .. 1.604 2.128 722 Chapter 39. Piping and Duct Insulation Table 7. Areas of Flanged Fittings, Square Feet3 Nominal Pipe Size (Ingres) i m m 2 2A 3 m 4 4A 5 6, 8` 10 . 12 . Flanged Coupling 90 Deg Ell Long Radiub Rij, Tee Cross Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy 0.320 0.383 0.477 0.672 0.841 0.945 1.122 1.344 1.474 1.622 1.82 2.41 3.43 4.41 0.438 0.795 1.015 0.892 1.083 1.235 1.575 1.622 2.07 0.510 0.957 1.098 1.084 1.340 ; 1.481 1.925 1.943 2.53 0.727 0.848 1.174 1.65 1.332 2.01 1.337 1.84 1.874 11.815 2.68 2.16 2.54 3.09 2.38 3.32 3.54 4.06 1.107 2.09 2.57 2.32 2.76 3.21 4.05 4.19 5.17 1.484 2.38 3.49 2.68 3.74 3.66 5.33 4.77 6.95 1.644 2.98 3.96 3.28, 4.28 4.48 6.04 5.83 7.89 1.914 3.53 4.64 3.96 4.99 5.41 7.07 7.03 9.24 2.04 3.95 5.02 4.43 5.46 6.07 7.72 7.87 10.07 2.18 4.44 5.47 5.00 6.02 6.81 8.52 8.82 10.97 2.78 5.13 6.99 5.99 7.76 ' 7.84 10.64 10.08 13.75 3.77 6.98 9.76 8.56 11.09 10.55 14.74 13.44 18.97 5.20 10.18 13.58 12.35 15.60 15.41 20.41 19.58 26.26 6.71 13.08 17.73 16.35 18.76 19.67 26.65 24.87 34.11 Including areas of accompanying flanges bolted to the fitting. would lose, at 100 lb steam pressure, an amount of heat equivalent to more than a ton of coal per year shows the necessity for insulating such surfaces. HEAT LOSSES FROM INSULATED PIPES The conductivities of various materials used for insulating steam and hot water pipes are given in Table 8. In this table the conductivities are given as functions of the mean temperatures'or the mean of the inner and outer surface temperatures of the insulations. This method of stating conductivities makes it possible to readily calculate the heat loss through single or compound sections. It should be emphasized that the conduc tivities given in Table 8 for the various insulations are the average of Table 8. Conductivities (k) of Various Types of Insulating Materials for Medium and. High Temperature Pipes3 Ttpss of Insulating Material* 85 oer cent Magnesia Type Corrugated Asbestos Type.-............... (4 Plies per 1 in. thick) Corrugated Asbestos Type--............... (8 Plies per 1 in. thick) . Laminated Asbestos Type (30-40 Laminations per 1 in. thick) Laminated Asbestos Type (20 Laminations per 1 in. thick) kock Wool IvDe.................... ...... High Temperature Type............................. (Diatomaceous Earthand Asbestos) Brown Asbestos Type (Felted Fibre) . . Mean Temperature 100 F 200 F 0.425 0.465 0.530' 0.650 300 F 0.505 0.770 400 F 0.550 0.890 0.480 0.555 0.630 0.705 0.360 0.545 0.415 0.605 0.470 0.665 0.525 0.725 0.350 0.410 0.470 0.530 0.515. 0.545 0.575 0.605 0.600 0.640' 0.675 0.715 500 F0.590 0.585 0.785 0.590 0.635 0.750 R. H. Heilman. Mechanical Engineering. Vol. 46 (1924)t p. 593. 723 Heating Ventilating Air Conditioning Guide 1938 Table 9. Coefficients of Transmission (E7) for Pipes Insulated ' ' with 85 Per Cent Magnesia Type Insulation These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still atr at 70 F 1 Thickness or !\ :. Insulation /(Inches) Nominal : ... Pipe ... . . .Size (Inches); / .. . 120 F .. Hot Wateb . 150 F. 180 F 210 F 227.1 F (5 Lb) ; Temperature DirrsHENCs Steam 297.7 F (50 Lb) 337.9 F (100 Lb) . 50 F 80T 110 F ` i.-L.- ` . > 'y 1 ........... ` i'A " .-: \Y .2 2'A 3 1 3Y 4 iY -- - J' > ..... ......... 5 6 . ~$ 10 12 > 0.744 0.672 0.613 0.562 0.532 ,0.500 0.475 :0.455 0.4410.429 0.420 0.411 0.402 0.387 0.375 .0.369 0.754 0.681 0.621 0.570 0.539 0.506 0.481 0:461 0.447 " 0.435 0.425 0.416 0.408 0.392 0.380 0.374 0.764 0.689 0.629 0.577 0.546 .0.512 0.487 ' 0.467 0.452 0.441 0.431 0.422 0.413 0.397 0.385 0.378 140 F 0.774 0.697 0.637 0.585 0.553 0.519 0.493 0.474 0.458 0.446 0.437 0.427.. 0.419 0.403 0.390 0,383. 157.1 F 0.779 0.701 0.641 0.589 0.557 0.523 0.497 0.477 0.462 0.449 0.440 0.430 01422 0.405 0.393 0.386 227.7 F 0.802 0.721 0.659 0.606 0.573 0.538 0.512 0.492 0.475 0.463 0.453 0.443 0.435 0.418 0.405 0.398 267.9 F 0.814 0.731 0.670 0.617 0.582 0.547 0.520 0.500 0.483 0.471 0.460 0.450 0.442, 0.425 0.412 0.405 :Y ! - ,1 -- i'A iY 2, 3' ... 2Y iY ' 3'Y 4 *Y 5 . .6 . 8 ' 10 ' 12. 0.617. 0.550 0.496 0.453 .0.424. 0.394 0.371 0.352- 0:339 0.328 0.320 0.312 0.303 0.287 0.276 0.272 0.625. 0.558 0.503 0.459 0.430 0.400 0.376 0.357 0.343 0.333 0.324 0.316 0.307 0.291 0.280 0.275 0.633 0.642 0.566 0.573 0.511 0.518 0.465 0.472 0.436 . 0.442 0.405 0.410 0.382 0.386 0.362 0.367 0.347 0.351 0.337 0.341 0.328 0.332 0.320 0.324 0.311 0.315 0.295 0.299 0.284 0.288 0.279 0.283 0.646 0.577 0.522 0.475 0.445 0.413 0.389 0.370 0.354 0.343 0.334 0.326 0.318 0.301 0.290 6.285 0.665 0.596 0.540 0.490 0.459 0.427 0.401 0.380 0.364 0.353 0.343 0.336 0.328 0.311 0.299 0.294 0.676 0.606 . 0.549 " 0.498 0.467 0.434 0.408 0.387 0.370 0.359 0.350 6.342 0.333 0.316 0.304 0.299 ' Y % 1 0.543 01484 0.433 0.551 0.490 0.439 0.558 0.497 0.445 0.565 0.503 0.451 0.569 0.507 0.454 0.587 0.523 0.467 0,597. 0.532 . 0.476 ` iY 1Y 2. 2Y ' 3 0.393 0.365 0.338 0.316 0.297 0.398 0.370 0.343 0.320 0.301 0.4030.376 0.347 0.324 0.305 0.409 0.381 0.351 0.328 0.309 0.412 0.424 0.432 . 0.384 0.397. 0.402 0.354 0.364 0.370 1.0.331:. ,0.341: 0.347 10.312" 0.321 . 0.326 '"2 " 3Y .- : 4 . 0.284. 0.288 0.292 0.295 0.297 0.275 0.278 0.282 0.285 0.287 0.306 0.311 0.296 0.301 , ' *Y 5' 0.266 0.270 0.273 0.276 0.278 0.286 0.290 0:258 0.262 0.265 . 0.268 0.270 0.278 0.283. 6 8 '' 0.250 0.254 0.257 0.236 0.239 0.242 0.260` | 0.262 0.245 0.247 0.270 0.274 . 0.255 0.258 10 12 0.224 0.219 0.227 0.230 0.222 , 0.225 0.233 0.235 0.228 1 0.230 0.242 0.237 0.246 0.240 724 Chapter 39. Piping and Duct Insulation Table 10. Coefficients of Transmission (U) for Pipes Insulated with Corrugated Asbestos Type Insulation (4 Plies .Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F Thickness . . or Insulation * (Inches) i 2 * , -.:j -.i t Nominal Pipe Size' (Inches) Yt % l iA 1Y 2 . 2Y .. 3 - ; 3Y . 4- 4Y 568 10 . :12- 120 F . 50 F 0.890 0.803 0.731 0.671 0.635 0.595 0.567 0.544 6.527 0.513 0.502 0.490 0.480 0.462 0.447 0.441 Hot Wateb 1 150 F 180 F 210 F 227.1 F U (5 Lb) Temperature Ditperencb 80 F 110 F 140 F g 157.1 F 0.919 0.829 0.756 0.693 0.656 0.615 0.586 0.562 0.544 0.530 0.518 0.507 0.496 0.477 0.462 0.456 0.949 0.857 0.780 0.716 0.677 0.635 0.605 0.580 0.561 0.548 0.535 " 0.523 0.512 0.493 0.476 0.470 0.978 0.883 0.804 0.738 0.698 0.656 0.624 0.598 0.578 0:565 0.551 0.539 0.528 0.508 0.491 0.485 0.995 0.898 0.818 0.751 0.710 0.667 0.635 0.608 0.588 0.575 0.561 0.549 0.538 0.517. 0.500 0.493 Steam 297.7F (50 Lb) 227.7 F 1.065 0.961 0.876 0.804 0.760 0.715 0.680 0.652 0.631 0.616 0.601 0.588 0.577 0.554 0.537 0.529 337.9 F (100 Lb) 267.9 F 1.106 0.997 0.909 0.834 0.788 0.742 0.705 0.677 0.654 0.639 0.624 0.611 0.599 0.575 0.557 0.550 Y Vi 1 . \A lY 2 2Y 3 iY 4 . 4Y 5 "6 8 10 12 0.737 0.762 0.657 0.679 0.594 0.614 0.542 0.559 0.507 0.524 0.471 0.487 0.443 0.458 0.421 0.435 0.403 0.417 0.393 0.405 0.383 0.394 0.372 0.384 0.362 . 0.374 0.343 0.354 0.328 0.339 0.323 0.334 0.787 0.702 0.634 0.577 0:541 0.503 0.473 0.449 0.430 0.418 0.407 0.397 0.387 0.366 0.351 0.346 0.812 0.725 0.654 0.596 0.558 0.519 0.488 0.463 0.443 0:432 0.420 0.409 0.399 0.378 0.362 0.357 0.826 0.737 0.666 0.606 0.568 0.528 0.497 0.472 0.451 0.439 0.428 0.417 0.406 0.385 0.369 0.364 0.884 0.790 0.713 0.649 0.609 0.565 0.533 0.506 0.483 0.471 0.460 0.447 0.436 0.413 0.397 0.391 0.918 0.820 0.740 0.673 0.632 0.587 0.553 0.525. 0.502 0.489 0.476 0.463 0.452 0.429 0.413 0.407 Y 0.648 3A 0:578 - 1 . 0.518 i A : 0.469 iY 0.438 2 0.404 2Y 0.379 3 0.356 ' 0.339 4 ' 0.328 4Y . 0.318 5 - 0.308 6 0.299 8 .. 0.282 10 ; 0:267 12 . 0.263 0.670 0.598 0.535 0.485 0.452 0.417 0.391 0.367 0.350 0.339 0.328 0:318 0.309 0.291 0.276 0.272 0.692 0.617 0.552 0.501 0.467 0.430 0:403 0.378 0.361 0.350 0.339 0.329 0.319 0:301 0:285 0:280 0.713 0.637 0.570 0.517 0.481 0.444 0.415 0.390 0.373 0.360 0.350 0.340 0.329 0:310 0.294 0.289 0.726 0.648 0.580 6.527 0:490 0.452 0.422 0.397 0.380, 0.367 0.357 0.346. 0.335. 0.315 0.299: 0.294 0.779 0.694 0.622 0.566 0.526 0.483 0.451 0.425. 0.406 0.392 0.381 0.370 0.358 0.336 0.319 0.314 0.810 0.720 0.645 0.587 0.545 0.502 0.466 0.440 0.421 0.406 0.395 0.384 0.371 0.349 0.332 0.325 725 1 r Heating Ventilating Air Conditioning Guide 1938 Table 11. Coefficients of Transm ission (U) for Pipes I nsulated with Corrugated Asbestos Type Insulation (8 Plies Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F Thkxnebs or Inboution ' (IffCHKS) Nominal Pipe Sob (Inches) . Hot Water 1 120 F 1 150 F 180 F 210 F 1 227.1 F (5 Lb) Temperature Dotebencb 50 F 80 v 110 F 140 F 157.1 F A A 0.801 0.820 0.838 0.857 0.868 0.723 0.739 0.756 0.773 0.783 l 0.658 0.673 0.688 0.704 0.713 lA 0.606 0.619 0.633 0.647 0.655 \A 2 0.573 0.586 0.599 0.612 0.619 0.538 0.550 0.562 0.575 0.581 2A 3 0.511 0.523 0.534 0.546 0.553 0.489 0.501 0.512 0.524 0.531 1 3A 0.474 : 0.485 0.496 0.507 0.514 . 4 0.461 0.472 0.482 0.493 0.500 4A 0.451 0.462 0.472 0.482 0.489 5 0.442 0.452 0.462 0:473 0.479 6 0.432 0.442 0.452 0.463 0.468 8 0.416 0.426 0.436 0.446 0.451 10 0.402 0.412 0.421 0.430 0.435 12 0.397 0.406 0.415 0.424 0.429 Steam 297.7 F (50 Lb) 337.9 F (100 Lb) 227.7 F 0.913 0.824 0.751 0.688 0.652 0.612 0.582 0.558 0.542 0.527 0.515 0.505 0.493 0.475 0.459 0.452 267.9 F 0.939 0.847 0.772 0.707 0.670 0.629 0.599 0.575 0.557 0.542 0.530 0.520 0.508 0.489 0.473 0.466 lA . ' .: i 2 A :a i :m lA .2 2A 3'' 3A .4 4A '5 * ,6 " 18 10 12 A A l lA lA 2 2A 3 3A 4 4A S 6 8 10 12 : ! 0.664 0.593 0.535 0.488 0.457 0.425 0.399 0.378 0.363 0.353 0.343 0.334 0.325 0.309 0.295 0.291 0.585 0.520 0.465 0.422 0.394 0.364 0.339 0.319 0.304 0.295 0.285 0.278 0.269 0.253 0.240 0.236 0.679 0.607 0.547 0.499 0.467 0.434 0.408 0.387 0.371 0.361 0.351 0.342 0.333 0.316 0.303 0:298 0.599 0.533 0.476 0.432 0.403 0.372 0.347 0.327 0.311 0.302 0.292 0.284 0.275 0.259 0.245 0.241 0.695 0.711 0.621 0.636 0.560 0.573 0.510 0.522 0.478 0.490 0.444 0.455 0.418 0.428 0.396 0.405 0.380 0.388 0.369 0.378 0.360 0.368 0.350 0.358 0.341 0.349 0.324 0.332 0.310 0.318 0.306\ 0.313 0.613 0.545 0.487 0.442 0.412 0.380 0.355 0.334 0.318 0.308 0.299 0.290 0.282 0.265 0.251 0.247 0.627 0.558 0.498 0.452 0.422 0.388 0.363 0.342 0.326 0.315 0.306 0.297 0.288 0.270 0.257 0.253 0.720 0.643 0.580 0.528 0.496 0.460 0.434 0.411 0.393 0.383 0.373 0.363 0.353 0.336 0.322 0.317 0.759 0.677 0.611 0.556 0.522 0.485 0.457 0.433 0.415 0.403 0.393 0.383 0.373 0.355 0.340 0.335 0.780 0.697 0.629 0.572 0.537 0.499 0.471 0.446 0.427 0.415 0.404 0.394 0.383 0.365 0.350 0.344 0.635 0.565 0.504 0.458 0.427 0.393 0.367 0.346 0.330 0.319 0.310 0.301 0.292 0.273 0.260 0.256 0.668 0.595 0.532 0.483 0.450 0.415 0.387 0.365 0.349 0.336 0.327 0.317 0.307 0.288 0.275 0.270 0.688 0.612 0.547 0.497 0.462 0.427 0.398 0.375 0.358 0.345 0.336 0.326 0.315 0.296 0.282 0.277 726 1 Chapter 39. Piping and Duct Insulation Table 12. Coefficients of Transmission (U) for Pipes Insulated with Laminated Asbestos Type Insulation (30 to 40 Laminations Per Inch Thickness) , These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F Thickness or Insulation (Inches) * i 2 Nominal Pipe Size (Inches) A A l tA iA 2 2A 3 3A 4 4A 5 6 8 10 12 A A .l 1A lA 2 2A 3 3A 4 iA 5 -6 8 10 12 A A 1 m lA 2 2A 3 3A 4 *A 5 6 8 10 : 12 ' 120 F 50 F 0.605 0.546 0.498 0.457 0.432 0.406 0.385 0.370 0.359 0.349 0.341 0.334 0.327 0.314 0.304 0.301 0.502 0.450 0.405 0.369 0.343 0.321 0.301 0.286 0.274 0.267 0.259 0.253 0.247 0.234 0.223 0.221 0.442 0.392 0.352 0.319 0.297 0.274 0.256 0.243 0.231 0.223 0.216 0.210 0.203 0.191 0.182 0.178 Hot Wateb 150 F 180 F | 210 F 227XF (5 Lb) Temperatube Ditterencb sO F 110 F 140F H 157.1 F 0.620 0.560 0.510 0.468 0.442 0.416 0.395 0.379 0.367 0.358 0.350 0.342 0.335 0.322 0.312 0.308 0.635 0.573 0.522 0.480 0.453 0.426 0.405 0.389 0.376 0.366 0.359 0.351 0.343 0.330 0.320 0.316 0.650 0.586 0.534 0.491 0.464 0.437 0.415 0.398 0.385 0.375 0.367 0.359 0.351 0.338 0.328 0.324 0.658 0.594 0.541 0.497 0.470 0.442 0.420 0.403 0.390 0.380 0.372 0.364 0.356 0.343 0.332 0.328 Steam 297.7 F (50 Lb) 227.7 F 0.695 0.627 0.570 0.525 0.496 0.467 0.443 0.425 0.413 0.402 0.393 0.384 0.376 0.362 0.350 0.346 337.9 F (100 Lb) 267.9 F 0.716 0.645 0.587 0.540 0.511 0.481 0.457 0.438 0.426 0.414 0.405 0.395 0.387 0.373 0.361 0.356 0.514 0.461 0.415 0.378 0.352 0.329 0.309 0.293 0.281 0.273 0.266 0.260 0.253 0.240 0.229 0.227 0.526 0.473 0.426 0.387 0.361 0.337 0.317 0.301 0.288 0.280 0.272 0.266 0.260 0.246 0.235 0.232 0.539 0.484 0.436 0.396 0.370 0.345 0.324 0.308 0.295 0.287 0.279 0.272 0.266 0.252 0.241 0.238 0.546 0.490 0.442 0.401 0.375 0.350 0.330 0.313 0.300 0.291 0.283 0.276 0.269 0.255 0.245 0.241 0.577 0.517 0.466 0.423 0.397 0.369 0.348 0.330 0.316 0.307 0.299 0.291 0.284 0.270 0.258 0.255 0.595 0.532 0.480 0.435 0.409 0.380 0.358 0.340 0.326 0.317 0.308 0.300 0.293 0.279 0.266 0.263 0.453 0.402 0.360 0.327 0.304 0.280 0.262 0.249 0.236 0.228 0.222 0.215 0.208 0.196 0.187 0.183 0.464 0.412 0.369 0.335 0.311 0.287 0.269 0.254 0.242 0.234 .0.227 0.220 0.213 0.201 0.192 0.187 0.475 0.422 0.378 0.343 0.319 0.294 0.275 0.260 0.248 0.240 0.233 0.225 0.218 0.206 0.196 0.192 0.481 0.428 0.383 0.348 0.323 0.298 0.279 0.264 0.251 0.243 0.236 0.228 0.221 0.209 0.199 0.195 0.508 0.452 0.405 0.367 0.341 0.314 0.293 0.277 0:265 0.257 0.249 0.241 0.233 0.220 0.210 0.205 0.523 0.465 0.417 0.379 0.352 0.324 0.302 0.285 0.273 0.265 0.256 0.248 0.240 0.227 0.215 0.210 727 S' Heating Ventilating Air Conditioning Guide 1938 Table 13. Coefficients of Transmission (U) for Pipes Insulated with Laminated Asbestos Type Insulation (Approximately 20 Laminations Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F Thickness Of ` ' Pipe . InHULATION Size* (Inches) - . (Inches) , Hot Water I 120 F 1 150 P 180 F 210 F | 227.1 F (5 Lb) Temperature Difference 140F50 F *0F 110 F 157.1 F y 0.910 0.925 0.940 0.956 0.964 Yi 0.823 0.836 0.850 0.863 0.871 i 0.748 0.760 0.773 0.785 0.792 m 0.686 0.698 0.710 0.721 0.728 iy 0.649 0.659 0.671 0.682 0.688 2 . 0.610 0.620 0.630 0.640 0.647 2)4 0.581 0.590 0.600 0.609 0.615 :3 0.558 0.567 0.576 0.585 0.591 . i 3Y 0.539 0.548 0.557 0.566 0.571 . i 4 : . 0.524 0.532 0.541 0.551 0.556 4)4 0.514 0.522 0.530 0.539 0.544 ,5 0.503 0.511 0.519 0.528 0.533 6 0.492 0.500 0.509 0.517 0.522 8 0.473 0.480 0.488 0.497 0.502 10 0.458 0.465 0.473 0.481 0.485 : 12 0.452 0.459 0.467 0.475 0.478 Steam 297.7 K (50 Lb) 337.9 F (100 Lb) 227.7 F 1.001 0.902 0.823 0.756 0.716 0.671 0.638 0.613 0.592 0.577 0.564 0.553 0.542 0.521 0.504 0.497 267.9 F 1.022 0.921 0.840 0.771 0.731 0.685 0.651 0.626 0.604 0.589 0.575 0.565 0.553 0.532 0.514 0.507 )4 : Yc 1 \Y > XY 5 2 ci 1Y : 3. ; 314 -4 : AY 5 6 ; :8 : i lo : .12 ,; 6.755 . .0.767 0.674 0.685 0.607 0.618 0.553 0.562 0.517 .0.527 6.481 0.490 .0.453 0.460 0.429 0.436 0.412 0.419 0.400 0.407 0.390 0.396 0.380 0.386 0.369 0.375 0.351 0.358 0.337 0.344 0.332 0.338 0.780 0.697 0.628 0.572 0.536 0.499 0.469 .0.444 0.427 0.415 0.402 0.393 0.382 0.364 0.350 0.344 0.793 0.708 0.639 0.581 0.545 0.508 0.477 0.452 0.434 0.422 0.409 0.400 0.389 0.370 6.356 0.350 0.800 0.715 0.645 0.587 0.550 0.513 0.481 0.456 0.438 0.426 0.413 0.403 0.392 0.374 0.359 0.353 0.831 0.743 0.670 0.610 0.572 0.535 0.500 0.475 0.456 0.443 0.429 0.418 0.408 0.388 0.373 0.367 0.848 0.759 0.684 0.622 0.584 0.547 0.511 0.485 0.465 0.453 0.437 0.427 0.417 0.397 0.382 0.375 : 14 % i tU iyi .2 ; .214 !3 2 * 3)4 . 4. : 4Y . r : 5 . . . -i 6 r. -8 - . ' io ; - 12. 0.664 0.591 0.529 0.480 0.445 0.412 0.385 0.364 0.346 0.336 0.325 0.316 0.306 0.288 0.275 0.269 0.675 0.601 0.538 0.488 .0.453 0.420 0.392 0.'370 0.352 0.342 0.332 0.322 0.312 0.293 0.279 0.274 0.687 0.611 0.547 0.497 0.462 0.427 0.398 0.376 0.358 0.348 0.338 0.327 0.317 0.298 0.284 0.278 0.698 0.621 0.557 0.505 0.470 0.434 0.405 0.382 0.365 0.354 0.343 0.333 0.323 0.303 0.289 0.283 0.704 0.627 0.562 0.510 0.475 0.438 0.409 0.385 0.368 0.357 0.346 0.336 0.326 0.306 0.292 0.286 0.732 0.652 0.584 0.529 0.494 0.455 0.425 0.400 0.382 0.371 0.360 0.349 0,338 0.317 0.302 0.296 0.747 0.665 0.597 0.540 0.504 0.464 0.434 0.408 0.390 0.378 0.367 0.356 0.345 0.324 0.308 0.302 728 Chapter 39. Piping and Duct Insulation Table 14. Coefficients of Transmission (U) for Pipes Insulated with Rock Wool Type Insulation ' These coefficients are .expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F - Thickness ` Of Insulation (Inches) ' Nominal Pipe Size (Inches) i -* )4 % 1 m lY 2 m 3 ^/4 .4 . 4Y .5 ' 6. 8 : 10 12 120 F 50 F 0.631 0.569 0.518 0.476 0.450 0.422 0.402 0.385 0.373 0.363 0.355 0.348 0.341 '0.327 0.317 0.313 Hot Water Steam 150 F 180 F 210 F r'227.1 F 1 (5 Lb) 297.7 F 1 337.9 F (50 Lb) (100 Lb) . Temperature Difference 80 F 110 F . 140F 157.1 F 227.7 F . 267.9 , 0.644 0.658 0.581 0.593 0.529 0.541 0.486 0.497 0.460 0.470 0.431 0.441 0.411 0.420 0.394 0.402 0.381 0.389 0.371 0.379 0.363 0.371 0.356 0.364 0.348 0.356 0.335 0.342 0.324. 0.331 0.320. 0.327 0.672 0.606 0.552 0.507 0.480 0.450 0.428 0.411 0.398 0.387 0.379 0.371 0.363 0.349 0.338 .0.334 0.680 0.613 0.559 0.513 0.485 0.456 0.434 0.415 0.402 0.392 0.383 0.376 0.368 0.353 0.343 0.338 . 0.712 0.642 0.585 0.537 0.508 0.478 0.455 0.435 0:421 0,411 0.402 0.394 0.386 0.372 0.360 0.355 0.730 0.659 0.600 0.551 0.522 0.490 0.466 0.446 0.432 0.422 0.413. 0.404 0.396 0.381 0.369 0.364 . = 0.523 0.534 0.545 0.556 0.563 0.590 0.606 Y 0.468 0.477 0.487 0.497 0.503 0.528 0.542. 1 ' 0.421 0.430 0.440 0.449 0.455 0.477 0.490 U4 0.383 0.391 0.399 0.407 0.412 0.433 0.444 114 0.359 0.366 0.375 0.383 0.387 0.407 0.419 2 0.333 0.340 0.348 0.356 0.360 0.378 0.389, VY 0.314 0.320 0.327 0.335 0.339 0.355 0.365 3 0.296 0.302 0.310 0.317 0.321 0.337 0.347 3)4 - 0.286 0 i 291 0.298 0.304 0.307 0.323 0.332 4 0.278 0.284 0.290 0.296 0.300 0.315 0.323 4Y 0.270 0.276 0.282. 0.287 0.291 0.305 0.313 5 0.263 0.269 0.275 0.280 0.284 0.298 0.305 6 -* : 8 0.257 0.262 0.267 0.273 0.277 0.290 0.297 0.244 0.249 0.254 0.260 0.263 0.276 ' 0.283 . 10 O'. 235 0,240 0.245 0.250 0.253 41.265; 0.272. . 12 0.230 0.234 0.239 0.245 0.247 0.260 0.267 - Ye 0.461 0.471 0.481 0.491 0.496 0.520 0.534 Yi 0.409 0.418 0.427 0.436 0.441 0.463 0.475 1 0.366 0.374 0.382 0.390 0.395 0.415 0.427 i 1M 0.333 0.340 0.347 0.355 0.359 0.377 0.387 . lY 0.310 0.316 0.323 0.330 0.334 0.351 0.360 2 2)4 0.286 0.292 0.298 0.304 0.308 0.323 0.331 : 0.268 0.274 0.279 0.285 0.289 0.302 0.310 : ' 3 0.252 0.257 0.262 0.268 0.272 0.284 0.292 2 3Y 0.241 0.246 0.251 0.257 0.260 0.272 . 0.280 . 4 0.232 0.237 0.242 0.247 0.250 0.262 0:269 4)4 0.225 0.230 0.235 0.240 0.243 0.255 0.262 5 0.218 0.223 0.228 0.233 0.236 0.247 0.253 . 6 0.213 0.217 0.221 0.226 0.228 0.239 0.245 8 0.200 0.204 0.208 0.213 0.215 0.225 0.231 10 0.189 0.193 0.197 0.-201 0.204 . 0.214 0.220 12 0.185 0.190 0.194 0.198 0.200 0.210 0.216 Heating Ventilating Air Conditioning Guide 1938 values obtained from a number of tests made on each type of material, also that all variables due to differences in thickness, pipe sizes, and air conditions are eliminated. Individual manufacturer's materials, will of course, vary in conductivity to some extent from these values. The heat losses through six of the types of insulation given in Table 8 for 1, \]/2 and 2 in. thick materials, and for temperatures commonly encountered in engineering practice can be obtained from Tables 9 to 14 inclusive. The loss through other thicknesses of the materials, and for other hot water or steam temperature conditions may be obtained by interpolation. The heat loss coefficients given in Tables 9 to 14 are based on the conductivities in Table 8 and were computed from data given in Chapter 22, The Guide 1931. The rate of heat loss from a surface maintained at constant temperature is greatly increased by air circulation over the surface. In the case of well-insulated surfaces the increases in losses due to air velocity are very small as compared with increases shown for bare surfaces, because of the fact that air flowing over the surface of the insulation can increase only the rate of heat transfer from surface to air, and cannot change the internal resistance to heat flow inherent in the insulation itself. The maximum increase in loss due to air velocity ranges from about 30 per cent in the case of 1 in. thick insulation, to about 10 per cent in the case of 3 in. thick insulation, provided that the insulation is thoroughly sealed so that air can flow only over the surface. If the conditions are such that the air may circulate through cracks and crevices in the insulation, the increases may be far greater than those given. Therefore, it is essential that insulation be sealed as tightly as possible. Pipe insulation out-of-doors should be provided with a water proof jacket, and other outdoor insulation should be thoroughly weatherr proofed. . HEAT LOSSES FROM DUCTS The heat transmission through sheet metal duct walls is mainly a function of the surface character of the metal since the thickness of the metal itself is not enough to appreciably retard the flow of heat. In other words, the two surfaces provide the resistance to heat flow through the metal. The surfaces of black iron probably offer the least resistance to the flow of heat, while metals with brighter1 and smoother surfaces, offer greater resistance. For ducts in service at normal air velocities and temperatures, the coefficient of heat transmission for black iron is 1.6 Btu per square foot per hour per degree Fahrenheit difference between the mean temperature in the duct and the temperature of the surrounding air and for galvanized iron is 1.1 Btu per square foot per hour per degree Fahrenheit difference. ' . The heat loss from a given length of duct is expressed by: . H = * P L [ -i- i, ] (1) The heat given up by the air in the duct is: . H = 0.24 M (t, - It) = 14.4 A V d (h - h) . 730 (2) Chapter 39. Piping and Duct Insulation Equating 1 and 2 enables the determination of the temperature drop in the duct: k PL [ - <,] = 14.4 A Vd (I, - <,) h + h-2t, 28.8.4 Vd h - t, kPL where H = heat loss through duct walls, Btu per hour. k = overall heat transmission coefficient, Btu per square foot per hour per degree Fahrenheit temperature difference. ,. P = perimeter of duct, feet, L = length of duct, feet. h = temperature of air entering duct, degrees Fahrenheit. . U. = temperature of air leaving duct, degrees Fahrenheit. ' h *= temperature of air surrounding duct, degrees Fahrenheit, M = weight of air per hour through the duct, pounds, A = cross-sectional area of duct, square feet. V = velocity of air in the duct, feet per minute, at specified temperature, d = density of air at the specified temperature at which V is measured. - In using the formula 3 one of the duct air temperatures will be unknown and will be solved for by substitution of the other known or assumed values. The assumed values dependent upon the mean duct air tem perature can be determined exactly by cut and try. Heat losses for insulated ducts are given in the warm air column of Table 15. The losses are based on a uniform series of material conduc tivities at 86 F mean temperature and an air temperature of 50 F outside of the duct. The losses may be interpolated for odd material conduc tivities and temperatures. The conductivities of various materials will be found in Table 2 of Chapter 5. For cases where the surrounding air temperature is other than 50 F the losses may be selected on the basis of temperature difference. Example 1. Determine the entering air temperature and heat loss for a duct 24 x 36 in. cross section and 70 ft in length, insulated with Yi in.'of a material having a conductivity of 0.35 Btu at 86 F mean temperature, carrying air at a velocity of 1200 fpm, measured at 70 F, to deliver air at 120 F with air surrounding the duct at 40 F. Solution. Assume the entering air temperature to be 130 F. Thus the mean tem perature difference will be 85 F. Referring to the warm air column of Table 15 and interpolating for 90 F temperature difference, the overall heat transmission coefficient is found to be 0.516 Btu. From Table 4, Chapter 1 the density of air at 70 F and 29.92 in. Hg. is found to be 0.07423 lb per cubic foot. Substituting these and the other given values in Formula 3, . ' h + 120 - (2 X 40) = 28.8 X 6 X 1200 X 0.07423 h - 120 .0.516 X 10 X 70 t, + 120 -- 80 = 42.62 (f, - 120) <i + 40 = 42.62 l, - 5114 . 5154 = 41.621, - , 123.8 = t, Based on 123.8 F entering air temperature the new mean temperature difference will be 731 r Heating VentiiiAting Air Conditioning Guide 1938 \ Chapter 39. Piping and Duct Insulation 81.9 F and the new transmission coefficient will be 0.515. Resubstituting in Formula 3, t\ becomes 123.9 F, which value is evidently exact within one tenth of one degree. . Substituting in Formula 1, H = 0.515 X 10 X 70 (123'9 f 12) - 40 J H = 0.515 X 10 X 70 X 81.95 H = 29,543 Btu. .: .. .., , Table 15. Heat Transmission Through Duct Walls Insulated with Materials of Varying Conductivities3 .. Values are expressed in Btu per hour per square foot of fiat surface per degree Fahrenheit difference in temperature, between air inside ana still air outside at 90 F for cold air and 50 F for warm air in ducts Conductivity OF Insulation at 86 F Mean Temp. 0.200 0.250 0.300 0.350 0.450 0.550 (Inches) Yi 1 m 2 1 2 y2 1 m 2 54 l 1 2 , .1 .... 2 y2 1 2 Cold Aib Warm Aib 40 F .60 F 80 F 120 F ISO F Temperatube Difference 50 F 30 F 10 F 70 F 100 F 130 F 0.319 0.175 0.121 0.092 0.382 0.214 0.149 0.114 0.440 0.252 0.176 0.135 . 0.494 0.286 0.202 0.156 0.323 0.177 0.122 0.093 0.387 0.217 0.151 0.115 0.445 0.255 0.178 0.137 0.499 0.289, 0.204 0.158 0.596 0.356 0.254 0.198 0.682 0.417 0.302 0.236 0.328 0.180 0.124 0.095 0.392 0.220 0.153 0.117 0.450 0.258 0.180 0.139 0.505 0.292 0.207 0.160 6.602 0.360 0.257 0.200 0.688 .0.422 0.305 0.239 0.324 0.178 0.390 0.218 0^48 0.256 0.502 0.290 0.599 0.358 0.685 0.418 6.330 0.181 0.125 0.337 0.184 0.127 0.344 0.188 0.129. 0.397 .0.404 0.221 0.225 0.154 0.156 0.412 0.229 0.159 0.457 0.466 0.475 0.260 0.264 0.268 0.181 0.184 0.187 0.511 0.295 0.208 0.521 0.300 0.211 0.530 0.306 0.215 0.610 ,0.621 0.364 0.370 0.259 . 0.263 0.633 0.376 0:267. 0.699 0.425 0.307 0.714. 0.730' 0.432 0.440 0.312 0.317 aFor round ducts less than 30 in. diameter, increase heat transmission values by the following percent ages: ,, Thickness of Insulation (Inches) ' & 1 1H . 2 21 to 30 in. Duct Diameter..................................................... i% 2% 3% 4% 12 to 21 in. Duct Diameter..................................................... 3% 5% 7% 9% 732 LOW TEMPERATURE INSULATION Surfaces maintained at temperatures lower than the surrounding air. . are insulated to reduce the flow of heat and to prevent condensation and frost. The insulating material should absorb a minimum amount of moisture, for one reason that the absorption of moisture substantially increases the conductivity pf the material. This property is particu larly important in the case of surfaces to be insulated that are below the dew point of the surrounding air. In such cases, due to vapor pressure difference, it is necessary to seal the surface :of the insulating, material against the penetration of water vapor which would condense within the material, causing a serious increase in heat flow, possible breakdown of the material and corrosion of metal surfaces. An insulating material with a high degree of moisture absorption might pick up moisture before application and then, when the seal is in place and the temperature of the insulated surface reduced, release that moisture to the cold surface. The thickness of insulation which should be used to prevent condensa tion on pipes and flat metallic surfaces may be obtained from Fig. 2. The maximum permissable temperature drop is indicated at the point where the guide line passes through the horizontal scale at the left center of the chart. This temperature drop represents the difference between the dry-bulb temperature and the dew point temperature for the con ditions involved. (See discussion of condensation in Chapter 7). The surface resistances used for calculating the family of curves in Fig. 2 are based on tests made on canvas covered pipe insulation surfaces at Mellon Institute. However, it has been found that the resistance for asphaltic and roofing surfaces is practically the same as for canvas surfaces, so that the curves may be followed with no alteration for surfaces commonly used. Heat gains for pipes insulated with a material having a conductivity of.0.30 Btu per square foot per hour per degree Fahrenheit difference per inch thickness are given in Table 16. Heat gains for insulated ducts are given in the. cold air column of Table 15. The heat gains are based on a uniform series of conductivities at 86 F mean -temperature and an air temperature of 90 F outside of the duct. The gains may be interpolated for odd material conductivities and temperatures. For cases where the surrounding air temperature is other than 90 F the gains may be selected on the basis of temperature difference. INSULATION OF PIPES TO PREVENT FREEZING If the surrounding air temperature remains sufficiently low for an ample period of time, insulation cannot prevent the freezing of still water, or of water flowing at such a velocity that the quantity of heat carried in the water.is not sufficient to take care of the heat losses which will result and cause the,temperature of the water to be lowered, tq.the freezing point. Insulation can materially prolong the time required for the water to give up its heat, and if the velocity of the water flowing in the pipe is main tained at a sufficiently high rate, freezing may be prevented. , ! Table 17 may be used for making estimates of the thickness of insu lation necessary to take care of still water in pipes at various water and' 733 1 Heating Ventilating Air Conditioning Guide 1938 surrounding air temperature conditions. Because of the damage and service interruptions which may result from frozen water in pipes, it is essential that an efficient insulation be utilized. This table is based on the use of a material having a conductivity of 0.30. The initial water temperature is assumed to be 10 F above, and the surrounding air tem- Fig. 2. Thickness of Pipe Insulation to Prevent Sweating Solve problems by drawing lines as indicated by dotted line, entering chart at lower left hand scale. perature 50 F below the freezing point of water (temperature difference, 60 F). ' . The last column of Table 17 gives the minimum quantity of water at initial temperature of 42 F which should be. supplied every hour for each linear foot of pipe, in order to prevent the temperature of the water from' being lowered to the freezing point. The weights given in this column should be multiplied by the total length of the exposed pipe line expressed in feet. As an additional factor of safety, and in order to provide against temporary reductions in flow occasioned by reduced pressure, it is ad 734 Chapter 39. Piping and Duct Insulation visable to double the rates of flow listed in the table. It must be. empha sized that the flow rates and periods of time designated apply only for the conditions stated. To estimate for other service conditions the following method of procedure may be used. If water enters the pipe at 52 F instead of 42 F, the time required to cool it to the freezing point will be prolonged to twice that given in the table, or the rate of flow of water may be reduced so that the quantity required will be . one-half that shown in the last column of Table 17. However, if the water enters the pipe at 34 F it will be cooled to 32 F in Table 16. Heat Gains for Insulated Cold Pipes Based on materials having conductivity, k -- 0.30 Nominal . Pips Size (Inches) h M .l m 2 3 m 4 5 6 8 10 1 12 Ice Water Thickness Brins Thickness Thickness of Insulation (Inches) Btu Per linear Foot 1.5 0.110 1.6 0.119 1.6 0.139 1.6 0.155 1.5 0.174 1.5 0.200 1.5 0.228 1.5 0.269 1.5 0.295 1.7 0.294 1.7 0.349 1.7 0.404 1.9 0.455 1.9 0.559 1.9 0.648 Btu Per Sq Ft Pipe Surface 0.502 0.431 0.403 0.357 0.351 0.322 0.303 0.293 0.282 0.248 0.239 0.233 0.201 0.198 0.194 Thickness of Insulation - (Inches) 2.0 2.0 2.0 2.4 2.5 2.5 2.6 2.7 2.9 2.9 3.0 3.0 3.0 3.0 3.0 Btu Per Linear Foot 0.098 0.111 0.124 0:131 0.134 0.151 0.170 0.186 0.191 0.209 0.241 0.259 0.318 0.383 0.438 Btu Per Sq Ft Pipe Surface 0.446 0.405 0.352 0.300 0..270 0.244 0.226 0.202 0.183 0.176 0.165 0.150 0.140 0.135 0.131 Heavt Brine Thickness Thickness of Insulation (Inches) Btu Per Linear Foot Btu Per Sq Ft. Pipe Surface 2.8 0.087 0.394 2.9 0.094 0.340 3.0 0.104 0.294 3.1 0.113 0.260 3.2 0.118 0.238 3.3 , 0.134 0.214 3.3 0.147 0.197 3.4 . 0.162 0.176 3.5 0.176 0.167 3.7 0.182 0.154 3.9 0.202 0.138 4.0 0.228 0.130 4.0 0.263 0.116 4.0 . 0.309 0.110 4.0 0.364 0.108 one-fifth of the time given in the table. It will then be necessary to increase.the rate of flow so that five times the specified quantity of water will have to be supplied in order to prevent freezing. -If the minimum air temperature is -- 38 F (temperature difference 80 F) instead of --18 F, the time required to cool the water to the freezing point' will be 60/80 of the time given in the table, or the necessary quantity of water to be supplied will be 80/60 of that given. ' :. In making calculations to arrive at the values given in Table 17, the loss of heat stored in the insulation, the effect of a varying temperature difference due to the cooling of pipe and water, and the resistance of the outer surface of the insulation to the transfer of heat to the air have all been neglected. When these factors enter into the computations it is necessary to enlarge the factor of safety. Also as stated, the time shown in the table is that required to lower the water to the freezing point. A longer period would be required to freeze the water blit the danger point is reached when freezing starts. The flow of water will stop and the entire line will be in danger as soon as the water freezes across the section of the pipe at any point. . , Heating Ventilating Air Conditioning Guide 1938 (L. B. McMillan. Proc. National Dili. Healing Ais'n., Vol. 18, p. 138.) ` Fig. 3. Chart for Determining Economical Thickness of Insulation 736 Chapter 39. Piping and Duct Insulation When water must remain stationary longer than the times designated in Table 17, the only safe way to insure against freezing is to install a steam or hot water line or to place an electric resistance heater along the side of the exposed water line. The heating system and the water line are then insulated so that the heat losses from the heating system are not excessive, and the heating effect is concentrated against the water pipe where it is needed. For this form of protection 2 in. of an efficient insu lation may be applied. ECONOMICAL THICKNESS OF PIPE INSULATION The thicknesses of insulation which ordinarily are used for various temperature conditions are given in Table 18. Where a thorough analysis of economic thickness is desired this may be accomplished through the the use of the chart, Fig. 3. The dotted line on the chart illustrates its use in solving a typical example. In using the chart, start with the scale at the left bottom margin representing the given number of hours of operation per year; then proceed vertically to the line representing the given value of heat; thence horizontally to the right, to the line representing the given tem perature difference; thence vertically to the line representing the con ' ductivity of the given material; thence horizontally, to the left, to the line representing the given discount on that material; thence vertically to the curve representing the required per cent return on the investment; thence horizontally to the right, to the curve representing the given pipe size; thence vertically to the scale at the top right margin where the economical thickness may be read off directly. UNDERGROUND PIPE INSULATION Underground steam distribution lines are carried in protective struc tures of various types, sizes and shapes. (See Chapter 42). Detailed data on commonly used forms of tunnels and conduit systems have been published by the National District Heating Association2. Pipes in tunnels are covered with sectional insulation to provide maximum thermal efficiency and are also finished with good mechanical protection in the form of metal or waterproofingvmenibrane outer jackets. Conduit systems are in more general use than tunnels. Pipes carried in conduits may be insulated with sectional insulation; however, the more usual practice is to fill the entire section of the conduit around the pipes with high quality, loose insulating material. The insulation must be kept dry at all times', and for this purpose effective waterproofing mem branes enclose the insulation. A drainage system is also provided to divert water which may tend to enter the conduit. The economical thickness of insulation for underground work is difficult of accurate determination due to the many variables which have to be considered. As a result of theories3 previously developed, together 'Handbook of the National District Heating Association, Second Edition, 1932. Theory of Heat Losses from Pipes Buried in the Ground, by J. R. Allen (A. S. H. V. E. Transactions Vol. 26. 1920. p. 335). 737 Heating Ventilating Air Conditioning Guide 1938 Table 17. Data for Estimating Requirements to Prevent Freezing of Water in Pipes Nominal Pips Size (Inches) 1 2 k 0.42 i 0.83 ik 1.40 2 1.94 3 3.25 4 4.55 5 5.92 6 7.35 8 10.05 10 13.00 12 15.80 Number op Hours to Cool Water to Freezing Point Water Required to Flow to Prevent Freezing. Pounds per Linear Foot op Pipe per Hour 3. 0.50 1.02 1.74 2.48 4.27 6.02 7.96 9.88 13.90 18.10 22.20 Thickness of Insulation in Inches 42 3 0.57 1.16 2.02 2.90 5.08 7.20 9.69 12.20 17.25 22.70 28.10 0.54 0.68 0.84 0.95 1.24 1.47 1.73 1.98 2.46 2.96 3.43 0.45 0.55 0.68 0.75 0.94 1.11 1.29 . 1.46 1.78 2.12 2.45 4 0.40 0.48 0.58 0.64 0.79 0.93 1.06 1.19 1.43 1.70 1.93 Table 18. Thicknesses of Insulation Ordinarily used Indoors3 Steam Pressures (la Gage) or Conditions . 0 to 25 25 to 100 100 to 200 Low Superheat Medium Superheat High Superheat Steam Temperatures Degrees Fahrenheit 212 to 267 267 to 338 338 to 388 388 to 500 500 to 600 600 to 700 Thickness or Insulation Pipes Larger loan 4 In. 1 in. IK in. 2 in. 2*^ in. 3 in. ZH in. Pipes 2 In. to 4 In. 1 in. 1 in. IK in. 2 in. .2^ in. 3 in. Pipes HIn. to 1H In. 1 in. 1 in. 1 in. 1 K in. . 2 in. 2 in. AU piping located outdoors or exposed to weather is ordinarily insulated to a thickness M in. greater than shown in this table, and covered with a waterproof jacket. Table 19. Thickness of Loose Insulation for Use as Fill in Underground Conduit Systems Steam Pressures (Lb Gage) ob Conditions Steam Temperatures Degrees Fahrenheit Minimum Thickness op Insulation in Inches Steam Lines Return Lines Pipes Less Pipes 4 In: Pipes Larger Pipes Less Pipes 4 In. than 4 In. to 10 In. than 12 In. than 4 In. and larger Hot Water, or 0 to 25 212 to 267 m 2 2K ik IK 25 to 125 267 to 352 2 m 3 IK IK Above 125, or superheat 352 to 500 2K 3 3K IK IK Minimum Between AND Return i IK IK 738 Chapter 39. Piping and Duct Insulation with other experimental data which have been presented, the usual endeavor is to secure not less than 90 per cent efficiency for underground piping. Table 19 can be used as a guide in arriving at the minimum thickness of loose insulation fills to use for laying out conduit systems. Other factors such as the number of pipes and their combination of sizes, as well as the standard conduit sizes, are primary controlling factors in the amount and thickness of insulation for use. When sectional insulation is applied to lines in tunnels or conduits, usual practice is to apply the most efficient materials in. less in thick ness than that determined by the use of Fig. 3. The data in Fig. 3 are based on conditions of insulation exposed to the air, whereas normal ground temperature is substituted for air temperature in determining the tem perature difference for use with the chart when applying it for under ground pipe line estimates. PROBLEMS IN PRACTICE 1 What precautions must be taken in selecting insulation used for covering pipe lines carrying materials at temperatures lower than the dew point? Materials intended for this service should be as moisture proof as possible and in addition an outer covering should be applied which is proof against diffusion of air and water vapor. If the material permits the diffusion of air, the air will reach a point in the covering where the temperature is below the dew point. The condensed water will gradually accumulate until the covering becomes saturated, which will increase the conductivity and perhaps lower the mechanical strength of the covering until it becomes worthless. 2 Compute the total annual heat loss from 165 ft of 2-in. bare pipe in service 4000 hours per year. The pipe is carrying steam at 10 lb pressure and is exposed to an average air temperature of 70 F. The pipe temperature is taken as the steam temperature, which is 239.4 F, obtained from Table 8, Chapter 1. The temperature difference between the pipe and air = 239.4 -- 70 ** 169.4 deg. By interpolation of Table 1 between temperature differences of 157.1 F and 227.7 F, the heat loss from a 2-in. pipe at a temperature difference of 169.4 deg is found to be K677 Btu per hour per linear foot per degree temperature difference. The total annual heat loss from the entire = 1.677 X 169.4 X 165 (linear feet) X 4000 (hours) = 188,000,000 Btu. 3 t Coal costing $11.50 per ton and having a calorific value of 13.000 Btu per pound is being burned in the furnace supplying steam to the pipe line given in Question 2. If the system is operating at an over-all efficiency of 55 per cent determine the monetary value of the annual'heat loss from the line. The cost of heat per 1 million Btu supplied to the system -- 1,000,000 X 11.5 (dollars) -5- 13,000 (Btu) X 2000 (lb) X 0.55 (efficiency) = $0,804. The total cost of heat lost per year = 0.804 X 188 (million Btu) = $151.15.4 4 If the steam line given in Question 2 is covered with 1-in. thick 85 per cent magnesia, determine the resulting total annual heat loss through the insula-' tion. Also compute the monetary value of the annual saving and the per centage of saving over the heat loss from the bare pipe. ' By interpolation of Table 9 between temperature differences of 157.1 F and 227.7 F, the coefficient of transmission for 1-in. magnesia on a 2-in. pipe is found to be 0.525 Btu per hour per square foot of pipe surface per degree temperature difference at a temperature difference of 169.4 deg. The total hourly loss per square foot of insulated pipe will then be 0.525 X 169.4 -- 89.04 Btu. From Table 5 the area per linear foot of 2-in. pipe is 4A closely approximate solution of this problem may be quickly made by use of the estimating chart given in Fig. 1. . r Heating Ventilating Air Conditioning Guide 1938 found to be 0.622 sq ft. The total annual loss through the insulation = 89.04 X 0.622 X 165 (linear feet) X 4000 (hours) = 36,550,000 Btu. The annual bare pipe loss as determined in the solution of Question 2 was found to be 188,000,000 Btu. The saving due to insulation is then 188,000,000 -- 36,550,000 =* 151,350,000 Btu per year. From the solution of Question 3 it was found that the heat supplied to the system cost $0,804 per million Btu; therefore, the monetary value of the saving = 0.804 (dollars) X 151.35 (million Btu) = $121.69, or 81.2 per cent of the cost when using uninsulated pipe. . : 5 The manufacturer's list price for 85 per cent magnesia insulation is $0.36 per linear foot for 1-in. (standard thick) material to cover a 2-in. pipe. De termine the period of time required for the saving found In Question. 4 to pay for the cost of the insulation if it can be purchased and applied at 80 per cent of list price (20 per cent discount). ' The applied cost of insulation = 165 (linear feet) X 0.36 (dollars) X 0.80 (net) = 47.52. Since the annual saving as found in Question 4 amounts to $121.69, the in sulation will pay for its cost in 47.52 -s- 121.69 = 0.3905 years; in other words, the cost will be repaid 2.56 times by the saving obtained in one heating season. 6 The conductivity of magnesia insulation is 0.455 at the mean temperature which will result under the conditions of Question 4. Estimate the most economical thickness of magnesia for application on the pipe when operating under the conditions which are given in the foregoing problems and when a 20 per cent return is required on the investment for insulation. Use chart given in Fig. 3. Begin at the left bottom margin and proceed successively as shown by the dotted line example to the following essential data which are collected from the problems previously given: . '` 4000 hours operation per year. $0,804 value of heat, dollars per million Btu. 169.4 deg temperature difference. 0.455 conductivity of insulation. 20 per cent discount from list, cost of insulation. ' 20 per cent fixed charges, return on investment. ; 2-in. pipe size. ... 1 Solution of the problem by use of Fig. 3 results in a required thickness of approximate!^ 1.05 in. The nearest commercial thickness procurable is standard thick (1^2 in.) magnesia. .. (It is of interest to note that the use of Fig. 3 will generally result involutions which, for all practical pur poses, agree closely with the specifications for thicknesses given in Table 18.) . 7 Determine the minimum thickness of wool felt insulation having a con? ductivity of 0.30 necessary to prevent condensation of moisture on a 4-in. pipe carrying cold water at a temperature of 40 F when the surrounding air reaches maximum conditions of 90 F with a relative humidity of 90 per cent. ' The difference between the temperature of the pipe and the surrounding air is 90 -- 40 = 50 deg. For quick estimating purposes use the chart given in Fig. 2. Enter this chart at the lower left margin on the 90 per cent relative humidity line and proceed horizontally to the right to intersect the 90 deg air temperature line. Project a line up to the 50 deg temperature difference line, and then horizontally to the right to the intersection with the 4-in. pipe size line. From this point proceed down to intersect the 0.30 line which denotes the conductivity of the insulation. Directly opposite this point of intersection the correct thickness of insulation is read from the scale on the lower right margin. . This chart solution denotes that woo! felt 2.4-in. thick is sufficient to prevent condensation. The nearest commercial thickness procurable is 2% in. .. ; For prevention of condensation as well as for protection against freezing, if the thickness determined theoretically cannot be had, it is better to apply the next greater thickness procurable rather than to use any lesser thickness because an additional factbr of safety is thus obtained. 740 Chapter 40 ELECTRICAL HEATING Resistors, Heating Elements, Electric Heaters, Unit Heaters, Central Fan Heating, Electric Steam Heating, Electric Hot Water Heating, Heating Domestic Water Supply, Industrial 1 Heating, Reversed Cycle Refrigeration, Auxiliary Electric Heating, Control, Calculating Capacities, Power Problems, Insulation ELECTRIC heating is. steadily assuming a more important place in heating, ventilating and air conditioning installations, accelerated in many territories by the load building efforts of the utilities which usually include reduced rates to encourage such installations. Electrical heating has a logical place in the heating industry because of its features of flexibility, cleanliness, safety, convenience and ease of control. Electrical heating practice has many basic principles in common with fuel heating, but there are also important differences. When heat units are delivered to each room by wire, no combustion process is necessary, either at a central plant or at the individual room units. The maximum output of an electric heater is a fixed constant, unaffected by the temperature of the surrounding air and it follows that the maximum total load on an electrical heating system is the total wattage of connected electric heaters, regard less of weather conditions. The real obstacle to the more general adoption of electric heating for buildings is the cost of the electricity itself. Because the heat units produced electrically are more costly, their conservation is of more relative economic importance than with fuel heating, so that sponsors of electric heating give greater attention to temperature-insu lated building construction, and to economy by accurate controls. All heat is a form of energy. Fuels hold stored chemical energy which is released into heat by combustion. Electrical power is a form of energy which can be released into heat by passing it through a resisting material. Both fuel and electric heating have two divisions: first, the conversion of energy into heat; second, the distribution and practical use of the heat after it is produced. In converting the chemical energy of fuels into heat by combustion, there is necessarily a considerable variation in thermal efficiency. This is not true, however, when converting electric power into heat, because 100 per cent of the energy applied in the resistor is always transformed into heat. In electric .heating practice the engineer need not be concerned about efficiencies of heat production, but rather about efficiencies of heat utilization. It is the engineer's problem to distribute the electrically 741 Heating Ventilating Air Conditioning Guide 1938 produced heat units in such manner as to obtain conditions of maximum comfort with the minimum consumption of electricity. DEFINITIONS Definitions of terms used in fuel heating are given in Chapter 45. The following terms apply particularly to electric heating: Electric Resistor: A material used to produce heat by passing an electric current through it. Electric Heating Element: A unit assembly consisting of a resistor, insulated supports, and terminals for connecting the resistor to electric power. Electric Heater: A complete assembly of .heating elements with their enclosure, ready for installation in service. RESISTORS AND HEATING ELEMENTS Solids, liquids, and gases may be used as resistors, but most com mercial electric heating elements have solid resistors, such as metal alloys, and non-metallic compounds containing carbon. In some types of electric boilers, water forms the resistor which is heated by an alternating current of electricity passing through it. One of the more common resistors is nickel-chromium wire or ribbon which, in order to avoid oxidation, contains practically no iron. Commercial electric heating elements are made in many types. Some have resistors exposed to the air being heated. The resistors may be coils of wire or metal ribbon, supported by refractory insulation, or they may be non-metallic rods, mounted on insulators. This type of element is used extensively for operation at high temperatures when radiant heat is desired, also at low temperatures for convection and fan circulation heating, especially in large installations. Some elements have metallic resistors embedded in a refractory insu lating material, encased in a protective sheath of metal. Fins or extended surfaces may be used to add heat-dissipating area. Elements are made in many forms, such as strips, rings, plates and tubes. Strip elements are used for clamping to surfaces requiring heat by conduction, and in some types of convection air heaters. Ring and plate elements are used in electric ranges, waffle irons, and in many small air heaters. Tubular elements may be immersed in liquids, cast into metal, and, when formed into coils, used in electric ranges and air heaters. Cloth fabrics woven from flexible resistor wires and asbestos thread, are used for many low temperature purposes such as heating pads and aviators' clothing. ELECTRIC HEATERS Electric heaters may be divided into three groups, conduction, radiant and convection. Conduction electric heaters, which deliver most of their heat by actual contact with the object to be heated, are used in such applications as aviators' clothing, hot pads, foot warmers, soil heaters, ice melters, and water heaters. Conduction heaters are useful in conserving and localizing heat delivery at definite points. They are not suitable for general air heating. 742 Chapter 40. Electrical Heating Radiant electric heaters, which deliver most of their heat by radiation, have high temperature incandescent heating elements and reflectors to concentrate the heat rays in the desired directions. The immediate and pleasant sensation of warmth which is caused by radiant heat makes this type desirable for temporary use where the heat rays can fall directly upon the body. They are not satisfactory for general air heating, as radiant heat rays do not warm the air through which they pass. They must first be absorbed by walls, furniture, or other solid objects which then give up the heat to the air. A typical radiant heater is shown in Fig. 1. Gravity convection electric heaters, designed to induce thermal air circu- lation, deliver heat largely by convection, and should be located and used in much the same manner as steam and hot water radiators or convectors, They generally have heating elements of large area, with moderate surface temperature, enclosed to give proper stack effect to draw cold air from Wall / MV, &Performated-*C| case Fig. 2. Convector Heater the floor line. See Fig. 2. The flexibility possible with electric heating elements should discourage the use of secondary mediums for heat trans fer. Water and steam add nothing to the efficiency of an electric heater and entail expensive construction and maintenance. UNIT HEATERS Unit electric heaters include a built-in fan unit which circulates room air over the heating elements. Heaters of this type are manufactured in many designs and sizes, and can be located in much the same manner as steam unit heaters. Electric unit heaters are used in industrial plants, sub-stations, power houses, pumping stations, etc., where the power rate for electric heating is found to be favorable. The best location of the heater depends upon local circumstances as they can be mounted either on the ceiling to direct the air downward, on the side wall about 7 ft from the floor, or at the floor line. Variations in design are necessary for different locations, but typical arrangements are indicated in Figs. 3, 4, and 5. The arrangement of the wiring circuits is very important for electric unit heaters. In principle they are all the same and include as essential 743 Heating Ventilating Air Conditioning Guide 1938 elements an automatic control panel, a thermostat, and a master hand switch. All heaters should be designed with a safety thermal trip wired in series with the magnet coil of the control panel and with the hand switch and thermostat. A typical wiring diagram is shown in Fig. 6. This applies to a single phase power supply, but for 3 phase the only difference is to have a 3 pole panel and a heater arrangement for 3 phase connection. Chapter 40. Electrical Heating zation of water, or for controlling air washer dew-point temperatures when mounted as preheating units on the intake side of the air washer. See Chapter 21. In coordinating the input of heat energy and the volume of air circu lation, a basic difference between electric heating and steam heating enters into the problem. Steam is approximately a constant-temperature source of heat for any given pressure as a change in air volume flowing over steam coils does not greatly affect the temperatures of the delivered air. The amount of steam condensed (heat input) varies in proportion to the air volume, but the surface temperature of the steam coils remains about the same. Electric heat is quite different, having a constant input of energy. If the volume of air flow over electric heating elements is changed, and no change is made in the electrical power connections, there will be a corresponding change in the temperature of the air delivered. Fig. 3. Ceiling Mounted Unit heater Power supply //////////////////// Fig. 5. Floor Mounted Unit Heater Heater Portable unit heaters are useful for temporary work, such as drying out damp rooms, or for warming rooms during construction. CENTRAL FAN HEATING Electric heating elements can be used for the prime source of heat in a central fan electric heating system or in the heating phase of a complete air conditioning system. They can be used in the same manner as steam served heating units for tempering, preheating or reheating the air at the main supply fan location and as booster heaters at the delivery terminals of the duct system. In the humidification phase of air conditioning electric heating, elements can be used to provide moisture by the evapori- 744 Fig. 7. Wiring Diagram of a Modulating Control for a Fan System This occurs because the electrical energy input remains constant and the surface temperature of the heating elements will vary as is necessary to. force the air to accept all the heat. With electric heat the total heat is constant unless some compensating action is performed by control. Automatic modulation to vary the electrical heat input and synchronize it properly with the air flow has been successfully applied to central fan systems. Electric booster heaters are often useful in balancing a system in which the air has been heated with steam coils. A typical wiring diagram of an automatic modulating system for central fan heating is indicated in Fig. 7. ELECTRIC STEAM HEATING Electric steam heating differs from fuel heating only in the use of electric boilers to generate steam. Electric steam boilers are entirely automatic and are well adapted to intermittent operation. Small electric boilers usually have heating elements of the enclosed metal resistor type im mersed in the water. Boilers of this construction may be used on either direct or alternating current since the heat is delivered to the water by 746 Heating Ventilating Air Conditioning Guide 1938 contact with the hot surfaces. To lessen the likelihood that the heating elements will burn out, they should be of substantial construction, with a low heat density per unit of surface area. Provision should be made for cleaning off deposits of scale which restrict the heat flow. A typical Fig. 8. Resistance Type Boiler for Steam or Hot Water Fig. 9. Diagrammatic Arrangement of an Electrode Boiler resistance type of hot water or steam boiler is shown in Fig. 8. Large electric boilers are usually of the type employing water as the resistor. Only alternating current can be used, as direct current would cause electrolytic deterioration. Large boilers of this kind have electrodes immersed in the water where heat is generated directly. Electric steam boilers are useful in industrial plants which require limited amounts of steam for local processes, and for sterilizers, jacketed vessels and pressing . machines which need a ready, supply of steam. It sometimes is economical 746 Chapter 40. Electrical Heating to shut down the main plant fuel burning boilers when the heating season ends, and to supply steam for summer needs with small electric steam boilers located close to the operation. In general, electric steam heating is confined to auxiliary or other limited applications. If the heating system is designed to use electricity exclusively, steam generating or distributing equipment is superfluous. A diagrammatic arrangement of an electrode boiler is shown in Fig. 9. ELECTRIC HOT WATER HEATING Electric water heating, using an electric boiler.in place of a fuel burning boiler, like electric steam heating, is generally confined to auxiliary or other limited applications. The use of insulated water storage tanks in which to store heat generated by electricity during off-peak hours at extremely low rates, is a development which has some special applications. In this system of heating, the primary storage tank is simply a large, well-insulated, pressure type steel tank, equipped with electric heating elements connected to line with automatic time switches, which also have automatic limit controls for temperature and pressure. The heating system installed in the building may be of any standard individual radiator or fan-served indirect type or with provisions.for the heating and humidification phases of an air conditioning system. A system of this kind requires very careful design to avoid- excessive overall radiation losses during periods of low heat demand. It is also important to provide for sudden changes in heat demand. A typical- hot water heating boiler is illustrated in Fig. 8. . HEATING DOMESTIC WATER SUPPLY 1 Electric water heaters of the automatic storage type for domestic hot water supply are simple and reliable, and in many sections of the country low electric rates have been established by the electric utilities to secure this load. In some districts, rate schedules divide the current used for water heating into two classifications, regular and off-peak. A time switch automatically limits use of the off-peak heating element to the hours of off-peak load, while the regular heating element is a stand-by at all times. Storage of this two-element type of water heater is larger than average to carry over the periods when the off-peak element is timed out, without too frequent demands on the regular heating element which takes the higher domestic lighting service rate. Some utilities now offer a schedule which, beyond a stipulated minimum, lowers the rate for all service if an electric water heater is installed. A comprehensive survey covering United States and Canada shows a rapidly growing use of electric water heaters, although the per cent of saturation, based on the total number of domestic power customers, is still low. Public acceptance is effected by the cost of other competitive fuels, by the electric power rate, and by the temperature of the cold water supply. `Test Results of Electric Water Heaters, by C. G. Hillier (A.S.H.V.E. Journal Section, Heating, Piping ana Air Conditioning, November, 1936, p. 632). .. Fourth Animal Survey, by B. J. Martin (Electric'Light and Power, March, 1937). 747 Heating Ventilating Air Conditioning Guide 1938 Competition with other fuels, especially gas, seems to be the major controlling factor. The first cost of electric storage heaters is also greater than for gas, owing to the need for larger tank storage due to off-peak service and slower recuperating capacity. It is often desirable to .connect an electric heater to a residential system having a coil in the fire-box of the furnace. In this case it is im portant to make the proper connections in order to benefit by any heat obtained from the furnace and at the same time to prevent dangerous overheating. The proper piping connections are shown in Fig. 10, and in this case the electric heater will only furnish heat when insufficient heat is supplied from the furnace. This arrangement has a further advantage in the summertime in that the bare tank through which the cold water passes on its way to the electric heater serves as a tempering tank, absorbing considerable warmth from the basement air and re quiring the use of less energy in the electric heater. Fig. 10. Piping Arrangement for Connecting Electric Water Heater to Fire-Box Coil ' Fig. 11. Domestic Hot Water Heater for Off-Peak Service A typical domestic hot water heater as shown in Fig. 11 is arranged with upper and lower heating elements for the usual type of off-peak heating service for which most utilities have especially attractive low power rates. The lower heating element is under the control of the offpeak time switch. However, the upper heating element is usually con nected to the line so that in case the supply of hot water in the tank becomes exhausted the top thermostat can turn on the top heater and heat a small supply of water. The top heater will not heat the water in . the tank below its location, but when the off-peak period arrives the lower heater is turned on and the entire tank becomes heated. INDUSTRIAL ELECTRICAL HEATING Electric heating elements have been successfully developed for indus trial work such as annealing, brazing, carburizing, enameling, forging, ceramic firing, hardening, metal melting, nitriding and process heating. Industrial ovens and furnaces where precise control of temperature is necessary can be very successfully operated with electric resistance ele 748 Chapter 40. Electrical Heating ments at temperatures as high as 1800 F. For higher temperatures the electric arc or high frequency induction methods are often used. Electric heaters for heating oil to high temperatures for secondary circulation in process work are used as a substitute for superheated steam. Special oil can be electrically heated as high as 700 F and pumped at a pressure just sufficient to cause flow. When used in heating coils or jacketed vessels, this gives a safe and convenient automatic system for moderate-sized installations. Pitch, waxes, and many chemicals are successfully heated by electricity, but require careful design and adequate automatic control. REVERSED CYCLE REFRIGERATION2 Reversed refrigeration is frequently referred to as a heat pump since the electric motor driving the refrigerating compressor furnishes the motive power to transfer heat from one temperature to a higher temperature level. The compressor acts as a reversible refrigerating unit to extract heat from the outdoor air in winter and deliver it indoors for heating purposes, and, by a reversal, to extract heat from the indoor air in summer and discharge it outdoors. In normal use a refrigerating machine is arranged to remove heat and the heat removed is dissipated to the condenser cooling water. The driving energy is-converted into heat most of which is added to the heat removed and extracted. In so-called reversed refrigeration the heat removed together with the heat converted from the driving energy is utilized to heat the building. This conservation of the heat converted from the driving energy enables the reversed refrigeration to show a better performance in heating service than straight refrigeration can show in cooling service. For a detailed description of this cycle see Chapter 24. AUXILIARY ELECTRIC HEATING In conjunction with heating systems of other types, an auxiliary elec trical heating arrangement is a convenient means of caring for mild days in the spring and fall which require little heat to make a building com fortable. Likewise, such electrical heating might be used on abnormally cold days to help out the main heating system and by this means reduce the necessary size of the system. Because of the feeling of comfort that a radiant type heater gives, bathrooms may be heated electrically with this type of heater while the rest of the house is cared for by some other system. Offices and rooms which require heat at periods when the main heating plant is shut down *Cpoling Homes, A Field for Refrigeration, by A. R. Stevenson, presented at the symposium of the Refrigeration with Gas Committee of the American Gas Association, April'20, 1926. ' The Heat Pump, An Economical Method of Producing Low-grade Heat from Electricity, by T. G. N. Haldane (Electric Review, Vol. 105, p. 1161-1162, December 27, 1929, and I. E. E. Journal, Vol. 68, p. 666-675, June. 1930). Edison Building Heated and Cooled by Electricity, by H. L. Doolittle (Power, Vol. 74, p. 384, Septem ber 8. 1931). House Heating by Pump with 5 to 1 Pick-up Ratio, by Gilbert Wilkes and R. E. Marbury (Electrical World, Vol. 100, p. 828, December 17, 1932). An All Electric Heating, Cooling and Air Conditioning System, by Philip Sporn and D. W. McLenegan (A.S.H.V.E. Transactions. Vol. 41,1935, p. 307). Using the Reversed Cycle Refrigerating Principle for a Self-Contained Heating and Cooling Unit, by Henry L. Galson (A.S.H.V.E. Journal Sbction, Heating, Piping and Air Conditioning, October, 1935, p.497). * - 749 Heating Ventilating Air Conditioning Guide 1938 can be conveniently cared for electrically. Fan type unit heaters de livering warm air at the floor zone are very effective. CONTROL Because the efficiency of electric heat production is the same for large or small units, it is possible to reduce heat waste to a minimum by applying local heating, locally controlled. Radiant heaters are usually controlled manually but new methods for automatic control are described in Chapter 41 on Radiant Heating. For all convection and fan circulation heaters thermostatic control is essential for economical operation. For duct systems having a variable volume of air flow the electric heater control must automatically vary the heat input in coordination with the changes in air volume and demand for heat. CALCULATING CAPACITIES The methods of calculating heat losses outlined in Chapters 6, 7. and 8 may be used for electric heating exactly as for fuel heating. The total heat requirements in Btu per hour may then be converted into the electrical rating of an equivalent heating system by using the equation: Total Btu per hour , . ' .-----------,T54r1rr5f--------- = kw rating of required electric heating ... (1) For comparison with steam radiation: 3--4--1--5---B---t-u---(-o--n--e---k--w---h--r)- = 14.2 sq f,t of, steam r_a_d. iation - While many empirical rules based on cubic contents, floor areas, etc., are used in steam heating practice, they should never be used to deter mine size of equipment for an electrical heating installation. POWER PROBLEMS The first point to determine is the cost of the power 'which is available for electric heating. Unlike fuels, there is no uniform cost for electric power because of the unequal cost of distribution to large and small users. The fact that electricity cannot be economically stored, but must be used as fast as it is generated, makes it impossible to operate power plants at uniform loads; hence, even the time,of use may affect the cost of power. . Special low rates are sometimes available during certain prescribed hours of use, but wherever the use of power is unrestricted a demand charge based upon the rated connected load of each heating device must form part of the basic rate structure, so that unlike fuel heating, the cost of operating electric heating systems depends not only upon the actual energy used but also upon the demand charge for the available electrical service. ' Homes are almost universally supplied with lighting current of 115 volts, which can only be used economically for small heaters. Usually 750 40.Chapter Electrical Heating the service lines will not permit more than plug-in devices. The Under writers permit approved heaters of 1320 watts or less to be plugged into approved baseboard receptacles. Where homes have 230 volt service for cooking and water heating, and rates are favorable, larger heaters can be installed. For industrial purposes, heaters should be designed to use polyphase power, which is usually supplied at 220, 440 or 550 volts. All polyphase heaters should be balanced between phases. INSULATION The value of building construction which incorporates built-in insu lation to reduce the outward heat loss in winter and the inward heat gain in summer has been placed in the spotlight by the increasing adoption of complete air conditioning. With electric heating, adequate insulation is very important and will pay even better returns on the investment than for less expensive fuels. . PROBLEMS IN PRACTICE * 1 # Under what conditions are electric heaters most feasible? - 0. When electric power rates are low and other fuels high in cost. b. Where the total required heat is not great and cost of attention tends to offset the higher actual energy cost of electricity. c. Where saving of space, elimination of a chimney and lower first cost of equipment are deciding factors. d. Where intermittent and local auxiliary use avoids the necessity of keeping up steam with large losses in long pipe lines. . e. Where accurate local automatic control reduces the total heat losses enough to com pensate for the higher energy rate for electricity over other fuels. . /. For isolated or unattended rooms and small buildings where other heat sources are not readily available. . g. For underground rooms and vaults where the return or disposal of condensation is difficult or*Where freezing may occur at times. h. Where corrosive conditions make pipe lines expensive to maintain. . 1. Where the use of power for heating can be staggard to avoid periods of other use such as large motors, and thus prevent an increase of the basic demand charges for electrical service. .' j. For fall and spring use, and as auxiliary to help out other heating systems at important points during extremely cold weather. . k. Where dust, gases, odor, noise, or access for attendants must be.excluded. 2 # On what basis should electrical heating cost be compared with other fuels? a. Initial investment with interest and depreciation. b. Operating cost for energy. . c. Saving in repairs and attendance. d. Economy due to local accurate temperature regulation. . e. Safety, convenience, and cleanliness. . /. Saving in space. 751 Heating Ventilating Air Conditioning Guide 1938 3 At what rate for electric power is electric heating feasible? a. The answer is complicated because operating cost of electric heaters depends upon at least three factors, namely, demand charge, energy charge, and the sliding scale accord ing to the amount of power used for all purposes. b. For off-peak use which avoids the demand charge an energy rate of 1 cent per kilowatthour is often attractive for heating systems of moderate size. Larger jobs usually require a rate of about % cents per kilowatt-hour. c. For unrestricted heating service for auxiliary purposes an average rate of 2 cents per kilowatt-hour may be satisfactory for small installations. d. Wherever other factors make electric heating especially desirable the rates may be even higher than those mentioned above. e. For domestic hot water supply a rate of 1 cent per kilowatt-hour is usually satisfactory. 4 What advantages have electric fan unit systems over plain convection heaters?. . Better distribution of heat to the floor level. . Elimination of condensation on machinery, windows, and other cool surfaces. c. Wider choice as to location of the heater, and reduced cost of wiring connections. d. The fan can be operated for air circulation only, during periods when heat is not required. 5 9 In a fan type electric heating system, what important features are re quired that are not needed for a steam system? . a. A heating coil supplied with steam at constant pressure will remain at approximately constant temperature regardless of the amount of air passing over it, but the conden sation rate will change. The temperature of an electric coil supplied with a constant amount of energy will rise if the quantity of air is decreased, and fall if the quantity of air is increased. This happens because the input of electrical energy is constant while the input of steam energy varies with the condensation rate. b. Because the temperature of an electrical coil will rise upon decreased air flow, the Underwriters require the installation of an approved thermal safety trip switch located in the heating chamber to cut off the electrical heating circuit automatically in case the air flow should be interrupted. This-switch should remain off until manually reset. c. Electrical heating elements vary greatly in their capacity for storing heat units after the power is shut off. In a fan system it is very important to use elements having the lowest possible heat storage capacity to avoid overheating motors and improperly operating the thermal safety trip switches when air flow ceases due to normal shut-downs. d. Because the input of an electric heater is constant for a given rating, it is necessary to provide a modulating electrical control which will automatically compensate for vari ations in the volume of air flow. This cannot be done by mixing dampers alone as in a steam system. ^6 6 0 What problems must be considered in connection with electric water heating? a. For the best available power rate consult the Electric Power Company supplying service. b. The maximum daily and hourly demand for hot water. c. The size of storage tank necessary to carry over the peak load periods when no re heating is done. d. The kilowatt rating required to reheat enough water during off-peak periods. e. Standby radiation losses of the storage tank and hot water piping. /. Cost of providing electrical supply lines of ample capacity with fuses, meters and switches. g. Tank materials and design to avoid expensive replacements due to corrosion. 752 Chapter 41 RADIANT HEATING Physical and Physiological Factors, Control of Heat Losses, Rate of Heat Production, British Equivalent Temperature, Application Methods, Calculation' Principles, Mean Radiant Temperature, Measurement of Radiant Heating HEATING for health and comfort is generally understood to mean that heat must be supplied in order to control the rate of heat loss from the human body so that the physiological reactions are conducive to a feeling of comfort. In convection heating, it is generally the function of the heating medium to transfer the heat to the air and thence to the occupant of the room, while the primary object of radiant heating is to warm the surrounding surfaces without appreciably heating the air. The difference between convection heating and radiant heating is there fore partly physical and partly physiological. Reference to low tempera ture radiation is actually not heating at all, except in a secondary sense. Low temperature radiation is produced not to heat the individual in the room, but to reduce the net rate at which the body surface loses heat by radiation. Comfort requires that heat be removed from the body at the same rate as it is generated by the oxidation of food stuffs in the body tissue. Furthermore, the heat should be dissipated in a manner conducive to the physiological requirements of the human body. Actually the feeling of heat and cold in an individual is not so much a measure of the rate at which body heat losses take place as compared with the heat generated within the body, as it is an indication that the sensation of the body is more susceptible to the manner in which the heat is abstracted from the body. This principle is the basis upon which radiant heating is founded. CONTROL OF HEAT LOSSES Heat is transferred from any warm dry body to cooler surroundings principally by convection and by radiation, the approximate total being the sum of the two. Where the body surface is moist as with the human body, there is additional loss of heat through evaporation from both the body surface and the respiratory tract. The rate of heat loss by convection depends upon the difference between the temperature of the body and of the surrounding air, and on the rate of air motion over the body. 753 Heating Ventilating Air Conditioning Guide 1938 The loss by radiation of a given surface depends entirely upon the difference between the temperature of the body and the mean surface temperature of the surrounding walls and objects. This latter tempera ture is called the mean radiant temperature (MRT). Because these two types of heat losses act in a supplementary manner toward each other, a required rate of heat loss can be secured by having a relatively low air temperature and a relatively high MRT, or vice versa. Thus, if the air is reduced from a given temperature to a lower tempera ture, the amount of heat lost from the body by convection is increased, and this increase can be compensated for by raising the MRT. Similarly, with a higher air temperature the same total heat loss will be maintained by a correspondingly lower MRT. Within limits the sensation of feeling cold can be avoided in two ways; first, by raising the air temperature surrounding the body, and secondly, by allowing the thermal radiation from warm objects to impinge on the body with sufficient intensity to make up for a lower air temperature. It is the object of a heating installation to avoid the necessity for human body adaptation and also to provide comfort for those individuals doing the least physical work. While some conditions may take care of the heat loss from the body without controlling the generation of heat within, other conditions stimulate-the production of heat within us, which . enables the body to respond to the environment and generate more heat to meet the conditions. . Rate of Heat Production ' The normal rate of heat production in a sedentary individual is about 400 Btu1 per hour, or (since the entire surface area of an average adult is 19.5 sq ft) about 20.5 Btu per square foot per hour. When considering radiant heating, it is necessary to calculate the radiation and the con vection loss separately. The human body is of complicated shape, and radiation only takes place freely from the exposed outer surface. There are considerable portions of the body which radiate most of their heat to other portions, such as: the legs, arms, lower part of head etc. It is necessary to determine the equivalent surface of the body from which heat is radiated and a .similar value for convection. The total surface for convection. may be assumed as an approximate value of 19.5 sq ft and 15.5 sq ft for radiation. .' The heat generated in the average human body is approximately 400 Btu per hour of which 75 per cent or 300 Btu per hour is the approximate value of the heat given off by radiation and convection. While it is difficult to differentiate the exact proportion of these two values, it is found that if the body gives off about 190 Btu per hour by radiation or 12.26 Btu per hour per square foot of radiant body surface, conditions of greatest comfort will result. This leaves 110 Btu per hour to be released by convection, or 5.64 Btu per hour per square foot of convected body surface. . *Heat and Moisture Losses from the Human Body and Their Relation to Air Conditioning Problems, by F. C. Houghten, W. W. Teague, W. E. Miller, and W. P. Yant (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 245). 754 Chapter 41. Radiant Heating The loss by evaporation, which depends on the air temperature,- air movement and humidity, together with the loss by respiration makes up the balance of 100 Btu per hour. All of these values are relative because the total will vary materially with change of position, occupation, age, race, etc. The mean normal surface temperature of the human body, taken over the whole area, including not only the exposed skin surface but also surfaces of the clothes and the hair, has been very extensively used as 75 F, particularly in England where radiant heating has been practiced for nearly 30 years. However, results obtained by Aldrich2 in rooms in which the air and wall surface temperatures were approximately 72 F gave mean values nearer 83 F than 75 F. In both England and America mean wall and air temperatures of 72 F seem to be unwarranted; so it is not unreasonable to* assume that a body surface temperature lower than 83 F may eventually be accepted. Some values have already been suggested as being the most suitable for the American climate, but the accepted standard for United States practice must be ultimately derived from research and practical experience. The mean surface temperature of an inert body which will maintain the optimum heat loss by radiation and convection in.a uniform environ ment of a given temperature may be calculated from fundamental equations for radiation and natural convection by substituting com parable cylinders for the body. While it may be possible to produce effects on a cylinder or any other body of a particular size and shape to estimate similar effects on the human body, it should be remembered that the heat loss from the body varies greatly with movement. Every movement of the body not only alters its shape but also the velocity of the air passing over it and the surface exposed to radiation. This fact makes it difficult to compare the effect of any environment on a cylinder to that of a human body. Heilman3 gives the following equations: = 0-1723 e[(^)4-(^)4] (l) (jy-ffc = 1-235 )0'2 X (^)181 X (rs - ^a)1-266 where . Hi = heat loss by radiation, Btu per square foot per hour. Hc = heat loss by convection, Btu per square foot per hour. Ts ----- absolute temperature of the body surface, degrees Fahrenheit. Tw = absolute temperature of the walls, degrees Fahrenheit. Fa = absolute temperature of the air, degrees Fahrenheit. t _ Ts + Ta I m -- -----------r.----------- = diameter of cylinder, inches. = the ratio of actual emission to black body emission. (2) If it is assumed that a normal adult has an average height of 5 ft 8 in. 'A Study of Body Radiation, by L. B. Aldrich (Smithsonian Miscellaneous Collections, Vol. 81, No.. 6, December 1928). Surface Heat Transmission, by R. H. Heilman (A.S.M.E. Transactions, Fuels and Steam Power Section, Vol. 51, No. 22, September-December, 1929). .- r Heating Ventilating Air Conditioning Guide 1938 and an average body surface of 19.5 sq ft and 15.5 sq ft for convection and radiation respectively, an equivalent effect can be considered on two cylinders 5 ft 8 in. high by 13.15 in. diameter and 10.45 in. diameter respectively. BRITISH EQUIVALENT TEMPERATURE The British Equivalent Temperature (BET) is the temperature of an environment which is effective in controlling the rate of sensible heat loss from a sizable black body in still air when the body has a maintained surface temperature equal to that of the human body. The BET is, therefore, a function of both the air temperature and the mean radiant temperature. Its numerical value in a uniform environment (walls and air at the same temperature) is equal to the temperature of the walls and the air. In a non-uniform environment (walls and air at different tempera tures) the BET for America is at present considered to be equivalent to that of a uniform environment in which an 83 F surface loses sensible heat at the same rate as it does in the non-uniform environment. As originally defined, the BET was based on a body surface temperature of 75 F, but 83 F has been accepted as giving results more nearly conforming with American practice4. Temperatures selected depend on the clothes worn by the individual, which explains why ladies in evening dress desire a higher body surface temperature than a man dressed in evening suit leaving only hands and head uncovered. For accurate calculations it would be more logical to assume a body surface temperature applicable to the room being occupied, but for general purposes it is considered sufficient to take an average of 83 F for all rooms. The higher the BET the less the heat loss from the body, as the rate of loss in still air is approximately proportional to the difference between the BET and the mean body surface temperature. If the BET were 83 F, there could be no sensible heat loss from a surface at that temperature; so the temperature of a normal body surface would have to rise to a point where the heat generated in the tissues could be dissipated. . APPLICATION METHODS There are several methods of applying ^radiant heating, as follows: X. By warming the interior surfaces of the building. Pipe coils are embedded in the concrete or plaster of the walls or ceilings, the heating medium being hot water circu lating through the pipe coils. These coils are generally constructed of small pipe spaced about 6 in. apart (Fig. 1). This has the effect of warming the entire concrete or plaster surface in which the pipes are embedded. Since the temperature of the heating medium should not exceed about 130 F due to the possibility of cracking the plaster, the area of the panel must be sufficient to supply the requisite quantity of heat at this low tem perature. When carefully designed, this method produces comfortable and economical results, but offers some slight obstacles when alterations or additions to the building are desirable. Normally the hot water circulation is maintained by means of a circulating pump and facilities have to be provided to eliminate all air at the top of the system. All of the pipes are welded together and tested after erection to a hydraulic pressure of 500 lb per square inch. Application of the Eupatheoscope for Measuring the Performance of Direct Radiators and Convectors in Terms of Equivalent Temperatures, by A. C. Willard, A. P. Kratz, and M. X. Fahnestock (A.S.H.V.E. Transactions, Vol. 39. 1933, p. 303). '. . 756 Chapter 41. Radiant Heating 2. By placing hot water or steam pipes under the. floor. With this arrangement the whole floor surface of a room is raised to a temperature sufficient to give comfortable conditions. This method is used extensively for schools and hospitals where large quantities of outside air are desirable (Fig. 2). In some cases special floors are con- Fig. 1. Pipe Coils Located in Interior Wall Surfaces Fig. 2. Arrangement of Continuous Pipe Coil in Floor Construction structed in sections so that a whole floor can be lifted to examine the pipes. The floor surface may be of concrete, wood blocks, marble or any other material unaffected by heat. Pipes under the floor may be larger than those embedded in the plaster walls and ceilings. ' 3. By circulating warm air through shallow ducts under the floor. In this design the entire floor surface of a room is heated as ih method 2. This method while being more 757 V Heating Ventilating Air Conditioning Guide 1938 expensive in construction, is effective and quite suitable for cathedrals and.large public buildings (Fig. 3). To provide a uniform floor temperature, special consideration should be given to the design of the air ducts so that equal distribution is.obtained:? 4. By attaching separate heated metal plates or panels to the interior surfaces. These1 plates or panels are placed either in an insulated recess so that the surface of the panel is flush with the surface of the walls or ceilings, or they may be secured to the face of the wall. They may be covered with wood veneers and decorated to harmonize with other parts of the room, or they can be cast into panels to imitate oak or other wood designs. With flat plate panels it is a common practice to use a frame of plaster, wood, metal or composition around the panels to allow for expansion. These plates may be heated with either hot water or steam and connected similarly to an ordinary radiator system. Fig. 3. Diagram of Air Ducts for Floor Heating 5. By electric heated metal plates or panels. These plates or panels are either placed in insulated recesses of walls or ceilings or fastened to the face as desirable. They should not have a surface temperature above 160 to 200 F. Some electric panels have a much higher surface temperature but a lower temperature gives a more comfortable condition and is more efficient. 6. By electrically heated tapestry mounted on screens and on the wall. For this purpose the screen is woven with an electric continuous conductor being the warp and wool or silk being the weft. Such screens are useful to plug in at any position for emergency local heating without taking care of a large room or office. Note. If all of the heating panel is installed at one end of a large room there may be a marked difference between the BET on the two sides of the body. It is usually desir able therefore that the heat be distributed at different parts in the room so that no uncomfortable effects will be felt from unequal heating. CALCULATION PRINCIPLES The calculations for radiant heating are entirely different from those for convective heating. The purpose of the latter is to determine the rate of heat loss from the room by conduction, convection, and radiation when maintained in the desired condition; radiant heating involves the regu lation of the rate of heat loss per square foot from the human body. The first step in the calculations for radiant heating is to ascertain the necessary mean radiant temperature (MRT); next, the size, temperature, and disposition of the heating surfaces required in the room to produce this MRT are estimated; and after this the determination of the convec tive heat is made. Mean Radiant Temperature . If the whole of the interior surface of a room were at the same tempera ture, this temperature would represent the MRT. Such a condition 758 Chapter 41. Radiant Heating Table 1. Total Black Body Radiation to Surroundings at Absolute Zero2 Boot or Mean Radiant Temper ature Deg Fahr Radiation in Btu per square foot per hour emitted to surroundings with a tempera ture of absolute sero by bodies at various temperatures and with emissivity factor e 9t 1.00 0.95 0.90 0.S0 Bodt OR Mean Radiant Radiation in Btu per square foot per hour emitted to surroundings with a temperature of absolute sero by bodies at various temperatures and with emissivity factor t ' Temper 'ature Deg Fahr 1.00 9 0.9S 9 0.90 oio 30 99.3 94.3 89.4 79.4 71 136.5 129.6 122.9 109.3 35 103.5 98.3 93.2 82.8 72 137.4 130.5 123.6 109.9 40 107.6 102.4 96.8 86.1 73 138.4 131.5 124.5 110.6 45 112.1 106.5 100.9 89.7 74 139.6 132.6 125.6 111.7 46 112.9 107.3 101.6 90.4 75 141.0 133.9 126.9 112.8 47 113.9 108.2 102.5 91.1 80 146.6 139.4 132.0 117.4 48 114.8 109.1 103.4 91.9 85 152.3 144.6 137.1 121.9 49 115.6 109.9 104.1 92.4 90 157.9 149.9 142.1 126.4 50 116.5 110.6 104.9 93.2 100 169.6 161.1 152.6 135.7 51 117.5 111.6 105.8 94.0 110 181.6 172.5 163.5 145.4 52 118.4 112.5 106.5 94.7 120 194.8 185.0 175.4 155.9 53 119.4 113.4 107.4 95.5 130 210.1 199.6 . 189.1 168.1 54 120.2 114.2 108.2 96.2 140 223.2 212.1 201.0 178.5 55 121.1 115.1 109.0 96.9 150 237.1 225.2 213.5 189.7 56 122.1 116.0 109.9 97.7 160 251.1 238.8 226.0 201.0 57 123.1 117.0 110.9 98.5 170 270.5 . 257.0 243.5 216.4 58 124.0 117-.8 111.6 99.2 180 288.0 273.8 259.1 230.4 59 124.9 118.6 112.4 99.9 190 306.5 291.0 275.8 245.1 60 125.8 119.5 113.4 100.7 200 325.2 309.0 292.8 260.3 61 126.6 120.3 114.0 101.4 210 348.0 . 330.6 313.1 278.4 62 127.7 121.4 114.9 102.2 220 371.5 353.0 334.4 . 297.1 63 128.6 122.2 115.8 102.9 250 437.8 415.9 394.0 350.2 64 129.6 123.1 116.7 103.7 300 575.0 546.1 517.5 460.0 65 130.5 124.0 117.5 104.4 350 740.0 703.0 666.0 592.0 66 131.6 125.0 118.4 105.4 400 942.1 895.0 847.5 753.5 67 132.5 125.9 119.3 106.0 450 1176.0 1117.0 1059.0 941.0 68 133.5 126.8 120.1 106.8 500 1464.0 1390.0 1318.0 1171.0 69 134.5 127.8 121.1 107.6 550 1791.0 1701.0 1613.0 1434.0 70 135.5 128.8 121.9 108.4 600 2405.0 2284.0 2165.0 1925.0 These factors are calculated from the formula where Q e T Q ( 0.1723 X T*\ \ 100.000.000 ) total black body radiation, Btu per square foot per hour, emissivity. absolute temperature, degrees Fahrenheit. seldom exists, however, since the actual surface temperature in any heated space having surfaces exposed to the outer air varies greatly for different sides of the enclosure. It is therefore necessary to ascertain by calculation the mean of these interior surface temperatures. The mean temperature in this sense is not the arithmetic average of the actual thermometric temperatures of the surfaces, but the temperature corresponding to the average rate of heat emission per square foot of surface. The temperature corresponding to this mean emission can be taken from Table 1. Conversely, the emission at different temperatures and-also the emissivity factors can be obtained from this table. For instance, 1 sq ft of surface at 50 F will emit 104.9 Btu per square foot per hour to surroundings at absolute zero if the emissivity of the surface is 0.9. 759 Heating Ventilating Air Conditioning Guide 1938 If the area in square feet of each part of the space is multiplied by the emission value corresponding to its actual temperature, and these products are added together, the gross amount of radiant heat discharged into the room by the wall surface per hour is obtained. This quantity, divided by the total interior surface, gives the average amount of heat coming into the room from the surface of the walls per square foot of surface per hour. Interpolating in Table 1, the total radiation from a surface at 83 F for an emissivity of 0.95 is 142 Btu per square foot per hour. The difference between 142 Btu and the average amount of heat coming into the room is the amount which will be lost per square foot per hour by radiation from a body at 83 F. If a rate at which it is desired that heat be lost from the body by radiation and convection be assumed, the mean radiant emission from the walls required to give the desired result can be determined from Table 1, as can also the required air temperature for the corresponding convective effect. The determination of the amount of radiant heating surface needed in a room requires knowledge of the climate, the type of structure, the type of heating, and the surface temperature of the walls. This problem can be solved only on an empirical basis. After some experience, however, it is possible to estimate these variables with a considerable degree of accuracy for any climate or construction. Assume that a mean radiant temperature of 65 F is desired. Table 1 shows that with all the. walls at this temperature, and with an emissivity of 0.95, the gross heat emission is 124 Btu per square foot per hour. The total emission of radiation into the room from that surface would there fore be A X 124, where A is the total inside area of the room. This is the desired emission. , If the whole area be divided into a number of different parts which are each at a uniform temperature--au a*, a,--and each is.multiplied by the value of the heat emission corresponding to that temperature, and if all these products are added together, their sum will represent the total actual emission of radiation into the room at these temperatures without the aid of any hot surface. The difference between the. desired emission and the actual emission represents the additional heat which must be supplied by the hot surface. The temperature of the proposed hot surface must then be selected, and its emission per square foot at that temperature determined from Table 1. This emission is divided into the additional amount of heat needed, ad justed for the fact that the heating units will shield the walls behind them, and the quotient obtained will be the area of the required heating surface. It is evident that this method of calculation. is approximate, arid depends for its accuracy on a correct estimate of the ultimate surface temperatures attained by the actual wall surfaces. It is necessary also to calculate how much heat will be given off by the same surfaces by convection, and thereby to determine whether this amount of convected heat will warm entering ventilating air to the tem perature maintained. If it will not, additional convection surfaces must be introduced to make up the deficiency. 760 Chapter 41. Radiant Heating Table 2. Surface Areas, Temperatures and Emissions for a Room of 5760 Cu Ft External Wall..................... Glass...................................... Inner Wall........................... Ceiling................................... Floor...................................... Total............................. Area Sq Ft 297 279 480 480 480 2016 Assumed Surface Temperature (Deg Fabb) 50 45 55 55 55 Heat Emission (Btu Per Sq Ft per Hour) 110.6 106.5. 115.1 ' 115.1 115.1 Total Heat Emission from Area (Btu per Hour) 32,850 29,710 55,250 55,250 55,250 228,310 Example 1. The surface areas, temperatures, and emissions for a room having a volume of 5760 cu ft are given in Table 2. The figures for temperatures are fairly representative of American practice with well-built walls, and are based on an emissivity of 0.95 which approximates that of most paints and building materials. The mean radiant temperature of the room is 228,310/2016 = 113.2 Btu per square foot per hour which, as seen from Table 1, corresponds to an MRT of 53 F for an average emissivity of 0.95. For an average individual having a body surface area of 15.5 sq ft under conditions of comfort with a body surface temperature of 83 F, the heat given off by radiation when calculated by means of Equation 1 is 217 Btu per hour, or 14 Btu per square foot per hour. This corresponds to an environmental emission of 142 -- 14 = 128 Btu per square foot per hour, and, according to Table 1, to an MRT of 69.2 F. If this body be placed in the room described, it will lose heat at the rate of 15.5 X (142 -- 113.2) = 446 Btu per hour. This loss is 229 Btu per hour more than the 217 Btu per hour calculated, or 14.77 Btu per square foot per hour, more than the rate of heat loss for comfort. In order to determine the amount of radiating surface necessary to maintain the MRT at 69.2 F, assume the surface temperature of the hot plates to be installed to be 160 F, which is approximately the temperature they would have if heated by hot water. The 2016 sq ft total area of the surfaces of the room multiplied by 128 which is the emission in Btu per square foot per hour necessary to maintain a body surface tempera ture of 83 F, gives a total desired emission of 258,048 Btu per hour. It is necessary to supply enough radiant heating surface to increase the total actual mean radiant heat emission by the room from 228,310, as shown in Table 2, to the 258,048 Btu desired. The additional heat needed is the difference between these figures, or 29,738 Btu. Since, from Table 1, the emission per square foot at 160 F is 238.8 Btu, the required radiant heating surface needed is 29,738/238.8 = 124 sq ft. The effect of this surface suitably placed would be to raise immediately the mean radiant temperature to the required degree and to maintain it at that value as long as the surfaces remained at the values assumed. The calculation may be simplified by preparing tables showing, at the usual temperatures, the area of hot surface required to bring each square foot of actual wall surface at various temperatures up to a general standard of from 60 F to 70 F. It would then be necessary only to multiply the respective areas by the appropriate factors, and to add the results, to obtain the required total. MEASUREMENT OF RADIANT HEATING Convection heating, having as its object the raising of the air tempera ture to a specified degree, must be measured by thermometric methods which indicate essentially the air temperature, and not the rate of heat loss from the human body. Radiant heating, having as its object the control of the rate of heat loss from the human body, can be measured 761 ; .i1. }| Heating Ventilating Air Conditioning Guide 1938 only by methods which basically are calorimetric, that is, which measure directly the rate of heat loss from an object maintained at the temperature of the body, irrespective of air temperature. The apparatus for this purpose consists essentially of a hollow sphere, or cylinder, containing a fluid which can be maintained accurately at the accepted mean surface temperature of the human body, with.an accurate means of measuring the rate of heat supply required to maintain the temperature at that exact point. The latter measurement can be made with sufficient accuracy by electrical methods. Although a definite BET is desirable, the mean radiant and air temperatures may both vary, provided the heat loss by radiation and convection from a surface at.83 F is maintained at the correct proportion or within reasonable limits. This instrument, the eupatheoscope, can readily be adapted as a thermo stat by electrical control to shut off or turn on heat when the critical temperature of 83 F or any other predetermined temperature on the surface of the vessel is increased or decreased. A modification of the instrument is called the eupatheostat. . Another instrument for maintaining comfort conditions is at present available'only in a model adapted to British practice as it is designed for a temperature of 75 F. It consists of a blackened copper sphere of approxi mately 6 in. diameter in which is housed a cylindrical sump containing a volatile liquid. In operation, a small electric heating coil drawing about 5 watts creates in the sphere a vapor pressure which is constant as long as the heat losses from the sphere are standard. If the temperature of the air or the MRT becomes too high for comfort, a greater pressure is created, owing to a smaller loss of heat from the sphere. This increase of pressure acts on a diaphragm and shuts off the supply of heat to the room. For testing work, the globe thermometer is a very useful instrument. It consists of an ordinary mercury thermometer, with its bulb placed in the center of a sphere from 6 to 9 in. in diameter, usually made of thin copper and painted black. The temperature thus recorded is termed the radiation-convection temperature. REFERENCES . Panel Warming, by L. J. Fowler (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 287). Room Warming by Radiation, by A. H. Barker (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 331). x What will be the Future Development of Heating and Air Conditioning, by W. H. Carrier (Heating, Piping and Air Conditioning, January, 1933, p. 16). American Practice in Panel Heating, by L. L. Munier (Heating, Piping and Air Conditioning, June, 1937, p. 424). ' Calculations for Radiant Heating, by T. Napier Adlam (Heating and Ventilating, October, 1931). Notes on Electric Warming with Special Reference to Low Temperature Panel Systems, by R. Grierson (Proceedings of The Institution of Heating and Ventilating Engineers, London, Vol. 28, 1929). " Notes on the Theory of Radiant Heating, by C. G. Heys Hallett (Proceedings of The Institution of Heating and Ventilating Engineers, London, Vol. 29, 1930). Radiant Heat, by A. F. Dufton (Proceedings of The Institution of Heating and Ven tilating Engineers, London, Vol. 30, 1931). Panel Heating, by C. M. Oates (Proceedings of The Institution of Heating and Ventila ting Engineers, London, Vol. 30, 1931). . 762 Chapter 41. Radiant Heating Principles of Calculation of Low Temperature Radiant Heating, by A. H. Barker, (Proceedings of The Institution of Heating and Ventilating Engineers, London, Vol. 30, 1931). ' ' : ' .: Radiant Heat, by A. F. Dufton (Proceedings of The Institution of Heating and Ven tilating Engineers, London, Vol. 31, 1932). , PROBLEMS IN PRACTICE 1 Where did radiant heating derive its name? The term radiant heaters was introduced about 28 years ago to designate flat heating surfaces made to give off practically , all their heat by radiant ether waves instead of relying on converted warm air. 2 What is actually -meant by radiant heating and what are its underlying principles? The term radiant heating now applies to methods of heating where, instead of heating the air in a room to a predetermined temperature, flat heating surfaces are placed in a room so that the average effective temperature of walls, ceiling, glass and floor surfaces exposed to the body is just sufficient to prevent the body losing too much heat by radi ation. It takes into consideration that the body generates more heat than it requires, so that it does not require any heat from without. The surplus heat, however, must be given off according to the physiological requirement of the body. " 3 What kind of heating surfaces are in general use? The heating units may have flat iron surfaces heated with steam or hot water and placed in side walls or under windows, or they may be supported on the ceiling and suitably decorated and connected as ordinary steam or hot water radiators. Hot water pipes may be embedded in the floor, walls or ceiling, and when in the floors they may be covered with concrete and wood blocks or other suitable material; the finish of the surface being more important than the composition of the material. When in the ceiling or walls, they can be covered with plaster to harmonize with the rest of the room. Elec trical radiant heaters are made by embedding resistance elements in porcelain, or electric conductors may be woven into thick paper and fastened to the walls and ceilings, electric wires may be woven with tapestry to form portable screens for local heating. 4 What surface temperatures are generally used? Where hot water pipes are embedded in plaster, the surface temperature varies from 90 to 130 F. Where flat iron plates are used these may vary from 140 to 220 F. With electric resistances embedded in porcelain the surface temperature may vary from 200 to 500 F. High surface temperatures are not recommended. 5 What kind of heat rays are commonly generated for radiant heating? All heat rays are generally assumed to be the same as light rays; they travel at the speed of light, but they are invisible and longer. The rays used in heating are 0.00005 to 0.0001 in. long, compared with invisible red rays of about 0.000027 in. : 6 # When and why docs the human body feel cold? The body feels cold not only when it loses heat at a greater rate than it can generate it but also when heat is abstracted from the body disproportionately. Since the human body generates more heat than is necessary, it is only necessary to provide conditions that will regulate the correct ratio of losses; the provision of suitable radiant heating surfaces is one way to establish these conditions. 7 i Why is the heat loss from the body by radiation important? The heat loss by radiation is proportional to the fourth power of the temperature dif ference between the surface of the body and the average surface temperature of the surrounding walls, windows, etc.; whereas, for convection losses, it is only proportional to the 1.25 power. ". Heating Ventilating Air Conditioning Guide 1938 8 What is the approximate relation for heat losses? Heat losses from the body when in a sedentary position are approximately as follows: radiation 49 per cent, convection 23 per cent, evaporation 15 per cent, respiration 11 per cent, and miscellaneous 2 per cent. Actually, it depends upon age, environment and other conditions. 9 What generally is the air temperature necessary to give equal comfort effect for sedentary conditions? With radiant heating, 64 to 66 F. With convection heating, 70 to 72 F. 10 Why is there a saving in fuel consumption with radiant heating? A saving is effected because the differential between inside and outside temperature is much less for radiant heating. Less ventilating air is necessary and this can be supplied at a much lower temperature. 11 Describe how to calculate the required amount of radiant heating surface. a. Obtain the mean heat emission in Btu per square foot per hour for room surfaces X, using values in Table 1, and surface temperatures as shown in second column of Table 2. b. Deduct X from 142 (142 being the emission per square foot given off by the human body at 83 F surface temperature) = Y in Btu per square foot per hour. c. From (142-X) deduct 11.1 (11.1 being the average radiation which the human body should lose per square foot for comfort conditions) = (1-12-A-l 1.1) = Z. d. Multiply total interior surface of room by Z and divide by the emission per square foot from radiant heater, giving the surface 5 of radiant heater in square feet. 12 Give a simple formula to calculate radiant heating surface required, and explain. ,, (142 -- X -- 11.1) A *------------------ B where . 5 = surface of radiant heater, square feet. . 142 = Heat emission, Btu per square foot per hour which the human body would give off at 83 F, with surroundings at absolute zero. X -- mean heat emission, Btu per square foot per hour from surfaces of room. 11.1 = heat emission, Btu per square foot per hour from human body. . A = total surface, square feet of walls, ceilings, windows, etc., in room. B = heat emission per square foot from radiant heater surface. 13 What natural evidence have we that air temperature alone is no criterion of comfort and that radiant heat affects the body more quickly? When standing in the sunshine on a cool spring day, a person feels perfectly comfortable, but when a cloud passes over the sun, he instantly feels much cooler as the shadow reaches him; A shielded thermometer recording the temperature of the air shows no reduction in air temperature in so short a period, so that the person actually feels a sensation of cold which an ordinary thermometer cannot register. This shows that light and heat rays are shut off simultaneously and travel at the same speed; it also proves that radiant rays affect the comfort of the body quicker than air temperature does. 764 Chapter 42 DISTRICT HEATING Piping Distribution, Selection of Pipe Sizes, Provision for Ex pansion, Capacity of Returns with Various Grades, Conduits for Piping, Pipe Tunnels, Building Service Connections, Steam Consumption, Fluid Meters and Metering, Rates THOSE phases of district heating which frequently fall within the province of the heating engineer are outlined here with data and information for solving incidental problems in connection with institutions and factories and for the design of heating systems for buildings which are to be supplied with purchased steam. A complete district heating instal lation should not be attempted without a thorough study of the entire problem by men competent and experienced in that industry. PIPING DISTRIBUTION The methods used in district heating work for the distribution of steam are applicable to any problem involving the supply of steam to a group of buildings. The first step is to establish the route of the pipes, and in this matter the local conditions so fully control the layout that little can be said regarding it. . Haying established the route of the pipes, the next step is to calculate the pipe sizes. In district heating work it is common practice to design the piping system on the basis of pressure drop. The initial pressure and the minimum permissible terminal pressure are specified and the pipe sizes are so chosen that the required amount of steam, with suitable allowances for future increases, will be transmitted without exceeding this pressure drop. The steam velocity is therefore almost disregarded and may reach a very high figure. Velocities of 35,000 fpm are not con sidered high. By the use of this method the pipe sizes are kept to a minimum with consequent savings in investment. The steam flowing through any section of the piping can be computed from a study of the requirements of the several buildings served. In general a condensation rate of 0.25 lb per hour per square foot of equiva lent heating surface is a safe figure. This allows for line condensation which, however, is a small part of the total at times of maximum load. Any unusual requirements such as those for process steam should be individually calculated. . The steam requirements for water heating should be taken into account, but in most types of buildings this load will be relatively small compared with the heating load and will seldom occur at the time of the heating . 765 Heating Ventilating Air Conditioning Guide 1938 peak. Unusual features such as large heaters for swimming pools should not be overlooked. The pressure at which the steam is to be distributed will depend, in part, upon whether or not it has been passed through electrical generating units. If it has, the pressure will be considerably lower than if live steam, direct from the boilers, is used. The advantages of low pressure distribu tion (2 to 30 lb per square inch) are (1). smaller heat loss from the pipes, (2) less trouble with traps and valves, and (3) simpler problems in pressure reduction at the buildings. With distribution pressures not, exceeding 40 lb per square inch there is little danger even if the full distribution pressure should build up in the radiators through the faulty operation of a reducing valve; but with pressures higher than this a second reducing valve or some form of emergency relief is usually desirable to prevent excessive pressures in the radiators. The advantages of high pressure distribution are (1) smaller pipe sizes and (2) greater adaptability of the steam to various operations other than building heating. . The different kinds of apparatus which frequently must be served require various minimum pressures. Kitchen. equipment requires from 5 to 15 lb per square inch, the higher pressures being necessary for apparatus in which water is boiled, such as stock kettles and coffee urns. An increased amount of heating surface, which is easily obtained in some kinds of apparatus, results in quicker and more satisfactory operation at low pressures. For laundry' equipment, particularly the mangle, a pres sure of 75 lb per square inch is usually demanded although 30 lb per square inch is sufficient if the mangle is equipped with a large number of rolls and if a slow rate of operation is permissible. Pressing machines and hospital sterilizers require about 50 lb per square inch. PIPE SIZES The lengths of pipe, steam quantities, and initial and terminal pressures having been chosen, the pipe sizes can readily be calculated by means of the Unwin pressure drop formula. This formula, which gives pressure drops slightly larger than actual test results, is as follows: 0.0001306 W*L (l + (!) where P = pressure drop, pounds per square inch. W = weight of steam flowing, pounds per minute. L = length of pipe, feet. D -- inside diameter of pipe, inches. d = average density of steam, pounds per cubic foot. This formula is similar to the Babcock formula given in Chapter 16. Information on provision for expansion will be found in Chapter 18. In general, return lines when installed follow the contour of the land, and Table 1 gives sizes of return pipes for various grades. It is evident that at points where the grade is great, smaller pipes can be installed. 766 . Chapter 42. District Heating CONDUITS FOR PIPING Conduits for steam pipes buried underground should be reasonably waterproof, able to withstand earth loads and to take care of the expan sion and contraction of the piping without strain or stress on the couplings, or without effecting the insulation or conduit. Expansion of the piping must be carefully controlled by means of anchors and expansion joints or bends so that the pipes can never come in contact with the conduit. Anchors can be anchor fittings or U-shaped steel straps which partially encircle the pipes and are firmly bolted to a short length of structural steel set in concrete. ' Table 1. Capacity of Returns for Underground Distribution Systems in Pounds of Condensate per Hour Size or Fife In. i m 2 3 4 5 6 8 10 12 6' 448 1740 2700 4980 13900 30900 54800 90000 190000 344000 555000 Pitch or Pipe per 100 Fr i- 998 2490 4190 . 7380 22500 44800 79800 138000 277000 498000 798000 V 1890 3990 . 5740 10700 30900 64800 120000 187000 404000 724000 1148000 y 2240 4880 7480 13900 37400 79700 144800 237000 508000 900000 1499000 S' 3490 6480 9480 16900 50400 105000 195000 312000 660000 1190000 1990000 10' 5490 9480 14500 24900 , 74800 154000 294000 449000 938000 -- 20' 7490 13500 20900 36900 105000 229000 418000 Size of pipe should be increased if it carries any steam. In laying out conduits of this type the following points should be borne in mind: 1. An expansion joint, offset, or bend should be placed between each two anchors. 2. If the distance between buildings is 150 ft or less and the steam line contains highpressure steam, the line may be anchored in the basement of one building and allowed to expand into the basement of the second building. If the steam line contains low-pressure steam (up to 4-lb pressure), this method may be used if buildings are 250 ft or less apart. 3. If the distance between buildings is between 150 ft and 300 ft and the steam line contains high-pressure steam, the lines should be anchored midway between the buildings and allowed to expand into the basements of both buildings. If the steam line contains low-pressure steam this method may be used if buildings are between 250 ft and 600 ft apart. No manhole is required at the anchor, and a blind pit is all that is necessary. 4. For longer lines, manholes must be located according to judgment and depending upon the expansion value of the type of expansion joint or bend that is used.. The minimum number of manholes will be required when an expansion bend or an anchor with double expansion joint is placed in each manhole and the pipes are anchored mid way between manholes. 5. A proper hydrostatic test should be made on the assembled line before the insula tion and the top of the conduit are applied. The hydrostatic pressure should be oneand-one-half times the maximum allowable pressure and it should be held for a period of at least two hours without evidence of leakage. In any case the pressure should be no less than 100 lb per square inch. The styles and construction of conduits commonly used may be classi fied as follows. Some of the more common forms are illustrated in Fig. 1. Wood Casing: The pipe is enclosed in a cylindrical casing usually having a wall 4 in. thick and built of segments which are bound together by a wire wrapped spirally around 767 Heating Ventilating Air Conditioning Guide 1938 the casing: The casing is lined with bright tin and coated with asphaltum. The pipe is supported on rollers carried in a bracket which fits into the casing. The lengths of casing are tightly fitted together with a male and female joint. This form of conduit is illustrated in Fig. 1 at A. The casing rests on a bed of crushed stone with tile drains laid bkow. The tile drains are of 4-in. field tile or vitrified sewer tile, laid with open joints. Filler Type: The pipes are supported on expansion rollers properly supported from the conduit or independent masonry base. The pipes are protected by a split-tile conduit, and the entire space between the pipes and the tile is filled with an insulating filler. Thus the pipes are nested and the insulation between them and the tile effectively prevents circulation of air. The conduit is placed on a bed of gravel or crushed rock from 4 to 6 in. thick, which is extended upward so as to come about 2 in. above the parting lines of the tile. A tile underdrain is plated beneath the conduit throughout the entire length and is connected to sewers or to some other point of free discharge. At B and D in Fig. 1 are shown two forms of tile conduit of the filler type. Circular Tile or Cast-Iron Conduit: The pipes are carried on expansion rollers sup ported on a frame which rests entirely on the side shoulders of the base drain foundation. 0ml jgSj^ ^ "Ear:: Concrete base 'Wvn runw T' W tif Fig. 1. Construction Details of Conduits Commonly Used The pipes are protected by a sectional tile conduit, scored for splitting, or a cast-iron conduit, both being of the bell and spigot type. The conduit has a longitudinal side joint for cementing, after the upper half of conduit is in place, so shaped that the cement is keyed in place while locking the top and bottom half of the conduit together with a water-tight vertical side joint. The cast-iron conduit has special side locking clamps in addition to the vertical side joint. The entire space between the conduit and the pipes is filled with a water-proofed asbestos insulation. The conduit is supported on the base drain foundation, each section resting on two sections of the base drain, thus inter locking. The base drain is so shaped that it provides a cradle for the conduit, resting solidly on the trench bottom and providing adequate drainage area immediately under the conduit. The underdrain is connected to sewers or some other point of free discharge. For tile conduit the base drain is vitrified salt glazed tile and for cast-iron conduit it is either extra heavy tile or cast-iron. A free internal drainage area is also provided to carry away any water that may collect on the inside of the conduit from a leaky pipe or joint in the conduit. Broken stone is filled in around the base drain and up to the vertical side joint. The broken stone is covered with an asphalted filter cloth to prevent sand from sifting through the broken stone and clogging the drainage area of the base drain. The tile conduit is made in 2-ft lengths and the cast-iron conduit in 4-ft lengths, cast in 768 Chapter 42. District Heating separate top and bottom halves. Special reinforcing ribs give the cast-iron conduit ample strength with minimum weight. . Insulated Tile Type: The insulating material, diatomaceous earth, is molded to the inside of the sectional tile conduit. The space between the pipes and the insulating con duit lining may.also be filled with insulation. The pipes are carried oh expansion rollers supported on a frame which rests on the side shoulders of the base drain foundation. This type of conduit has the same mechanical features as those described under the heading Circular Tile or Cast-Iron Conduit. Sectional Insulation Type (Tile or Cast-Iron): Each pipe is insulated in the usual way with any desired type of sectional pipe insulation over which is placed a standard water proof jacket with cemented joints. The pipes are enclosed in a sectional tile or cast-iron conduit as described under the heading Circular Tile or Cast-Iron Conduit. Sectional Insulation Type (Tile or Concrete Trench): A type of construction frequently used in city streets, where service connections are required at frequent intervals, the pipes are insulated as described in the preceding paragraph, and are enclosed in a box or trench made either entirely of concrete, or with concrete bottom and specially con structed tile sides and tops. The pipes are supported on roller frames secured in the concrete. At C and E, Fig. 1, are shown two tile conduits using sectional insulation. In these particular designs the space surrounding the pipe is filled partially or wholly with a loose insulating material. The use of loose material in addition to the sectional insula tion is, of course, optional and is only justifiable where high pressure steam is used. The conduit shown at F is of a similar type and has the advantage of being made entirely of concrete and other common materials. . Sectional Insulation Type (Bituminized Fibre Conduit): Each pipe is individually insulated and encased in a bituminized fibre conduit. The insulating material is 85 per cent carbonate of magnesia sectional pipe covering, applied in the usual manner as on overhead pipes, except that bands are omitted. After every fifth section of magnesia covering there is applied a short, holjow section of very hard asbestos material in the bottom portion of which rests a grooved-iron plate carrying ball-bearings upon which the pipe rides when expanding or contracting. This short expansion section is of the same outside diameter as the adjacent 85 per cent magnesia covering. Over the pipe covering and expansion device there are placed two layers of bituminized fibre conduit with all joints staggered, and the surface of each conduit is finished with liquid cement. Conduits are placed on a bed of crushed rock or gravel, approximately 6.in. deep, and this is extended upward to about the center line of the conduit when trench is backfilled. Underdrains leading to points of free discharge are placed in the gravel or crushed rock beds. . Special Water-Tight Designs: It is occasionally necessary to install pipes in a very wet ground, which calls for special construction. The ordinary tile or concrete conduit is not absolutely water tight even when laid with the utmost care. The conduit shown at G, Fig. 1, is of cast-iron with lead-calked joints and is water tight if properly laid. It is obviously expensive and is justified only in exceptional cases. A reasonably satisfactory construction in wet ground is the concrete or tile conduit with a waterproof jacket encjosing the pipe and its insulation, and with the interior of the conduit carefully drained to a manhole or sump having an automatic pump. It is useless to install external drain tile when the conduit is actually submerged. PIPE TUNNELS Where steam heating lines are installed, in tunnels large enough to provide walking space, the pipes are supported by means of hangers or roller frames on brackets or frame racks at the side or sides of the tunnel. The pipes are insulated with sectional pipe insulation over which is placed a sewed-on, painted canvas jacket or a jacket of asphalt-saturated asbestos water-proofing felt. The tunnel itself is usually built of concrete or brick and water-proofed on the outside with membrane water-proofing. On account of their relatively high first cost as compared with smaller conduits, walking tunnels are sometimes not installed where provision for the heating lines is the only consideration, but only where they are required 769 . Heating Ventilating Air Conditioning Guide 1938 to accommodate miscellaneous other services or provide underground passage between buildings. BUILDING SERVICE CONNECTIONS Most district heating companies enforce certain regulations regarding the consumer's installation, partly to safeguard their own interests but principally to insure satisfactory and economical service to the consumer. Chapter 42. District Heating operation of the line in case of failure in the reducing valve. In the smaller sizes, the reducing valve can be removed, a filler installed, and the house valve used to throttle the flow of steam. Fig. 4 shows a typical installation used for high pressure steam service. The first reducing valve, usually furnished by the utility company, Pressure reducing valve Fig. 2. Connections foe Reducing Valves of Size Less than 4 In. There are certain fundamental principles that should be followed in the design of a building heating system which is to be supplied from street mains. Although some of these apply to any building, they have been demonstrated to be especially important when steam is purchased. Fig. 4. Steam Supply Connection when Using Condensation Meter effects the initial pressure reduction. The second reducing valve, usually furnished by the customer, reduces the steam pressure to that required. 1. Provision should be madefor conveniently shutting off the steam supply at night and at other limes when heal is not needed. It has been thoroughly demonstrated that a considerable amount of heat can be saved by shutting off steam at night. Although there is, in . Return mam Fig. 3. Connections for Reducing Valves of Size 4 In, and Larger, and for Expanded Valves Figs. 2 and 3 show typical service connections used for. low pressure steam service. As shown in Fig. 2, no by-pass is used around the reducing valve on sizes less than 4 in. Fig. 3 illustrates the use of a.by-pass around reducing valves 4 in. and larger. This latter construction permits the 770. some cases, an increased consumption of heat when steam is again turned on in the morning, there is a large net saving which may be explained by the fact that the lower inside temperature maintained during the night obviously results in lower heat loss from the building, and less heat need therefore be supplied. Steam can be entirely shut off at night in most buildings even in very 771 . r Heating Ventilating Air Conditioning Guide 1938 772 House sew er^' . HiSh Pressure trap Low pressure trap Vacuum type air valve F i g . 6. T y p ic a l Se r v ic e n s t a l l a t io nI Chapter 42. District Heating cold weather without endangering plumbing. It is necessary, however,-to have an ample amount of heating surface so that the building can be quickly warmed in the morning. Where the hours of occupancy differ in various parts of the building, it is good practice to install separate supply pipes to the different parts. For example, in an office building with stores or restaurants on the first floor which are open in the evening, a separate main supplying the first floor will permit the steam to be shut off from the remainder of the building in the late afternoon. The division of the building into zones each with a separately controlled heat supply is sometimes desirable, as it permits the heat to be adjusted according to variations in sunshine and wind. 2. Residual heat in the condensate should be salvaged. This heat may be salvaged by means of a cooling radiator, or as is more frequently done, by a water heating economizer (see Fig. 5) which pre heats the hot water supply to the building. Fig. 6 shows a typical steam service installation for high pressure steam, complete for steam flow metering, water heating, preheating, automatic heating control, and for using steam for other purposes. . The condensation from the heating system, after leaving the trap, passes through the preheater on its way to the meter. The supply to the hot water heater passes through the preheater, absorbing heat from the condensation. If the hot water system in the building is of the recircu lating type, the recirculating connection should, be tied in between the preheater and the water heater proper, not at the preheater inlet, because the recirculated hot water is itself at a high temperature. The number of square feet of heating surface in the preheater should be approximately equal to one per cent of the equivalent square feet of heating surface in the building. Because of the lack of coincidence between the heating system load and the hot water demand, a greater amount of heat can be extracted from the condensation if storage capacity is provided for the preheated water. Frequently a type of preheater is used in which the coils are submerged in a storage tank. S. Heat supply should be graduated according to variations in the outside temperature. This may be done in several ways, as by the use of thermostats of various types or by orifice systems. Another method which is very simple is the use of an ordinary vacuum return line system in which the pressure in the radiators is varied between a high vacuum and a few pounds pres sure, thus producing some control over the heat output. One form of con trol which appears to be well suited for controlling district steam service to a building is the weather compensating thermostat. It regulates the steam supply automatically according to the outdoor temperature, and gives frequent short intervals of intermittent steam supply, and at the same time insures delivery of steam to all the radiators. Another form of regulation, known as the time-limit control, is sometimes employed for regulating the steam supply from the central station main to the building. Such a control provides an intermittent supply of steam to the radiators either throughout the 24 hours of the day or during the day- 773 Heating Ventilating Air Conditioning Guide 1938 time hours' only: The setting of a switch may. provide no service, con tinuous service: or periodic service. For the latter,.'by-means-of several intermittent settings, steam will.be supplied during each period in in crements of a certain number of minutes for each successive setting of the switch, steam being shut off during the balance-of the period. These settings afford from 15 to 80 per cent of the maximum heating effect required on days of zero temperature. A night switch with a variety of settings may be adjusted so as to maintain throughout the night the intermittent supply called for by the day switch setting, or may be set to interrupt the operation of the day switch and entirely cut off the supply of steam to the radiation at night during certain hours which are selected by the operating engineer. . ,. . FLUID METERS No one thing , has contributed more-to the advancement of district heating than the perfection of fluid meters, which may be classified as follows: . . . .: 1. Positive Meters: The fluid passes in successive isolated quantities--either weights or volumes. These quantities are separated from the stream and-isolated by alternately .filling and emptying containers,of known capacity. 2. Differential Meters: The fluid does not pass in isolated separately-counted quan tities but in a continuous stream which may flow through the line without actuating the primary device of the meter. In the differential meter, the quantity of flow is not `determined by simple counting: as with the positive-meter, but is determined from the action of the steam on the primary element. . .. Additional subdivisions of these two general classifications can be made as follows: : Fluid Meters Positive - quantity Weighing Volumetric j Weighers Tilting trap < Rotary Bellows Quantity - Current - Turbine Differential Rate of flow Head (Kinetic) Venturi Flow nozzle ' Orifice - Pitot tube Area _ (Geometric) Head area (Weir) {Orifice and plug Cylinder and piston f V-notch \ Special notch In selecting a meter for a particular installation, the number of different makes and types of meters suitable for the job is usually limited by one or more of the following considerations: . ' 1. Its use in a new or an old installation: 2. Method to be used in charging for the service. 3. Location of the meter. 4. Large or small quantity to be measured. 5. Temporary or permanent installation. 774 Chapter 42. District Heating Pressure reducing valve Drill and tap yfor nipple Customer's control valve Note.- All valves, fittings, and traps up to and including customer's control valve to be at least equal to American Standard 175 lb S. S. P. Pipe to be standard weight Vents and loops unnecessary where meter is 5 feet or more below pipe. Pipe size K1 K2 X Y 3- 3*1 2}' 1*6' 6' 4' 4" 2}' 3^6" 8' r6' 6* 3- 6-6' i Fig. 7. Orifice Meter Steam Supply Connection 6. Cleanliness of the fluid to be measured. 7. Temperature of the fluid to be measured. 8. Accuracy expected. 9. Nature of flow: turbulent, pulsating, or steady. 10. Cost. . (a) Purchase price. (ft) Installation cost. (c) Calibration cost. . (d) Maintenance cost. 11. Servicing facilities of the manufacturer. 12. Pressure at which fluid is to be metered. 13. Type of record desired as to indicating, recording or totalizing. 14. Stocking of repair parts. 15. Use of open jets where steam is to be metered. 16. Metering to be done by one meter or by a combination of meters. 17. Use as a check meter. 18. Its facilities for determining or recording information other than flow. Condensation Meters The majority of the meters used by district heating companies in the sale of steam to their customers are of the condensation or flow types. The condensation meter is a popular type for use on small and medium sized installations, where all of the condensate can be brought to a com mon point for metering purposes. Its simplicity of design, ease in testing, accuracy at all loads, low cost, and adaptability to low pressure distri bution has made it standard equipment with many heating companies. Two types of condensation meters are in general use: the UUing bucket meter and the revolving drum or rotor meter of which there are several makes on the market. Condensation meters should not be operated under 775 Heating Ventilating Air Conditioning Guide 1938 pressure; they are made for either gravity or vacuum installation. Con tinuous flow traps are necessary ahead of the meter if a vented receiver is not used. Where bucket traps are used, a vented receiver before the meter is essential. If desirable a receiver may be used with a continuous flow trap, but this is not necessary. Steam flow meters are available in many types and combinations, as indicated in the sub-division covering fluid meters on page 774. The orifice and plug meter is one in which the steam flow varies directly as the area of the orifice. The vertical lift of the plug, which is proportional to the flow, is transmitted by means of a lever to an indicator and to a Chapter 42. District Heating 3. The meter body should be placed at a lower level than that of the pressure differ-, ential medium. Special instructions are furnished where the meter body is above. 4. Meter piping should be kept free from leaks. 5. Sludge should not be permitted to collect in the meter body. 6. The meter body and meter piping should be kept above freezing temperatures. 7. It is best not to connect a meter body to more than one service. 8. Special instructions are furnished for metering a turbulent or pulsating flow. STEAM CONSUMPTION The following factors are used in New York City for the different classes of buildings listed. The factors are based.on maintaining an inside tem- Fig. 8. Gravity Installation for Condensation Meter Using Vented Receivers pencil arm which records the flow on a strip chart. The total flow over a given period is obtained by measuring the area by using a planimeter on the chart and applying the meter constant. Fig. 7 shows a typical orifice type meter connection and indicates typical requirements in the installation of this type of meter. Fig. 8 illustrates. a gravity installation using a vented receiver ahead of the meter, while Fig. 9 shows a vacuum installation without a master trap. Flow meters using an orifice, Venturi tube, flow nozzle, or Pitot tube as the primary device are made by a number of manufacturers and can be obtained in either the mechanically or electrically operated type. The electric flow meter makes it possible to locate the instruments at some distance from the primary element. Flow meters employing the orifice, Venturi tube, flow nozzle or Pitot tube should be so selected as to keep the lower operating range of the load above 20 per cent of the capacity of the.meter. This is desirable for accuracy as the differential pressure at light loads is too small to properly actuate the meter. uA few general points to be considered in installing a meter of this type are: 1. It is desirable to place the differential medium in a horizontal pipe in preference to a vertical one, where either location is available. 2. Reservoirs should always be on the same level and installed in accordance with the instructions of the meter company. 776 Fig. 9. Vacuum Condensation Meter Installation without Master Trap perature of 70 F for certain hours, with a minimum outside temperature of 0 F and an average of 43 F for the heating season of eight months (October 1 to June 1). In this group are six types of buildings Manufacturing or commercial loft type where steam is used to heat the premises during the day hours to maintain 65 to 68 F from 9 a.m. to 5 p.m. No Sunday or holiday use and no night use. Factor: 325 lb per square foot of heating surface per season. Office buildings using steam during daylight hours to maintain 70 F from 9 a.m. to 6 p.m. for approximately 240 days (heating season). No night use. Factor: 400 lb per square foot of heating surface per season. . Office buildings using steam during day hours and at night when required to 7, 8 and 9 p.m. (customary where there are stock brokers or banking offices), 240 days. Factor: 500 lb per square foot of heating surface per season. Residences of the block type (not detached) where high-class heating service is re quired; somewhat similar to apartment buildings. Factor: 550 lb per square foot of heating surface per season. 777 Heating Ventilating Air Conditioning Guide 1938 Apartment houses where high-class heating service, is required. (Steam off at mid night.) Factor: 650 lb per square foot of heating surface per season. Hotels (commercial type) where very high-class service is required for 24 hours. Factor: 800 lb per square foot of heating surface per season. By assuming one square foot of equivalent heating surface for each 100 cu ft of space heated, which seems a fair ratio in. New York City, it is possible roughly to estimate the steam required per cubic foot of space, information which is often more easily obtained than the square feet of heating surface. Additional data on the heating requirements of various types , of buildings in a number of cities may be found in the Handbook of the National District Heating Association. RATES Fundamentally, district heating rates are based upon the same princi ples as those recognized in the electric light and power industry, the main object being a reasonable return ori the investment. However, there are other requirements to be met; the rate for each class of service should be based upon the cost to the utility company, of the service supplied and upon the value of the service to the consumer, and it must be between these two limits. The profit need not be divided proportionately among the rate groups, but should be established from a competitive stand point. District heating rates should be designed to produce a sufficient return on the investment regardless of weather conditions, although existing rate schedules do not conform with this principle. Lastly, the rate schedule must be reasonably easy for the intelligent layman to comprehend. . Depreciation should be based on a careful estimate of the life of various elements of the property. Appropriations to reserves should be made, with generosity in good years and with discretion in less favorable years. Glossary of Terms Load Factor. The ratio, in per cent, of the average load to the maxi mum load. This is usually based on a one year period but may be applied to any specified period. Demand Factor. The relation between the connected radiator surface or required radiator surface and the demand of the particular installation. It varies from 0.25 to 0.3 lb per hour per square foot of surface. Diversity Factor. The ratio of the sum of the individual demands of a number of buildings to the actual composite demand of the group. , Types of Rates . . A. Flat Rates. 1. Radiator surface charge. Obsolescent. . B. Meter Rates. 1. Straight-line. 2. Step. Obsolescent. 3. Block. (a) Class rates. .. C. Demand Rates. 1. Flat demand. 2. Wright. 3. Hopkinson. 4. Doherty (or Three charge). 778 . . -. . ' ` ' Chapter 42. District Heating Straight-Line Meter Rate. The price charged per unit is constant, and the consumer pays in direct proportion to his consumption without regard to the difference in costs of supplying the individual customers. '. Block Meter Rate The pounds of steam consumed by a customer are divided into blocks of M lb each, and lower rates are charged for each successive block consumed. This type of charge predominates in steam heating rate schedules for it has the ad vantage of proportioning the bill according to the consumption and the cost of service. It has the disadvantage of not discriminating between customers having a high load factor (relatively low demand) and those having a low load factor (relatively high demand). The utility company must maintain sufficient capacity to serve the high demand customers and the cost of the increased plant investment is divided equally among the users, so the high demand customers are benefitted at the expense of the others. Demand Rates. These refer to any method of charge based on a measured maximum load during a specified period of time. . The flat demand rate is usually expressed in dollars per M lb of demand per month or per annum. It is based on the size of a customer's installation, and is seldom used except where a flow meter is not practicable. The Wright demand rate is similar in calculation to the block rate except that it is .expressed in terms of hours' use of the maximum demand. It is seldom used but forms the basis for other forms of rates. . The Hopkinson demand rate is divided into two elements: (a) A charge based upon the demand, either estimated or measured: (b) A charge based upon the amount of steam consumed. This rate may be modified by dividing the quantities of steam demanded and consumed into blocks charged for at different rates. ' '' Demand rates are comparatively new and are not yet widely used; though they are equitable and competitive they are difficult for the average layman to understand. They are of benefit to utility companies and to consumers because the investment and operating costs can be divided to suit the particular circumstances into demand, cus tomer, and consumption groups through the use of some modification of the Hopkinson rate. Fuel Price Surcharge. It is usually desirable to establish a rate upon a specified basic cost of fuel to the utility company. Where there are wide variations in the price of fuel, it is also desirable to add a definite charge per M lb of steam sold for each increment of increase in the price of fuel. This surcharge automatically compensates for the variations without necessitating frequent changing of the whole rate structure. REFERENCES Pipe Line Design for Central Station Heating, by B. T. Gifford (A.S.H.V.E. Trans actions, Vol. 17, 1911, p. 84). Engineering and Cost Data Relative to the Installation of Steam Distributing Systems in a Large City, by F. H. Valentine (A.S.H.V.E. Transactions, Vol. 22, 1916, p. 547). Transmission of Steam in a Central Heating System, by J. H. Walker (A.S.H.V E Transactions, Vol. 23, 1917, p. 161). Efficiency of Underground Conduit, by G. B. Nichols (A.S.H.V.E. Transactions Vol. 23, 1917, p. 173). Economical Utilization of Heat from Central Plants, by N. W. Calvert and J. E. Seiter (A.S.H.V.E. Transactions, Vol. 30, 1924, p. 21). Standard Connections for Condensation Meters, (N.D.H.A. Proceedings, Vol. XII, pp. 63-76). Installation and Maintenance of Steam Meters, (N.D.H.A. Proceedings Vol. XIII pp. 177-183). inaccuracy in r low merer calculations, Uv.L). 183-193). A VU1. Testing of Steam Meters, (N.D.H.A. Proceedings, Vol. XIV pp. 272-276). 779 1 Heating Ventilating Air Conditioning Guide 1938 Meter Accuracy Guarantees, (N.D.H.A. Proceedings, Vol. XIV, pp. 276-277). Effect of Pulsations on the Flow of Gases, (N.D.H.A. Proceedings, Vol. XIV, pp. 277-281). Meter Connections, (N.D.H.A. Proceedings, Vol. XX, pp. 126-143). Layout for Testing Meters, (N.D.II.A. Proceedings, Vol. XX, pp. 391-392). Characteristic Meter Calibration Curves, (N.D.H.A. Proceedings, Vol. XX, pp. 444-453). . Rates, (N.D.H.A. Handbook, 1932, Chapter 10). PROBLEMS IN PRACTICE 1 What is the common method of determining the size of mains in a dis tribution system? On the basis of pressure drop: The initial pressure and the minimum permissible terminal pressure are specified, and the pipe' sizes are so chosen that the maximum estimated amount of steam may be transmitted without exceeding this pressure dif ference. The steam's velocity is disregarded and it may reach a magnitude in excess of 35,000 fpm which is not considered high. 2 # a. What are the advantages and disadvantages of a low pressure distribu tion system? b. High pressure? . . o. The advantages of a low pressure distribution system include: 1. Smaller heat loss from the pipes. 2. Less trouble with traps and valves. 3. Simpler problems with pressure reducing equipment at the buildings. 4. No danger to building heating equipment from high pressure through failure of the : reducing valves. The disadvantages of a low pressure system are: 1. Larger pipe sizes. 2. Decreased field of usefulness owing to small pressure range. b. The advantages of a high pressure system are: 1, Smaller pipe sizes. . 2. Greater adaptability of the steam to various uses other than building heating. . The disadvantages of a high pressure system are: 1. Large heat loss from the pipes. ' 2. The high pressure traps and valves required often give more trouble than low pressure traps and valves do. N 3. Extra heavy fittings are required. 4. Usually two reducing valves or some form of emergency relief is necessary to protect the building piping system. 3 Determine the size of pipe from the following data using Unwin's formula: Length of pipe, 600 ft. Steam to be carried, 90,000 lb per hour, dry saturated. Initial pressure, 100 lb per square inch, gage. Final pressure, 40 lb per square inch, gage. .Using the formula: 0.0001300 W*L ( 1 + ^) ' P dD* r The pressure drop P = 100 -- 40 = 60 lb per square inch. 780 Chapter 42. District Heating The weight of steam per minute W = = 1500. - The length of pipe in feet L = 600. The average density of steam d in pounds per cubic foot, taken from Keenan's Table: At 100-lb gage, d = 0.2578 At 40-lb gage, d = 0.1285 Average, d -- 0.1932 The diameter of the pipe in inches = D. . Substituting the values in the formula: 0.0001306 X 1500* X 600 ^ 1 + 3J?\ d) 60 0.1932 X Ds D = 7.35 in. Therefore, an 8-in. pipe should be used. 4 Wbat points should be borne in mind when laying out an underground steam conduit? The conduit should be reasonably waterproof, able to withstand earth loads and to take care of the expansion and contraction of the piping without strain or stress on the couplings; or without affecting the insulation or the conduit. . Expansion of the piping must be carefully controlled by means of anchors and expansion joints or bends so that the pipes can never come in contact with the conduit. 5 What is considered the proper pressure for a hydrostatic test before com* pleting the conduit? . In the case of any underground piping which is to be buried or otherwise made inacces sible, the assembled lines shall first be tested hydrostatically at a pressure of one and one-, half times the maximum allowable service pressure and held for a period of at least two hours without evidence of leakage. In any case the hydrostatic pressure should not be less than 100 lb per square inch. 6 9 What factors should be considered before determining the route of a steam line? 1. The line should be so located that it will bring in the greatest revenue (or supply the most steam) with the least cost. 1 . 2. The ultimate length and size of. services and branches necessary with each possible location should be estimated, for mains should be run near to the big loads. 3. The location of the boiler room or piping center of present and future buildings to be served should be considered. 4. Where possible, make the lines straight between manholes. '. 5. Avoid such obstructions as other lines, sewers, ducts, curb drains, manholes, valve boxes, catch basins, fire hydrants, and poles; especially avoid electric ducts and water lines. . 6. Avoid locating lines near where pile driving and foundation construction for new buildings will take place. 7. Consider construction difficulties such as traffic, hard rock, and wet earth, which increase time and labor. 8. Consider the economies of using available sidewalk vaults of buildings. Weigh the advantage of less excavation against the cost of obstruction removal. 9. Consider all operating difficulties. 10. Consider the difficulties of negotiating agreements for lines on private property where public and private rights-of-way are available. . 11. Consider the effect of proposed municipal and other improvements. 12. Consider municipal regulations. . 781 X. m Heating Ventilating Air Conditioning Guide 1938 7. State the advantages and disadvantages of tunnels over conduits. The advantages of pipe tunnels over conduits are: 1. Accommodation for miscellaneous services other than steam. 2. Provision of an underground passage between buildings. 3. Easy installation of additional pipes and easy replacement of existing pipes with larger sizes. 4. Easy inspection and maintenance of pipes. . The disadvantages of pipe tunnels over conduits are:. 1. Higher firet cost. 2. Higher maintenance cost in general. 8 Is the steam consumption less in a building that shuts off its steam at night than in one that does not? Why? It has been thoroughly demonstrated that the steam consumption is less in a building where the steam is shut off at night. Although there is, in some cases, an increased con sumption of heat when steam is again turned on in the morning, there is a large net saving which may be explained by the fact that the lower inside temperature maintained during the night obviously resultsin lower heat loss from the building, and less heat need therefore be supplied. 9 # Is the condensate from a building supplied with purchased steam always discharged to the sewer? - No. In some cities where the customers are not spread over too wide a territory and where natural water conditions make the treatment of boiler feed water expensive, the steam company provides mains for the return of the condensate to the boilers. 10 What are the common methods for salvaging heat in condensate? The most common methods are: '. .; 1. The use of a water heating economizer for preheating the hot water supply to the building. 2. The use of a cooling radiator. '. 11 What are the common means used to graduate the heat supply according to variations in outside temperature? . a. A weather compensating thermostat regulates the steam supply automatically according to the outdoor temperature; and gives frequent short intervals of inter mittent steam supply, at the same time it insures delivery of steam to all the radiators. b. Another method, which is very simple is the use of an ordinary vacuum, return line system in which the pressure in the radiators is varied between a high vacuum and a few pounds to produce some control over the heat output!' . c. The use of an orifice system graduates heat supply. d. The time-limit control which may be set to provide no service, continuous service, or periodic service, is also used. For periodic service, steam may be supplied during each period in increments of a certain number of minutes for each successive setting of the switch, steam being shut off during the balance of the period. This type of service is provided by several intermittent settings. A night switch will maintain the intermittent day setting, or interrupt the day operation and cut off the supply of steam at night during any desired hours.* 782 . Chapter 43. WATER SUPPLY PIPING AND WATER HEATING Maximum Possible Flow, Maximum Probable Flow, Average Probable Flow, Factor of Usage, Kind of Pipe Used, Sizing of Risers, Sizing of Mains, Sizing of Systems, Hot Water Supply, Hot Water Heating, Hot Water Storage, Swimming Pool Heat . mg Requirements . DOMESTIC water supply systems present the engineer with a design problem that requires combining the somewhat empirical rules and: formulae in use with the more or less exact hydraulic principles involved. Unlike heating and ventilating layouts, there are practically no definite data for estimating the quantity of water likely to be consumed or the probable rate of water flow at any particular moment. Metered results in one building often show two or three times the . metered amount in another building of the same size and with the same type of tenants. In hotels, one riser will often have an almost constant flow that may never be reached by another at peak load. In office buildings, the women's toilets show a far greater daily consumption than those of the men, yet at no time will they approach the hourly consump tion of the men's toilet during the first hour of the day. This condition has led to a multiplicity of rules of practice which vary as much as the data used. All must of necessity be based on an assumed rate of con sumption and on an assumed probability of simultaneous use, and while the formulae employed may have been derived on sound technical basis the assumptions are often in error. , To arrive at a safe standard, the approximate rate of flow of each fixture to be supplied must be known and the probable number of fixtures in use at any one time must be assumed. Obviously, the maximum . number of fixtures assumed to be in use must be taken at the peak of demand and the lines must be made adequate to supply such a peak regardless of the riser or branch on which the demand may occur. This: means that all water piping under the usual conditions will be over-sized. In tall buildings it is customary to divide the water supply systems, both hot and cold, into sections of 10 to 20 stories. Such zoning1 or *It is impractical to attempt to size piping so as to produce the proper pressure on fixtures at different levels by employing friction, owing to the fact that this friction will be built up to the amount desired only in times of maximum demand and at all other times the friction will be only a fraction of the maximum friction so that the fixtures by this method are subjected to a varying pressure on the water supply line. A much more practical method is to throttle the flow at the fixture, or to use flow regulators, so that the quantity of water delivered will approximate the fixture demands and so that this is accomplished without splashing or noise. . .. 783 Heating Ventilating Air Conditioning Guide 1938 sectionalizing is for the purpose of avoiding excessive pressure on the fixtures in the lower stories of each system. This limits the consideration of water pipe sizes to horizontal mains and to risers not exceeding 20 stories in height or about 200 ft. For the purpose of this chapter the following terms will be used and should be clearly distinguished from one another: Maximum Possible Flow: The flow which would occur if the outlets on all fixtures were opened simultaneously. This condition is seldom, if ever, obtained in actual practice except in cases of gang showers controlled from one common valve, and similar conditions. Maximum Probable Flow: The maximum flow which any pipe is likely to carry under the peak conditions. This is the most important amount to be considered in pipe sizing. Average Probable Flow: The flow likely to be required through the line under normal conditions. It is evident that any pipe adequate to take care of the maximum Fig. 1. Chart Showing Relation Between Maximum Possible Flow and . Maximum Probable Percentage of Use probable flow will also be more than able to take care of the average probable flow, and hence the latter has no bearing on the pipe size. MAXIMUM PROBABLE FLOW There are two factors to be considered in calculating the maximum probable flow, namely, (1) the quantity of water that will flow from the outlets when they are open, and (2) the number of outlets likely to be open at the same time. Table 1 shows the maximum approximate rate of flow from each fixture when it is in use, and will serve as a guide in estimating maximum probable flow demands although there is considerable variation in different fixtures and valves. Probably the flow under normal water pressures, or with the pressure properly throttled, will not differ greatly from the values stated. With the aid of this table it is possible to calculate the maximum possible flow with all outlets open in both the hot and cold water lines. 784 Chapter 43. Water Supply Piping and Water Heating To obtain the maximum probable flow it is necessary to multiply the maximum possible flow by a factor of usage, and this factor varies with the installation and the number of fixtures in the installation. It is evident that with two fixtures it is quite possible that both will at some time be in operation simultaneously. With 200 fixtures, it is unlikely the entire 200 would ever operate at the same time. Consequently, the factor of usage reduces as the number of fixtures becomes greater, all other things being equal. Table 1. Approximate Flow from Fixtures Under Normal Water Pressures Fixtures Water-closets, flush valve.................... ...... Water-closets, flush tank.................. .... Urinals, flush valve ..................... Urinals, flush tank............ Urinals, automatic tank..;........................................ Urinals, perforated pipe per font Lavatories ... Showers, 4 in. heads, in. inlets Showers. 6 in. heads or larver..... Needle hath - Shampoo SDrav............................ Liver sorav.............................. Manicure table.................................. Baths, tub..................................... Kitchen sink ..................... Pantry sink, ordinary................. Pantry sink, large bibb....................... .... Sloo sinks....................... Wash travs...........................:. Laundrv trav..................... Garden hose bibb..................... . " Cold Water (Gallons per Minute) 45a 10 30a 10 1 10 3 3 6 30 1 2 m 5 4 2 6 6 3 6 10 Hot Water (Gallons per Minute) o o o o 0 o 3 3 6 30 1 2 m 5 4 2 '6 6 3 A 0 ^Actual tests on water-closet flush valves indicate 40 gpm as the maximum rate of flow with 30 lb pres- sure at the valve; this would increase to 60 gpm (about 50 per cent) at 00 lb pressure. The 45 gpm has been j*s a*1 average now; possibly, with very low pressures just sufficient to operate the flush valve, 30 gpm could be allowed with safety. Urinal flush valves would vary proportionately in the same manner. 1 I j In practice all the elements will vary according to conditions; in the case of flush valve closets the duration of flush with the kind and condition of supply apparatus, the interval between flushes with the number of people using the system and their habits; and the length of the rush period with the type of installation and its location. The effect of each of these time elements on the results should be considered in connection with any data on which it is based before passing judgment on the selection of the factor of usage. The longer the duration of the flush the greater is the probability of overlapping flow. In selecting the factor of usage shown in Fig. 1 for systems having flush valves, 10 seconds was chosen as the maximum, duration of flush, a value that. represents an approximate average as water closets are installed. While the curve has been calculated for systems composed of water closets alone, it is possible to calculate probabilities for mixed systems of water closets and other smaller fixtures. It has been found however.that for two systems both having the same maximum possible flow, one.composed entirely of water closets and the other a mixed system .of water 785 .I !: j; , -- --5 "s | 1 X Heating Ventilating Air Conditioning Guide 1938 closets and smaller fixtures, the probability, of a given rate of flow is greater for the system composed of water closets than for the mixed o 8 CM 6 -8 (x* Utd (/> td -H 2 * .04 oo Ot0dS) H0. . o Q Zo m3 o 00 Cd u, 5 ot- 2 o 6 o<0 Q M mai. o oh oa tNt g CO ofe. S< '* 04 w g 04 nu US in 250 X CO 04 XX 04 04 XX 04 04 X 04 X 04 X 04 xv X 04-./ 04 C4 ^ X 04 XX 04 04 XX 04 04 XX 04 04 :x CO X 04 X XX 04- 04- 04 X x- X 04 04 04 X 04 XX 04 04 X x- X 04 04 04 XX 04 04 X' X 04 XX 04 04 CO 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 - 04 04 ,CJ4 oi-CO 04 .04 04- 04 04 04 04 04 04 04- 04 04 ;_04% 04 04 04 04 04 v CO - 04 04 Ot 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 - X 04 04 X XX XX X X XX XX X XX XX XX X X X X X X X X X X X X X X X X X. X X .04 04 X X XX XX X X XX XX X XX XX XX 04 04 X X 3 3 X 3 X 3 3 3 3 3 3 3 -3 X X 3 X 04 3 3 3 X 3 X X X 3 3 3 X 3 3 3 X X 3 X 04 3 3 X X 3 X 3 3 3 3 3 X -X 3 3 X 3 X X 3X `f-* -- - - - ^. - 5 -1 - - - - X w -4 - - - - - - X XX XX X X XX XX X XX XX XX X X X X 'X X X X X X X X X X X X X X CM U o CQ < .flU ISo-Jfc- - H a j* <C &. x X XX XX X X XX XX X XX XX XX '' ' o*o CO -8- g 8 O CO CQ CQ . CQ CQ CQ CQ CQ -CQ CQ 88 CQ 8 88 Ka-,lhl 5T : h.' tQ ' * O a< o X * *-> - ft: O UJ Q o' \ oCsd o2 OSQ.J 1- c c' [fZ iZ ' -o CO VO iZ 04 o C iZ iZ o CO . V0 in (Z iZ Q <** veZ6 D ^CQ * i l l I I I 1 li l t 1 1 i 1 !H t ls| m mm r' n ^ r' 11 w. ' .' ^ ^ r> rC)J- oa X .J. -' CM CM . -CrU',OohS. system. The use of this chart then-would produce results which would be on the safe side for mixed systems. ; ' For systems composed entirely of fixtures other thafi .'flush valve fixtures the curve Has been extended for smaller maximum possible'flow Values. ' ' ' .' 786 Chapter 43. Water Supply Piping and Water Heating This chart applies to a normal building and not to installations where the inmates may all be required, for instance to bathe on certain days of the week and at certain hours of those days; or in schools for example where all the showers in the gymnasium may be used simultaneously after instruction periods. In such special cases a new factor of usage must be developed based on the maximum probable usage under the conditions involved. Example 1. Assume that in a normal building, such as a residential hotel or an apart ment house, there are 50 flush valve water-closets, 50 lavatories, 50 sinks and 50 baths, and that it is desired to determine the maximum probable flow in a line supplying all of these fixtures with both hot and cold water. . Cold Water 50 W. C. x 45 gpm_..............2250 gpm 50 Lavs, x 3 gpm 150 gpm _, 50 Sinks x 4 gpm'_^__ ____ 200 gpm ~ 50 Baths x 5 gpm_____ ;___ 250 gpm Maximum possible flow___ 2850 gpm Fig. 1 shows a factor of usage of 9 per cent. . `. T . ` Maximum probable flow of '. . . cold water is 2850 X 0.09____________ 257 gpm Hot Water ' ` . 50 Lavs, x 3 gpm.................. 150 gpm ' 50 Sinks x 4 gpm..... ............ 200 gpm 50 Baths x 5 gpm__________ 250 gpm Maximum possible flow. 600 gpm Fig. 1 shows a factor of usage of 23 per cent. - Maximum probable flow of hot water is 600 X 0.23 138 gpm Total for main supplying cold and hot water (2850 + - 600) X 0.08._________ ______________ 276 gpm , It should be noted that this is a raie'of flow or an instantaneous demand. ' KIND OF PIPE USED Before entering into the actual sizing of pipe, it is necessary to consider the kind of; pipe to be used, and to make suitable allowance for corrosion and fouling during the lifetime of the system. For example, if brass, copper or alloy pipe is contemplated, it is probable that the quantities indicated in Example 1 are ample; if galvanized pipe is to be used, then it is quite likely that after a period of say 15 years the area may be decreased as.much as 25 per cent and the quantitities. of water-assumed should be increased Jby 35 per cent to allow for this reduction of area; if the water contains lime it is possible that 50 per cent of the area may be lost and in such: cases-the flow should be doubled and no branch pipe connected to. fixtures should-be less than % in. In all of the following calculations, the assumption is made that the water' is fairly good and that a corrosion resistant type of pipe is to be used.- ' . SIZING A DOWN-FEED RISER Down-feed systems are commonly used for tall buildings. In sizing a riser arranged for down-feed, the gravity head permits a pressure drop that is almost prohibitive in an up-feed riser. There is a gain in riser head of .0.43 X 100 or 43 lb per 100 ft of run and hence it is quite permissible to size such a riser on the basis of a pressure drop of 30 lb per 100 ft of run, as the difference between the 43 lb generated and the 30-lb drop under maximum probable demand is ample to take care of the friction caused by the fittings. This method applied to the typical riser shown in Fig. 2 gives the schedule of sizes indicated in Table 2 for any flow from 5 to 250 gal. 787 Heating Ventilating Air Conditioning Guide 1938 SIZING AN UP-FEED RISER When the riser is an up-feed, the opposite condition occurs; that is, there is a drop in pressure as the top of the riser is approached, due to the natural reduction in the gravity pressure, and to this must be added the pipe friction plus that introduced by the pipe fittings, all of which produce an excessive drop when compared to the conditions existing with a downfeed riser. To size an up-feed riser the minimum pressure of the street main, or other source of supply, should be ascertained and from this should be subtracted the pressure to be maintained at the highest fixture, namely, 15 lb per square, inch, plus the height in feet above the source of water pressure, multiplied by 0.43 to change from feet of head to pounds of pressure. The total length of run from the source of pressure to the farthest and highest fixture should be ascertained, and this should be changed to equivalent length of run to allow for the loss occasioned by Table 3. Approximate Allowances for Fittings and Valves in Feet of Straight Pipe Size op Pipe _ (Inches) 90-Deg Elbow . 45-Den Elbow Ttpb of Fitting ob Valve Return Bend Gate Valve Globe Valve Angle Valve ' a 43 8 2 48 8 SA 5 3 10 3 60 10 1 5 3 10 3 60 10 m 6 4 12 3 72 12 m 7 5 14 4 84 14 2 7 5 14 4 84 14 V3 A 10 7 20 12 8 24 5 120 20 6 144 24 4 18 13 36 9 216 36 5 25 18 50 13 300 50 . 6 30 21 60 15 360 60 the pipe fittings. Table 3 gives the additional lengths necessary to allow for the various fittings and valves. The drop allowable in pressure per 100 ft of run may then be obtained by multiplying the. surplus pressure (over that required for the gravity head and to supply 15 lb at the fixture) by 100 and by dividing this by the equivalent length of run to the farthest or highest fixture. Where street water pressures are available .the pressure drop through the meter and service pipe must be taken into consideration. Table 4 shows the pressure loss through meters. It also gives the minimum sizes of recommended service and maximum meter deliveries. . Example^. Assume a street pressure of 60 lb, the height of the highest fixture 50 ft, and the length of the longest run 200 ft. Without knowing the additional length of pipe to be added for the fittings it will be assumed that this is about 100 ft. The surplus pressure which will be available for pressure drop will then be 60 lb -- (15 lb + 50 ft X 0.43 lb) = 60 lb - (15 lb + 21.5 lb) = 23.5 lb. . To change this into drop per 100 ft: 200 ft'-f-'^loo ft = per ^ The pipe may then be sized from the maximum probable flow by selecting a size that does not give a drop in excess of 7.8 lb per 100 ft. Chapter 43. Water Supply Piping and Water Heating It will be seen from Example 2 that it is impossible to size up-feed risers without determining the drop allowable in both the horizontal feed mains and the toilet room branches. Having once ascertained this allow able drop, it is simply a matter of applying it throughout the system. Rats or Flow Gfm 5 10 15 20 25 30 35 40 45 50 75 100 125 150 175 200 . 250 300 350 . 400 500 600 800 1000 Table 4. Pressure Loss Through Water Disc Meters11 A. W. W. A. Standards Approx. Pbessubb Loss Thsougb Metres, Lb pbb Sq In Pipe Size (In.) X 1.5 6.0 14.0 25.0 X1 0.5 .0.2 2.0 1.0 5:0 2.0 9.0 3.5 1* 2 0.2 0.6 0.2 1.0 0.4 34 6 13.5 5.5 1.5 0.6 19.5 8.0 2.0 0.9 11.0 3.0 1.0 14.0 4.0 1.5 18.0 22.0 5.0 6.0 14.0 25.0 2.0 2.5 5.5 10.0 15.0 22.0 0.7 1.5 2.8 1.0 4.0 1.5 6.0 2.2 8.0 3.0 10.4 4.01.0 16.0 1.5 23.0 2.2 ' 3.0 4.0 6.5 9.0 16.0 25.0 Minimum She op Sebvicb Recommended Sapb Maximum Dsuvert op Meters Rate op. Flow Gpm Appbox. Minimum Pipe Size op Service Main to Meter (In.) Maximum Length (Ft) Meter Size In. Capacitt, Gpm Based on 25 Lb Loss 30 75 100 150 200 1-20 20-30 30-50 50-100 100-150 K Vi %1 1 . IA 1A m 1A 2 11 1m 1A lA 2. 2 2- . 2A 1 ' Vs M m1 1A 2 23 6 2A 8 . . 20 34 53 100 160 315 500 1000 ' .`uPltCSanufaSureraU8h compound and current meters are less thanshown in table. Forexact information 789. X K Heating Ventilating Air Conditioning Guide 1938 HORIZONTAL SUPPLY MAINS The horizontal mains supplying the risers at the top of a down-feed system must be liberally sized unless the house tank is set at a much higher elevation than usual. To provide a gravity head on the highest fixtures of 15 lb per square inch it is necessary for the water line in the house tank to be nearly 40 ft higher, and with the line loss considered this becomes about 45 ft. Such heights are not often practical and as a result the pressure on the highest fixtures either is reduced to 7 lb (which is sufficient to operate a flush valve), or flush tank water-closets are sub stituted, or a separate cold and hot water supply is installed with a small pneumatic tank to give the increase in pressure necessary. The chief objection to the use of a pneumatic tank is that a separate hot water heater is required and this heater must be located either sufficiently below the highest fixtures to obtain a gravity circulation, or it must be provided with a circulating pump in order to force the hot water to the top floor level. . The most common solution is to place the house tank as high as the structural and architectural conditions will permit and then to use liberally-sized lines between the house tank and the upper fixtures, say for the two top stories, below which the riser sizes may be reduced to those indicated in Fig. 2 and Table 2. Where the house tank is only one story above the top fixtures, flush tank water-closets must be used and the drop in the entire run from the house tank down to the farthest fixture should not exceed .1 lb; the less, the better. This means1 that if the total equivalent run to the farthest top fixtures supplied is 300 ft, the drop per 100 ft should not exceed ,. oUU or 0.33 lb per 100 ft. The; friction curves shown in Fig. 3 may be used for quickly determining the proper size of pipe to give any desired drop in pounds per 100 ft of equivalent run. OVERHEAD DISTRIBUTION MAIN Example S. Suppose an installation has a house tank in which the water line is 20 ft above the level of the top fixtures to be supplied and that the length of run to the farthest fixtures on this level is 400 ft with the pipe fittings adding another 200 ft, making an equivalent length of 600 ft. What would be the size of main coming out of the tank where a maximum flow rate of 400 gpm may be expected, of the horizontal main where a maximum flow rate of 200 gpm may be expected, and of the riser down to the fixture level where the maximum flow rate is approximately 100 gpm? Here the level of the water in the house tank is 20 ft above the faucet of the highest fixture and the gravity pressure will be 0.43 lb X 20 ft = 8.6 lb and, if a total pressure drop of 1 lb is assumed, the pressure on the farthest fixture under times of peak load will be 8.6 lb -- 1 lb = 7.6 lb while the drop per 100 ft of equivalent run will have to be lib X 100 = 0.16671b. 600 Referring to Fig. 3 it will be noted that where the flow through the main is 400 gpm, an 8-in. pipe would be required; that where the flow is reduced to 200 gpm, a 6-in. pipe would be sufficient; and that where the flow is 100 gpm in the riser branch and riser, a 5-in. size would be correct. Of course these are somewhat excessive flows and the head from the tank is small so that large sizes are to be expected. It would be necessary to carry a 5-in. riser down to the branch to the top floor, then reduce to 4 in. for the branch to the floor below the top, and below this the sizes in Table 2 could be followed. In such a-case, flush tank closets should doubtless be substituted. Had the tank been set 10 ft higher, the head available to be used up in friction, but 790 Chapter 43. Water Supply. Piping and Water Heating RATE OF FLOW IN GALLONS PER MINUTE still giving the same pressure at the top fixtures, would have been 0.43 lb X 10 ft or 4.3 lb greater and this, with the 1 lb drop used previously, would give a.total allowable drop of 1 lb. + 4.3 lb -- 5.3 lb which, divided by the 600 ft equivalent run gives a drop per 100 ft , 5.3. X. 100. n: f ----- 600-- = 0 9 lb '. -. Heating Ventiulting Air Conditioning Guide 1938 Fig. 4. Typical Layout for Down-Feed System House Tank'f House Supply --r Fire Reserve ' 197 197 4' |t 8th. 4 W. C.-F.V. 2U.-F.V. 3 Lav. ^ 4W.C.-F.V. 166 ? 2U.-F.V. 7th. - 3 Lav. . 145 2" 6th. t > 4W.C.-F.V. 2U.-F.V. 3 Lav. . 117 2 5th. . B 4W.C.-F.V. 2U.-F.V. 3 Lav. 25 1" 4th. 10 Lav. 11 f 3rd. 1S.S. - 8 4" .2nd. . 4 I" 1S.S. 1S. S. 1st (J) V 255 215 4- 6W.C.-F.V. 4 Lav. >--> ,,1t 21- 6W.C.-F.V. 2U 2 4 Lav. . 196 21 6W.C.-F.V. 4 Lav. 5' 180 2- '6W.C.-F.V. 4 Lav. . 160 2 . 130 2 4W.G-F.V. 2U.-F.V. 3Uv- 4W.C.-F.V. 2U.-F.V. 3 Lav. 98 li 2W.C.-F.V. 1U.-F.V. 1 Lav. ' 45 li 1W.C.-F.V. (2) H-h* 282 122 31 1 S.S. tX. m 2 1S.S. 120 t 1 S. S. 120 2' is. a 3 W.C.-F. V. H9 2" 1 Lav. . ^ 1 s. s; 9 2" 2 Lav. tr 3W.C.-F.V. 89 1 Lav. 4 T IS. S. (3) and, with this drop, the sizes according to the chart (Fig. 3) are 6 in., 5 in., and 4 in., respectively, while if the run is reduced to 200 ft instead of 600 ft, the allowable drop will be ^ ^ = 2.7 lb per 100 ft. This gives 5 in., '4 in., and 3 in., respectively, for the flows of 400, 200, and 100 gpm. From Example 3 it is evident that, while the down-feed system possesses certain economies in size for the riser portion, it is quite likely to involve large distribution main sizes, especially when the tank is not elevated to a considerable degree. SIZING A PIPING SYSTEM Example 4- Fig. 4 shows a typical layout with three risers extending eight stories and with the Extures noted on each floor. First this will be solved for a down-feed arrange ment assuming that the level of the water in the bouse tank is 30 ft above the fixtures on the top floor, that the length of run from the tank to the farthest fixture is 200 ft, equiva lent length of fittings 100 ft, and the pressure required at the fixture is 7 lb. 792 Chapter 43. Water Supply Piping and Water Heating Table 5. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals {Riser No. 1. Fig. 4) Floor of Blog. 1st 2nd 3rd 4th 5th 6th 7th 8th Fixtures on Floor Gpm . PER Fixture 1 S. S. l S. S. 1 S. S. 10 Lav. 4 W. C. 2 U. 3 Lav. 4 4 4 3 45 30 3 Maximum Gpm on Floor Maximum Gpm on Riser Probable Use (pee cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft 4 4 100 4 30 4 8 100 8 30 4 12 92 11 30 30 42 58 25 30 180 60 9 4 W. C. 2 U. 3 Lav. 45 30 3 249 291 180 60 9 40 117 30 4 W. C. 2 U. 3 Lav. 249 45 - 180 30 60 39 540 27 145 30 4 W. C. 2 U. 3 Lav. 45 30 3 249 789 180 60 9 21 166 30 249 1038 19 197 2 Pipe Size In. % H H 1 2 2 2 4 The 30-ft head is equal to a static pressure of 0.43 X 30 or 12.9 lb per square inch and to maintain a pressure of 7 lb at the highest fixtures the drop allowable in pressure is 12.9 -- 7.0 lb or 5.9 lb. As the total equivalent run is 300 ft, this is a drop per 100 ft of 1.97 lb, or practically 2 lb. Therefore, all risers and mains from the top floor back to the tank must be sized on the basis of a drop of 2 lb per 100 ft. Tables 5, 6, 7 and 8 show the schedule for RisersNos. 1, 2 and 3 with the maximum possible flow taken from Table 1, the percentage of use at the peak taken from Fig. 1, and the maximum probable flow at the peak worked out for each portion of the riser, the riser sizes being taken from Table 2 as far as possible and from Fig. 3 where the amounts exceed the values given in this table; a drop of 30 lb per 100 ft is used except on the riser from the top floor back to the tank where 2 lb per 100 ft is the allowable limit. The reduction in pipe size which would occur if flush tank water-closets were used on the top floor and only 3 lb pressure used on the fixtures is given in Tables 9 and 10. This illustrates why flush tank closets so frequently are substituted on the uppermost floor when a house tank is the source of water pressure. If it is now assumed that Riser No. 1 is to be fed from the bottom and the minimum . street pressure is 75 lb with the top fixture of the riser 80 ft above the main, the problem would be solved by determining the maximum rate of flow in each portion of the riser as shown in Table 11 and then finding the allowable drop which can be used per 100 It. The 80 ft of riser height will use up 0.43 lb X 80 = 34.4 lb and the pressure at the top of the required 15 lb will make the total reduction 49.4 lb, leaving a balance of 25.6 lb which may be used up in friction. If the distance from the street main to the bottom of the riser, which will be assumed to be the farthest one on the horizontal line, is 100 ft, and if the fittings are sufficient to add another 100 ft, as well as the 80 ft of vertical distance up the riser, the total equivalent run will be 280 ft, which will be taken as an even 300 ft. 793 Heating Ventilating Air Conditioning Guide 1938 Table 6. Typical Calculation of Pipe Sues on Down-Feed Rises with Flush Valve Wateh-Closets and Urinals Floor of Bldg. 1st 2nd - 3rd 4 th 5tb 6th 7th 8th Fixtures ON Floor Gpm per Fixture i w. c. 2W. C. 1 u. - 1 Lav. 45 45 30 3 4 W. C. 2 U. 3 Lav. 45 30 3 4 W. C. 2 U. 3 Lav. 45 30 3 6 W. C. 4 Lav. 45 3 6 W. C. 4 Lav. 45 3 6 W. C. 4 Lav. 45 3 6W.C. 4 Lav. 45 3 (Riser No. S. Fig. 4) ------------ Maximum Gpm on Floor Maximum Gpm ON Riser 45 45 Probable Use PER CENT) Probable Demand Riser Gpm 100 45 Allowable Drop Lb per 100 Ft 30 Pipe Size In. 90 30 3 123 168 58 98 30 180 60 9 249 417 31 130 30 * 2 180 60 9 249 666 24 160 3 ; 2 270 12 282 948 19 180 i 30 2 270 12 282 1230 16 196 30 2K 270 12 282 1512 14 211 30 2H 270 12 282 1794 12 215 2 4 25.61b X 100 o -Y Then the allowable drop per 100 ft will be --------ggg--------- = 8.5 lb and the sizes shown in Fig. 5 are based on this amount of drop. Of course the other risers will have the same maximum flows at the bottom as they formerly had at the top, namely 215 and 122 gal, respectively, for Risers Nos. 2 and 3., Combining these maximum flows in the same man ner as pursued in the down-feed system it is seen that the maximum flow between Riser No. 2 and Riser No. 3 is 255 gpm, and between Riser No. 3 and the street main, 282 gpm which at a drop of 8.5 lb gives the main sizes indicated. It.will be noted that in determin ing the maximum Sow in an up-feed riser it is necessary to begin at the top floor and work down instead of beginning at the bottom floor and working up as was done in the down-feed sizing. '- SIZING UP-FEED AND DOWN-FEED HOT WATER SYSTEMS Hot water supply systems, when of the circulating type, have a few differences to be considered although the same general principles of sizing apply to these lines as to the cold water lines. Owing to .the fact that there are no flush valves on the hot water piping and also because many plumbing fixtures have no hot water connections, the sizes of the hot water piping in general will be considerably less than the cold, water piping in the same building. On the other hand it is almost invariably 794 Chapter 43. Water Supply Piping and Water Heating Table 7. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals (Riser No. S. Fig. 4) Floor of Bldg. Fixtures on Floor 1st 1 S. S. 2nd 3 W. C. 1 Lav. 3rd 2 Lav. 4th 3 W. C. 1 Lav. 1 S. S. 5th . ' 6th 7th 8th 1 S. S. 1 S. S. 1 S. S. 1S.S Gpm PER Fixture Maximum Gpm on Floor Maximum Gpm ON Riser Probable Use (per cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft 4 4 4 100 4 30 45 135 33 138 142 63 89 30 3 6 148 61 90 30 45 135 33 44 142 290 41 119 30 4.` . 4 294 . 41 120 30 .4 4 298 40 120 30 4- 4 302 40 121 30 4 4 306 40 122 2- Pipe Size In. H. IH 2 2 2 2 3 . required that a gravity circulation be kept up in such hot water lines and this often has a considerable influence on the size. There are three methods of arranging circulation lines, as follows: . . . 1. By using the,plain up-feed with a return carried back from the top of.the riser and paralleling it. ' ' ' ` 2. By carrying a supply riser up in one location thus supplying fixtures on up-feed, then-crossing over at the top and coming down past, another collection of fixtures and supplying these by a down-feed. . . ' ; ... . 3. By carrying all of the water to the top of the building and dropping risers wherever needed, feeding all hot water on a down-feed system. . . Table 8." Size of.Distribution Main for Down-Feed Systems (See Fig. 4)' Riser No. 1 2 3 Maximum ` Gpm ' Riser 1038 1794 306 Maximum Gpm Main 1038 2832 3138 ' Probable Use (per cent) 18 9 ,9 1 Probable . Gpm Allowable Drop Lb per 100 Ft - Size of ' Main In. 187 255 282 . '- 2 2 2 4 4 5 In the first instance the up-feed riser may be sized for the same pressure, drop as used for the cold water riser and, from the top of the riser just below the top fixture connection, a return circulation line may be carried back to the main return line in the basement and connected through a check valve, set on a 45-deg angle, and a gate valve; these return circu lation lines should never be less than % in., and on the farther half of the risers, not less than 1 in. to favor circulation in the far end. Typical top and bottom connections for such risers are shown in Fig.;6. , . 795 r Heating Ventilating Air Conditioning Guide 1938 Table 9. Typical. Calculation of Pipe Sizes on Down-Feed Risers with Flush Tank Water-Closets and Urinals on Top Floor Only (See Fig. 4) Floor of Bldg. Fixtures on Floor Gpm PER Fixture Maximum Gpm on Floor Maximum Gpm on Riser Probable Use (per cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft Pipe Size In. 7th and ' below Sth 4 W. C. 2 U. 3 Lav. 10 10 3 Riser No. 1 789 40 20 9 69 858 21 . 166 20 172 30 .2 3.3 4 7th and below 8th 6 W. C. 4 Lav. 10 3 Riser No. 1512 60 12 82 1594 ; 14 14 211 223 30 . 2M . 3.3 4 7th and below. 8th 1 S. S. 4* Riser No. S 302 4 306 40 40 121 122 30 3.3 - 2 3 For the second arrangement of hot water risers (Fig. 7b), circulation lines are run back from the last fixture supplied to the main return circulation line in the same manner as just described, using % in. for the near risers and 1 in. for the far risers. The sizing is much more difficult, as it is necessary to start at the bottom floor of the return riser and work back to the top of this riser and then carry the maximum flow across on to the top of the corresponding supply riser and work down on this riser from the top floor to the bottom. Naturally this gives a much greater flow in the supply riser and aids circulation by reducing pipe friction. The allowable loss per 100 ft in such lines must be made about half that used for the cold water risers which do not have the combined up- and down-travel which the hot water must make. In the third and most common arrangement (Fig. 7c) all of the water is car ried from the tank or heater directly to the top of the building and is there distributed to the risers which are down-feed and may be sized in the Table 10. Summary op Riser Sizes to Given Main Sizes with Flush Tank Water-Closets and Urinals on Top Floor Only. . (See Fig. 4) Riser No. 1 2 3 Maximum Gpm RtSER 858 1594 306 Maximum Gpm Main 858 2452 2758 Probable Use (per cent) 20 10 9 Probable Gpm 172 245 248 Allowable Drop Lb per 100 Ft 3.3 3.3 3.3 Size of Main . In. 4 4. 4 796 Chapter 43. Water Supply Piping and Water Heating regular down-feed manner if the total equivalent run either from the street main or house tank is taken into consideration. The return circulation lines from the bottom of each riser should be arranged in the manner already outlined and any riser not going to the basement to supply fixtures must have these returns carried down to the basement from the termination of the supply riser at whatever level it may end. 4W.C.-F.V. 2 U.-F. V. 8th. ^ 3 Lav. 4W.C.-FV. 24 2 U.-F V. 7th. 3 lav. 4W.C.-F.V. 2j 2 U.-F. V. 6th. :i 3 Lav. 4W.C.-F.V 3* 2 U.-F. V. 5th. , ^ 3 Lav. 3" 10 lav. 4th. 3" l&S. 3rd. 3" 1 S. S. 2nd. 3" 1S.S. 1st 3" 3" Main (1) Fig. 5. Up-Feed - "System Fig. 6. Supply and Return Main Connections for Hot Water Supply System All risers, both hot and cold, should be valved at the main with an extra check valve on the hot water return circulation- so that the risers may be cut off and repaired when necessary without disturbing the service in the remainder of the system. HOT WATER SUPPLY Having designed the service hot water piping, the next step is to furnish some means of heating the water and in this respect it is necessary to pass from the maximum probable flow to the maximum probable hourly demand, which is quite different. If an instantaneous heater were used, it would require adequate capacity to provide for the heating of the water as fast as it is drawn and a heater of this type should be sized on the basis of the maximum probable flow with the accompanying heavy drafts on the heating device and with intervals of no draft at all. To balance these inequalities of flow the storage-type heater is often utilized so that the 797 Heating Ventilating Air Conditioning Guide 1938 Table 11. Typical Calculation of Pipe Sizes on Up-Feed Riser with ' ' Flush Valve Water-Closets and Urinals (See Fig. 5) Floor of Bldg. 8th 7th . 6th 5th 4th 3rd 2nd 1st Fixtures on Floor Gpm - PER Fixture Maximum Gpm on Floor Maximum Gpm on Riser Probable Use (per cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft 4 W. C. 2 U. 3 Lav. 45 30 3 180 60 9 249 249 44 109 8.5 4 W. C. 2 U. 3 Lav. .45 30 3 180 60 9 249 498 28 139 8.5 4 W. C. 2 U. 3 Lav. 45 30 3 180 60 9 249 747 ` 22 164 8.5 4 W. C. 2 U. 3 Lav. 45 30 3' 180 60 9 249 996 18 179 8.5 10 Lav. .3 30 1026 18 185 8.5 1 S. S. 4 4 i030 18 186 8.5 1 S. S. . 4 4 1034 18 187 8.5 1 S. S. 4 4 1038 18 188 8.5 Pipe Size In. m 2H 3 3 3 3 3 3 Table 12. Suggested Storage Tank Sizes for Homes and Apartments Ai.t.-Yiear Service ` Based on Boiler Water at 180 F ` Tank ' . Capacity Gal '30 35 40 50 60 72 80 100 125 150 200 250 300 400 500 Piping Connections Boiler, In.. Tank, In. i . IK 04 04 m 04 2 2 2 2 2 2K m 3 3 3A . ' 3A - 3A 3A 1 1 1 04 OA IK. 04 04 m 2 2 Number of Baths or Families i i 1-2 1-2 1-2 2-3 2-3 ` 3-4 4-5 . ' 5-6 6-7 7-9 9-11 11-15 15-18 Service During Heating 8eabon Based on Boiler Water at 215 F Tank Capacity 30 v 40 52 66 82 . 100 120 144 160 200 250 300 400 500 600 Piping,Connections ' Boiler, In.- i i i IK IK IK IK 04 .2 2* 2' 2 2K 2K 3 Tank, In.. 3A ' 3A. M-, 1 1 1 1 1 IK IK 04 . 04 2 2 04 Number of Baths or Families i, i i 1-2 2-3 3 4 . .5 6 6^7 7-9 9-11 ;il-15 15-18 . 18-21 798 " Chapter 43. Water Supply Piping and Water Heating water demand can be heated during periods of light demand, and stored up for use during the periods of heavy demand.- The total water con sumption per person usually varies between! 100 and 150 gal per day when laundry and culinary operations for the occupants are carried out on the same premises. The maximum hourly demand under these conditions will be found to be about one-tenth of the average daily consumption. If one-third of the total water used is hot water and 125 gal per day is assumed as a fair average of consumption per person, it is apparent that each person uses about 40 gal of hot waiter per day. If one-tenth of this represents the peak hourly load, then 4 gph must be allowed per person for the heaviest demand.. If the average occupancy of apartments is 3 persons, the peak hour demand per apartment will be about 12 gph. It is customary to allow 10 gph of heating capacity per apartment.. Water in excess of this heating capacity drawn out during the peak hours is * -- Vent rL f >r t t^ t >* - r t . 1- ^>, a C3O t } 1+ -> I T.: | " ^% * T* a ,g : a ' t 1 .. a y CO y 1 i^ 1 J'l \ l > ao. CO y \ \ aa CO TT Return // (o) / <*> /` ^ - 'f A' . \^ )A /<f \ L^ > /qf \ /i> f /<f Fig. 7. Methods of Arranging Hot Water Circulation Lines' provided for by storage in the hot water tank where this water is heated during hours when the demand is below the average. Table 12 gives suggested storage tank sizes for homes and apartments based on the number of families or baths. ' ,i - HOT WATER HEATERS .. Various types of heaters are available for supplying the hot water for domestic service in buildings. In any hot water supply system ,the water should be heated to a temperature :between 150 and 180. F. Where the hot water requirements include supplies for kitchens, laundries or! process work, the higher temperatures are used. In buildings where steam is available throughout .the year, the hot water supply is usually taken from this source. In smaller domestic-installations the fuel-burning device is generally automatically arranged so that hot water, is supplied the entire year and not merely when the boiler is used for heating purposes! ; 799 Heating Ventilating Air Conditioning Guide 1938 ' Water is heated by various methods using heat exchangers arranged so that the boiler heating medium gives up its heat to the water in the hot water circulating system. These heat exchangers may be classified as follows: 1. Submerged steam heating coil in storage tank. 2. Submerged water heating coil in storage tank. (Fig. 8). 3. Indirect water heater, mounted on side of boiler below water line. (Fig. 9). 4. Submerged indirect water heater, placed in boiler below water line. (Fig. 10). The efficiency of these heaters may be estimated as nearly 100 per. cent as the heat loss from surface radiation of the heater and tank shell when covered with insulating material is generally reduced to a minimum. The capacities of these heaters are usually available from manufacturers Chapter 43. Water Supply Piping and Water Heating storage tank and the piping arrangement between the boiler, heater and tank. It is generally good practice to allow a margin of safety when selecting an indirect heater of the proper size to provide for loss of efficiency due to the accumulation of scaling on the coils and piping. Heat exchangers classified according to (3) and (4) may be used with or without a storage tank, but when tanks are omitted, the indirect water heaters should be increased in size so as to heat the water instantaneously as it is needed. The storage tank should be installed as high as possible. Horizontal tanks are preferable for all medium size installations and absolutely, essential on larger installations. Where possible the storage tank should be installed with the bottom of the tank at or above the boiler water line. Horizontal storage tanks smaller than 18 or 20 in. diameter are not 1 hot watef to fixtures Fig. 8. Hot Water Heating Coil Submerged in Storage Tank rating tables. The area of the inside surface of a heating coil may be determined from the following equation: where = Q X 8.33 (to - ft) K0 X (1) A -- surface area of coil, square feet. \ Q = quantity of water heated, gallons per hour. ft, -- hot water outlet temperature, degrees Fahrenheit. ft = cold water inlet temperature, degrees Fahrenheit. ' K0 coefficient of heat transmission, Btu per hour per square foot surface. . For copper or brass coils K0 = 240 (steam) and 100 (hot water). For iron coils K0 = 160 (steam) and 67 (hot water). tm = logarithmic mean of the difference between the temperature of the heating medium and the average water temperature, ftn is approximately = Equation 1 may also be used for determining revised heating coil ratings under different temperature conditions as stated in the manu facturers ratings. When selecting a water heater, the conditions of operation should be carefully considered, as well as the location of the 800 - Fig. 9. Indirect Water Heater Mounted on Side of Boiler Fig. 10. Indirect Water Heater Placed in Boiler recommended because of the difficulty of preventing the hot and cold s water from_mixing, and especially is this an important consideration when large'quantities of water are withdrawn. Pipe sizes between the water heater and boiler should be full size of the heater tappings (Table 12). When a heater is connected to a horizontal sectional boiler, it is recommended that connections be made to all sections and joined together a few inches below the water line as shown in Fig. 8, so that steaming is prevented in those sections which are not connected to the header. When a steam coil is used for heating the water, an automatic ther mostatic valve may be installed in the steam supply to the coil. The operation of this automatic valve is controlled by a thermostat located in the.storage tank which permits the proper amount of steam to enter the coil so as to maintain an even water temperature. An indirect water heater may be used on either a steam or hot water system, and generally this type of heater is provided with a temperature control device located in the boiler water circulating connection to the water heater. The setting on this thermostatic valve may be as low as 801 Heating Ventilating Air Conditioning Guide 1938 140 F or as high as 180 F and may be readily adjusted to meet particular requirements. With this type of control it is impossible to overheat the hot water supply which is an important safety consideration in some installations; This type of system may also be conveniently used during the non-heating season with the operation of the fuel burning device controlled by the water heater thermostat. (See Chapter 37).. During the heating season the water heater temperature control functions as a low limit control. When an indirect water heater is applied to a gravity hot water system, - it is necessary to provide a valve in the supply to the heating system to prevent the flow of hot water from the boiler when heat is not required in the house. This valve may be controlled from a room thermostat and the automatic fuel-burning device controlled from the water heater thermostat. To prevent circulation in a forced hot water heating system flow control valves may be installed in the flow and return lines which act merely as check valves when the circulating pump is not operating. In this arrangement the pump is controlled by the room thermostat and the automatic fuel-burning device is controlled from the water heater thermostat. STORAGE CAPACITY AND BOILER ALLOWANCES The amount of storage provided in the hot water tank or heater is somewhat a matter of choice but is usually made ample to carry over the peak shortage which is likely to occur and is based on the assumption that only 75 per cent of the storage capacity will be available, as it has been found that if more than this amount is withdrawn from storage, the tank is so cooled down as to make the balance useless. The general rule may be cited that the less the heating capacity the greater must be the storage, and the greater the storage the less may be the heating capacity down to a point where the heating capacity will fail to be sufficient to heat up the tank storage during the periods of. small load. Example 5. A heater to supply 500 persons will have an average daily use of about: 500 X 40 gal = 20,000 gal and this is an average of 2'^ ^ = 833 gph but the peak hour will require Ho of 20,000 = 2000 gal and the shortage during the peak hour, if the heating capacity is made to suit the average hourly use of 833 gal, will be 2000 -- 833 = 1167 gal so that the storage capacity, based on 75 per cent being available from this 1167 capacity without cooling the tank excessively, will be ^ ^ = 1556 gal. Should it be desired to reduce the size of storage tanks and to use a greater heating capacity, it is only necessary to increase the heating capacity to say 1200 gph which then gives 2000 -- 1200 = 800 gal as the shortage during the peak hour, and the necessary ' storage will be = 1067 gal; or the heating capacity can be increased to 1500 gal, leaving a shortage of 2000 -- 1500 = 500 gal. Good design requires that the heating capacity be made as small as possible without introducing undesirable amounts of storage, as the heating capacity directly determines the load on the source of heat. 802 Chapter 43. Water Supply Piping and Water Heating As indicated in Example 5, the heating load is proportional to the heating capacity and the boiler capacity must be increased for higher heating capacities and may be reduced for smaller heating capacities with greater storage. It may be assumed that a boiler capacity of about 4 sq ft of equivalent steam heating surface5 (radiation) must be provided for every gallon of water heated 100 F or from 50 F to 150 F, which is the temperature rise most commonly assumed and required. On this basis it will be seen that the various conditions cited in Example 5 will require additional boiler capacity as follows: ` Heating Capacity (gph) 833 : 1200 1500 Additional Boiler Capacity . (Sq Ft EDR) 3332 4800 6000 From this it is apparent that it is less costly to provide ample storage and to reduce boiler capacity than to diminish the storage and supply a greatly increased boiler capacity to compensate. The boiler allowance value of 4 sq ft of equivalent steam radiation for " each gallon of water heated through a temperature range of 100 F is based on an hourly heating rate. When reduced heating capacities are desired for economic reasons of boiler design and selection, engineers frequently recommend that the heating rate be extended over a period of two hours in which case the boiler allowance value would be reduced to 2 sq ft of equivalent steam radiation. Similarly any other heating rate may be established and a corresponding value of boiler allowance deter mined. ' Reliable information, based upon the installations of several heaters in existing heating systems indicates varying arbitrary values of boiler allowances to be used. When these values are selected for usage, a careful analysis of the varying factors involved in determining these values should be considered so that the proper heating allowances may be provided. ESTIMATING HOT WATER DEMAND BY FIXTURES In buildings where the occupancy is doubtful and only the number of plumbing fixtures can serve as a basis for determining the probable hot water demand, the problem is not so simple owing to the fact that a fixture gives no information as to how heavy a service may be demanded from the fixture and this amount of service is really the governing factor in making an estimate of the probable hot water demand. Table 13 may prove of some value in this respect as it gives the maximum assumed quantity of hot water per hour which will be demanded of any fixture and then gives a percentage of this amount which may be assumed as probable in different types of buildings. Table 14 gives approximate hot water re quirements in various types of buildings. . Example 6. Let it be assumed that an apartment house with 20 apartments has 20 baths, 20 lavatories, 20 kitchen sinks and 20 laundry trays; what is the probable maxi mum hourly demand for hot water? Actual requirement for 100-deg temperature; difference = - water heated. 803 = 3.33 sq ft per gallon of Heating Ventilating Air Conditioning Guide 1938 20-Baths at 40 gal and 33 per cent................................................................................... ................ - 270 gal 20 Lavs, at 20 gal and 25 per cent ................. ...................-............ ............................................ 100 gal 20 Sinks at 30 gal and 33 per cent.___________ ___________ : 200 gal 20 Trays at 50 gal and 60 per cent_________________________________ 600 gal Total.___ __________________________________________________________________ ______ _______ 1170 gal Probable peak use at one time........ .......... ................................................. ................ ................. -- 35 per cent Probable actual peak demand__ 409 gph If three persons Eire assumed to an apartment the total daily use of hot water should approximate 20 X 3 X 40 gal = 2400 gal and if the peak hour is 10 per cent of this amount, the peak hour by this method shows a probable demand of one-tenth of 2400 gal, which indicates that the values in Table 13 are safe. SWIMMING POOL HEATING REQUIREMENTS Swimming pools present a problem of hot water heating demand which is frequently overestimated. Few outdoor swimming pools require water heating, and in some cases they require the addition of cold water to regulate the. temperature. The recirculation system, of a swimming pool consists of the pumps, hair and lint catchers, and filters together with all necessary pipe connections to the inlets and outlets of the pool. The water heater, the sterilizing equipment and suction cleaner are usually installed or connected to the recirculation system and may be considered as integral parts of the system. ' The recirculation system and all its component parts should be designed to provide the required volume of circulation so that the water turnover ratio is at least two times per day and where heavy loads are anticipated the turnover ratio should be increased to three times or more. Many states have regulations prescribing the circulation turnover. The water heaters for swimming pools are usually instantaneous steam Table 13. Ordinary Maximum Hourly Demand for' Hot Water for Various Fixtures in Gallons and Probable Percentage of Usage Ttpb o? Building Mizonni Phobablb GPH Lavatories Private Public Baths Showebs Slop Sinks Kitchen Pantot Sinks Sinks Foot Baths Wash Teats Av. Max. Use* 20 20 40 300 30 30 20 20 50 \ Probable Usage in .Per Cent of Maximum Ordinary Use Apt. house Club Gym. Hospital Hotel Industrial Laundries Office building Baths Residences Schools Y. M. C. A. 25 50 33 67 67 , 33 50 25 60 35 25 75 50 67 67 67 100 25 80 60 25 100 100 100 100 . 80 25 75 50 33 67 67 100 25 80 45 25 100 50 33 100 67 100 25 80 70 25 150 100 100 67 67 100 90 25 100 33 _____ 100 100 25 75 50 .... _____ 20 25 150 150 100 50 100 25 50 33 50 33 50 50 60 50 25 75 100 67 33 100 50 25 25 100 100 100 67 67 100 100 80 75 Percentage of fixtures likely to be demanding maximum probable usage at any one time. 804 Chapter 43. Water Supply Piping and Water Heating coil heaters. These heaters should be sized so that they will have suf ficient capacity to heat the water delivered by the circulating pump 15 F per hour. , The water temperature in a pool is usually maintained at about 72 F. A few states have regulations prohibiting higher water temperatures than 70 F. The room temperature should be approximately 5 F higher, but not more than 8 F higher nor less than 2 F lower, than the water tem perature. Example 6. Assume a swimming pool 75 ft long, 30 ft wide with an average depth of 6 ft. If the water is to be heated from a temperature of 50 to 65 F, what capacity heater and steam consumption is required with a turnover ratio of two times per day? Pool volume: 75 X 30 X 6 X 7.5 = 100,000 gal. ' With a turnover ratio of twice in 24 hr, the heating capacity is: X 2 _ gggg gal per hour. The steam consumption would be:---------------- --------------------- = 1080 lb steam per hour. Regulation of swimming pool temperatures is essential for successful operation and economy. It is therefore recommended that the steam supply to the heater be provided with a by-pass which may be used for pool filling and initial heating and that a smaller by-pass be installed with an automatic control valve having the capacity to heat the cir culation water approximately 5 F per hour. Table 14. Hot Water Consumption in Various Types of Buildings for Different Purposes Type op Building Conditions Gallons Hotels Room with basin only Room with bath (Transient) (Men) (Mixed) .. , (Women) ____ Two-room suite and bath Three-room suite and bath 10 (per day) 40 (per day) 40 (per day) 60 (per day) 80 (per day) 80 (per day) 100 (per day) Buildings Public bath or lavatory 150 (per day per fixture) Public shower 200 (per day per fixture) Public lavatory with attendant 200 (per day per fixture) . Industrial Buildings Per office employee Per factory employee Cleaning floors 2 (per day) 5 (per day) 3 (per 1000 sq ft per day) $0.50 Meals Restaurants $1.00 Meals $1.50 Meals 0.5 (per customer with hand washing) 1.0 (per customer with machine washing) 1.0 (per customer with hand washing) 2.0 (per customer with machine washing) 1.5 (per customer with hand washing) 4.0 (per customer with machine , washing) 805 r Heating Ventilating Air Conditioning Guide 1938 . PROBLEMS IN PRACTICE 1 The heating capacity of an indirect water heater is 100 gal per hour, using steam at 215 F and raising the water from a temperature of 50 to 150 F. Deter mine the heating capacity of the same water heater using water at a tem perature of 180 F for the heating medium. Using Equation 1, and because the surface area of the water heater is the same for each condition, the two conditions may be equated as follows: 100 X 8.33 (150 - 50) Q X 8.33 (150 - 50) 240 [215 - (150 2+ 50)] " 100 [180 - (15 2+ ] Q -- 28.98 gal per hour, capacity of heater using water at a temperature of 180 F. 2 Why is it impractical to size water supply piping so pipe friction will pro duce an equal pressure on each fixture? . . Because the friction would be built up only in periods of maximum flow and at all other times it would be only a fraction of that required. 3 f What is the purpose of zoning water supply systems in tall buildings? To avoid excessive pressures in the lower stories. 4 # Define the maximum possible flow, the maximum probable flow, and the average probable flow. ' '' The maximum possible flow is the flow which would occur if all of the outlets on the system were opened at one and the same time. The maximum probable flow is the flow which will occur with probable peak conditions. The average probable flow is the flow likely to occur under a normal condition of use. . 5 # What is the factor of usage? This is the percentage of the maximum possible flow which is likely to occur at peak load. 6 9 How many feet higher than the uppermost fixtures must the water line in a house tank be to provide about 15 lb per square inch pressure at the fixture outlet? Allowing for pipe losses, about 45 ft. 7 9 What methods of hot water circulation commonly are employed with hot water supply systems? a. Up-feed risers with returns having no connections paralleling the risers. b. Up-feed risers with returns in other locations, and with connections taken off both supply and return. . .. . c. One main up-feed riser, without connections, supplying all down-feed risers for all fixtures. 8 9 Which method of hot water supply generally is the most satisfactory? The single main up-feed riser supplying drop risers for all fixtures. 9 9 How much of the water stored in a hot water storage tank really is available for use? . About 75 per cent, because when only 25 per cent of the original water remains in the tank it has been so cooled down by the entering water that it is too cold for satisfactory use.10 10 # In cases of intermittent demand, does a large hot water storage tank increase or decrease the steam load for water heating? It decreases the steam load in cases of intermittent demand but causes no change in the steam load if the demand is constant. . 806 Chapter 44 TEST METHODS AND INSTRUMENTS Pressure Measurement, Temperature Measurement, Air Move ment, Humidity Measurement, Carbon Dioxide Determina tion. Dust Determination, Flue Gas Analysis, Measurement of Smoke Density, Heat Transmission, Eupatheoscope . SEVERAL types of measuring apparatus are available for accurately determining the thermal capacity and air movement of gaseous vapors and homogeneous materials. This chapter gives a.brief description of the principal instruments used in connection with the proper control and testing of heating and air conditioning installations. TEST METHODS The Society has adopted standard test methods or codes for testing and rating most heating, ventilating and air conditioning equipment. A list of the titles of these test codes may be referred to on pages 839 and 840. Many of the test instruments required are specified and des cribed in these codes. PRESSURE MEASUREMENT Atmospheric pressure is usually measured by a mercurial barometer which, in its simplest form, consists of a glass tube about 3 ft long, closed at the upper end, filled with mercury and inverted in a shallow bath of mercury. The pressure of the atmosphere on the exposed top of the mer cury in the cistern supports a column of mercury in the tube to a height of about 30 in. Readings are taken of the height of the column between the levels of mercury in the tube and in the cistern. Atmospheric pressure is the same as the pressure exerted by this supported column of mercury, and, in pounds per square inch, is equal to its height in inches times 0.491, which is the weight in pounds of 1 cu in. of mercury at 32 F. At latitude 45 deg and sea level, and at a temperature of 32 F, the atmosphere will support a column of mercury 29.921 in. in height. The pressure of 14.7 lb per square inch, derived by multiplying 29.921 by 0.491, is called standard or normal barometric pressure. Since the height of the barometer depends on the density of the mercury as well as on the pressure of the atmosphere, and since the density is dependent on the temperature, mercurial baro meter readings should always be corrected for temperature. 807 Heating Ventilating Air Conditioning Guide 1938 The following equation may be used to make corrections for temperature: h -- h[l -- 0.000101 (f, - I)] (1) where h = height of mercury column corrected to temperature t, inches. hi = actual height of mercury column, inches. . ti = actual temperature of mercury column, degrees Fahrenheit. t = temperature to which column is to be corrected, degrees Fahrenheit. Atmospheric pressure may also be measured by means of an aneroid barometer. In this instrument atmospheric pressure is made to move an indicating pointer either by bending the thin corrugated top of a partially exhausted metallic box, or by distorting a bent, thin-walled metal tube. The aneroid barometer contains no liquids, is portable but is less accurate than the mercurial barometer. Pressures above or below atmospheric are usually measured by means of gages which indicate the difference between the pressure being measured and atmospheric pressure at the same time and place. A gage which indicates pressures higher than atmospheric is known as a pressure gage, and a gage which indicates pressures lower than atmospheric is known as a vacuum gage. The most common type of these gages contains a flexible hollow metal tube of oval cross section, known as a Bourdon tube. When subjected to unequal inside and outside pressures, this tube tends to straighten out, and a pointer motivated by this straightening indicates the pressure difference on a suitable graduated scale. High vacuum readings such as are encountered in condenser and steam jet refrigeration practice are commonly obtained by the use of mercury column vacuum gages. When the readings obtained with the mercurial barometer and those with the mercury vacuum gage have both been corrected to 32 F, the difference in the two readings will give the absolute vacuum in inches of mercury. Equation I may be used to make cor rections for temperature. In the measurement of small pressure differences, the U tube in one of its many forms is convenient, inexpensive and it may be built for any desired degree of accuracy. U tube manometers may be fabricated from glass and rubber tubing or any of the numerous commerical forms may be used. A gage which indicates pressures slightly above or below atmospheric is known as a draft gage. It is essentially a U tube containing either water, kerosene, alcohol, or mercury, with one leg exposed to the air and the other connected to a point where the pressure is to be determined. When the pressure being read is equal to atmospheric, the level of the liquid in the legs will be the same, indicating a zero gage pressure. When a pres sure is applied to one leg, one side will fall and the other will rise an equal amount. The difference in height between the two liquid levels indicates the pressure expressed in inches of liquid used in the gage. Various forms of high sensitivity draft gages1 frequently called micro manometers* are available for the measurement of small pressure differen 1Fluid Velocity and Pressure, by J. R. Pannell (Edvard Arnold and Co., London, 1924). 'Illinois Micromanometer, University of Illinois (Engineering Experiment Station Bulletin No. 120, p. 91). 808 Chapter 44. Test Methods and Instruments tials and may be sensitive to pressures as small as 0.001 in. of water. These gages are often useful where measurements are to be made on pressure differentials less than 0.1 in. of water, although their total range may extend as high as 5 to 10 in. of water. TEMPERATURE MEASUREMENT In engineering work, thermometers are largely employed to measure the intensity of heat. Those most commonly used are liquid-in-glass ther mometers. Mercury and alcohol are the liquids most frequently used. Mercurial thermometers depend on the uniform expansion of mercury to indicate changes in temperature. An'amount of mercury held in a sealed tube with a bulb at one end will rise to one definite level when immersed in melting ice, and to another definite level when immersed in boiling water. These two points are marked, and the space between them is divided into a number of equal portions, each of which-is called a degree. In the Fahrenheit scale, there are 180 deg thus obtained, while the centi grade scale has 100 and the Reaumur has 80. Like divisions are marked off on the column above and below these two determined points in order that a greater range of temperature may be read. Mercurial thermometers may be used in a temperature range from --40 to +932 F. Alcohol thermometers are similar in construction to mercurial thermo meters but are useful in a lower temperature range ( -- 94 to +248 F). Industrial thermometers in a large number of designs are available, but for test purposes etched stem thermometers are most frequently used. The etched stem thermometer has greater sensitivity and less lag than most industrial thermometers. ` For precision temperature measurements, it is necessary to correct the thermometer reading for emergence of the stem if any part of the mercury column is exposed to a temperature other than that being measured (unless the thermometer has been calibrated under like conditions). The emergent stem correction may be calculated by the following equation: _ ... where K = 0.00009 D {h - h). K = correction to be added, degrees Fahrenheit. D = length of emergent stem, degrees Fahrenheit on thermometer stem. <i = temperature indicated on the thermometer, degrees Fahrenheit. ii = temperature of exposed mercury stem, degrees Fahrenheit. (2) Thermocouples* may be used to measure any range of temperatures up to 2,900 F. When two dissimilar metals are joined at two points and a temperature difference exists between these junctions, an electromotive force will be developed. Its magnitude depends on the character of the metals and the difference in temperature between the junctions. A poten tiometer or sensitive galvanometer of high resistance connected to the thermocouple will give a deflection which is a function of the temperature difference between the hot and cold junctions. Thermocouples con- 'Study of the Application of Thermocouples to the Measurement of Wall Surface Temperatures, by A. P. Kratz and E. L. Broderick (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 55). 809 Heating Ventilating Air Conditioning Guide 1938 nected in series are called thermopiles. Thermocouples for the measure ment of high temperatures are calibrated with the aid of the known melting points of pure metals. ' Resistance thermometers are suitable for temperature measurements up to 1800 F. These thermometers depend for their operation on the change of resistance with temperature of a platinum, nickel, or copper wire coil, and they are calibrated in the same way as thermocouples. Pyrometers of various types may be used, for temperatures above 500 F. The mercurial pyrometer is a thermometer'with' an inert gas, such as nitrogen or carbon dioxide, above the mercury column to prevent the mercury from boiling. The radiation pyrometer 'consists of a thermopile upon which the radiation from a hot source is focused by aeoncave mirror or lens. A sensitive galvanometer or potentiometer with a calibrated, temperature scale indicates the thermo-electromotive force created by the heat on the thermopile. The optical pyrometer measures radiant energy by comparing the intensity of a narrow spectral band, usually red light emitted by the object, with that emitted by a standard light source (electric lamp). Thermo-electric pyrometers operate on the same principle as thermocouples. When measuring high temperatures, it is customary to ; hold the cold junction at room temperature and this may cause some error' if the room temperature is above or below the calibration point. For extremely precise temperature measurements, the cold junction is usually- immersed in melting ice to fix the cold junction temperature. Various forms of hand-operated and automatic cold junction temperature com pensators are also available. ' . In the. measuring of room temperature care must be exercised to pre vent the results from being affected by the'body heat of the observer, by air currents from doors, windows and other openings, or by radiant heat from some local source such as a radiator or wall. All glass thermo meters should be mercury thermometers with engraved stems. The total graduations of the thermometers should-be from 20 to 120 F, in one degree graduations. No ten degrees should occupy a space-of less than one-half inch. The accuracy throughout the whole scale must be within one-half degree. The operator should take hold of the top and no part of the body, including the hand, should be hearer than 10 in. to the bulb. The ther-" mometer should not be closer than 5 ft to any door, window, or other opening; should not be closer than 12 in, to any wall; and should be between 3 and 5 ft from the floor.' A sling instrument should be used for extreme accuracy.. Thermocouples or resistance thermometers may also be used for room temperature measurements, an advantage being that the operator can read temperatures from outside the room if desired, and thus eliminate the errors which might be caused by his presence close to the temperature measuring device. . . For measuring duct temperatures a duct thermometer should be used, with the bulb extending into the duct at least 6 in. When the thermo meter is to be permanently located in the duct, a pipe flange or nipple should be used to receive the threaded portion of the thermometer stem. When the thermometer is not to be permanently located, a cork or rubber stopper may be placed around the stem to prevent errors from air leakage. Readings should be taken at various locations , in. a duct so .due con sideration may be given to temperature stratification. Other forms of 810 Chapter 44. Test Methods and .Instruments. temperature measuring devices may be used, but the active part must be at least 6 in. from the duct wall. . Recording instruments may be used for testing and for making con tinuous records of operation. Potentiometer and Wheatstone bridge recorders for thermocouples and resistance thermometers respectively may have accuracies of =*= per cent of their range, or, for example, to =*= 1 F in a range of 0 to 300 F. This accuracy compares favorably with that of other forms of temperature measuring devices. . . AIR MOVEMENT MEASUREMENT The quantify, velocity and pressure of air moved by a fan or flowing through a duct or grille may be determined by various methods. The instruments in common use are the Pitot, tube, anemometer, direct reading velocity meter, and Kata-thermometer, the latter being suitable for low air velocities and being commonly used for measurements at points where the air is not confined in a duct. Electrical anemometers are also available, operating on the principle of measurement of the variation of resistance of a hot wire cooled to various degrees by air velocities past the wire! The use of calibrated nozzles, orifice plates, and Venturi meters are recognized methods,; which, however, have little application in con nection with ventilation practice. - - Pitot Tube ' .- i '. . .. This usually consists of two tubes, one within' the other, which when properly held in the air stream will register the .total or impact pressure and the static pressure, respectively. If these tubes are connected to opposite sides of a draft gage, or other type of U tube, the recorded pres sure will be the differential or velocity pressure. Volume measurements may thus be made in a duct of known area. Pitot tube measurements are preferably used for air velocities exceeding 20 fps. Volumetric determi nations from Pitot tube readings should take into account the barometric pressure and the temperature and humidity of the air measured. Air flow in ventilation practice is generally in the turbulent range. When stratification of velocity, vortex motion, or violent eddy currents of air in ducts exist, accurate velocity pressure measurements are difficult. To insure accuracy a straight section of duct from 5 to 10 times its own diameter is desirable in order to straighten out the air currents. If it is necessary to take Pitot tube readings in shorter sections of straight duct, the results must be considered subject to some doubt and checked accor dingly. For accurate work it is necessary to make a traverse of the duct, dividing its cross section into a number of imaginary equal areas and taking a reading in the center of each, the average of the velocities cor responding to these pressures giving the true velocity in the duct. A pitot tube of standard design and the traverse method of obtaining average velocity are completely described in the A.S.H.V.E. Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers.4 For precise work the shape, size and calibration of the pitot tube are important considerations in the determination of the correct air flow. <A.S.H.V.E. Transactions. Vol. 29. 1923. p. 407. Amended June. 1931. 811 Heating Ventilating Air Conditioning Guide 1938 Extensive test results comparing the characteristics of several pitot tube types are available in the published reports5 of the government. Anemometer The vane-type anemometer is most frequently used for test work. It consists of a small, delicate, fan-like rotor connected to a revolution counter. The instrument is held in the air stream where the velocity is to be measured. It is calibrated to read directly in linear feet. The velo city in feet per minute is obtained by dividing the reading (linear feet) by the elapsed time, in minutes. The vane anemometer is delicate, requires frequent calibration and is suited only to low velocities (less than 3000 fpm). The vanes of the instrument should never be touched. The following procedure for obtaining anemometer readings is based on research conducted at Armour Institute of Technology in cooperation with the A.S.H.V.E. Research Laboratory5, Supply Grilles. The surface of the grille should be marked off into a number of equal areas approximately 6 in. square. A 4-in. anemometer should be used and should be held at the center of each section in contact with the grille (or as close as possible) for a period of time sufficient to insure an average reading. In the case of supply grilles, the instrument should always be held with the dial facing the operator. The average of the corrected readings should then be used in the following formula to obtain the flow in cubic feet per minute: where A + a CVA (1 + p) cfm = CV 2 or 2 (3) V = average of corrected anemometer readings, feet per minute. . A = gross area of grille, square feet. a = net free area of grille, square feet. . 'P = percentage of free area of grille expressed as a decimal. C = a coefficient that varies with the velocity from grille and may vary slightly with type of grille. For average use, with supply grilles, C can be taken as 0.97 at velocities from 150 to 600 fpm, and as 1.00 at higher velocities. . Particular care should be exercised in the case of long, narrow grilles. The nature of the approach sometimes results in there being a narrow strip along the top or bottom of the grille through which no air will be flowing. This may be detected by holding the anemometer completely out of the air stream and then moving it slowly inward over the grille until the vanes just start to move. The distance which the vanes extend over the grille opening at this moment will indicate the width of the dead strip. Only the remaining portion of the grille should be considered in making the calculations for gross and free area. Exhaust Grilles. The surface of the grille should be marked off and readings taken in the same manner as with supply grilles, except that the instrument should be held with the dial facing the grille, and in contact with it. The traverse should be taken at a uniform rate, allowing suf- Technical Notes No. 646, Notional Advisory Committee for Aeronautics, November, 1935. Measurement of the Flow of Air through Registers and Grilles, by L. E. Davies (A.S.H.V.E. Trans actions, Vol. 36. 1930, p. 201; Vol. 37, 1931, p. 619, and Vol. 39, 1933, p. .373). ... * 812 . Chapter 44. Test Methods and Instruments ficient time in each space to minimize the percentage of error. In the case - of exhaust grilles it is found that the formula: ! in which cfm = KVA (4) V = average indicated velocity obtained by the anemometer traverse. A = gross area of grille, square feet. . K -- coefficient determined by experiment. For average use, with exhaust grilles, K may be taken as 0.8 for all usual velocities. This formula is of advantage, especially with ornamental grilles, in that the free area need not be measured. . The flow of air through registers and grilles is of considerable impor tance, being frequently the only convenient method of measuring the volume of supply air to a room. While duct measurements, if available, are more dependable, grille measurements provide a fairly accurate method, if care is taken in the technique of using the anemometer. Direct Reading Velocity Meter . An instantaneous direct reading air velocity instrument available in a portable case is used for .recording air movement on a calibrated scale. Air entering the meter actuates a vane movement to which is attached a pointer with control hair springs and a magnetic damping arrangement. Velocity meters are available in either orifice, shutter or tube types. The orifice unit is used where the instrument can be placed in the air stream when obtaining a reading such as in rooms or large spaces or at unrestricted outlets of ducts. The use of the shutter type is similar to the orifice style except that it has means for changing the scale range. The shutter is adjusted so that the large ports are fully open for low velocity readings. For high range readings the shutter is turned until the large openings are closed and only a small port is open. The shutter is omitted in the tube type of meter and in place of this fitting a tube attachment is threaded to the case. A flexible rubber tube and specially designed metal jets are used for obtaining high range readings. Jets may be secured for unusual applications such as in obscure locations, surging air currents or leakage from ducts and similar requirements. Due to the connecting tube flexibility, the jet can be moved as required while the instrument is held stationary. Where it is desired to obtain air velocity readings within a duct, special jet and additional meter fittings are used which indicate directly the true air velocity with no corrections being essential for static pressure conditions. Air enters the meter through one side of the jet and is discharged back into the duct through the other side of the jet. , i \ ; . Kata-Thermometer The Kata-thermometer can be used to determine air velocities pro vided the walls and surrounding objects are at or near the room tern- perature. Especially at low velocities it constitutes a useful instrument for readily detecting drafts. - ______ --- . 8X3 Heating Ventilating Air Conditioning Guide 1938 The instrument is essentially an alcohol thermometer with a bulb approximately % in. in diameter and Y2 in. long with a stem 8 in. long reading from 100 F to 95 F, graduated to tenths of a degree. To take readings the bulb is heated in water until the alcohol expands and rises into a top reservoir. The time in seconds required for the liquid to fall from 100 F to 95 F is recorded .with a stop watch and this time, is a measure of the rate of cooling. The. dry Kata loses its heat by radiation and by convection so for constant velocities the time of cooling is a function of the dry-bulb tem perature of the surrounding air. The wet Kata, which has a cloth covering fitted snugly around its bulb, loses heat by radiation, convection, and evaporation, and for constant velocities its rate of cooling is a-function of the wet-bulb temperature of the air irrespective, of the dry-bulb tem perature or relative humidity. It does not follow, however, that the difference in rate of cooling of the dry and the wet Kata is caused by evaporation. A change in the wet-bulb temperature produces a change in the surface temperature of the wet Kata which in. turn affects the heat lost by radiation and by convection. Several precautions should be taken to obtain the best results with this instrument: . \ .1. '.To obtain velocity readings use the dry Kata since the error in timing is reduced. 2. The instrument should be heated and allowed to cool two or three times before recording the final time of cooling. The first reading is not reliable. 3. All traces of moisture must be removed from the dry Kata before timing to eli minate error introduced by evaporation. ' 4. Use only the formula applying to a particular instrument. Each Kata receives an individual calibration. HUMIDITY MEASUREMENT The sling psychrometer is the recognized standard instrument for determining humidities. In order to obtain accurate readings considerable skill is required on the part of the operator. The wicking and water must be.clean and the temperature of the water should be slightly above the wet-bulb temperature of the surrounding air. The psychrometer should be swung rapidly and several and frequent observations should be made to see that the wet-bulb temperature has become stationary before the final reading is noted. Care should be taken that the wet-bulb has reached, a minimum temperature, but. the wick must still be moist. Standard psychrometric tables should be used7. In making wet-bulb measurements below .32 F the same procedure is followed as above 32 F. The water is liquid at the start, but as the sling is operated it will freeze rapidly enough so that in quickly giving up the latent heat of fusion, the indicated wet-bulb temperature may drop below the actual wet-bulb temperature. After the liquid on the bulb has become thoroughly frozen the wet-bulb temperature will rise to normal. A very thin film of ice is more desirable than a thick film. Care must be. taken to read the temperatures in the region below 32 F accurately because the spread between the wet- and dry-bulb is small. ' 'Psychrometric Tables for Vapor Pressure, Relative Humidity, and Temperatures of the Dew Point; U. S. Department of Agriculture, Weather Bureau, Washington. D. C. S14 Chapter 44. Test Methods and Instruments .. : In taking humidity readings in ducts it is usually impracticable to use a sling psychrometer. For this work the stationary hygrodeik arranged for bolting on to the side of. the duct, with two bulbs extending into the duct, will be found very convenient. Owing to the velocity of the air' passing over the bulbs within the duct an accurate reading will be secured, corresponding to that given by the sling psychrometer. . . ' Various forms of humidity recorders are available, some merely re cording wet- and dry-bulb" temperatures, and others recording relative humidity directly. Any form of wet- and dry-bulb device must have sufficient air velocity over the thermometer bulbs to insure accurate readings; this velocity should be secured by a fan if the air is not itself in' motion. A minimum velocity of 900 fpm is usually recommended but velocities from 300 to 1000 fpm have been found suitable.under favorable: conditions8. For extremely low humidities, or for humidity measure ments above 212 F, a thermal conductivity method is available9. CARBON DIOXIDE DETERMINATION 10 . At ordinary concentrations carbon dioxide is not harmful. The amount of carbon dioxide in the air is a convenient index of the rate of air supply, and of the distribution of the air within rooms. Unequal carbcjn dioxide concentrations in parts of a room indicate improper air distribution. The Petterson-Palmquist apparatus has been generally accepted as the standard device for the determination of carbon dioxide in air investigaitions. The principle involved is the measurement of a given volume ,`af air, the absorption of the contained carbon dioxide in a caustic potash solution, and the remeasurement of the volume of air at the original pressure in a finely graduated capillary tube, the difference in volume representing the absorbed carbon dioxide. (See Report of Committee on Standard Methods for Examination of Air, American Public Health Asso ciation, Vol. 7, No. 1; American Journal of Public Health, Jan., .1917.) A thermal conductivity method may also be used to measure carbon dioxide in air over a range of 0 to 1.5 per cent11.. ' ' ', ' Where field conditions are such that this apparatus may not be con veniently" "used, as in street cars,, air samples may be collected in clean bottles having mercury-sealed rubber stoppers, and these may be sub jected to laboratory analysis. .. DUST DETERMINATION Many laboratory methods have been developed to measure the dust in the air. These involve the collection of dust on sticky plates, on filter paper, in water, on porous crucibles, or by electric precipitation, and the subsequent determination of the amount of dust by microscopic counting;; weighing, or titration. While there is no standard method, the Hill. Discussion, W. H. Carrier and C. O. Mackey (A.S.M.E. Transactions, Vol, 59, No. 6, August. 1937, p. 528-30). . ,. Gas Analysis by Measurement of Thermal Conductivity, bv H, A. Daynes {Cambridge Press, 1933). `Indices of Air Changes and Air Distribution, by F. C. Houghten and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 261). . . ..................- "Loc. Cit. Note 9. 815 Heating Ventilating Air Conditioning Guide 1938 dust-counter, using a microscope, the impinger12, using chemical changes in water, and the Lewis sampling tube13, involving the analytical weighing of a porous crucible, are accepted. All test results should be accompanied by the name of the instrument used as great variation in counts with the . different instruments will be obtained. The Society has developed a code14 for the testing and rating of air cleaning devices used in general ventilation work. FLUE GAS ANALYSIS The analysis of flue gases by chemical means is made with the Orsat apparatus. A solution of KOH is used to absorb the COj. Free oxygen is absorbed by a mixture of pyrogallic acid and KOH. The solution for absorbing the CO is cuprous chloride. The apparatus consists of a burette surrounded by a water jacket, to receive and measure the volume Fig. 1. Ringelmann Smoke Chart of gas. The burette is connected by a manifold of glass to pipettes con taining liquids for absorbing COi, Ot and CO. Various forms of automatic indicating and recording gas analysis devices are available, operating on either chemical or physical principles. Such devices are convenient for plant operation. MEASUREMENT OF SMOKE DENSITY Relative smoke density is usually measured by comparison with the Ringelmann Chart (Fig. 1). In making observations of the smoke issuing from a chimney, four cards'ruled like those in Fig. 1, together with a card printed in solid black and another left entirely white, are placed in a horizontal row and hung at a point 50 ft from the observer and con veniently in line with the chimney. At this distance, the lines become invisible, and the cards appear to be of different shades of gray, ranging from very light gray to almost black. The observer glances from the smoke coming from the chimney to the cards, which are numbered from 0 to 5, determines which card most nearly corresponds with the color of "Public Health Bulletin. No. 144. 1925, V. S. Public Health Service. ' "Testing and Rating of Air Cleaning Devices Used for General Ventilation Work, by Samuel R. Lewis (A.S.H.V.E. Transactions, Vol. 39, 1933. p. 270). "A.S.H.V.E. Standard Code for Testing and Rating Air Cleaning Devices Used in General Ventilation Work (A.S.H.V.E. Transactions, Vol. 39. 1933, p. 225). 816 Chapter 44. Test Methods and Instruments the smoke, and makes a record accordingly, noting the time. Observa tions are made continuously during one minute, and the estimated average density during that minute recorded. The average of all the records made during a boiler test is taken as the average figure for the smoke density during the test, and the entire record is plotted on cross-section paper in order to show how the smoke varied in density from time to time. Smoke recorders are available which give a much more accurate in dication of the amount of smoke being produced than does the Ringel mann Chart. They all depend upon projecting a beam of light through the smoke flue or through a separate compartment from which a sample of the flue gas is drawn continuously. The light of the beam which passes through without being absorbed by the smoke is measured to determine the smoke density. Most of these instruments make use of a photo electric cell or a thermopile to measure the relative amount of light which has not been absorbed. Standard electrical instruments serve for in dicating or recording. MEASUREMENT OF RATE OF HEAT TRANSMISSION The standard methods of testing built-up wall sections are by means of the guarded hot-box15 and the guarded hot-plate16. The Nicholls heat-flow meter may be used for testing actual walls of buildings. It would be obviously impossible to determine the air-to-air heat trans mission coefficients of every type of wall construction in use with the heat-flow meter, the guarded hot-box or the guarded hot-plate on account of the great amount of time involved. Hence, the method of computing the coefficients from the fundamental constants must be resorted to in most cases. The guarded hot-plate is used to determine the fundamental constants. The heat-flow meter, guarded hot-box and guarded hot-plate tests can be used to good advantage in checking the accuracy of the computed values. If the hot-box or hot-pl^te methods are used, tests are usually run under still air conditions, which means there is no wind movement over the surfaces of the wall during the test. In the hot-plate method of test the inside surface coefficient is eliminated by the plates being in direct contact with the wall. In practice, some wind movement over the exterior surface of the wall should always be allowed for; hence, still-air coefficients cannot be used over the outside of the building during the heating season. Moreover, still-air transmission coefficients cannot be corrected to provide for moving-air conditions by applying a single constant factor. Computed coefficients of transmission for various types of construction are given in Chapter 5. . EUPATHEOSCOPE The eupatheoscope affords a means of evaluating the combined effect of radiation and convection in a given environment in terms of a standard environment and in some terms related to human comfort. See Chapter 41. "Standard Code for Heat Transmission through Walls (A.S.H.V.E. Transactions, Vol. 34 1928 d 253) and Report of the Committee on Heat Transmission, National Research Council. ' .. Heat Transmission in Building Structures and a Heat Transmission Meter, by P. Nicholls (A.S.H.V.E. Transactions, VoL 30, 1924, p. 65). . * 817 Heating Ventilating Air Conditioning Guide 1938 / PROBLEMS IN PRACTICE 1 The hand on a pressure gage attached to a steam line indicates a pressure of 15 lb per square inch and the barometric pressure is 14.7 lb per square inch. What is the. absolute pressure, in pounds per square inch, being exerted by the steam? * The absolute pressure exerted by the steam in the pipe is equal to the pressure indicated by the gage plus that exerted by the atmosphere. - - . Total pressure - 15 + 14.7 = 29.7 lb per square inch. . \ . 2 What is the corrected barometric pressure of the atmosphere at 32 F when a mercurial barometer reading of 29.51 in. Hg, is determined in a room having a temperature of 91 F? Substitute in Equation 1. h = 29.51 [1 -- 0.000101-(91 -- 32)]. h = 29.33 in. Hg. . 3 Outline the procedure to be followed in taking room temperatures. In taking room temperatures, a standard mercury thermometer should be used, with care taken that no part of the .observer's body is nearer than 10 in. to the thermometer bulb. The thermometer should be held at least 5 ft away from any window, door or opening; it should be at least 12 in. away from any wall, and should be between 3 and 5 ft from the floor. .. 4 What advantages other than its sensitiveness, has the U tube draft gage or manometer for measurement of low pressures? . Inherent accuracy without calibration and low cost of the essential parts, which are glass tubing and an ordinary scale. 5 Are thermocouples as accurate as mercury thermometers? Within the range which can be measured with both instruments (below 1000 F) either one may be made as sensitive as the service requires. The accuracy of a thermocouple temperature measurement depends chiefly on: (1) an accurate calibration of the wire, (2) the sensitiveness, of the electrical instrument, (3) accurate cold-junction control, and (4) proper placement of the sensitive junction. . 6 When an anemometer is used for measuring the air discharged from a grille or register, does it read the velocity through the gross face area or the velocity through the net free-area? Neither. If either of these velocities is required, it should be calculated by means of Equation 3. 7 Do common errors made in humidity determination produce a result that is too high or too low? ^ A higher relative humidity than the true value is likely to be found, either because there is insufficient velocity over the wet-bulb or because the reading is not taken at the right time. . 8 t What is the purpose of the carbon dioxide determination? It is an index of the adequacy of fresh air supply and also an indicator of air distribution. .818 Chapter 45 TERMINOLOGY Glossary of Physical and Heating, Ventilating and Air Condi tionihg Terms Used in the Text, Standard Abbreviations, Conversion Equations, Drafting Symbols, A.S.H.V.E. Codes . Absolute Humidity: See Humidity. Absolute Pressure: The sum, at any particular time, of the gage pressure and the atmospheric pressure. Absolute Temperature: The temperature of a substance measured above absolute zero. . ' Absolute Zero: The temperature (--459.6 F) at which the molecular motion of a substance theoretically ceases. This is the temperature at which the substance theoretically contains no heat energy. . Acceleration:. The rate of change of velocity. . In the fps system this is expressed in units of one foot per second per second. .V a =-- Acceleration Due to Gravity: The rate of gain in velocity of a freely, falling body. In the fps system this is 32.174 ft per second per second. Adiabatic: An adjective pertaining to or designating variations in volume or pressure not accompanied by gain or loss of heat! When a substance undergoes adiabatic expansion, since it does not receive heat from without, the work which it does is at the expense of its internal energy, and therefore its temperature falls; similarly, when it is adia- batically compressed its temperature rises. . Adsorption: The adhesion of the molecules of gases or dissolved sub stances to the surfaces of solid bodies, resulting in a concentration of the gas or solution at the place of contact. . . ^*r Cleaner: A device designed for the purpose of removing air-borne impurities such as dusts, fumes and smokes. (Air cleaners include air washers and air filters.) / , ' Air Conditioning: The simultaneous control of all or. at least the first three of those factors affecting both the physical and chemical conditions of the atmosphere within any structure.- These factors include tempera ture, humidity, motion, distribution, dust, bacteria, odors, toxic gases, and ionization, most of which affect in greater or lesser degree, human health or comfort.. ... , - . . ... -; . 819 Heating Ventilating Air Conditioning Guide 1938 Air Infiltration: The inleakage of air through cracks and crevices, and through doors, windows and other openings, caused by wind pressure or temperature difference. Air Inlet and Air Outlet: Used to designate that point or location in an air handling device or system where air enters or leaves. These terms are misleading and meaningless standing by themselves; must be accompanied by other words to designate location, space, or device which the air is entering or leaving. Thus, air inlet to a room may be opening in end of a duct leading from the air outlet of a fan. Air Washer: An enclosure in which air is forced through a spray of water in order to cleanse, humidify, or dehumidify the air. . Anemometer: An instrument for measuring the velocity of moving air. Atmospheric Pressure: The pressure exerted by the atmosphere in all directions, as indicated by a barometer. Standard atmospheric pressure is considered to be 14.7 lb per square inch, which is equivalent to 29.92 in. of mercury. Baffle: A plate or wall for deflecting gases or fluids. Blast: This word was formerly used to denote forced air circulation, particularly in connection with central fan systems using steam or hot water as the heating medium. As applied in this sense, the word blast is now obsolete. . Boiler: A closed vessel in which steam is generated or in which water is heated. Boiler Heating Surface: That portion of the surface of the heattransfer apparatus in contact with the fluid being heated on one side and the gas or refractory being cooled on the other, in which the fluid being heated forms part of the circulating system; this surface shall be measured on the side receiving heat. This includes the boiler, water walls, water screens, and water floor. (A.S.M.E. Power Test Codes, Series 1929.) Boiler Horsepower: The equivalent evaporation of 34.5 lb of water per hour from and at 212 F. This is equal to a heat output of 970.2 X 34.5 = 33,471.9 Btu per hour. British Thermal Unit: The mean British thermal unit is^-r of the ioU heat required to raise the temperature of 1 lb of water from 32 F to 212 F. It is substantially equal to the quantity of heat required to raise 1 lb of water from 63 F to 64 F. One Btu = 3415 kwhr. By-pass: A pipe or duct, usually controlled by valve or damper, for short-circuiting fluid flow. Calorie: The mean calorie is --of the heat required to raise the temperature of 1 gram, of water from Zero C to 100 C. It is substantially equal to the quantity of heat required to raise one gram of water from 14.5 C to 15.5 C. Central Fan System:: A mechanical indirect system of heating, ventilating, or air conditioning, in which the air is treated or handled by 820 Chapter 45. Terminology equipment located outside the rooms served, usually at a central location, and is conveyed to. and from the rooms by means of a fan and a system of distribution ducts. See Chapters 21 and 22. . Chimney Effect: The tendency in a duct or other vertical air passage for air to rise when heated, owing to its decrease in density. . Coefficient of Transmission: The amount of heat (Btu) transmitted from air to air in one hour per square foot of the wall, floor, roof or ceiling for a difference in temperature of 1 F between the air on the inside and that on the outside of the wall, floor, roof or ceiling. Column Radiator: A type of direct radiator. This radiator has not been listed by manufacturers since 1926. Comfort Line: The effective temperature at which the largest per centage of adults feel comfortable. Comfort Zone (Average): The range of effective temperatures over which the majority (50 per cent or more) of adults feel comfortable. Comfort Zone (Extreme): The range of effective temperatures over which one or more adults feel comfortable. (See Chapter 3.) Concealed Radiator: A heating device located within, adjacent to, or exterior to the room being heated but so covered or enclosed or con cealed that the heat transfer, surface of the device, which may be either a radiator or a convector, does not see the room. Such a device transfers its heat to the room largely by convection air currents. Conductance: The amount of heat (Btu) transmitted from surface to surface in one hour through one square foot of a material or construc tion, whatever its thickness, when the temperature difference is 1 F between the two surfaces. Conduction: The transmission of heat through and by means of matter unaccompanied by any obvious motion of the matter. Conductivity: The amount of heat (Btu)-transmitted in one hour through one square foot of a homogeneous material 1 in. thick for a difference in temperature of 1 F between the two surfaces of the material. - Conductor (heat): A material capable of readily conducting heat. The opposite of an insulator or insulation. Constant Relative Humidity Line: Any line on the psychrometric chart representing a series of conditions which may be evaluated by one percentage of relative humidity; there are also constant dry-bulb lines, wet-bulb lines, effective temperature lines, vapor pressure lines, and lines showing other physical properties of air mixed with water vapor. Control: Any manual or automatic device for the regulation of a machine to keep it at normal operation. If automatic, it is considered that the device is motivated by variations in temperature, pressure, time,' light, or other influences. ' Convection: The transmission of heat by the circulation of a liquid or a gas such as air. Convection may be natural or forced. Convector: A heat transfer surface designed to transfer its heat to surrounding air largely or wholly by convection currents. Such a surface may or may not be enclosed or concealed. When concealed and enclosed 821 Heating Ventilating Air Conditioning Guide 1938 the resulting device is'sometimes referred to as a concealed radiator. (See also definition of Radiator. See also Chapter 14.) Corrosive: Having the power to wear away or gradually change the texture or substance of a material. . Decibel: The standard unit for noise or sound intensity. One decibel is equal to ten times the logarithm to the base e of the ratio of the sound intensities. Degree-Day: A unit, based upon temperature difference and time, used in specifying the nominal heating load in winter. For any one day there exists as many degree-days as there are degrees Fahrenheit dif ference in temperature between the average outside air temperature, taken over a 24-hour period, and a temperature of 65 F. Dehumidify: To remove water vapor from the atmosphere; to remove water vapor or moisture from any material. Density: The weight of a unit volume, expressed in pounds per cubic W foot, d = -y- . ... Dew-Point Temperature: The temperature corresponding to satura tion (100 per cent relative humidity) for a given moisture content. Diffuser: A vaned device placed at an air supply opening to direct the air flow. . ". Direct-Indirect Heating Unit: A heating unit located in the room or space to be heated and partially enclosed, the enclosed.portion being used-to heat air which enters from outside the room. . Direct Radiator: Same as Radiator. . Direct-Return System (Hot water): A hot water system in which the water, after it has passed through a heating unit, is returned to the boiler along a direct path so that the total distance traveled by the water is the shortest feasible, and so that there are considerable. differences in the lengths of the several circuits composing the system. Down-Feed One-Pipe Riser (Steam): A pipe which carries steam downward to the heating units and into which the condensation from the heating units drain. Down-Feed System (Steam): A steam heating system in which the supply mains are above the level of the heating units which they serve. Draft Head (Side Outlet Enclosure): The height of a gravity convector between the bottom of the heating unit and the bottom of the air outlet opening. . , Draft Head (Top Outlet Enclosure): The height of a gravity convector- between the bottom of the heating unit and the top of the enclosure. Drip: A pipe, or a steam trap and a pipe, considered as ai unit, which conducts condensation from the steam side of a piping system to the water or return side of the system. ; ...- . : Dry Air: Air with which no water vapor is mixed. This term is used comparatively, since.in nature there is always some water vapor included in air, and such water vapor, being a gas, is dry. ' . 822 . Chapter 45. Terminology Dry-Bulb Temperature: The temperature of the air indicated by any type of thermometer not affected by the water vapor content or relative humidity of the air. ' Dry Return: A return pipe in a steam heating system, which carries both water of condensation and air. -The dry return is above the level of the water line in the boiler in a gravity system. See Wet Return. Dust: Solid material in a finely divided state, the particles of which are large and heavy enough to fall with increasing velocity; due to gravity in still air. For instance, particles of fine sand or grit, the average diameter of which is approximately 0.01 centimeter, such as are blown on a windy day, may be called.dust. Dynamic Head or Pressure: The total or impact pressure. This is the sum of the radial pressure and the velocity pressure at the point of measurement. . Effective Temperature: An arbitrary index of the degree of warmth or cold felt by the human body in response to temperature, humidity, and movement of the air. Effective temperature is a composite index which combines the readings of temperature, humidity, and air motion into a single value. The numerical value of the effective temperature scale has been fixed by the temperature of saturated air which induces an identical sensation of warmth. . Enthalpy: Total heat or thermal potential. Entropy: A ratio, evaluated for practical purposes by dividing the heat content of a unit weight of a substance, by its absolute temperature. Useful in examining changes during a heat cycle. Entropy is constant during a reversible adiabatic change of state. Equivalent Evaporation: The amount of water a boiler would evaporate, in pounds per hour, if it received feed water at 212 F arid vaporized it at the same temperature and atmospheric pressure. " Estimated Design Load: The load, stated in Btu per hour or equiv alent direct radiation, as estimated by the purchaser for the conditions of inside and outside temperature for which the amount of installed radiation was determined. It is the sum of the heat emission of the radiation to be actuallyjnstalled plus the allowance for the heat loss of the connecting piping plus the heat requirement for any apparatus requiring heat con nected with the system. (A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers--edition of April 1932.) Estimated Maximum Load: Construed to mean the load stated in Btu per hour or equivalent direct radiation that has been estimated by the purchaser to be the greatest or iriaximum load that the boiler will be called upon to carry. (A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers--edition of April 1932.) Extended Heating Surface: See Heating Surface. Extended Surface Heating Unit : A heating unit having a relatively large amount of extended surface which may be integral with the core ' containing the heating medium or assembled over such a core, making good thermal contact by pressure or by being soldered to the core or by both pressure and soldering. An extended surface heating unit is usually placed within an enclosure and therefore functions as a convector. . 823 , Heating Venturing Air Conditioning Guide 1938 Fan Furnace System: See Warm Air Heating System. Force: The action on a body which tends to change its relative conWV dition as to rest or motion. F = ----. - gt Fumes: Particles of solid matter resulting from such chemical pro cesses as combustion, explosion, and distillation, ranging from 0.1 to 1.0 micron in size. Furnace: That part of a boiler or warm air heating plant in which combustion takes place. Also, a firepot. Furnace Volume {total): The total furnace volume for horizontalreturn tubular boilers and water-tube boilers is the cubical contents of the furnace between the grate and the first plane of entry into or between tubes. It therefore includes the volume behind the bridge wall as in ordinary horizontal-return tubular boiler settings, unless manifestly in effective (i.e., no gas flow taking place through it), as in the case of wasteheat boilers with auxiliary coal furnaces, where one part of the furnace is out of action when the other is being used. For Scotch or other internally fired boilers it is the cubical contents of the furnace, flues and combustion chamber, up to the plane of first entry into the tubes. (A.S.M.E. Power Test Codes, Series 1929.) Gage Pressure: Pressure measured from atmospheric pressure as a base. Gage pressure may be indicated by a manometer which has one leg connected to the pressure source and the other exposed to atmospheric pressure. Grate Area: The area of the grate surface, measured in square feet, to be used in estimating the rate of burning fuel. This area is construed to mean the area measured in the plane of the top surface of the grate, except that with special furnaces, such as those having magazine feed, or special shapes, the grate area shall be the mean area of the active part of the fuel bed taken perpendicular to the path of the gases through it. For furnaces having a secondary grate, such as those in double-grate down-draft boilers, the effective area shall be taken as the area of the upper grate plus one-eighth of the area of the lower grate, both areas being estimated as defined above. (A.S.H.V.E. Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers.) . '' Gravity Warm Air Heating System: See Warm Air Heating System. Grille: A perforated covering for an air inlet or outlet usually made of wire screen, pressed steel, cast-iron or plaster. Grilles may be plain or ornamental. Heat: A form of energy generated by the transformation of some other form of energy, as by combustion, chemical action, or friction. Accord ing to the molecular theory, heat consists of the kinetic and potential energy of the molecules of a substance. The addition of heat energy to a body increases the temperature or the kinetic energy of motion of its molecules {sensible heat) or increases their potential energy of position but does not increase the temperature, as when melting or boiling occurs {latent heat). ' . 824 Chapter 45. Terminology Heat Capacity: The amount of heat (Btu or calories) required to raise the temperature of a body of any mass and variety of parts one degree (Fahrenheit or centigrade). This will depend on die masses and specific heats of the various parts of the body. Therefore 5 = mi si + mt st -f- m, s,. ... etc. where S is the heat capacity and mi, mt, mi, and Ji, s,, st stand for the masses and cor responding specific heats of the parts, respectively. Heating Medium: A substance such as water, steam, air, electricity or furnace gas used to convey heat from the boiler, furnace or other source of heat or energy to the heating unit from which the heat is dissipated. Heating Surface: The exterior surface of a heating unit. Extended heating surface {or extended surface): Heating surface having air on both sides and heated by conduction from the prime surface. Prime Surface: Heating surface having the heating medium on one side and air (or extended surface) on the other. (See also Boiler Heating Surface.) Heat of the Liquid: The sensible heat of a mass of liquid above an arbitrary zero. Horsepower: A unit to indicate the time rate of doing work equal to 550 ft-lb per second or 33,000 ft-lb per minute. (One horsepower = . 745.8 watts. In practice this is considered 746 watts.) Hot Water Heating System: A heating system in which water is used as the medium by which heat is carried through pipes from the boiler to the heating units. . Humidify: To add water vapor to the atmosphere; to add water vapor or moisture to any material. Humidity: The water vapor mixed with dry air in the atmosphere. Ab solute humidity refers to the weight of water vapor per unit volume of space occupied, expressed in grains or pounds per cubic foot. Specific humidity refers to the weight of water vapor in pounds carried by one pound of dry air. Relative humidity is a ratio, usually expressed in per cent, used to indicate the degree of saturation existing in any given space resulting from the water vapor present in that space. Relative humidity is either the ratio of the actual partial pressure of the water vapor in the air to the saturation pressure at the dry-bulb temperature, or the ratio of the actual density of the vapor to the density of saturated vapor at the dry-bulb temperature. The presence of air or other gases in the same space at the same time has nothing to do with the relative humidity of the space. Humidistat: A regulatory device, actuated by changes in humidity, used for the control of humidity. Hygrostat: Same as Humidistat. . Inch of Water: A measure of pressure which refers to the difference in the heights of the legs of a water-filled manometer. Insulation {heat): A material having a relatively high heat-resistance per unit of thickness. Isobaric: An adjective used to indicate a change taking place at con stant pressure. 825 Heating Ventilating Air Conditioning Guide 1938 Isothermal: An adjective used to indicate a change taking place at constant temperature. Latent Heat: See Heat. Laws of Thermodynamics: The first law states that the total energy of an isolated system remains constant and cannot be increased or dimin ished by any physical process whatever. The second law states that no change in a system of bodies that takes place of itself can increase the available energy of a system. Manometer: An instrument for measuring pressures; essentially a U-tube partially filled with a liquid, usually water, mercury, or a light oil, so the amount of displacement of the liquid indicates the pressure being exerted on the instrument. Mass: The quantity of matter, in pounds, to which the unit of force (one pound) will give an acceleration of one foot per second per second. W. ' m = --. g' Mb, Mbh1: Symbols which represent, respectively, 1000 Btu and 1000 Btu per hour. . Mechanical Equivalent of Heat: The mechanical energy necessary to produce 1 Btu-of heat energy. J = 777.5 ft-lb. Micron: A unit of length, the thousandth part of one millimeter or the millionth of a meter. Mol: The unit of weight for gases. It is defined as tn lb where m denotes the molecular weight of a gas. For any gas the volume of 1 mol at 32 F and standard atmospheric pressure is 358.65 cu ft and the weight of a cubic foot is 0.002788 m lb. . Neutral Zone: The level within a room or building at which the pressure is exactly equal to the outside barometric pressure. One-Pipe Supply Riser (steam): A pipe which carries steam upward to a heating unit and which also carries the condensation from the heating unit in a direction opposite to the steam flow. One-Pipe System (hot water): A hot water system in which the water flows through more than one heating unit before it returns to the boiler; consequently, the heating units farthest from the boiler are supplied with cooler water than those near the boilet in the same circuit. One-Pipe System (steam): A steam heating system consisting of a main circuit in which the steam and condensate flow in the same pipe, usually in opposite directions. Ordinarily to each heating unit there is but one connection which must serve as both the supply and the return, although separate supply and return connections may be used. Overhead System: Any steam or hot water system in which the supply main is above the heating units. With a steam system the return must be below the heating units; with a water system, the return may be above the heating units. - - Panel Radiator: A heating unit placed on or flush with a flat wall surface and intended to function essentially as a radiator. 'These symbols were approved by the A.S.H.V.E., June. 1933. ' :826 Chapter 45. Terminology Panel Warming: A method of heating involving the installation of the heating units (pipe coils) within the wall, floor or ceiling of the room, so that the heating process takes place mainly by radiation from the wall, floor or ceiling surfaces to the objects in the room. Plenum Chamber: An air compartment maintained under pressure and connected to one or more distributing ducts. Potentiometer: An instrument for measuring or comparing small electromotive forces. , Power: The rate of performing work, expressed in units of horse power, one of which is equal to 550 ft-lb of work per second, or 33,000 ft-lb per minute. Prime Surface: See Heating Surface. Psychrometer: An instrument for ascertaining the humidity or hygrometric state of the atmosphere. Psychrometric: Pertaining to psychrometry or the state of the atmosphere as to moisture. Psychrometry: The branch of physics that treats of the measurement of degree of moisture, especially the moisture mixed with the air. Pyrometer: An instrument for measuring high temperatures. Radiation: The transmission of heat through space by wave motion. Radiator: A heating unit exposed to view within the room or space to be heated. A radiator transfers heat by radiation to objects "it can see" and by conduction to the surrounding air which in turn is circulated by natural convection; a so-called radiator is also a convector but the single term radiator has been established by long usage. Recessed Radiator: A heating unit set back into a wall recess but not enclosed; ; Refrigerant: A substance which produces a refrigerating effect by its absorption of heat while expanding or vaporizing. Register: A grille with a built-in. multiblade damper or shutter. Relative Humidity: See Humidity: see also discussion of relative humidity in Chapter 1. Return Mains: The pipes which return the heating medium from the heating units to the source of heat supply. Reversed-Return System (hot water): A hot water heating system in which the water from several heating units is returned, along paths arranged so that all circuits composing the system or composing a major subdivision of the system are practically of equal length. Roof Ventilator: A device placed on the roof of a building to permit egress of air. ... Saturated Air: Air containing as much water vapor as it can hold without any condensing out; in saturated air, the partial pressure of the water vapor is equal to the vapor pressure of water at the existing tem perature. ' Sensible Heat: See Heat. Smoke: Carbon or soot particles less than 0.1 micron-in size which result from the incomplete combustion of carbonaceous materials such as coal, oil, tar, and tobacco. Heating Ventilating Air Conditioning Guide 1938 Smokeless Arch: An inverted baffle placed in an uprdraft furnace toward the rear to aid in mixing the gases of combustion and thereby to reduce the smoke produced. Specific Gravity: The ratio of the weight of a body to the weight of an equal volume of water at some standard temperature, usually 39.2 F. Specific Heat: The quantity of heat, expressed in Btu, required to raise the temperature of 1 lb of a substance 1 F. Specific Volume: The volume, expressed in cubic feet, of one pound of a substance, v = -i- = ^ . Split System: A system in which the heating and ventilating are accomplished by means of radiators or convectors supplemented by mechanical circulation of air (heated or unheated) from a central point. Square Foot of Heating Surface (equivalent): Equivalent direct radiation (EDR). By definition, that amount of heating surface which will give off 240 Btu per hour. The equivalent square feet of heating surface may have no direct relation to the actual surface area. Stack Height: The height of a gravity convector between the bottom of the heating unit a'nd the top of the outlet opening. Standard Air: As defined by A.S.H.V.E. codes, standard air is air weighing 0.07488 lb per cubic foot, which is air at 68 F dry-bulb and 50 per cent relative humidity with a barometric pressure of 29.92 in. of mercury. (Most engineering tables and formulae involving the weight of air are based on air weighing 0.07492 lb per cubic foot, which is dry air at 70 F dry-bulb with a barometric pressure of 29.921 in. of mercury. The error involved in disregarding the difference between the above two weights is very slight and in most instances may be neglected). Static Pressure: The compressive pressure existing in a fluid. It is a-measure of the potential energy of the fluid. Steam: Steam is water vapor which exists in the vaporous condition because sufficient heat has been added to the water to supply the latent heat of evaporation and change the liquid into vapor. Steam in contact with the water from which it has been generated may be dry saturated steam or wet saturated steam. The latter contains more or less actual water in the form of mist. If steam is heqted, and the pressure main tained the same as when it was vaporized, its temperature will increase and it will become superheated. Steam Heating System: A heating system in which heat is trans ferred from the boiler or other source of steam to the heating units by means of steam at, above, or below atmospheric pressure. . Steam Trap: A device for allowing the passage of condensate and preventing the passage of steam, or for allowing the passage of air as well as condensate. Superheated Steam: See Steam. Supply Mains {steam): The pipes through'which the steam flows ' from the boiler or source of supply to the run-outs and risers leading to the heating units. . 828 Chapter 45. Terminology Surface Conductance: The amount of heat (Btu) transmitted by radiation, conduction, and convection from a surface to the air or liquid, surrounding it, or vice versa, in one hour per square foot of the surface for a difference in temperature of 1 deg between the surface and the sur rounding air or liquid. Synthetic Air Chart: A chart for evaluating the air conditions maintained in a room. Therm: Symbol used in the gas industry representing 100,000 Btu. Thermal Resistance: The reciprocal of conductance. Thermal Resistivity: The reciprocal of conductivity. Thermodynamics: The science which treats of the mechanical actions or relations of heat. Thermostat: An instrument which responds to changes in tempera ture and which directly or indirectly controls the source of heat supply. Ton of Refrigeration: The extraction of 12,000 Btu per hour. Ton Day of Refrigeration: The heat removed by a ton of refriger ation operating for one day; 288,000 Btu. Total Heat: A thermodynamic quantity, variously called heat con tent, thermal potential, enthalpy. It is the heat required per unit mass (Btu per pound) to raise a given substance to a given point from an arbi trary datum point. It is the sum of the heat of the liquid, the latent heat, and any miscellaneous heat which may be present. Total Pressure: The sum of the static and velocity pressures in a fluid. It is a measure of the total energy of the fluid. Tube (or Tubular) Radiator: A cast-iron heating unit used as a radiator and having small vertical tubes. Two-Pipe System {steam or water): A heating system in which one pipe is used for the supply of the heating medium to the heating unit and another for the return of the heating medium to the source of heat supply. The essential feature of a two-pipe system is that each heating unit receives a direct supply of the heating medium which medium cannot have served a preceding heating unit. Underfeed Distribution System {hot water): A hot water heating system in which the main flow pipe is below the heating units. Underfeed Stoker: A stoker which feeds the coal underneath the fuel bed. Unit: As applied to heating, ventilating and air conditioning equip ment this word means a factory-built and assembled equipment with apparatus for accomplishing some specified function or combination of functions. It is loosely applied to a great variety of equipment. Usually the function is included in the name, and hence come terms like Unit Heater, Unit Ventilator, Humidifying Unit, and Air Conditioning Unit. Units are said to be direct, or room, when intended for location, or located in, the treated space; indirect, or remote, when outside or adjacent to the treated space. They are ceiling units when suspended from above, 829 Heating Ventilating Air Conditioning Guide 1938 and floor when supported from below. Other descriptive words include free delivery when the unit is not intended to be attached to ducts or similar resistance-producing devices, and pressure when for use with such ducts. Complete description requires the use of several of these qualifying words or phrases. See Chapter 23. ' Up-Feed System {steam): A steam heating system in which the supply mains are below the level of the heating units which they serve. Vacuum Heating System: A two-pipe steam heating system equip ped with the necessary accessory apparatus which will permit operating the system below atmospheric pressure when desired. Vapor: Any substance in the gaseous state. Vapor Heating System: A steam heating system which operates under pressures at or near atmospheric and which returns the condensa tion to the boiler or receiver by gravity. Vapor systems have thermo static traps or other means of resistance on the return ends of the heating units for preventing steam from entering the return mains; they also have a pressure-equalizing and air-eliminating device at the end of the dry return. Direct Vent Vapor System: A vapor heating system with air valves which do not. permit re-entry of air. . Vapor Pressure: The equilibrium pressure exerted by a vapor in contact with its liquid. Velocity: The time rate of motion of a body in a fixed direction. In .. ` 5 the fps system it is expressed in units of one foot per second. V = --. , 't Velocity Pressure: The pressure corresponding to the velocity of flow. It is a measure of the kinetic energy of the fluid. Ventilation: The process of supplying or removing air by natural or mechanical means, to or from any space. Such air may or may not have been conditioned. (See Air Conditioning.) ' Warm Air Heating System: A warm air heating plant consists of a heating unit (fuel-burning furnace) enclosed in a casing, from which the heated air is distributed to the various rooms of the building through ducts. If the motive head producing flow depends on the difference in weight between the heated air leaving the^casing and the cooler air entering the bottom of the casing, it is termed a gravity system. A booster fan may, however, be used in conjunction with a gravity-designed system. If a fan is used to produce circulation and the system is designed especially for fan circulation, it is termed a fart furnace system or a centralfanfurnace system. A fan furnace system may include air washers and filters. ., ,. Wet-Bulb Temperature: The lowest temperature which a. water wetted' body will attain when exposed to an air current. This is the temperature of adiabatic saturation. . , ; Wet Return: That part of a return main of a steam heating system which is filled with water of condensation; . The wet return usually is below the,level of the water line in the. boiler, although not necessarily so.' See.Dry Return. .... . ., . 830, Chapter 45. Terminology . ... ABBREVIATIONS2 Absolute.................................................................. Acceleration, due to gravity . Acceleration, linear Air horseoower............................................. Alternating-current (as adjective).......... Ampere-........... .......... ................... .......... Ampere-hour._ ..................................... ............ Area........................................ ........ Average........ --................ Avoirdupois...................... Barometer.......................... Boiler pressure................. Boiling point, Brake horsepower............ Brake horsepower-hour.. British thermal unit....... Calorie............. ..............--.. Centigram......................... Centimeter.. Centimeter-gram-second (system)----- --------- -----Change in specific volume during vaporizationCubic........................ ..... ......................................... ........ Cubic foot........ ..--....................................................... Cubic feet per minute......,.................. -..................... Cubic feet per second.................. ...................--------Decibel...... ...................................... ...... _.................... Degree5...... ..............................................,...............,.__ . Degree centigrade............................... -................... . Degree Fahrenheit--......... ..................................... ... Degree Kelvin...................... ............ ..................... ..... Degree Reaumur.. Density, Weight per unit volume. Specific weight__ i-. . .' ................................-4 .......atm -------avg .....avdp ....... bar. -------- bp --------bp ------bhp -bhp-hr ....... Btu ......._cal ........ -eg ____ .cm ........ cgs ..... rig ...____cu .---CU ft ------cfm ------- cfs ..db .........deg or` ..... _.............C ............. .......F .......... ......... K .................... R ..d or p (rho) Diameter......................................... Direct-current (as adjective)__ Distance, linear.. D or diam ............. d-c .s Dry saturated vapor, Dry saturated gas at saturation pressure and temperature, Vapor in contact with liquid..................... ............................... ............................ Subscript g Entropy (The capital should be used for any weight, and the small letter for unit weight.)_____ " .5 or r Feet per minute.- ..fpm Feet per second.... ...dps Foot.________ ____ ..ft Foot-pound ..ft-lb Foot-pound-second (system)..;............................................................ .............. ........................ -dps Force, total load............ -..................................................................................... ..............................F Freezing point......................................................................................................-............................ fp Gallon.-.._...................................... ..................................................................................................... gal Gal,lons p. er minute.- ------------------------- -------- -........ .......... ....................... -................... gpm Gallons per second.................................................................... ......................................................gps Gram: --:......................................... ............----.....;........................................................ :....... .......... g Gram-calorie........................................................................ ...................1...................................... g-cal 'From compilations of abbreviations approved by the American Standards Association. Z, 10 a, c, f, and . i. As a general rule the period is omitted in all abbreviations except where the omission results in the formation of an English word. - .- - ... '' 'it is recommended that the abbreviation .for the temperature scale. F, C, K, be included in expressions for numerical temperatures but, wherever feasible, the abbreviation'for degree be omitted; as 68 F. .831 . Heating Ventilating Air Conditioning Guide 1938 Chapter 45. Terminology Head____________________________________________---------------------------------------------- :----- H or * Heat content, Total heat, Enthalpy. (The capital should be used for any weight Thermal conductivity (heat transferred per unit time per unit area, and per ' degree per unit length);;____________________________________________________________k and the small letter for unit weight)--------------------------------------------------------------- Ef or h Heat content of saturated liquid, Total heat of saturated liquid, Enthalpy of g saturated liquid, sometimes called heat of the liquid.. -hi Heat content of dry saturated vapor, Total heat of dry saturated vapor, Enthalpy of dry saturated vapor. Heat of vaporization at constant pressure.Horsepower.. hg X or Afg hp Horsepower-hour.. Inch______________ Inch-poundIndicated horsepowerindicated horsepower-hour.. _hp-hr ..in. . in .-lb -ihp ..ihp-hr Internal energy, Intrinsic energy. (The capital should be used for any weight and the small letter for unit weight.)---------------------------------------------------------------------- EE or u k = (h A -,) X Surface coefficient of heat transfer, Film coefficient of heat transfer, Individual coefficient of heat transfer (heat transferred per unit time per unit area per degree)f A f h - f. Kilogram:------------------------------------------------------------------------------------ -------------------------------- ;hg Kilowatt_______________________________ kw Kilowatthour---------------------------------------- -kwhr Length of path of heat flow, thickness.. _____ L Load, total-------------------------------------------- .W (In genera] / is not equal to k/L, where X is the actual thickness of the fluid film.) Over-all coefficient of heat transfer, Thermal transmittance per unit area (heat transferred per unit time per unit area per degree over-all)_____________ ___ ______V Mass.. Mechanical efficiency-------------------Mechanical equivalent of heat___ Melting point------------------------------Meter_____ --____________________ Micron.. Miles per hour- __7 ,,mp ..m -P (mu) ___ mph V= Thermal transmission (heat transferred per unit time) -g Minute.. Molecular weightMol_______________ OuncePower, Horsepower, Work per unit time ..mol. wt _____ mol ______ oz _______ P Thermal resistance (degrees per unit of heat transferred per unit time) R Pressure, Absolute pressure, Gage pressure. Force per unit area.. Quantity (total) of fluid, water, gas, heat; Quantity by volume; Total quantity of heat transferred.. Q R= kA Quality of steam, Pounds of dry steam per pound of mixture. Revolutions per minute. -_x ..rpm Saturated liquid at saturation pressure and temperature, Liquid in contact with vaporSubscript f Specific gravity--SP gt Specific heat------------------------------------------------------------------------------------------------------ SP ht or c Specific heat at constant pressurerp Specific heat at constant volume-- _ Thermal resistivity. ___________________________________________________________ Vaporization values at constant pressure. Differences between values for saturated vapor and saturated liquid at the same pressure Subscript f. Velocity.;_________________________________________________________________ __ y Volume (total)________________________ _____________________________ `__ !L.I--Z--!-.J_-~ V Volume per unit. time, Rate at which quantity of material passes through a m 3 flip . rllOnflhtf Af flMf - unit (*)an ntit aX Lnnt _ ---- . . ?z. f 1_ z _ Specific volume, Volume per unit weight, Volume per unit mass. Square foot----------------------------------------------------.----------------------------- -.sq ft Watthour.-----------------------------------------------------"___ 7......7...-.....-".-....-."-__ 7.7.--7...".r-whr Square inch ::____________________________________------------------------- ------------------Wsqeimgh. t of a major item, Total weight________________________________ _____......... ........ IF Temperature (ordinary) F or C. (Theta is used preferably only when t is used for Weight rate, Weight per unit of power, Weight per unit of time ________ w Time in the same discussion.)__________________________________ _______ 1 or 0 (theta) Work (total);:`________________________________________________ jy Temperature (absolute) F abs or K. (Capital theta is used preferably only when small theta is used for ordinary temperature.)---------------------------T or 0 (capital theta) Thermal conductance4 (heat transferred per unit time per degree)----------- :--------------------C kA C = 1T = X h -h Thermal conductance per unit area. Unit conductance (heat transferred per . unit time per unit area per degree)-------------------------------------------------------------------- C* r _ JL _ J_ ______L aA RA A(h - (,) . X Terms ending ivity designate properties independent of size or shape, sometimes catted specific proper- tits. Examples are--conductivity and resistivity. Terms ending cnee designate_ quantities depending not only on the material, but also upon size and shape, sometimes called total quantities. Examples are- conductance and transmittance. Terms ending ion designate rate of heat transfer. Examples are--con duction and transmission. - 832 CONVERSION EQUATIONS Fahrenheit degrees = 9/5 (centigrade degrees) + 32. . Centigrade degrees = 5/9 (Fahrenheit degrees -- 32). Absolute temperature, expressed in Fahrenheit degrees = Fahrenheit degrees + 459.6. In heating and ventilating work, 460 is usually used. ' Absotate temperature, expressed in centigrade degrees = centigrade degrees + 273.1. ' ' 833 Heating Ventilating Air Conditioning Guide 1938 Power, Heat and Work 1 ton refrigeration Latent heat of ice 1 Btu 1 watthour 1 kilowatthour 1 mean calorie . 1 kilowatt (1000 watts) 1 horsepower 1 boiler horsepower _ (12.000 Btu per hour \200 Btu per minute = 143.33 Btu per pound f 777.5 ft-lb = -I 0.293 watthours I 252.02 mean calories 2,655.2 ft-lb 3.415 Btu 3600 joules . . 860.648 mean calories ( 3,415 Btu / 3.52 lb water evaporated from | and at 212 F I 34.15 lb water raised 100 F ( 0.003968 Btu ' I 3.085 ft-lb . . I 0.0011619 watthours 56.92 Btu per minute 44,252.7 ft-lb per minute 0.746 kilowatt 42.44 Btu per minute 33,000 ft-lb per minute " 550 ft-lb per second / 33,471.9 Btu per hour \ 9.80 kwhr Weight and Volume 1 gal (U. S.) 1 British or Imperial gallon 1 cu ft .................. 1 cu ft water at 60 F 1 cu ft. water at 212 F 1 gal water at 60 F........... 1 gal water at.212. F . 1 lb (avdpj . 1 bushel 1 short ton 1 long ton Pressure 1 lb per square inch l.oz per square inch _ / 231 cu in. _ \ 0.13368 cu ft = 277.274 cu in, _ / 7.4805 gal . .. \ 1728 cu in...... : . = 62.37 lb, . = 59.76 lb' = 8.34 lb = 7.99 lb . ' ............. ; _ / 16 oz \ 7000 grains . ' = 1.244 cu ft = 2000 lb = 22401b 144 lb per square foot 2.0416 in. mercury at 62 F 2.309 ft water at 62 F 27.71 in. water at 62 F / 0.1276 in. mercury at 62 F \ 1.732 in. water at 62 F 834 .-Chapter 45.- Terminology . 1 atmosphere 14.7 lb per square inch 2116.3 lb per. square foot1 33.974 ft water at 62 F 30 in, mercury at 62 F 29.921 in. mercury at 32 F ' 1 in. water at 62 F 1 ft water at 62 F 0.03609 lb per square inch 0.5774 oz per square inch 5.196 lb per square foot , ( 0.433 lb per square inch - \ 62.355 lb per square foot ' . 1 in. mercury at 62 F Metric Units I 0.491 lb per square inch I 7.86 oz per square inch ' " ) 1.131 ft water at 62 F ( 13.57 in. water at 62 F 1 cm 1 in. 1m 1 ft 1 sq cm . 1 sq in. 1 sq m 1 sq ft 1 cu cm 1 cu in. 1 cu m 1 cu ft 1 liter 1 kg 1 lb 1 metric ton 1 gram , 1 kilometer per hour . - .' . . ' = 0.3937 in. = 2.54 cm = 3.281 ft = 0.3048 m . = 0.155 sq in. . = 6.45 sq cm , 1 = 10.765 sq ft : = 0.0929 sq m = 0.061 cu in. '=. .16.39 cu cm . , = 35:32 cu ft . = 0.0283 cu m = 1000 cu cm = 0.264 gal = 2.2046 lb = 0.4536 kg 2205 lb (avdp) , = 980.59 dynes = 0.002205 lb ; = 0.6214 mph 1 gram per square, centimeter 1 kg per square centimeter (metric atmosphere) / 0.0290 in. mercury, at 0 deg C \ 0.394 in. water, at 15 C = 14.22 lb per square inch 1 gram per cubic centimeter 1 dyne 1 joule . _ / 0.03614 lb per cubic inch 1 l 62.43 lb per cubic foot = 0.00007233 poundals _ / 10,000,000 ergs _ \ 0.73767 ft-lb ' 1 metric horsepower . _ / 75 kg-m per second ~ \ 0.986 bp (U. S.) 1 kilogram-calorie (large calorie) 1 kilogram-calorie per kilogram 1 gram-calorie per square centimeter ,. ( 1000 gram-calories (small = ( calorie) I 3.97 Btu .: = 1.8 Btu per pound . = 3.687 Btu per square foot . . 1 gram-calorie per square centimeter per centi meter = 1.451 Btupersquarefootperincb 1 gram-calorie per second per square centimeter [2903 Btu per hour per square foot [or a temperature graduation of 1 deg C per = ['for a temperature graduation of centimeter .. 11 deg F per inch of thickness. 835 Heating Ventilating Air Conditioning Guide 1938 SYMBOLS FOB HEATING. VENTILATING AND AIR CONDITIONING DRAWINGS5 1. The objects of this standard set of symbols are to insure the correct interpretation of drawings and to conserve drafting room time by establishing simple and unmistakable symbols for the component parts of the heating and ventilating systems. In preparing the list of symbols an effort has been made to follow existing practice in so far as possible but the list cannot be expected to match exactly the existing practice of every drafting room. t. General _ . . Piping 6. Air Piping * -------*----- * 2. Steam _ Piping 7. Vacuum ___ Piping . 3. Condensate _ Piping - 4. Cold Water Piping " 8. Gas Piping ---------- --------------------- 9. Refrigerant .. ,, Piping----- 1-----H------1-----+-- 5. Hot Water Piping - 10. Oil Piping ____________________ 11. Lock and Shield Valve -C^O- -okh 12. Reducing Valve 23. Indirect Radiator Plan 24. Indirect Radiator . Elevation E=3 00 13. Diaphragm Valve -da- Jj- 14. Thermostat 15. Radiator Trap Elevation 16. Radiator Trap Plan 17. Tube Radiator Plan -I 18. Tube Radiator Elevation | | P 19. Wall Radiator Plan . * i 20. Wall Radiator Elevation | | [] 21. Pipe Coil Plan i---- 1-- 25. Supply Duct, Section 26. Exhaust Duct, Section 27. Butterfly Damper Plan (or Elevation) 28. Butterfly Damper Elevation (or Plan) \ 29. Deflecting Damper Rectangular Pipe 30. Vanes 31. Air Supply Outlet 0 0 22. Pipe Coil Elevation 32. Exhaust Inlet I . From A.S.H.V.E. .Code of Minimum Requirements for the Heating and Ventilation of Buildings, edition of 1929, and American Standard Drawings and Drafting Room Practice Graphical Symbols (American Standards-Association, ZX1.2--1935), - 836 Chapter 45. Terminology 33. Joint 34. Elbow--90 deg 35. Elbow--45 deg 36. Elbow--Turned Up 37. Elbow--Turned Down Flanfcd Screwed B<0 od Spigot Welded Solknd -tf- --1-- -e- YY r YYr 44444 Ott-- Of-- ax- ox- Q-- GHf-- Gf-- o >- Gx- 0s-- 38. Elbow--Long Radius 39. Side Outlet Elbow--Outlet Down 40/ Side Outlet Elbow--Outlet Up 41. Base Elbow 42. Double, Branch Elbow 43. Single Sweep Tee 44. Double Sweep Tee 45. Reducing Elbow 46. Tee 47. Tee--Outlet Up . 48. Tee--Outlet Down 49. Side Outlet Tee--Outlet Up 50. Side Outlet Tee--Outlet Down 51. Cross ' rY 4r r j 7? U Y r Y+\pHrY X-i- -Ah r L -H0H- -xox- -*o -##- 40h *o<r -xx-. A* X-AtYY 837 Heating Ventilating Air Conditioning Guide 1938 52. Eccentric Reducer 53. Reducer 54. Lateral ,. 55. Gate Valve 56. Globe Valve 57. Angle Globe Valve 58. Angle Gate Valve 59. Check Valve 60. Angle Check Valve . 61. StopCock 62. Safety Valve \. 63. Quick Opening Valve 64. Float Operating Valve 65. Motor Operated Gate Valve 66. Motor Operated Globe Valve 67. Expansion Joint Flanged 68. Reducing Flange 69. Union 70. Sleeve 71. Bushing 838 Chapter 45. Terminology A.S.H.V.E. CODES The following codes and standards relating to the design, installation,, testing, rating, and maintenance of materials and equipment used for the heating, ventilation and air conditioning of buildings, have been adopted by the American Society of Heating and,Ventilating Engineers: Subject Air' ; Cleaning Devices Title A.S.H.V.E. Standard Code for Testing and Rating Air Clean ing Devices Used in General Ventilation. Work* When Adopted June,.1933 Reference A.S.H.V.E. Transactions, Vol. 39, 1933, p. 225 Air Purity Synthetic Air Chart June, 1917 . A.S.H.V.E. Transactions, Vol. 23, p. 607, and Tfe Guide, 1931 Boilers . (testing) Standard and Short-Form.Heat Balance Codes for Testing Low Pressure Steam Heating Solid Fuel Boilers (Codes 1 and 2) June, 1929 A.S.H.V.E. Transactions, Vol. 35, 1929, p. 322 Boilers . (testing) A.S.H.V.E. Performance .Test Code for Steam Heating Solid Fuel Boilers (Code 3) b June, 1929 Boilers-- Oil Fuel (testing) A.S.H.V.E. Standard Code for Testing Steam Heating Boilers Burning Oil Fuela June, 1932 A.S.H.V.E. Transactions, Vol. 35, 1929, p. 332 A.S.H.V.E. " Transactions, Vol. 37, 1931, p. 23 Boilers (rating) A.S.H.V.E. Standard Code for January, 1929 A.S.H.V.E. Rating Steam Heating Solid; . Revised Transactions, Fuel Hand-Fired Boilers ... April, 1930 Vol. 36, 1930, p. 42 Concealed ' "Gravity Type Radiation A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radiation (Hot .Water Section) June, 1933 A.S.H.V.E........... Transactions, Vol. 39, 1933, p. 237 Convectors A.S.H.V.E. Standard Code for Testing and Rating Coqcealed Gravity Type Radiation (Steam Code) ; January, 1931 A.S.H.V.E. Transactions, Vol. 37,1931, p. 367 Ethics. Code of Ethics for Engineers January, 1922 A.S.H.V.E. Transactions, Vol. 28, 1922, p. 6 (See frontispiece The Guide, 1938) Fans Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers May, 1923. Revised June, 1931 A.S.H.V.E. Transactions, Vol. 29, 1923, p. 407c . Garages Code for Heating and Ven tilating Garages June, 1929 Revised January, 1935 A.S.H.V.E. Trans actions, Vol. 35, 1929. p. 355 A.S.H.V.E. Reprint Reprints available. ^Originally adopted by the National Boiler and Radiator Manufacturers Association. ' eAlso. see Heating, Piping and Air Conditioning, August, 1931, p. 713. 839 Heating Ventilating Air Conditioning Guide 1938 Subject Title ' Heat Transmission Through Walls Standard Test Code for Heat Transmission through Walls3 Minimum Requirements Code of Minimum Require ments for Heating and Ventila tion of Buildings, Edition--1929 Pitot. Tube Code for Use of Pitot Tube Radiators Code for Testing Radiators3 Unit Heaters Standard Code for Testing and Rating Steam Unit Heaters3 d Unit ' Ventilators Vacuum Heating Pumps A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Ventilators3 A.S.H.V.E. Standard Code for Testing and Rating Return Line Low Vacuum Heating Pumps3 When Adopted January, 1927 June, 1925 January, 1914 January, 1927 January, 1930 June, 1932 June, 1934 Reference A.S.H.V.E. Transactions, Vol. 34, 1928, p. 253 A.S.H.V.E. Codes A.S.H.V.E. Transactions, Vol. 20, 1914, p. 211 A.S.H.V.E. Transactions, Vol. 33, 1927, p. 18 A.S.H.V.E. Transactions, Vol. 36,1930, p. 165 A.S.H.V.E. Transactions, Vol. 38, 1932, p. 25 A.S.H.V.E. Transactions, Vol. 40, 1934, p. 33 Ventilation Report of Committee on Ventilation Standards3 August, 1932 A.S.H.V.E. Transactions, Vol. 38,1932, p. 383 The following Codes and Standards have been endorsed or approved by the American Society of Heating and Ventilating Engineers : Subject Title Sponsored bt Reference Air Conditioning Equipment Standard Method of Rating and Testing Air Conditioning Equipment3 American Society of Refrigerating Engineers American Society of Refrigerating Engi neers, New York, N. Y. Chimneys Standard Ordinance for Chim National Board of Chapter 14, ney Construction Fire Underwriters The Guide, 1931 Condensing Units Standard Method of Rating and Testing Mechanical Con densing Unitse American Society of Refrigerating Engineers American Society of Refrigerating Engi neers, New York, N. Y. Piping Systems Identification . of Piping Systems* American Society Heating, Piping and of Mechanical A ir- Conditioning, Engineers ` July, 1929 Warm Air Furnaces Standard Code Regulating the Installation of Gravity Warm Air Furnaces in' Residences National Warm Air Heating and Air Conditioning Association National Warm Air Heating and A ir Con- ditioningA ssociation, Columbus, Ohio ' ^Adopted jointly by the Industrial Unit Heater Association, E. . Proposed code prepared by Joint Committee of A merican tmg Engineers, American Society of Heating and Ventilating Engineers, RefrignottTtjtrMachiiic^iJrsMciation, National Electric Manufacturers Association and Air Conditioning 'Manufact4ifffAss<mqtion&^\ ' '' ^ (Adopted^November, 1928, Sponsored by (1) Amcricdjr&&et$tfpffltchoki*A Engineers, (2) National 840 \Vo>V U 1938 jN i.'>7-----------LvV ------------------- ------ > . N"" CA TALC >G DI lTA ECTI ON Xs Heating, Ventilating Air Conditioning INDEX TO ADVERTISERS PAGE 843 INDEX TO MODERN EQUIPMENT PAGE 1165 . In this section of The Guide manufacturers of heating, 'ventilating and air conditioning equipment present their latest developments in apparatus and materials--303 pages of descrip tive data, profusely illustrated. By consistent adherence to a benefit-of-user . policy, over a period of 16 years, this Catalog Data Section has become a valuable supplement to the Technical Data Section--a dependable source of information for engineers, architects, contractors, and others in this field of industry. . Products are grouped in alphabetical arrange ment so that a specific type of equipment or material may be located readily by reference to the page headings--Boilers, Heaters, Insulation, etc.--on pages 843-848. On pages 1165-1188 is a complete Index to Modern Equipment. INDEX TO ADVERTISERS Heating, Ventilating, Air Conditioning Guide, 1938 A ' . Page Acme.Heating & Ventilating Co., The, 4224 S. Lowe Ave., Chicago, 111___ ___1..... 881 Aerofia Corporation, 410 S. Geddes St., Syracuse, N. Y.....:................. ............. 996-998 Air Controls, Inc., 1937 West 114th St., Cleveland, Ohio--__ ____;.......................... 878 Air Devices Corporation, Thermal Units Mfg. Co., Div., 70 Brittania St., ' v Meriden, Conn.--...................... ....................................................;.... ........ ........... 849 Air-Maze Corporation, 813 Huron Road, Cleveland, Ohio............................... 924-925 ^Airtemp Incorporated, Dayton, Ohio.................... ............................................... 882-883 ^'-Airtherm .Manufacturing Co., 1474 S. Vandeventer, St. Louis, Mo............ ............. 990 AIco Valve Co., Inc., 2626 Big Bend Blvd., St. Louis Mo..,,.................................... 1155 Alfol Insulation Company, Incorporated, 155 East 44th St., New York, N. Y. 1022-1023 Aluminum Aircell Insulation Co., 415 Curtis Bldg., Detroit Mich.......................... 1021 American Air,Filfer Co., Inc., First St. and Central Ave., Louisville, Ky...... . 926-927 American Artisan (a pub.), 6 N. Michigan Ave., Chicago, 111.......................... -- 1072 American Blower Corporation, Detroit, Mich................................. ;.................... 850-851 American Brass Company, The, Waterbury, Conn.._...................................... 1062-1063 American Coolair Corporation, 3604 Mayflower St., Jacksonville, Fla...... ....... 978-979 American District Steam Company, North Tonawanda, N. Y............... __....... 975-1052 American Gas Products Corp., 40 West 40th St., New York, N. Y___ _ 886-953 American-Marsh Pumps, Inc., Battle Creek, Michigan.............. .......... ........... ........ 1082 American Moistening Company, Providence; R. I......................'......................... ...... 852 American Radiator Co., 40 West 40th St., New York, N. Y......884^-885, 940-943, 1061 American Rolling,Mill Co., The, Middletown, Ohio................................................. 1098 American Society of Refrigerating Engineers, 37 West 39th St., New York, N.` Y.... 1080 Anderson Products, Inc., Cambridge, Mass..... ..................... --.....--............. 1156-1157 Anemostat Corp. of America, 10 East 39th St., New York City, N. Y `. 1088 Aquatic Chemical Laboratories, Inc., 118 East 28th St., New York, N. Y...... 1161 Armstrong Cork Products Company, Lancaster, Pa.--............... ,,................... 1024-1025 Armstrong Machine Works, 851 Maple St., Three Rivers, Mich.................... 1102^1103 Auer Register Co., The, 3608 Payne Ave., Cleveland, Ohio.................*................... 1089 . Automatic1 Burner Corporation, 1823 Carroll Ave., Chicago, 111...... ....... 1................. 964 Autovent.Fan & Blower Co., 1809-23 N. Kostner Ave., Chicago, 111................. :.... 977 843 Heating Ventilating Air Conditioning Guide 1938 B ' Page Babcock & Wilcox Company, The, 85 Liberty St., New York, N. Y........................ 954 E. B. Badger & Sons Co., 75 Pitts St., Boston, Mass ........... ....... -......... ............ 976 Baker Ice Machine Co., Inc., 1518 Evans St., Omaha, Nebr...... '............... ;..... 854-855 Barber-Colman Company, Rockford, 111.............................. _......... ................. 1138-1139 Barber Gas Burner Company, The, 3704 Superior Ave., Cleveland, Ohio............... 887 Barnes & Jones, Incorporated, 129 Brookside Ave., Jamaica Plain, Boston, Mass 1106. Bayley Blower Company, 1817 South 66th St., Milwaukee, Wis........................... 980 Beaton & Cadwell Mfg. Company, The, New Britain, Conn.......................... 1104-1105 Bethlehem Steel Company, Bethlehem, Pa........... .........................^......................... 1099 Binks Manufacturing Co., 3114-3140 Carroll Ave., Chicago, 111......................... 972-973 Branford Div. of Malleable Iron Fittings Co., Branford, Conn................................. 966 Bristol Company, The, Waterbury, Conn...... ............................................................ 1012 Brownell. Company, The, Dayton, Ohio.^................................................................... 1130 Bryant Heater Company, The, 17825 St. Clair Ave., Cleveland, Ohio. .......... 888-889 Buffalo Forge Company, 450 Broadway, Buffalo, N. Y.............................................. 981 Buffalo Pumps, Inc., 450 Broadway, Buffalo, N. Y.................................................. 1083 Burnham Boiler Corporation, Irvington-on-Hudson, N. Y..:............................ 944-945 Butler Manufacturing Co., 1282 Eastern Ave., Kansas City, Mo............................ 1131 C Carboiidale Division, Worthington Pump & Machinery Corp., Harrison, N. J 856-857 Carey, Philip Co., The, Lockland, Ohio......................................... .....m............. 1028 Camegie-Illinois Steel Corporation, Pittsburgh, Pa................................../................ 1100 * Carrier Corporation, Syracuse, N. Y________ ___ :...................................................... 853 Celotex Corporation, The, 919 N. Michigan Ave., Chicago, 111................ ll.... 1029-1031 Century Electric Company, 1806 Pine St., St. Louis Mo......................................... 1057 Chamberlin Metal Weather Strip Co., 1254 Labrosse St., Detroit, Mich...... 1032-1033Champion Blower & Forge Co., Lancaster, Pa......................... ................................... 982 Chicago Metal Hose Corporation, Maywood, 111.................................. .... ......... :..... 1068 (formerly Chicago Tubing and Braiding Co.) Chicago Pump Company, 2330 Wolfram St:, Chicago, 111............ :........................... 1084 Clarage Fan Company, Kalamazoo, Mich.................. :................................................. 858 Cochrane Corporation, 3130 N. 17th St., Philadelphia, Pa....................................... 1107 Combustion Engineering Company, Inc., 400 Madison Ave.,'New York, N. Y...... 1132 Consolidated Ashcroft Hancock Co., Inc., Bridgeport, Conn................... ................. *1013 Cooling Tower Co., Inc., The, 15 John St., New York, N. Y.................... ................ 971 Coppus Engineering Corporation, 339 Park-Ave., Worcester, Mass...... .................... 928 Cork Insulation Co., Inc., 155 East 44th St., New York City, N. Y.... .................. 1026 Crane Co., 836 S. Michigan Ave., Chicago, 111.............:....................................... 946-947 Curtis Refrigerating Machine Co., Division of Curtis Manufacturing Co., 1959 Kienlen Ave., St. Louis, Mo........................... .-..................._..._................... 859 D DeBothezat Division American Machine & Metals, Inc., 100 Sixth Ave., New York, N. Y...... .............................................. :........................... :........ :......................:...... 983 Decatur Pump Co., Decatur, III.................................................... ;......................... . 1085 Delco-Frigidaire Conditioning Division, General Motors Sales Corp., Dayton, Ohio....'.............................................................................................................. 890-892 Detroit Lubricator Company, Detroit, Mich.................................................... 1140-1141 Index to Advertisers D Page Detroit Stoker Company, General Motors Bldg., Detroit, Mich............................. 1133 Dole Valve Company, The, 1901-1941 Carroll Ave., Chicago, 111............................ 1158 Domestic Engineering (a pub.), 1900 Prairie Ave., Chicago, 111..................... 1074-1075 C. A. Dunham Company, 450 E. Ohio St., Chicago, 111.................................. 1100-1109 E Eagle-Picher Lead Company, The, Temple Bar Bldg., Cincinnati, Ohio................ 1036 Ehret Magnesia Manufacturing Co., Valley Forge, Pa...... ............................. 1034-1035 Electrol Incorporated, 934 Main Ave., Clifton, N. J......... -......................... 898-899, 967 F Fairbanks Morse & Co., 600 So. Michigan Ave., Chicago, 111__________ .......... _.... 860 Farrar & Trefts Incorporated, Buffalo, N. Y............................................. .................. 955 Fedders Manufacturing Co., 57 Tonawanda St., Buffalo, N. Y............... ................. 991 Fitzgibbons Boiler Company, Inc., 101 Park Ave., New York, N. Y............... . 956-957 Fox Furnace Co., The, Elyria, Ohio...................... ............................................... 893-897 Frick Company (Incorporated), Waynesboro, Pa........................................................ 861 Julien P. Friez & Sons, Inc., Baltimore, Md.............................................................. 1144 Fueloil Journal (a pub.), 420 Madison Ave., New York, N. Y.........:................ ..... - 1077 Fulton Sylphon Company, The, Knoxville, Tenn.......... .................................. 1142-1143 G G & O Manufacturing Company, The, 138 Winchester Ave., New Haven, Conn.... 999 V/Gar Wood Industries, Inc., 7924 Riopelle St., Detroit, Mich.............................1 900-901 General Controls, 1368 Harrison St., San Francisco, Calif................................1145 General Electric Company, Bloomfield, N. J..................................:........... .... 902-903 General Electric Company, Schenectady, N. Y.............................................. ? 1058-1059 General Insulating & Mfg. Company, Alexandria, Ind...... ....... :....................1......... 1037 . General Refrigeration Corp., Beloit, Wis................................................................. :__ 864 Gilbert & Barker Mfg. Co., Springfield, Mass___s................................................ 904-906 Grinnell Company, Inc., Providence, R. I.;.... ........................................ 1000-1002, 1110 H William S. Haines .& Company, 12th and Buttonwood Sts., Philadelphia, Pa........ 1111 Arthur Harris & Co., 210-218 N. Aberdeen St., Chicago, IU............. ...................... 1066 Hart & Cooley Manufacturing Co., 61 W. Kinzie St., Chicago, 111.-.?.'.......... 1090-1091 Heating Journals, Inc., 232 Madison Ave., New York, N. Y...;.:.............;............... 1076; Heating & Ventilating (a pub.), 140-148 Lafayette St;,.New York, N. Y............... 1078 Heating, Piping and Air Conditioning (a pub.), 6 N. Michigan Ave., Chicago, 111.... 1073 . Henry Furnace & Foundry Co., 3471 East 49th St., Cleveland, Ohio............... 912-913 Hoffman Specialty Co., Inc., Waterbury, Conn.... ........................ ........ J........ 1112-1113 I Ilg Electric Ventilating Company, 2880 N. Crawford Ave., Chicago, 111..;........... . 984 Illinois Engineering Company, Chicago, 111............................... ....:......... :....... 1114-1115 Illinois Testing Laboratories, Inc., 422 N.'LaSalle St., Chicago, 111........................ 1014 845 ' Heating Ventilating Air Conditioning Guide 1938 I . ' Page Independent Air Filter Co., 228 No. LaSalle St., Chicago, III.... ............................... 929 Independent Register Co., The, 3753 East 93rd St., Cleveland, Ohio.!................... 1094 Ingersoll-Rand Company, 11 Broadway) New York, N. Y................................. 862-863 Insulite Company, The, Minneapolis, Minn...... ................................... ........... 1038-1039 Insul-Wool insulation Corp., Wichita, Kansas........................................................... 1040 International Exposition Co., Grand Central Palace, New York, N. Y.................. 1101 International Fibre Board Limited, Ottawa, Ont.,.Canada...................................... 1041 Iron Fireman Manufacturing Company, Portland, Oregon............................. 1134-1135 J Jenkins Bros., 80 White St., New York, N. Y.................................................... 1159 Johns-Manville, 22 East 40th St., New York, N. Y........................................ 1042-1043 S. T. Johnson Co., 940-950 Arlington Ave., Oakland, Calif............................. 968-969 Johnson Service Company, Milwaukee, Wis.... ................................................ 1146-1147. Jones & Laughlin Steel Corporation, Jones & Laughlin Bldg., Pittsburgh, Pa.......... 1070 K E. Keeler Company, Williamsport, Pa................................................... :........... 958-959 Kelvinator Division of Nash-Kelvinator Corp., Detroit, Mich.......................... 90.7-911 Kewanee Boiler Corporation, Kewanee, III.............................................-............-960-961 Kieley & Mueller, Inc., 34 West 13th St., New York, N. Y..... ).............................1116 Kleen Heet, Inc., 1823 Carroll Ave., Chicago, 111....;..........I....................................... 965 L Lau Blower Company, The, 954-972 E. Monument Ave., Dayton, Ohio.................. 879 Leeds & Northrup Company) .4941 Stenton Ave., Philadelphia, Pa.TM..................... 1015 Lennox Furnace Co., Inc., Syracuse, N. Y...................................;....................... 914-915 Liquidometer Corporation, The, 36-16 Skillman Ave., Long Island City; N. Y...... 1016 Lochinvar Corporation, 14247 Tireman, Dearborn, Mich ......................... ........... . 916 J. E. Lonergan Co., 207 Florist St., Philadelphia, Pa......................... 1.................... 1117. M Marley Co., The, 1915 Walnut St., Kansas City, Mo............. ........................... ....... 974 Martocello, Jos. A. & Company, 229-231 North 13th St., Philadelphia, Pa............. 866 McCord Radiator and Manufacturing Co., 2587 E. Grand Blvd., Detroit, Mich...;... 992 `McDonnell & Miller, Wrigley Bldg., Chicago, 111............... ....................-----...... 938-939 McQuay Incorporated, 1600 Broadway, N.E., Minneapolis, Minn...... ........... :........ 865 Merchant & Evans Co., 2035 Washington Ave., Philadelphia, Pa................. ;.......... 867 Mercoid Corporation, The, 4201 Belmont Ave., Chicago, III.................................... 1150 Meyer Furnace Company, The, Peoria, III............ :................................. :................... 917 Milwaukee Valve Co., Milwaukee, Wis.._.............:............................................ 1118-1119 Minneapolis-Honeywell Regulator Company, Minneapolis, Minn....;..........I.. 1148-1149 Modine Manufacturing Co., 17th and Holburn Sts., Racine) Wis............................. 993 Mueller Brass Co.. Port. Huron, Mich....................... ........... --........................ 1064-1065 L. J. Mueller Furnace Co., 2009 W. Oklahoma Ave., Milwaukee, Wis......!...... 918-919 ' Mueller Steam Specialty Co.,. Inc., 349-351 West 26th St., New York, N. Y.... A.. 1120 Mundet Cork Corp., 450 Seventh Ave., New York, N. Y....:....................................1027 Index to Advertisers . N . . - . ' - Page Nash Engineering Company, The, South Norwalk, Conn.............)................. 1086-1087 Herman Nelson Corp., The, Moline, 111....................................... ..................... 1004r1005 John J. Nesbitt, Inc., Holmesburg, Philadelphia, Pa.............................................. . 1003 New York Air Valve Corporation, 611-621 Broadway, New York, N. Y................ 1160 Niagara Blower Company, 6 East 45th St., New York, N. Y...... ............................. 868 O Oakite Products, Inc., 22 Thames St., New York, N. Y..... .............................. 1162 Ohio Electric Manufacturing Co., The, 5906 Maurice Ave., Cleveland, Ohio......... 1060 Owens-Illinois Glass Company, Toledo, Ohio........................... :......................... ........ 930 P Pacific Lumber Company, The, 100 Bush St., San Francisco, Calif........................ 1046 . Palmer Company, The, 426 Clay St., Cincinnati (St. Bernard), Ohio..................... 1017 Parks-Cramer Company, Fitchburg, Mass.................................................................. 869 Penn Electric Switch Co., Goshen, Ind................................. ..... ............................... 1151 Plumbing and Heating Trade Journal (a pub.), 515 Madison Ave., New York, N. Y.TM_...................................................................... ............................................ 1079 H. W. Porter & Co., 825 Frelinghuysen Ave., Newark, N. J..................... .............. 1053 Powers Regulator Co., The, 2719 Greenview Ave., Chicago, III.................. . 1152-1153 Preferred Utilities Manufacturing Corp., 33 West 60th St., New York, N. Y......... 970 R Republic Steel Corporation, Cleveland, Ohio...................................................... 1071 Research Corporation, 405 Lexington Ave., New York, N. Y...... ...................... :..... 870 Revere Copper and Brass Incorporated, 230 Park Ave., New York, N. Y.._.......... 1067. Ric-wiL Company, The, Union Trust Building, Cleveland, Ohio....... 1.................... 1054 Ruberoid Co., The, 500 Fifth Ave., New York, N. Y...... .............................. ; 1044-1045 S Sarco Company, Inc., 183 Madison Ave., New York, N. Y........................... 1122-1123 Schwitzer-Cummins Company, Indianapolis, Ind-.......... :..... ...................... 880, 1136 Servel, Inc., Evansville, Ind .....: ...................................................................... 871 Sheet Metal -Worker (a pub.), 45 West 45th St., New York, N. Y.......................... 1081 H. J. Somers, Inc., 6063-69 Wabash Ave., Detroit, Mich.................. ... ................931 Spence Engineering Co., 28 Grant St., Walden, N. Y.......................................... . 1154 Spencer Heater Division, Lycoming Mfg. Co., Williamsport, Pa....... ................ 948-949 Standard Lime & Stone Company,.The, First National BankBldg., Baltimore, Md. 1047 Staynew Filter Corporation, 6 Leighton Ave., Rochester, N. Y..................... . 932-933 Sterling Engineering Company, 3740 N. Holton St., Milwaukee, Wis.._`_................ 1121 Streamline Pipe and Fittings Division, Mueller Brass Co., Port Huron, Mich. . 1064-1065 B. F. Sturtevant Co., Hyde Park, Boston', Mass......... ....... ................... ..... ............ : 985 Heating Ventilating Air Conditioning Guide 1938 T . . Page Taco Heaters, Inc., 342 Madison Ave., New York City, N. Y....................... 1008-1009 Taylor Instrument Companies, Rochester, N. Y............................................. 1018-1019 Thermal Units Manufacturing Company, Meriden, Conn......................................... 849 H. A. Thrush & Co., Peru, Ind...... ........ -.... -.................................................... 1010-1011 Titeflex Metal Hose Co., 500 Frelinghuysen Ave., Newark, N. J.._......................... 1069 Torrington Mfg. Co., The, 50 Franklin St., Torrington, Conn........................... 986-987 Trane Company, The, 2021 Cameron Ave., LaCrosse, Wis.............................. 872-873 Tuttle & Bailey, Inc., New Britain, Conn....................................................... 1092--1093 U Underground Steam Construction Co., 75 Pitts St., Boston, Mass....... :................. 1055 Union Iron Works, Erie, Pa....................................................... ......................... -....... 962 Unit Heater and Cooler Co., The, Wausau, Wis.......................... .--......................... 994 United.States Gauge Co., 44 Beaver St., New York, N. Y................... -.................. 1020 United States Gypsum Company, 300 W. Adams St., Chicago, 111......................... 1048 United States Radiator Corporation, Detroit, Mich............................................ 950-951 United States Register Co., Battle Creek, Mich...................................................... l. 1096 Universal Air Filter Corp., 332 W. Michigan St., Duluth, Minn.._........................... 934 Universal Cooler Corporation, Detroit, Mich--..................... .................................... 874 -Utica Radiator Corporation, Utica, N. Y............................................................. 920-921 V Vilter Manufacturing Company, The, Milwaukee, Wis.............................................. 875 Vinco Company, Inc., The, 305 East 45th St., New York, N. Y....................... 936-937 Vulcan Anthracite Stoker Corp., 642 So. Main St., Wilkes-Barre, Pa._,,................. 1137 W ,, ' i f ' Warren Webster & Company, Camden, N. J--.................. .1........................... 1124-1127 Waterfilm Boilers Incorporated, 154 Ogden Ave., Jersey City, N. J......................... 963 Waterloo Register Company, The, Waterloo, Iowa..... ..... v..................................... 1096 Weil-McLain Company, 641 W. Lake St., Chicago, 111......... .;......... ~~..................... 952 Western Felt Works, 4029-4117 Ogden Ave., Chicago, III........................................ 1049 Westinghouse Electric & Manufacturing Co., Mansfield, Ohio .--............................. 876Wickwire Spencer Steel Co., 41 E. 42na St., New York, N. Y................................ 1097. Williams Oil-O-Matic Heating Corporation, Bloomington, 111...................-........ 922-923 L. J. Wing Mfg. Co., 59 Seventh Ave., New York, N. Y............... .................... 988-989 Worthington Pump & Machinery Corp., Harrison, N. J...................i................. 856^-857 Wright-Austin Co., 317 ,W. Woodbridge St., Detroit, Mich..................................... 1128 Wyckoff, A. & Son.Co., Elmira, N. Y......................................................................... 1056 Y Yamall-Waring Co., Mermaid Lane, Philadelphia, Pa............................................. 1129 . York Ice Machinery Corporation, York, Pa.... ...............*.... ........................................ 877 Young Radiator Company, Racine, Wis...:.................. ................................................. 995 Young Regulator Company, 4500 Euclid Ave., Cleveland, Ohio.....*.......................... 935 Z Zonolite Company, The, 5905 Second Blvd., Detroit, Mich..........................- 1050^1051 848 Air Conditioning Air Devices Corporation Thermal Units Manufacturing Company Division 70 Britannia Street, Meriden, Connecticut Representatives in Ali Principal Cities . PRODUCTS--Heaters, Unit; Coolers, Unit; Humidifying Units; Coils, Heating and Cooling, Fans and Automatic Refrigerating Compressors for Commercial and Air Conditioning Work THERMAL UNIT HEATERS--Six Sizes With permanent one piece--integrally cast-- aluminum element. Ca pacities from 15,000 to 500,000 Btu per unit. No joints, welds, brazed or soldered con nections. Leakproof, Freezeproof, indefinite life without servicing. Maximum air delivery per horsepower, with low outlet air temperature. Built for troubleproof service and long life. THERMAL UNIT COOLERS--Five Sizes For Ammonia, Brine, Freon, water and other refrigerants. Three types: Circulating, Flooded or direct Expansion. Capa cities from too to 8 tons refrigerating effect. Employs the same sturdy heat transfer ele ment as our Unit Heater above. . Automatic operation, Automatic defrosting, with controls. Eight years of success ful applications, of all types. Thermal Unit Automatic Humidifier - For use in conjunction with steam, hot water and vapor heating systems. Made in five sizes to fit virtually any industrial or residential requirements. Will automatically maintain any de sired percentage of relative hu midity. Sturdy, compact, using Thermal Unit all-aluminum heattransfer elements as in Thermal Unit Heaters and Coolers. Fully automatic, being governed'-* by handset humidistat. Catalogs, information, and Engi neering date furnished on request 849 Air Conditioning American Blower Corporation Division of American Radiator and Standard Sanitary Corporation General Offices and Factory Detroit, Mich. Branches in All Principal Cities AIR CONDITIONING -- HUMIDIFYING -- DEHUMIDIFYING -- COOLING -- VENTILATING -- HEATING -- VAPOR-ABSORPTION -- DRYING -- AIR WASHING AND PURIFICATION -- EXHAUSTING EQUIPMENT AND MECHANICAL DRAFT APPARATUS. American Blower Multi-Blade Fan For heating, ventilating, cooling and air conditioning system. High volumetric and mechanical efficiency. Driven by belt, steam engine, motor or turbine. Capaci ties 30,000 to 500,000 cfm. Write for Bulletin No. A-403. American Blower Central Air Con ditioning Systems with Sirocco Fan For more than 30 years, particularly adapted to heating, ventilating, air wash ing, purifying and cooling large buildings. Write for complete data. Ventura Ventilating Fan For exhausting bad air, odors, steam, etc., in a wide range of buildings and in dustrial processes, restaurants, garages, etc. Write for Bulletin No. A-1913. , 'American Blower Dehumidifiers and Washers Fordehumidifying, cooling and washing air in connection with central systems, for air conditioning, for process work or for use with a ventilating system where large quan tities of fresh, washed air are required. Thousands of these dehumidifiers are al ready in operation in theatres, public buildings, office buildings, garages, hotels and industrial plants. Write for Special Bulletin No. 3523. 850 American Blower Corporation Air Conditioning TYPES OF AMERICAN BLOWER CORPORATION AIR HANDLING AND CONDITIONING EQUIPMENT All types of air handling and air conditioning equipment for industrial applications, process work, drying, cooling; also equipment for stores, offices, shops, public buildings, power plants, etc., and attic ventilation for homes. American Blower Series B Conditioner For installation in stores, res taurants, offices and other com mercial establishments. May be installed in present buildings or new buildings for cooling, venti lating, dehumidifying as well as heating and humidification. Write for technical Bulletin No. 5127. American Blower Series K Conditioner For use with a duct system in a wide variety of air con ditioning applications. For complete data on this con ditioner write for Bulletin No. 3927. Decalorator Steam Refrigeration Units . Furnished for air condition ing and process cooling. By means of a jet of steam and the flow of condensing water, they function to produce cool, re frigerated water at any tem perature above 35 F. For com plete data on steam refrigera tion, send for Bulletin No. 3727. Ventura Home Conditioner For comfort cooling by means of attic ventilation. Made in various sizes for all home needs. No refrigerating - machine required. Thousands already in operation. Write for Bulletin No. A-3713. 851 Air Conditioning American Moistening Company Atlanta. Ga. Boston, Mass. Established 1888 nProv.idj ence,-Rn.rI. *. a c.Charlotte, N. C. grmwtill UNIT HUMIDIFYING AND AIR CONDITIONING EQUIPMENT A few of many AMCO products with a Long Record of Dependable Performance Sectional Humidifiers. Amtex Humidifiers. Hand Sprayers. Mine Sprays. Fabric and Paper Dampeners. Mechanical Psychrometers. Electro Psychrometers. Sling Psychrometers. Hygrometers. ' The Amco line of devices for the supply, maintenance and control of humidity is com plete in its ability to meet any presented problem of applied humidification. Used independently or as ah adjunct to Central Station equipment, these devices auto matically maintain any required humidity condition in a capable uniform performance. IDEAL HUMIDIFIERS--Senior Type A high capacity unit for use where conditions require a great amount and good distribution of moisture. Motor driven fan gives wide distribution of atomized spray. Amco heads serve the triple purpose of humidifying, air washing and cooling. IDEAL HUMIDIFIERS--Junior Type Similar in construction to Senior Type. Used where medium capacities are required. AMCO ATOMIZER--No. 4 Quality and quantity of spray are maintained even under adverse conditions because this atomizer is automatically self-cleaning. When the compressed air supply is shut off, either manually or in response to a humidity control, both air and water nozzles are thoroughly cleaned. AMCO HUMIDITY CONTROLS Compressed Air Operated - An extremely accurate and active device operated by compressed air which assures a regulation of humidity within exceedingly close ranges. AMCO HUMIDITY CONTROL Electrically Operated Similar in principle to the Compressed Air Type except that the hydroscopic element operates electrical contacts which control the units. 852 Air Conditioning Carrier Corporation AIR CONDITIONING - REFRIGERATION - HEATING Home Office: Syracuse, N. Y. District Sales Offices: NEW YORK, PHILADELPHIA, CHICAGO, LOS ANGELES Branch Offices and Dealers in Principal Cities International Division--Syracuse, N. Y. Marine Division--405 Lexington Ave., New York City AIR CONDITIONING FOR INDUSTRY Central Station type for process and comfort. Unitary equipment. Humidifiers. ' Spray type dehumidifiers. Surface type dehumidifiers. Centrifugal refrigeration using Carrene. Reciprocating refrigeration using Freon or methyl chloride. Evaporative condensers. Marine refrigerating machines. AIR CONDITIONING FOR BUSINESS Centra! station type. Unitary equipment. Centrifugal refrigeration using Carrene. Reciprocating refrigeration using Freon or methyl chloride. Evaporative condensers. Cold diffusers. Room units. Carrier Central Station Type Air Conditioning Equipment AIR CONDITIONING FOR HOME Home furnace (for oil or gas). Home air conditioners (for winter and summer). . Oil burner. Room units (for selected rooms). Carrier Store Weaihermaker For Commercial Installations REFRIGERATION Reciprocating refrigeration machines. Centrifugal refrigeration machines. Cold diffusers. . Evaporative condensers. Accessory equipment. . SPACE HEATING Unit heaters. Heat diffusers. . Carrier Centrifugal Refrigeration Machine - There is a Carrier system exactly fitted to each requirement and the nearest Carrier dealer or office of Carrier Corporation offers a complete service in solving any air con ditioning, drying, space heating or refrigerating problem. 853 Air Conditioning Baker Ice Machine Co., Inc. Omaha, Nebr. MANUFACTURERS OF INDUSTRIAL AND COMMERCIAL REFRIGERATION AND AIR CONDITIONING Branch Factories: Fort Worth, Los Angeles, Seattle Eastern Sales: New York City Central Sales: Chicago Sales and Service in All Principal Cities Authority on Mechanical Cooling for Over 30 Years Get specifications for your requirements from the Baker line of equipment. Every machine and cooling assembly has been precision-manufactured and designed to offer maximum service, dependability and economy per dollar invested. Baker Ammonia Compressors Available to 100 tons ca pacity, with synchronous, direct-con nected or Vbelt drive. Baker Com- Baker Ammonia Compressor pbereasrsroarnsgemdainy duplex or multiple installations for any desired capacity. Also equipped with double-suction, capacity reduction where conditions require utmost economy of operation. Available in automatically con trolled self-contained units ranging from 1 to 25 tons capacity, 2 and 4 cylinder types. Baker Cold Stream Brine Spray Units Designed for applications requiring uni form control of tempera tures and rela tive humidity. Equipped with slo w-speed, blowers mount- Baker ColdStream Brine Spray ^ n ball Unit--forced draft type bearings. Fan speeds may be changed to suit air velocity requirements. Housing is of boiler plate construction. Baker Shell and Tube Condensers Baker Shell and Tube Condensers are made in all sizes up to 2500 sq ft of effective cooling surface. Vertical, horizontal, multi Baker Shell and Tube Condenser pass or singlepass types available, with diameters and tube lengths to fit any specification. Easily cleaned. Baker Freon or Methyl Chloride Units Baker offers a complete line of 77 models assembled in both single and dual mounted self-contained automatic Baker Freon or Methyl-Chloride Unit units from hp to 60 hp capacity, two and four cylinder types. Mechanical features include double-trunk type, semi-steel pistons, full force feed lubrication, Timken Bearings and shell and tube condensers. Both air cooled and water cooled models available. Baker Fan Type Cold- ' Stream Units f Rigidly con structed for compact, high- capacity, heavy duty service in re frigerating and air condition ing foods and Baker Fan Type ColdStream Unit other perisha bles requiring positive control of tempera tures above the freezing point. Finned coil surfaces and air velocity designed for a correct combination of temperature and relative humidity. Baker Ceiling Type Cold Stream Blow er Units Designed for Baker ColdStream Blower Unit comfort cooling or com- --ceiling type, front and ...rear views . . mercial and industrial air cooling. Equip ped with finned or galvanized bare pipe coil; fans direct connected or V-belt driven. Also made in. Floor Type Units ranging in size from 2 to 16 tons refrig erating, 2,000 to 16,000 cfm air capacity. 854 Air Conditioning Baker Ice Machine Go., Inc. Omaha, Nebr. Baker ColdStream Air Conditioner Baker ColdStream Air Conditioners A wide range of capacities is available to suit every need. Condensed capacities for largest and smallest sizes: (Entering air 80 F dry bulb and 50% relative humidity. Entering refrigerant, either water or direct expansion, 40 F.) Cfm 3,000 12,000 Water Btu 65,200 433,000 Direct Expansion Btu 64,500 484,000 Baker ' Evaporative Condensers Compactly designed, elim inates expense of cooling towers with separate con densers and saves space. Drastically re duces water costs. Casing is ofheavy metal, rigidly braced Baker Evaporative Condenser and thorough ly reinforced. Non-corrosive type elimi nators. Outdoor units are weatherproofed. Baker Liquid Coolers Baker Two- Cylinder Freon Compression Units Baker 2-cyl inder vertical enclosed type Freon com pression unit, assembled on a rigid metal base with Baker Two-Cylinder Freon motor and Compression Unit automatic con trol. Available in 20 to 30 hp. Timken anti-friction roller bearings, balanced bel lows crankshaft seal, and built-in remov able cartridge-type oil filter. Automatic pressure-type temperature control and high-pressure cut-out (thermostat type also available). V-belt drive. Compactly built, all parts easily accessible. Baker FourCylinder Freon Compression Units Same general construction as 2-cylinder unit. Available in 40 to 60 hp. Either directconnected or V-belt drive. Baker Four-Cylinder Freon Compression Unit Baker Liquid Cooler Designed to cool quickly large quantities of water or brine. Horizontal multipass shell and tube construction. Design of water head insures even distribution of water through the tubes. Complete range of sizes, 12 in. to 50 in. diameter, with tube lengths 9, 12, 14, 16 and 18 ft long. Cooling capacity up to 150 tons each. Baker Dual Condensing Units Designed especially for variable heat load requirements. Dual 4-cylinder type water cooled Freon or Methyl Chloride unit, with automatic capacity control. Shell and tube type extra capacity con densers standard equipment when used*' with evaporative type condenser. Cut away view shows position and length of tubes. 855 Air Conditioning Atlanta Boston Buffalo Chicago E Garbondale Division WORTHINGTON Worthington Pump and Machinery Corporation General Offices: HARRISON, NEW JERSEY Cincinnati Cleveland Dallas Denver Detroit El Paso Houston Kansas City Los Angeles ' New Orleans New York Philadelphia Pittsburgh St. Louis St. Paul San Francisco Representatives in Principal Cifiej of Foreign Countries Seattle Tulsa Washington ca e-i REFRIGERATION SYSTEMS FOR AIR CONDITIONING IN COMFORT COOLING OR INDUSTRIAL PROCESS Complete refrigerating systems for use with "Freon-12", Methyl Chloride, Ammonia, or Carbon Dioxide, either direct-expansion of water cooling applications. A complete line of refrigeration compressors, permit ting impartial recommendations. A nation wide organization of Dealer-Distributors in major cities to provide sales and engi neering service and plan complete air con ditioning systems of the central or unit type. Architects, Engineers, and Con tractors are invited to consult with us. Write to Harrison, N. J., or any branch office, for bulletins on these products. Small Self-contained Units "Freon-12" or methyl chlo ride commer cial units; motors up to 25 hp; ratings up to 25 tons. Vertical "Freon-12" Compressors Overall Dimensions Smallest: 22 in. long, 16 in. wide. 17 in. high Largest: 98 in. long, 40 in. wide, 41 in. high Medium Self-contained Units "Freon-12" or methyl chlo ride units, equipped with capacity control; pat ented Fea ther Valves; motors of 30, 40 and 50 hp; ratings up to 50 tons. Overall Dimensions 8 ft 9 in. long, 3 ft 8 in. wide, 6 ft 1J4 in* high The features, methods of drive, and overall dimensions for these units are the same as for Vertical Ammonia Compressors. Ratings up to 250 tons. Horizontal Ammonia Compressors Vertical Ammonia Compressors Pressurelubricated; roller main bearings; safety heads; patented Feather Valves; belt drive, or di rect-connec ted to electric motor, Diesel or gas engine; ratings from 2 to 100 tons in one unit. Overall Dimensions (Without Motor) Smallest:2ft 3in. long. 2 ft 3^in. wide, 3ft3H in. high Largest: 6 ft 7^ in- long, 5 ft wide, 7 ft in. high Single and duplex; single-stage and two- stage; belt drive, or direct-connected to electric motor, Diesel, gas or steam engine; patented Feather Valves; ratings from 60 to 750 tons. Automatic capacity control features are easily applied. Space require ments vary greatly depending upon type and drive. Compressor requirements above 250 tons are best met with these machines. Similar units for "Freon-12" are also produced, in rugged design. 856 Air Conditioning Carbondale Division, Worthington Pump and Machinery Corporation Carbon Dioxide Compressors Liquid Cooling Equipment A series of convenient types and sizes for every re quirement is available. Brine coolers and pumps for air con ditioning ser vice for any size installa tion, large or small. Air Conditioning Units Horizontal Condensers Vertical and horizon tal; 500 to 15,000 cfm; large air passages; slow speed, quiet, rugged fans; heavy welded steel frames; separable sections; readily acces sible. The design per mits a wide degree of flexibility in installa tion arrangements. Shower Condensers A combined con denser, receiver, and modified cool ing tower, in one as sembly, for "Freon12" or methyl chloride systems; 5 to 50 tons re frigeration; built in separable sections; all parts easily ac cessible. Saves 90 to 95 per cent in cost of water. Liquid Cooling Equipment Various desi g n s of horizontal single and multi-pass types, for a wide range of services; also verti cal types. Chillers for oil dewaxing. Single and double-pipe for milk, wort, chemicals, etc. Cold liquid circulating systems. Atmospheric drip type, for warm corrosive waters. Double-pipe for closed systems, can be retubed without shutting down. Multi-pass for closed systems and space saving. Vertical Condensers The Carbon- dale "SpiraFlo" posses ses the ad vantages of both the at mospheric and double pipe types. Usable with any kind of water. Com pact; instal led indoors, outdoors, or on the roof. Easily cleaned. Miscellaneous High and low side equipment for every purpose: Coils Air Coolers Separators Receivers Controls Pumps Valves Purgers Tanks Traps Connections Fittings Space requirements and other data on request. 857 / Air Conditioning Clarage Fan Company Kalamazoo, Michigan Sales Engineering Offices In All Principal Cities (Consult Telephone Directory) CLARAGE AIR HANDLING AND CONDITIONING EQUIPMENT For Over a Quarter-Century Clarage has been a leading manufacturer of air handling and conditioning equipment. There is a Clarage fan or blower unit or system to meet every need, from the simplest ventilating or cooling job to the most exacting temperature and humidity control installation. Whatever your ventilating, unit heating, cooling, drying, air cleaning, humidifying, dehumidifying or complete air conditioning problem, we can meet your requirements successfully and economically. Clarage Experience covers every conceivable type of installation, commercial, industrial and public build ing. Clarage equipment is used in the largest industrial plants, office buildings, auditoriums, theatres, hotels, restaurants, retail stores, hospitals, churches and schools. Architects, Engineers and Contractors find our service specially helpful. This Company is an inde pendent manufacturer selling through regular trade channels, and cooperating fully with those who specify and those who install. Your inquiry for complete data on any Clarage product is invited. Clarage Systems for complete air conditioning Mtdlilherm Units--968 different combinations for cooling or com plete conditioning Duotherm Units, complete con ditioning plants for fine homes Clarage Fan with Vortex (con stant speed) Volume Control Unitherm Unit Heaters with Syncrotherm Temperature Control 858 Unitherm Unit Coolers for pro duct cooling and refrigeration Air Conditioning Curtis Refrigerating Machine Company Division of Curtis Manufacturing Company 1959 Kienlen Avenue St. Louis, Mo. Double Tube Type High efficiency, double lube counter flow condenser multi-banked for pressure drop. ' SOME FEATURES OF CURTIS UNITS "Centro-Ring Positive Pressure" oiling, Timken tapered roller bearings. Water jacketed head and cylinders. Each unit equipped with built-in oil separator with automatic return. Balanced sylphon bellows seal. Efficient drop-forged, heat-treated crank shaft and connecting rod construction. Stainless steel disc type suction and discharge valves. ' Automatic water valves. Extra large water-cooled condensers. Compressors of proven "V" type radial design. 86 models comprise the Curtis line of condensing units for air conditioning and refrigeration. There are 41 aircooled units ranging in size from ^ to 5 hp inclusive and 45 water cooled units in sizes from ^ hp to 30 hp inclusive. Counterflow, con densers are supplied in models from }/i to 15 hp. Cleanable shell and tube conden sers available with units from 3 to 30 hp. All models supplied for either Freon (F12) or Methyl Chloride. Shell and Tube Type Dual shell and lube condensers Permitting series or parallel operation to suit every condition. CURTIS coils and forced draft unit coolers for refrigera tion and air conditioning are designed and built to balance with the highly efficient Curtis condensing units. A complete stock of standard coils and unit coolers is always available, while special coils and unit coolers can be furnished on short notice. jVJRTIS has been in business since 1854 and has built condensing units since 1922. Today a .million dollar corporation with the engineering and production facilities of a 20 acre plant produces and stands behind every Curtis product. Write to Curtis Refrigerating Machine Company, St. Louis, Mo. for further details and information on the complete Curtis line. 859 V-V-'Tf J Air Conditioning Fairbanks, Morse & Co. Manufacturers of Air Conditioning Equipment 600 So. Michigan Avenue, Chicago, 111. Atlanta, Ga. Baltimore, Md. . Birmingham. Ala. Bostpn, Mass. Buffalo, N. Y. Chicago, III. Cincinnati, Ohio Cleveland. Ohio Columbus, Ohio Branch Offices Dallas. Texas Denver. Colo. Des Moines, Iowa Detroit, Mich. Indianapolis, Ind. Jacksonville, Fla. Kansas City, Mo. Lbs Angeles, Calif. Louisville, Ky. Memphis, Tenn. Milwaukee, Wis. Minneapolis. Minn. New Orleans, La. New York, N. Y. Omaha, Neb. Philadelphia, Pa. Pittsburgh, Pa. Portland, Ore. Providence, R. I. San Francisco, Calif. Seattle, Wash. St. Louis, Mo. St. Paul, Minn. Stuttgart, Ark. , Toledo, Ohio Washington, D. C. Equipment and Service Air Conditioning equipment is the pro duct of exact science. It requires precision engineering. When you specify Fairbanks- Morse Air Conditioners you are specifying equipment that is the product of 108 years of precision engineering and manufactur ing experience. You are specifying equip ment that is backed by the warranty of a company that has never failed the users of its products. . Whether your requirements call for self-contained units, remote units, or central station systems, you will find the correct type and size in the Fairbanks- Morse 1938 complete line of air condi tioning equipment. Thirty-five branches throughout the United States stand ready with Fairbanks- Morse 24-hour service. Every Branch maintains a corps of engineers to give expert counsel on any type of Fairbanks- Morse unit or installation problem. A complete stock of standard repair parts enables each.-Branch to make quick-time service a working reality. Plans, specifi cations and cost estimates on air condi tioning homes, offices, stores, factories, theatres, hotels, shops, or any type of building will gladly be furnished, without cost or obligation. . Self-Contained Units . Fairbanks-Morse self-contained air con ditioning units for summer cooling are available in two types. The air-cooled model is of % and 1 ton capacity while the water-cooled type may be had in 1, 3 and 5 ton capacities. Both of these units are completely self-contained within the cabinet and can be located within the conditioned space. Remote Units Remote air conditioners for use with either water or F 12 as a cooling medium, are built in capacities of from % to 5 tons. This type of conditioner is located in the conditioned space and is connected to a condensing unit which is usually located in the basement. These units can be furnished to perform all the functions of year-round air conditioning or they can be supplied for partial conditioning if desired. C'xentral Station S ystems Central system plants for complete yearround air conditioning are built by Fair- banks-Morse in both vertical and hori zontal types for capacities of from 3 to 30 tons. The central plant is usually located in the basement and furnishes conditioned air to the desired space through ducts. Fairbanks-Morse has available a complete line of Direct Expansion Water and Heating Coils, Compressors from 1/2 to 30 hp, inclusive, and a com plete line of Evaporative Condensers. Automatic gas engine driven Freon compressors can also be furnished. 860 i Air Conditioning Albant Atlanta Baltimore Boston Buffalo Charlotte Chicago Cincinnati Cleveland Dallas Detroit Frick Company (Incorporated) ` Air Conditioning, Refrigerating and Ice-Making Equipment Waynesboro, Penna. Distributors in 100 Principal Cities Kansas Cm Los Angeles Memphis New Orleans New York Oklahoma Cm Palatka Philadelphia Pittsburgh Sr. Louis Seattle AIR CONDITIONING WITH AMMONIA REFRIGERATION FRICK REFRIGERATION Machines in Is the term applied all capacities to our service in supplying refriger from % ton up. Combined ating equipment units, vertical i and engineering as enclosed type sistance for com plete air condition compressors, horizontal ing jobs, which are handled by Frick machines: complete high Branches and Dis and low sides. ! The PhUiower and Pkdcade Buddings at Tvlsa are Air tributors -- located in principal cities throughout the world. Estimates cheer Widely used for air con ditioning. Bul letins 102 to 138. The Standard Carmel Company of Lancaster, Penna., has used Frick Ammonia Refrigeration for Air Conditioning Since 1910 Conditioned with 1000 Tons fully submitted. % of Frick Refrigeration Get data on special CARBON DIOXIDE Frick air conditioning systems for auto REFRIGERATION matic direct or indirect operation. Econ omical, safe, highly satisfactory: let us Six sizes of enclosed CO* compressors: refer you to typical installations. Ask smooth running, efficient and reliable for Bulletins^504 and 512. machines; condensers, coolers, etc. Bul letins 118 and 124. FRICK FREON-12 REFRIGERATION Includes a com plete line of en closed type Freon-12 com pressors. Large capacity, ample gas passages, pressure lub rication from internal pump, patented One of Two Water Cooling Units, FLEXO-SEAL at shaft. Coils, coolers, conden- each with Two 15 in. x 10 in.Frick Freon-lt Compressors: H. 0. L. C. Bldg., Washington, D. C. sers and controls for Freon-12 systems. Bulletin 508. LOW PRESSURE REFRIGERATION 16-Ton Freon-lt Unitfor Air Conditioning Work Commercial units in more than 50 sizes and types, with motors of M to 30 hp. Charged with Freon-12 or methyl chloride. Air and water cooled conden sers. Finned coils, fan and blower units, ice cube and bever age coolers, etc. Bulletins 97 and 98. Frick Enclosed Freon-lt Compressor ' Enclosed Type " Enclosed Compressor for Ammonia Compressor Carbon Dioxide 861 Law Pressure Refrigerating Units 1 Air Conditioning Air Conditioning Atlanta Birmingham Boston Buffalo Butte Ingersoll-Rand Company 11 Broadway, New York City Branches or Distributors the World Over Chicago Cleveland Dallas Denver Detroit Duluth El Faso Hartford Houston Kansas Citt Knoxville Los Angeles Newark New Yore Philadelphia Picher Pittsburgh Pottsville Salt Citt San Francisco Scranton Seattle Sr. Louis Tulsa Washington 1 CAMERON PUMPS Cameron Moiorpump The units consist of standard "Motorpumps" mounted on 15-, 30-, or 60-gal tanks and controlled by a float switch. They are suitable for use in schools, apartment houses, greenhouses, industrial plants, chemical plants, etc. They are often used to replace inefficient steam traps. AIR COMPRESSORS WATER-VAPOR REFRIGERATION The use of water as the only refrigerant eliminates the leakage, storage and yearly replacement cost often encountered with systems using other refrigerants. Building owners are relieved from restrictive ordin ances governing the use and storage of such refrigerants. Water-Vapor Refrigerating Units oper ate entirely under vacuum, and may be opened up for inspection whenever desired. They give low operating costs by saving refrigerant replacement and by economical operation at all loads. Ability to handle . overloads is an inherent characteristic. Full capacity is retained for the life of the machine. Two types of units--Steam-Jet Cooler and Centrifugal--permit the selection of the type of equipment designed to meet widely varying conditions of steam or electric power, cooling water supply and refrigerating requirements. I-R Units are sold through reliable con tractors for field installation as a part of air conditioning systems. There is an efficient, reliable Cameron pump for every purpose. Single-stage STEAM-JET COOLER TYPE CENTRIFUGAL TYPE centrifugal units range from 40 to 100,000 gpm, and multi-stage units (2 to. 8 stages) range from 125 to 3000 gpm for pressures up to and over 3000 lb. The Cameron 11 Motorpump" is ideal for general service everywhere, ranging in sizes from 3^ to 40 hp. Pumps and motors are built as one compact and efficient unit on a single shaft. They can be mounted in any position on the door, wall or ceiling. Type "S0n Tvo-Stape Comprettor Capacities range from 5 to 1000 gpm for heads as high as 240 ft. single-stage; and from 20 to 275 gpm for heads up to 500 ft two-stage. Motors for any common current conditions; open, splash-proof, totally-enclosed, or explosion-proof types. A "Type 30" Air Compressor is an ex cellent source of compressed air for use with regulating devices or control equip ment, and for many other applications re quiring small capacities. It is a self- contained plant, consisting of a compres CONDENSATE RETURN UNITS sor, driving motor, air receiver and auto matic pressure control switch. The com pressor is either single- or two-stage, using I-R plate valves. Cylinders and inter cooler are air cooled. Capacities range Cooling is effected by direct evaporation The centrifugal water-vapor refriger of water at high vacuum. Steam-jet ating unit likewise cools water by direct ! boosters maintain the vacuum and dis- evaporation of water at high vacuum. A I charge the evaporated water vapor into a centrifugal type compressor maintains the ` surface condenser. (When desired, baro vacuum by compressing the water vapor from 1.2 to 102 cfm. Pressures range from. 5 to 1000 lb per sq in. Ingersoll-Rand manufactures more than metric type condenser units can be fur and discharging it into the condenser. nished). The heat carried away by the Units can be furnished with electric- evaporation of the water vapor chills the motor or highly efficient steam-turbine 1000 sizes and types of compressors. in main body of water as it is circulated drivers. Turbines may be either of the cluding a complete line of ammonia com through the unit. low-pressure or high-pressure type, and pressors. The I-R patented design has been may be designed for back pressure or for specially developed to insure reliability condensing operation. OTHER I-R PRODUCTS and simplicity of operation. Steam-Jet An important feature is self-regulation; Coolers are free from noise and vibration, units simply float on the load, giving in Surface condensers; counter-current and and are easy to install and maintain. herently reduced power consumption with ejector-jet barometric condensers; steam- Standard sizes are available for capaci decreasing demand. The capacity, is jet ejectors; vacuum pumps; centrifugal ties of approximately 10 tons upward for sustained for life due to the elimination of "Motorpump" Condensate Return Units blowers; air aftercoolers and receivers; chilled water temperatures of 35 F and wearing parts. are designed to return condensation from Diesel and gas engines; air and electric higher. Units are built for steam pres Standard sizes are available for capaci radiation systems, heaters, steam coils, hoists; rock drills; and pneumatic tools of sures of 2 lb gauge and upward. ties of approximately 100 tons upward. etc. many kinds. 862 863 Air Conditioning General Refrigeration Corporation Beloit, Wisconsin, U. S. A. Suspended Ceiling-Type Cooling Unit--for use with or without air ducts. Especially adapted for small commercial establishments--suspended from ceiling or placed in transom above entrance door. GR-Lipman Methyl Chloride,-- Freon-12 and Ammonia type refrigerating machines have successfully met most rigid tests--in laboratory and in actual service. Smaller sizes use Methyl Chloride or Unit Cooler--suspended type, pro peller-fan unit designed for cooling, de humidification and circulation of air. Direct-expansion Freon-12, or Methyl Chloride; or coid water circulating type. Self-Contained Cooling Unit Self-Contained Air Conditioners-- shipped ready to operate as soon as con nections are made. Electric motor control, refrigerant control and valves integral parts of equipment and adjusted before ship ment. Domestic, commercial and indus trial service. Sizes to 145,000 hourly Btu capacity; blower fan capacities to 4000 cfm. GR Evapora tive Type Con denser--utilizes air and water spray to remove heat of condensation; re frigerant gas con densed by cooling effect of water sprayed over con denser coil with large volumes of air forced over the coil. Copper tubing coil for use with Freon-12 or Methyl Chloride. Freon-12 refrigerant; in larger sizes Am monia is used. Models up to and including 2 hp may be either water cooled or air cooled; where electricity is not available, gas-engine driven units are obtainable. Types and Capacities Methyl Chloride....... 34 to 5 hp Freon-12....................34 to 15 hp Ammonia...................1 to. 40 hp Small sizes self-contained, fully automat ic; larger sizes, not self-contained, manual control optional, available up to 40 hp. Many different models of GR-Lipman refrigerating units are available--complete information sent upon request. Air conditioning units for industrial pur poses, for railroad cars and for air liners are also available. A complete line--practical, depend able. Dealers, contractors, engineers, architects--write for full information. 864 Air Conditioning McQuay, Inc. 1600 Broadway, N.E., Minneapolis, Minn. MANUFACTURERS OF EQUIPMENT For AU Phases of AIR CONDITIONING McQuay Unit Heaters-- all copper heating elements, full floating. Furnished in 43 sizes. McQuay Comfort Cooler --combination cooling and heating units for water or brine and direct expansion refrigerants. Numerous sizes with capacities to fit any re quirement. Comfort Cooler Unit Healer Air Conditioning Coils McQuay Air Condition ing Coils--for central fan heating and cooling systems. Using direct expansion refrig erants or water for cooling; or steam or hot water for heating. Wide variety of sizes for any air conditioning application including indus trial processed drying. McQuay Unit Coolers-- for storage rooms, truck refrig eration , etc. Available in seven sizes. For all types of refrig erants, including ammonia. Unit Cooler McQuay Concealed and CabinetCopper Convectors --furnished in exposed or recessed types. McQuay Cabinet Room Cooler--Floor Type, using water or refrigerant as the cooling medium; available in a number of sizes. Evaporator Coil McQuay Evaporator Coils--for all phases of com mercial refrigeration work. A flexible line of special coils tailor-made to fit specific re quirements. .. Coils for am monia installations available. McQuay Suspended and Floor Type Heating and Cooling Units--capacities 3 to 35 tons. Air Conditioning Unit Floor Type Blower Cooler New descriptive bulletins on all McQuay products available upon request. 865 Air Conditioning Jos. A. Martocello & Company 229-31 North 13th Street, Philadelphia, Pa. ATOMIZING SPRAY NOZZLES Martocello Atomizing Spray Nozzles contribute greatly to the general ef ficiency of air washing and air conditioning installations, and permit the complete apparatus to function at its maximum rated capacity. Successful--efficient oper ation of air washing and air conditioning equipment de pends largely upon having the proper design of spray nozzles. Martocello Atomizing Spray Nozzles are used ex clusively by many manufac turers because they give a uniformly fine, wide spray having a spread of 95 to 115 deg. For obtaining maximum efficiency from our Standard Spray Nozzles, we recommend with orifices as indicated in the table below. Any reason able range of capacities at various pressures can be ob tained from the sizes shown. Types of Martocello Spray Nozzles We appreciate all difficult Air Conditioning problems being submitted to us for proper recommendations and results. . Sizes and Capacities v Pipe Size Inches Part No. Diam. Orifice Inches Vs 1930 '/ 1910 1910 Double '/ 1920 Vt 2300 Vi 2304 V* 2306 7/64 13/64 5/32 17/64 7/32 5/16 11/32 51b .22 .54 .86 1.48 1.98 2.66 3.59 iOlb .29 .77 1.18 1.96 2.63 3.77 4.87 Capacity, Gallons per Minute 151b .34 .96 1.48 2.38 3.15 4.71 5.92 20 lb' .39 1.13 1.76 2.75 3.62 5.52 6.83 25 lb .44 1.29 2.02 3.08 4.05 6.24 7.62 301b .49 1.44 2.24 3.36 4.44 6.87 8.33 35 lb .54 1.58 2.44 3.60 401b ' .59 1.71 2.63 3.82 4.80 7.47 8.98 5.13 8.04 9.60 Brass Forged Nozzles illustrated and also Cast Red Brass Nozzles in 1 in. to 2 in. Pipe Size carried in stock for prompt shipment. Satisfaction Guaranteed 866 Air Conditioning Merchant & Evans Company Est. 1866 2035 Washington Ave. Philadelphia, Pa., U. S. A. Manufacturers of Condensing Units for Refrigeration and Air Conditioning Cable Address Mervenlry Philadelphia A complete line of M & E compressors variety of speeds necessary for various and condensing units for commercial and temperature work such as ice-cream pro air conditioning service are available in duction, milk cooling and air conditioning capacities from M to 25 hp. Compressors are carried in M & E stock. On models 5 are made either air cooled or water cooled to 25 hp a special automatic belt tightener for use with either Methyl Chloride or is supplied to ease motor starting loads, | Freon as refrigerant. save power and minimize wear on belts. ) Water-Cooled Models, are provided All models of M & E compressors and ; with high and low pressurestat, across-the- condensing units are approved by the J line starter, overload protection and water Underwriters' Laboratories. j valve, as standard equipment. Water coil Catalogs and data sheets giving com ] . in receiver--continuous flow type--up to plete information about M & E equipment | and including 15 hp; shell and tube type in may be had upon request. 20 and 25 hp models, M & E ratings are certified to the Refrig j Air cooled condensers are of large size eration Division -- National Electrical and made of seamless tubing with continu Manufacturers Association in accordance ous fin condenser tubes of ample capacities. with standard methods sponsored by the Pulleys and Belts suitable for the large A merican Society of Refrigerating Engineers. i 867 Air Conditioning Niagara Blower Company AIR ENGINEERING EQUIPMENT AND SYSTEMS General Sales Office: 6 East 45th Street, New York City Buffalo Rochester Boston Philadelphia Pittsburgh Chicago St. Louis Seattle Cleveland Toledo San Francisco 16 Years' experience in the engineering, design and installation of complete air conditioning PRODUCTS--Exact Control Air Conditioning, Humidifying, Dehumidifying. Drying, Moistening, Chilling, Comfort Systems, Niagara Air Con* ditioners, High Humidity Spray Coolers, Fan Coolers, Fan Heaters, Cool ing Coils, Heating Coils, Evaporative Aero Condensers. NIAGARA AIR CONDITIONING SYSTEMS For human comfort and for all industrial applications requiring controlled climatic conditions of temperature, relative humidity, air purity and air movement. NIAGARA AIR CONDITIONER, TYPE A Seven sizes. Available both in floor mounted and space saving suspended types. Maintains constantly or makes any change required in temperature and relative humidity. NIAGARA AIR CONDITIONER, TYPE C (Illustrated) Uses Surface Cooling Coil method for cooling and dehumidifying. Seven sizes. NIAGARA SURFACE COOLING COIL METHOD A year around operating system providing winter heating and humidifying and summer cooling and dehumidifying. NIAGARA FAN COOLER Niagara Type C Air Conditioner Niagara All Aluminum Surface Coil Air Conditioner, manufac tured in 7 sizes, both floor mounted and ceiling suspended models. In 1-, 2-, 3-, and 4-fan units and in seven sizes. For comfort cooling, process cooling, low temperature storage for dairies, fruits, meats, food products, fur storage vaults, etc. NIAGARA DISK FAN COOLER For overhead suspension in small storage areas, market coolers, etc. NIAGARA SPRAY COOLER For all cooling applications requiring high humidity or high capacity in small space. Available both in floor mounted and space-saving suspended types. In 1-, 2-, 3-, and 4-fan units--seven sizes. NIAGARA EVAPORATIVE AERO CONDENSER--{Illustrated) Saves power and water cost utilizing atmospheric air to remove heat of condensation. Seven sizes. NIAGARA FAN HEATERS For heating and ventilating large areas. Manufactured in 1-, 2-, 3-, and 4-fan units and in seven sizes. \ NIAGARA HUMID HEATER Recommended for industrial applications where heat and humidity are required. NIAGARA COOLING COILS . 13 standard lengths for blast cooling installations in both 20-in. and 30-in. widths. Manufactured in aluminum and copper. Niagara Evaporative Aero Con denser. Manufactured in 7 sizes. Furnished for use with all re frigerants. NIAGARA ALUMINUM HEATING COILS For use with fan heating systems giving the advantage of aluminum, light weight and resistance to corrosion. Complete range of sizes. NIAGARA DISK FAN HEATERS Operate with low discharge temperature, cut down roof and wall losses. All aluminum and copper core models. 868 Air Conditioning Parks-Cramer Company Fitchburg, Mass. Charlotte, N. C. CERTIFIED CLIMATE Complete Air Conditioning Systems including Heating, Cooling, Humidifying, De-humidifying, Ventilating, Refrigeration, Air Filtering and Air Washing AUTOMATIC REGULATION Industrial Heating by Oil Circulation with Merrill Process Central Station High Duly Humidifier Psychrostat Pettifogger Central Station Air Conditioning A centrally located apparatus supplying maximum moisture needed with positive pre-determined air change. Usually includes indirect radiation for heating --may include refrigeration and cooling. All air is washed. Where absolute and centralized control is desirable:-- helps in many industries, notably, Textiles (Cotton, Wool, Worsted, Silk, Rayon, Jute); Printing and Lithographing; Cigar, Cigarette and Tobacco; Clothing; Paper and Envelope; Leather and Shoes; Wood Products; Cereals; Storage of Perishables; Cera mics; Celluloid; Glassine Paper; Starch and Dextrine;Cement. Installations similar in design are effective in Hospitals, Art Galleries, Auditoriums and Restaurants. Nozzles For Central Station Air Washer (not illustrated) Low pressure type, durable, economical. High Duty Humidifier Water under pressure generates spray. Excess water returns to filter tank and recirculates. Evaporation per unit high; two sizes of heads each with two sizes of noz zles give flexible capacity for varying conditions. Circu lation increased by individual motor-driven fan. Spray thoroughly diffused and distributed over wide area. Turbo and Turbomatic Humidifiers (not illustrated) Efficient humidifiers of the atomizer type. For direct humidification and as humidity boosters for Central Station systems of all makes. Automatic Regulation The Psychrostat for accuracy, durability, sensitivity. Hygrostat (not illustrated) where requirements are not so exacting. Psychrostat employs the principle of the Sling Psychrometer, used by U. S. Government in all Weather Bureau Stations. An Air Conditioning System is no better than its Regulation. The Pettifogger A compact humidifier for offices, stores, storerooms, testing laboratories, and other isolated departments. Entirely self- contained in attractive lacquered copper casing. Permanently though flexibly connected to water and electrical supplies. Automatic control. Adjustable capacity. Reduces dust. ,, Neutralizes drying effect of heating. Conditions textiles and other hygroscopic substances for testing purposes. - 869 Air Conditioning Research Corporation 405 Lexington Avenue, New York City RESEARCH SYSTEM OF AIR CONDITIONING (Patented and Patent Pending) The Research System of Air Condi tioning functions without the use of refrigeration. The conditioning unit, called the Calorider, cools and dehumidihes the air, the latent heat being carried off as sensible heat together with a portion of the original sensible heat of the air, by cooling water. In a Concentrator unit the hygro scopic brine is continuously reconcen trated at the same rate that it is diluted in the Calorider, under fully automatic control. By a completely automatic reversal of the cycle, the identical equipment gives heating and controlled humidifi# cation in the winter. This sytem has two distinct functions: (I) Control of temperature, humidity and air purity for human comfort and health at low operating cost. (2) Control of humidity and air purity for industrial applications, including the drying and purification of gases. Advantages of Research System of Air Conditioning 1. Installation costs are moderate, opera ting costs are cut 50 to 80 per cent. 2. Cooling water at 70 deg gives condition ed air with dew-point as low as 22 deg. 3. Maintenance is simple, cheap and in frequent. No reciprocating machinery --no gas to leak. The only moving parts are fans, pumps and their motors. 4. Noise and vibration limited to that of main air supply blower. 5. Fully automatic control, all year around if desired; relative humidity may be held =*= 3 per cent at any point between 15 and 50 per cent. 6. Equipment available in sizes of 1000, 3000, 6000, 9000 and 12000 cfm. COEY MULTISTAGE COOLING TOWERS (Patented and Patent Pending) "Water Saved is Money Earned" The Coey Multistage Cooling Tower is constructed of a copper bearing steel shell, nickel iron castings, Red Gulf Cypress wood baffles, a non-overloading reverse blade centrifugal fan rotor, and the Coey Spray Eliminator of copper bearing steel. Compact, light in weight, spray free and quiet in operation, it is desirable for instal lation anywhere, but is especially well-suited to roof and basement installations. Controlled Cooling. Minimum Noise Level. Sprayless Operation. Architectural Harmony. No. Gpm l in Short Dia meter Height Above Beams Net Weight Tower Est. Weight of Water Total Oper. Weight 4 40 10 100 26 250 33 375 SO 550 85 850 110 1100 ISO 1400 6 3'-2' 6 5'-0* 6 9MT 6 lO'-O* 6 ll'-9' 8 !4'-6' 8 I6'-9# 8 \yjy 9'-0# U'4" l4'-9^ IT-*' ivjp 25'-<r 1000 3000 10000 13000 16500 24000 35000 44000 500 1300 3500 4500 6500 11000 14000 19000 1500 4300 13500 17500 23000 35000 49000 63000 Other Equipment: Cottrell Electrical Precipitation Systems--Multiclone Dust Collectors--Impact Separator--Cottrell Royster Deodorizer--Royster Stove for High Temperature Heat Exchange. 870 Air Conditioning Servel, Inc. Electric Refrigeration and Air Conditioning Division Evansville, Indiana AIR CONDITIONING True Summer air conditioning demands simultaneous control of at least five functions, but paramount in the customer's mind are cooling and dehumidification. To meet the customer's demand in this regard, the architect and the contractor must be sure that the cooling elements selected are adequate and dependable. In the warm, humid climates where a real demand for Summer air conditioning exists, it has been thoroughly demon strated that there is no practical, economical substitute for mechanical refrigeration, if both temperature and humidity are to be kept within bounds. Good mechanical refriger ation products are therefore the cornerstone of the air conditioning industry--the indispensable foundation upon which all other elements are erected. Servel contributes to the air condition ing industry a proven line of mechanical refrigeration products. These products are backed by over 15 years of engineering research and practical application experi ence in air conditioning and allied fields. Sound basic designj plusjneticulous care in selecting materials and in manufactur ing operations, plus continuous field testing, insure a product that delivers full capacity--economically--with a minimum of service. A BROAD LINE 15 to SO Tons Servel machines for air conditioning duty cover the entire range of popular sizes, including 1, 1^, 2, 3, 5,-6, 7Ht 10, 15 ana 20 ton capacity, and offer ing in various brackets air-cooled, water- cooled and evaporative type condensers. Small, compact units are available in popular sizes for self-contained or com partment application. Larger sizes may be located.remotely and used either with multiples of small room coolers or with central fan systems. 4 to 7 Tons SPECIAL MACHINES Servel has facilities for building any practical type of refrigerating machine required for special applications. Nine distinct compressor sizes, 2, 3, and 4 cylinder, may be combined with almost any con denser, base, or frame arrangement on quantity purchases. Typical Compressor Our engineers will gladly give assistance in planning your program, without obligation. Technical data, specifications and other details wjH be forwarded to responsible firms on request. EVAPORATIVE CONDENSERS High water rates, and sometimes actual shortage of water or sewage facilities, demand these economical auxiliary units. Servel offers five sizes--5 to 20 ton--shipped complete in every detail including coil, blower, pump, receiver, eliminator, by-pass connection, motor, drive and control. All sizes designed to handle full capacity with condensing temperature within 25 F of entering wet bulb. . 871 Air Conditioning The TRfillE Company 2021 Cameron Avenue, La Crosse, Wisconsin MANUFACTURERS OF HEATING, COOLING AND AIR CONDITIONING EQUIPMENT ' Over 70 U.S. Branch Offices. Albany, N. Y., Altoona, Pa., Amarillo, Tex., Atlanta, Ga., Aurora, 111., Baltimore, Md., Birmingham, Ala., Boston, Mass., Bridgeport, Conn., Brooklyn, N. Y., Buffalo, N. Y., Canton, Ohio, Charleston, W. Va-, Chattanooga, Tenn., Chicago, 111., Cincinnati, Ohio, Clarksburg, W. Va., Cleveland, Ohio, Columbus, Ohio, Dallas, Tex., Davenport, la., Dayton. Ohio, Denver, Col., Des Moines, la., Detroit, Mich., Flint, Mich., Greensboro, N. C., Harrisburg. Pa., Houston, Tex., Indianapolis, Ind., Jackson, Miss., Jacksonville, Fla., Juneau, Alaska, Kalamazoo, Mich., Kansas City, Mo., LaCrosse. Wis., Lake Charles, La., Little Rock, Ark.. Livingston, Mont., Louisville, Ky., Los Angeles, Calif., Memphis, Tenn., Milwaukee, Wis., Missoula, Mont., New Haven, Conn., New Orleans, La., New York City, Newark, N. J., Norwich, Conn., Oklahoma City, Okla., Omaha, Neb., Peoria, 111., Philadelphia, Pa., Phoenix, Ariz., Pittsburgh, Pa., Portland, Ore., Portsmouth, Ohio, Richmond, Va., Rochester, N. Y., St. Louis, Mo., St. Paul, Minn., Salt Lake City, Utah, San Francisco. Calif., Schenectady, N. Y.. Seattle, Wash., Sioux City, la., South Bend, Ind., Syracuse, N. Y., Toledo, Ohio, Washington, D. C., White Plains, N. Y., Wilkes-Barre, Pa., Wilmington, Del., Zanesville, Ohio In Canada: Trane Company of Canada, Ltd., Toronto, Ont. TRANE PRODUCTS Convectors Blast Coils Booster Coils Water Cooling Coils Direct Ex pansion Coils Projection Heaters Unit Heaters Unit Coolers Unit Ven tilators Air Conditioners Humidifiers Evaporative Condensers Railroad Air Conditioners Sub Coolers Product Coolers Air Washers Pumps Heating Specialities TRANE DATA FOR ARCHITECTS AND ENGINEERS Material is in bulletin form, 8% in. x 11 in. size, carefully arranged and profusely illustrated for convenient reference. Bulletin 290--Trane Products. The complete Trane line of Heating, Cooling, and Air Conditioning equipment at a glance. Capacity ranges indicated. Includes index to all Trane bulletins. 16 pages. Bulletin 110--Trane Convectors. A general bulletin of Convector appli cation information. Design and construc tion. Typical installations. 24 pages. Bulletin V205--Technical Data on Trane Convectors. Models. Designs. Applications to vapor, vacuum, hot water, and one-pipe steam systems. Installation details. Piping connections. Specifications. Roughing-in dimensions. Capacities. 28 pages. Bulletin 284--Trane Projection Unit Heaters.. Bulletin 294--Trane Multiple Projection Heaters. Revolutionary new draw-through pro peller type, unit heaters. Construction. Features. Advantages. Trane patented Temperature Equalizing System illus- trated and described. Examples of fuel saving. Roughing-in dimensions and ca pacities. Each Bulletin 8 pages. Bulletin 284 covers single fan units. Bulletin 294 covers two and three fan units. Bulletin 75--Torridor Unit Heater Bulletin. Complete description. Operation. Range of sizes. Capacities. Wiring diagrams. Piping details. Application suggestions. Selection data. Roughing-in dimensions. Specifications. 24 pages. Bulletin 85--Trane Propeller Type Cra dle Coil Unit Heaters. ' Where and how to use. Explanation of Cradle Coil and Floor-Line-Spread. Data on over sixty sizes. How to figure special capacities. Control details. Piping and wiring diagrams. Roughing-in dimen sions. Capacities. 16 pages. Bulletin V260--Trane Heating Special ties. Construction and operation of traps, valves, vents, and specialties for heating systems and industrial applications. Tech- 872 The Trane Company Air Conditioning nicaldata. Pipe sizing details. Application suggestions. Roughing-in dimensions. Weights. Capacities. 36 pages. Bulletin V235--Trane Air Conditioners.. DeLuxe, Hotel and Office, and Com mercial Air Conditioners completely and simply described. General information on Trane Evaporative Condensers. Oper ating features explained. 16 pages. Bulletin V234--Technical Data: Com mercial Air Conditioners. 36 pages. Bulletin V271-- Technical Data: DeLuxe Floor Model Air Conditioner, 16 pages. Bulletin V241--Hotel and Office Air Conditioner. 12 pages. ... The above technical air conditioning bulletins contain control, duct work details, application suggestions, specifications, roughing-in dimensions and capacities, in addition to valuable general air con ditioning data. Bulletin 230--Trane Climate Changers. Data on year around air. conditioners for residences and small buildings. Con struction details. Control data. Instal lation suggestions. Data on Split System. Roughing-in dimensions. Capacities. 8 pages. Bulletin V239--Trane Air Conditioning Installations. " A host of outstanding Trane Air Con ditioning installations. 20 pages. Bulletin 285--Trane Type "X" Comfort Cooler. A unit especially designed for appli cations where water is used as a refrigerant. For small and medium size jobs. Features and operation. Installation suggestions. Roughing-in-di'mensions. Capacities. 2 pages. Bulletin 42--Trane Evaporative Con densers. . Where and why used. Operation fea tures. Construction details. Dimension and capacity data. 4 pages. Bulletin V98--Technical Data on Evap orative Condenser. ' Advantages. How they operate. Con struction data. Installation and main tenance information. Use of capacity tables. Essential cooling data. Specifi cations. Roughing-in dimensions. Capa cities. 12 pages. Bulletin 152--Trane Extended Surface Heating Coils. Construction features. Heating surface and air friction tables. Selection guide. Temperature rise chart. Piping and.instal lation details for high and low pressure systems. Methods of applying automatic temperature control. Pipe sizes and details. Performance data. Specifications. Roughing-in dimensions. Capacities. 40 pages. Bulletin 172---Trane Direct Expansion Cooling Coils. Complete, accurate data on direct ex pansion cooling. Design. Selection.. Piping details. Header arrangements. Properties of air and water mixtures. Heat content of air data. Trane psychrometric chart. Refrigeration pipe sizes. Rough ing-in dimensions. Capacities. 28 pages. Bulletin 182--Water Cooling and Heat ing Coils. Applications of water cooling with ex amples. Comparative operating cost charts. Coil construction. Heat content of air data. Properties of air and water mixtures. Mean temperature differences. Piping details. Specifications. Roughingin dimensions. Capacities. 32 pages. Bulletin V292--Type "S" Water Cool ing Coils. Supplement to Bulletin 182. Infor mation about Trane Type "S" Coils. Roughing-in dimensions. 4 pages. Bulletin 65--Trane Air-O-Lizers. Description of the Trane Unit Venti lator for schoolroom heating and venti lating. Also larger capacity Air-O-Vent described. Operating cycles and features. 8 pages. Bulletin 102--A Simplified Method of Figuring Radiation. How to figure radiation without the aid of tables. Practical examples. Written for the layman. 4 pages. Controls, by C. L. Ringquist. Series of articles assembled in bulletin form. Thorough technical discussion of controls for every phase of air condition ing. Complete tables and engineering examples. Drawings show operation of each control system. Articles, by William Goodman. Reprints of published articles covering interesting points in air conditioning. (1) "Air Conditioning Problems Solved by Spray Water--Air Chart." (2) "How to Avoid Trouble on Cooling Jobs With Evaporators Above Condenser." (3) "Pumping Head on Air Conditioning Systems Reduced by Using Siphon." (4) "Solving the Four Types of Process Air Conditioning Problems." (5) "How to Solve Heat Transfer Problems." (6) "Dehumidification of Air . With Coils." (7) "New Uses for the Psychrometric Chart in Simplifying Air Conditioning Problems." Air Conditioning UNIVERSAL COOLER CORPORATION Detroit, Michigan Automatic Refrigeration Exclusively Since 1922 Air Conditioning The Vilter Manufacturing Company Since 1867 Milwaukee, Wisconsin AIR CONDITIONING EQUIPMENT FOR INDUSTRIAL OR COMFORT COOLING COMPRESSORS OF MODERN DESIGN Ammonia "Freon 12" . Methyl Chloride Model W-1600, 15 hp Condensing Unit. A complete LINE of CONDENSING UNITS AND COMPRESSORS OF proved PERFORMANCE Whatever the job, there is a Universal Cooler condensing unit of outstanding capacity and performance . . . developed by an engineering organization WHO KNOW the requirements of the Air Con ditioning industry. More than 100 stan dard units covering- all motor sizes from ^ hp to 15 hp provide a complete line from which to choose. In addition, special units to meet specific requirements can be readily adapted from 13 Universal Cooler compressors. Because of high quality, low costs and a sales policy that eliminates competition in the field from the supplier . . . many leading manufacturers arebuying and selling Universal Cooler con densing units for air conditioning ap plications. For complete information, write to Universal Cooler Corporation. In Canada, Universal Cooler Co. of Canada Ltd., Brantford, Ont. Listed under Reexamination Service of Underwriters Laboratories, Inc. 874 Compressors by Vilter are the result of nearly seventy years of research, development and experience gained through thousands of installations in sizes from one ton to several hundred tons. These installations cover a range of applications from the most simple comfort cooling installation to the exacting requirements of temperature and humidity control necessary to the successful operation of certain industries. The Vilter "Freon 12" Compressors embody many outstanding new features two of which are of major importance and exclusive. A new, Vilter developed, shaft seal which prevents leakage, and the elimination of certain friction factors which result in extremely low relative horsepower per ton. Vilter Air Washers--designed for industrial air conditioning. Positive control of humidity, temperature, and circulation of air. Automatic or hand operated. Eliminators are incorporated for entrained moisture removal. Odors and dust are removed by water sprays. No filter replacement. Low cost operation. Good for low or high temperature cooling. . Vilter Mono-Unit Air Conditioners--are built in a complete range of sizes and types from small ceiling units to large floor units. For refrigeration and air conditioning projects Vilter can supply the equipment. UNIT AIR CONDITIONERS Dry Coil Spray Type Air Washer available for the asking. Whether the application requires a standard unit conditioner of the dry coil or spray type or a large central system of the Washer type, Vilter Equipment of sturdy construc tion and ample capacity is available. 875 Air Conditioning Air Conditioning Westinghouse Electric & Manufacturing Co. Mansfield, Ohio Sales, engineering and service facilities available through local distributors in principal cities York Ice Machinery Corporation General Offices: York, Pennsylvania Direct Factory Branches in 70 U. S. Cities Complete Air Conditioning and Refrigerating Systems for maintaining proper atmospheric conditions for industrial pro cesses and human comfort. Available in central and unit sys tems . . . from fractional tonnage up to any capacity required. HERMETICALLY-SEALED CONDENSING UNITS A proved development of Westinghouse Research and Design Engineers is a complete line of Hermeticallysealed Condensing Units for air con ditioning--from 1 to 40 tons capacity. These new machines are forty per cent smaller in size, as much as fifty per cent lighter in weight. They permit great flexibility in the design of systems, save money in original installation costs and upkeep. Entire operating mechanism is en closed in one solid casting, eliminating protruding shafts and troublesome "stuffing boxes." Direct drive of crankshaft by motor located inside the housing eliminates the necessity of,a heavy supporting chassis, while greatly reducing noise and vibration. The complete mechanism is water-cooled, including the motor, permitting instal lation in unventilated locations. By removing the side plates of the crankcase casting, the entire operating mechanism is accessible for adjustment Westinghouse Hermetically-sealed Unit, Type CLS-795 Rated capacity: 266,400 Blit/Hour. Weight: 2,000 lb. and service. No refrigerant or water lines need be disconnected. In all, seventeen important improvements have been introduced in these new Westinghouse Condensing Units for air conditioning. Air Conditioners--Horizontal and Vertical Models: Capacities up to thirty-five tons, unit air conditioners for horizontal or vertical installation, with or without ducts; with complete or partial automatic control, for complete year-round air conditioning--summer cooling and dehumidification, winter heating and humidification; year-round circulation, filtering and ventilation, including a definite supply of outside air introduced under the positive pressure of the supply fan of the conditioner. Standard Dehumidifiers--With or Without Coils: York air dehumidifiers have been developed to obtain unusually efficient performance when compared with conventional air washer design--accomplished by a refined system of water distribution and improved inlet deflector and eliminator arrangement. Can be furnished in all sizes and capacities, seven feet standard length, with and without cooling coils depending upon require ments. When evaporator coil surface is included in the spray chamber of an air dehumidifier the usual water cooler furnished with the refrigeration system can be eliminated. Both types of air dehumidifiers regularly furnished as a part of central station air conditioning systems being so arranged with fans, heating equipment, automatic controls, air distributing ductwork, and acces sories to provide year-round air conditioning. York Water Cooling and Condensing Systems: For dehumidification duty York offers a complete line of water cooling systems built in standard sizes up to 1000 NEW EVAPORATORS . . . CONDITIONING UNITS . . . MOBILAIRE hp capacity. Supplied for both industrial as well as comfort cooling applications. Long Life--made possible by the use of non-ferrous heat transmission surfaces in condenser and cooler--slow speed positive displacement reciprocating compressors. Safety--made possible by the use of the safe refrig erant Freon-12. . High Efficiency--made possible only by the careful proportioning of condensing and cooling surface against refrigeration compressors of the vertical single acting reciprocating type. Economical operation obtained at York Standard Dehumidifier with Coils all conditions of load through manual or automatic capacity reduction bypass valves built in the compressor. Space Requirements--50 per cent less than steel tube designs--arranged for easy access and maintenance. 1 For applications of direct expansion cooling the water WE Evaporators--A new line of extended surface Freon Evaporators ex actly matching in capacities the new Westinghouse Hermetically-sealed Con densing Units. Air Conditioning Units--Westing house provides over 30 different styles and sizes of air conditioning units in ceiling, wall or floor types. Available for summer conditioning, winter conditioning, or com plete year around service. Standard Water-cooled Mobilaire-- A self-contained room cooler, the Westing house Mobilaire provides complete summer air conditioning by cooling, dehumidifying, filtering and gently circulating the air. Easily installed in any room where electrical and water connections are avail able. It is powered by the famous West inghouse Hermetically-sealed Mechanism backed by a long term Protection Plan. York Water Cooling System cooling systems are furnished less the water cooler, thereby making possible the same advantages in Con densing Systems. The York Economizer, a combined forced draft cooling tower and refrigerant condenser. Replaces usual shell and tube condenser when water rates are prohibitive; where municipal ordinances restrict the use of water or where drainage systems or. sewers are inadequate. York Engineering Service: In York branches throughout the world, trained engi neers cooperate in preparation of plans for all types of Air Conditioning Applications. 876 877 Air Conditioning (Accessory Units) Air Controls, Inc. Div. of The Cleveland Heater Co. 1937 West 114th Street, Cleveland, Ohio Manufacturers of REX AIR-PAK Blower Filter Units, REX A C Blowers and REX AIRATE Air Circulators REX AIRATE ATTIC VENTILATOR Keeps a whole house cool in hot weather. Quickly and quietly draws the heat of the day up into the attic and exhausts it to the outside. AV-30-2 circulates 6,000 cfm; AV-36-2 circulates 9,000 cfm. All metal construction. Economical to operate. Complete ready to install. REX AIR-PAK CONDITIONER REX AIR-PAK blower-filter unit in conjunction with a modem humidifier will quickly convert a warm air furnace into a. winter air conditioning system. Auto matic By-pass Louvres permit unobstruc ted gravity circulation when blower is not operating. Easily assembled. Quiet in operation. REX-AIRATE VENTILATOR Ideal (or theatres, restaurants, stores and other commercial establishments where large volumes of air must be circu lated. Silent in operation and economical . to operate. 42 in. high. Circulates 7,000 cfm. Can also be furnished in many differ ent styles and sizes. REX A C BLOWERS A C Blowers are ruggedly built and carefully engineered. Self-aligned bearings are isolated on rubber pads and require oiling only once a year. Unusually quiet. Can be installed to any furnace without inconvenience. ' BLOWER PARTS REX A C Blower parts such as wheels, housings, bearings, etc., can be furnished as standard equipment to furnace manu facturers and sheet metal contractors. 878 Air Conditioning (Accessory Units) The Lau Blower Company 954 E. Monument Ave., Dayton, Ohio Manufacturers of Furnace Blowers, Blower Wheels, Housings, Pulleys and Complete Assemblies 100 Series Blower Assembly Style HVS A complete blower assembly with motor, for manufacturers who have an established casing design, or for those who require an installation of a special nature. This unit is available in both single and double series, with or without motor assem bly. Guaranteed certified ratings. The 100 and 200 series (double unit) are available in five sizes. Write for perfor mance data and dimension charts to determine tfie size unit to meet your requirements. Blower Housings Constructed of extra heavy gauge steel. Welded construction. Scientifically de signed to guarantee uniform distribution of air. Blower Wheels Squirrel cage, forward curve, multi blade wheels. Double inlet, double width. All die-formed parts. Tested for dynamic balance. Guaranteed true and without vibrations at operating speeds. 700 Series Package Unit Furnace Blower The complete furnace blower for coal, oil or gas fired heating systems. Complete with Furnacestat automatic control, motor, filters, stream lined blower cabinet with chrome trim, variable speed drive, blower and full size access doors on both sides. Reversible motor and drive assembly --permitting the unit to be placed on the most convenient side of the heater--on the job. A knock-down unit, easily and quickly installed. 700 series package unit is available in twelve sizes. Knock-down casing can be assembled in a matter of a few minutes, yet makes a rigid completely assembled job. Send for simplified selector chart, performance data and dimension charts. Blue prints on wheels, housings, variable and constant speed pulleys supplied on request* 879 y Air Conditioning (Accessory Units) Schwitzer-Cummins Company Indianapolis, Indiana, U. S. A. BLOWER FANS VENTILATING FANS HOME-VENTILATORS HY- DUTY BLOWER-FILTERS HUMIDIFIERS HY-DUTY BLOWERS A superior line of blower fans from 10 in. to 25 in. dia.-- with or without motors and drives--available with either top or bottom horizontal, top or bottom vertical outlets-- efficient, thoroughly balanced and silenced. BLOWER-FILTER UNITS STOKOLAIR, de luxe unit with AIR MAZE all-metal filter and summer comfort damper door, and HY-DUTY models for the competitive priced field. Six models-- many useful exclusive features. All units furnished complete with full floating rubber mounted motor brackets, adjustable speed pulley, canvas connection and clamps, junction box and wired in BX cable. All openings cut and flanged. BLOWER-FILTER HUMIDIFIERS An advanced design embodying a dual system of humid ity control and all-metal indestructible filters. HY-DUTY BLOWER WHEELS Multi-blade type, diameters from 4 in. to 50 in., fur nished in single inlet and double inlet types. KIDNEY BLADE TYPE FANS Quiet and efficient. A full range of sizes. Blower Wheels and Propeller Fans for Every Purpose (See also Page 1136) 880 Air Conditioning, Automatic Heating Systems Acme Heating & Ventilating Co., Inc. 4224 Lowe Avenue, Chicago, 111. THE ACME HEATER--"It's in the Fins" The Acme Heater has been designed by experienced heating engineers, and is con structed by expert craftsmen. It combines the best practice in the design of direct transmission heaters, with marked improvements resulting from practical experience. Burns Any Kind of Fuel: A direct-transmission heater, such as the Acme, is not dependent upon the kind of fuel used--any type of fuel may be burned. Suitable grates may be provided so that bituminous, semi-bituminous, anthracite coal, or other solid fuels may be used with equal efficiency. Replacement of grates and linings by proper refractory material permits the use p of automatic stokers or oil burning ' equipment. Large Combustion Chamber: Provides ample space for ignition of gases of combustion, regardless of kind of fuel used. The unusually large combustion chamber, acting as "primary" heating surface, effects efficient transfer of heat, because of the great temperature difference be tween the burning gases inside the chamber and the air passing over the outside surface. Efficient Radiator Section: Although the heating surface of the combustion chamber is large and efficient, still more heat must be extracted to obtain satisfactory overall efficiency. The "phantom view" as shown reveals how the Phantom View of Acme Heater Showing Flow of Gases and .. Air Travel. Physical Data--Large Series gases of combustion enter the rear smoke chamber, flow to the front of the heater, and return again to the smoke-box. The gases are held in intimate contact with the heating surface, six times the length of the heater, before they are permitted to escape. Size No. Lgth Width Ht sq (t Heat Free Free Surf, sq ft sq ft Min. sq ft Max. Wt. Lb Max. Capacity Btu 7 6'-6* 8 8'-1' 9 9'-8' 10 IP-3' 4'-0jr T-<y 10.31 260 4'AT T-O' 11.91 340 4'-0" T-0* 13.06 430 4MT TV 14.43 300 6.55 10.25 5900 900,000 7.73,12.50 7000 4,100,000 8.91114.75 8000 1,300,000 15.82 22.62 9300 1,500,000 1 Junior Series High Ratio of Heating Sur face to Grate Area: The radiator tubes are covered with extended surfaces, or fins, typical of those used on indirect heating coils. The long, oval tubes of the radiator pro vide an exceptionally large heating surface which, combined with the surface of the combustion chamber, 2 4'-6' 3'-6' 5'-8' 3.9 136 4.7 4 7 3200 350,000 3 6'-O' 3'-6' yjr 6.1 183 5.9 6.9 4800 527,000 4 7'-6`r 3'-6' y-8' 7.2 230 7 l 9.1 5000 634,000 5 9/-0/f 3'-6' 5'-8' 9.3 280 8.3 11.3 6000 800,000 affords a remarkably high ratio of heating surface to grate area. Balanced Construction of the Acme Heater provides ample free Note: For automatic firing add 10% to ratings given. area and allows proper velocity of the air to be heated. Moreover, this air is brought into direct contact with as much heating surface as possible, resulting in the Acme of Efficiency. 881 Air Conditioning, Automatic Heating Systems Air Conditioning and Refrigeration Equipment /4/RTCMP m /NCORPORA TED CHRYSLER SUBSIDIARY DAYTON, OHIO Unitary and Central Station Equipment AIRTEMP RADIAL CONDENSING UNITS Self-Contained... in 10 and 75 Hp Capacities AIRTEMP "ALL-IN-ONE" 3 HP CONDITIONER The Airtemp "All-In-One" Air Condi tioner with exclusive Hermetically-Sealed Radial Compressor is a most advanced type of unitary equipment for commercial cooling. Compact--Entirely self-contained, the complete assembly occupies a floor space of approximately 20 in. x 33 in. . . . stands " 7 ft 6 in. high overall. Efficient--Truly a commercial air con ditioner designed and engineered for highly efficient duty. Mechanical Cooling--Airtemp's radi cally new and extremely efficient Her metically-Sealed Radial Compressor with '.automatic unloader is so compact that it is totally enclosed within the base of the cabi net. Operates at 1750 rpm. Has more cool ing capacity per pound of metal used. Unusually quiet, trouble-free operation - is assured, because the Radial Compressor has been designed to include the principles of the famous "Floating Power" mounting. Chrysler Engineered--The Airtemp "All-In-One" Air Conditioner is complete ly assembled at the factory, delivered ready for installation. Only 3 connections are needed. Chrysler's Airtemp line of equip ment is complete . . . meets every commer cial comfort air conditioning application. ..Consult the Airtemp representative or branch in your territory for complete . details and specifications. OUTSTANDING FEATURES Exclusive Airtemp Radial Compressor. Dynamically balanced . . . practically no vibration. Direct connected... no belts, no flywheel. Compact . . . requires less space. Reduced weight per ton of refrigerating effect. Automatic starting unloader permits starting without load. Low starting effort permits use of "gen eral purpose" motors. Automatic capacity regulator keeps unit constantly balanced to varying load re quirements . . . economical. Operates at peak efficiency under all loads. More tons of refrigeration per hp. Forced-feed lubrication. Uses Freon . . . the safe refrigerant. Shipped completely assembled . . . read ily installed. Designed, developed and backed by Chrysler Engineering. . 882 Air Conditioning, Automatic Healing Systems Direct-Fired Winter and Summer Air Conditioning Systems for Homes 0MTEMP m /NCORPOPA TED Oil Burners, Oil-Burning and Gas-Burning Boilers for Homes CHRYSLER SUBSIDIARY* DAYTON,OHIO________ AIRTEMP DIRECT-FIRED WINTER CONDITIONERS (Oil and Gas-Burning Models) (At Right) A complete line of compact, depend- ' able winter air conditioning units that heat, humidify, filter and circulate the air at the cost of heating alone. Equipped with Airtemp's Oil Burner or Airtemp's Gas Burner. Available in ' capacities of from 100,000 to 250,000 Btu per hour ' AIRTEMP BOILERS Made in sizes to meet every domestic heating need. Dependable in operation. Unusually economical. May be had with Airtemp's Oil Burner orAirtemp's Gas Burner. For steam or hot water in capacities of from 114,000 Btu per hour to 540,000 Btu per hour. Cast iron, sectionalized wet base construction. AIRTEMP OIL BURNERS Gun type. fFor use in Winter Air Conditioners, Boilers or for conversion work. Burn No. 3 fuel oil. Highly efficient. - Features such as Streamlined Draft Chamber, wasteless Carburetor, self-aligning Duprene Coupling, and.flame focusing adjustment make Airtemp's Oil Burners unusually dependable as well as economical. Engineered by Chrysler. Adjustable oil pressures. Capacities of from 1 to 9.5 gal oil per hour. ..! Completely enclosed wiring. Shielded transformer. AIRTEMP SUMMER CONDITIONER A single compact unit designed to operate with Airtemp's Oil and Gas-Burning Direct-Fred Winter Air Conditioners. Airtemp's Summer Conditioners can be added at any time. Unitcontains filters, com plete automatic controls, cooling and dehumidifying coil and Airtemp's exclusive, hermetically - sealed Radial Compressor . . . needs no special foundation. AIRTEMP CONDITIONER FOR SPLIT SYSTEM OPERATION , (At Right) A complete indirect-fired unit, consisting of fan, filters, humidifiers and heating coil. Designed for use with both Oil and Gas-fired steam or hot water boilers in connection with split system application. Ranging in capacities of from lift),000 to 191,000 Btu per hour for steam and from 95j000 to 111,000 Btu per hour for hot water. . 883 Air Conditioning, Automatic Healing Systems AMERICAN 'RADIATOR COMPANY division orAmerican Radiator & Standard Sanitary Corporation 40 West 40th Street, New York, N. Y. NEW AMERICAN RADIATOR CONDITIONING SYSTEMS Air Conditioning, Automatic Heating Systems AMERICAN RADIATOR COMPANY division ofAmerican Radiator & Standard Sanitary Corporation . 40 West 40th Street, New York, N. Y. NEW AMERICAN RADIATOR CONDITIONING SYSTEMS In this new kind of home conditioning presented by American Radiator Com pany, the heating operates independently of the other functions of air conditioning. This permits operation of the conditioning even when the heating is off, or of heating alone when no conditioning is necessary. It simplifies duct work, too, since ducts do not carry the heating load. The illustration on page 884 shows a typical system. The Conditioning Unit is suspended from the ceiling of the basement on rubber dampers. Air is filtered as it enters, then brought to a comfortable tem perature by tempering coils. A spray hu midifier provides correct moisture content. A Sirocco Blower in the unit silently forces the conditioned air through the house. A radiator system---steam, hot water or vapor--provides heat. There are new con trols, new valves, new vents which improve heat distribution. Arco Pipe and Fittings of pure wrought copper connect boiler, radiators and hot water supply system. Because of low conductivity they cut down heat loss; they are rustproof, cakeproof, and corrosion resisting. The system is simple to install. There is a minimum of duct work . . . outlets and return grilles being generally recommended only for the first floor, in as few rooms as is advisable. Introduced even at only one point, the conditioned air will naturally permeate the entire house. Another advantage of the system is in modernization work as the air conditioning unit is easily added to existing radiator systems. NEW ARCO AIR CONDITIONERS ARCO AIR CONDI TIONERS 101-B, 201-B CONTROLLED WARMTH SYSTEMS .. The Arco Model K Vapo-Orifice System is an engineered and coordinated unit which operates to insure equal distribution of warmth. On each radiator there is in stalled a special inlet valve with an adjust able orifice, by means of which flow of steam to each radiator can be accurately calibrated in accordance with the capacity of the radiator. The adjustment can be made while the system is in operation. Pressure is so controlled that no more steam.-is admitted to the radiators than they .are capable of condensing. There fore nqlthermostatic traps are required on the*retu^gconnections of the radiators. A .thermostatic air eliminator equipped with a.vacuum check is provided. If the pressure .^through inadvertence should exceed-*tnedesign pressure, steam will enter the return.lines, close the vent port of the air eliminator, arid the system will automatically equalize itself, insuring the return of condensate to the boiler. When a zone system is used, the zone valves prevent the self-equalizing action and it is necessary to install an Arco Condensation Pump to insure the return of condensate to the boiler. Simplicity of design and moderate cost make possible the installation of this system for little more than the cost of a One Pipe Steam System. "Standard Specifications" and "Design and Installation Guide" including all details are available at American Radiator Company branch offices. . USED WITH MODEL K SYSTEM Arco No. 900 Adjust able Orifice Valve--Orifice may be adjusted per manently to "meter" the correct amount of vapor to each radiator according to its capacity, to effect balanced heating. Designed to be part of American Radiator Con ditioning Systems, Arco Air Conditioners add Fresh Air Ventilation, ARCO AIR CONDITIONER 301-B ARCO AIR CONDITIONER 1101-B Humidification, Air Clean For larger homes--pro Combines in one jacket ing, Circulation to any vides heat as well as air No. 11 Oil Burning Boiler, radiator heated home or conditioning in conjunc Arco Air Conditioner and small building. Needing tion with steam or hot Taco Heater for domestic only simplified air mains, water boiler. hot water. Arco Air Conditioners are especially suitable for ARCO HUMIDIFIER No. 8000 modernization work. Adds correct moisture to [. radiator heated homes. Needs only one 3 in. main. Easily connected to any ARCO AIR FILTER boiler. ' Replacement type. Viscous coated. Pro vides 90 deg change in air flow. Available in many sizes. ARCO HUMIDIFIER No. 7000 A simple device, designed to be installed on the basement wall or ceiling. Blows hu midified air through a short duct and outlet grille into the rooms above. (See also American Radiator Co. pages 940-943. 1061, and Subsidiaries) 884 885 T Air Conditioning, Automatic Heating Systems American Gas Products Corporation Division of American Radiator & Standard Sanitary Corporation 40 West 40th Street, New York, N. Y. Gas Fired Air Conditioners The AGP Gas Fired Air Conditioner Type 2-FE has 32 features that place it in a class by itself. Among them are: A Single Combustion Chamber, AGP Thermotor Gas Valve, double inlet, double width, "Sirocco" Type a-c fan with down ward discharge through heater unit. This AGP Conditioner utilizes the highly effi cient counter-flow principle of heat trans fer. The furniture steel jacket of lustrous gun-metal enamel completely encloses all controls. AGP Air Conditioners embody all the improvements of completely auto matic conditioned heating that the finest research laboratories have produced. AGP Air Conditioner Type 2-FE RATINGS--DIMENSIONS--DATA Conditioner Number 2-FE- 4-100 2-FE- 4- 80 2-FE- 5-100 2-FE- 5- 80 2-FE- 6-100 2-FE- 6- 80 2-FE- 8-100 2-FE- 8- 80 2-FEIO-lOO 2-FE-10- 80 2-FE-12-100 2-FE-I2- 80 AGA Rating AGP Guaranteed Rating Input Btu/hour 100,000 100,000 125,000 125,000 150,000 150,000 200,000 200,000 250,000 250,000 300,000 300,000 Input Btu/hour 90,000 100,000 112,500 125,000 135,000 150,000 180,000 200,000 225,000 250,000 270,000 300,000 Output at Bonnet Btu/hour Output at Register* Btu/hour 72,000 80,000 64,800 72,000 90,000 100,000 81,000 90,000 108,000 120,000 97,200 108,000 144,000. 129,600 160,000 144,000 >80,000 200,000 162,000 180,000 216,000 240,000 194,400 216,000 Conditioned Space Cu Ft Maximum Fan CFM at 65 F Approximate Shipping Weight Lb 10,600 ^14,700 13,300 18,400 15,800 x22,000 21,100 29,400 26,600 36,600 31,700 44,000 . 660 920 830 1150 990 1375 1320 1840 1660 2290 1980 2750 1210 1210 . 1290 1355 1355 1520 1760 1775 2275 . 2315 2450 2500 For 1X0 Volt, 60 cycle, a-c or for d-c equipment. ' Note: AGP Guaranteed Ratings are based on thermal efficiency of not less than 80% of the rated AGP Btu Input. Register Output is based on 10% deduction for normal average heat loss in ducts. Conditioned Sfroce indicates the maximum cubic feet of the space which can be conditioned at rated fan CFM to insure quiet operation and adequate air circulation. - ' (See also Page 95S) . 886 Air Conditioning, Automatic Heating The Barber Gas Burner Company 3704 Superior Ave., Cleveland, Ohio Address Michigan Inquiries to The Barber Gas Burner Co., of Mich., 4475 Cass Ave., Detroit, Mich. Barber Automatic Jet Gas Burners for Heating and Air Conditioning Equip* ment and Numerous Gas-burning Appliances have won leadership through 20 years of research and manufacture. Used for heating thousands of homes and buildings throughout this country and Canada. Adopted by leading makers of gas appliances. The exclusive Barber jet principle of combustion, other basic advantages of design and numerous recent improvements, have kept Barber Burners apace with modern heating and air conditioning practice. Shown are only a few items from Barber's complete line. Write for No. 37-A catalog and price list. No. S. P.-15 Barber Burner Unit iz Vl- No. P.U.-160 Burner Unit Barber Gas Pres sure Regulators A.GjL. Approved Made in the following sizes: H". H*. M*. *A",\0. IK", 1M". 2*. No. C. U.-90 Barber Burner with Safety Pilot BARBER BURNERS AND REGULATORS are Adaptable to: Air Conditioning Equipment, High Pres sure Boilers (Tubular and Tubeless), Bakery Ovens, Garage Heaters, Coffee Urns, Hair Dryers, Space Heaters, Floor Furnaces, Clothes Dryers, Water Heaters, Confec tioners' Stoves,Vul canizing Machines, Pressing Machine Boilers, Japanning Ovens, Core Ovens, Banana Room Heaters, Other Ap pliances. Conversion Burner for Round Furnaces or Boilers Made to fit grate diameters from 12 in. to 34 in. Also to fit grates of oblong furnaces and boilers. Supplied with Baltimore Safety Pilot. Listed in the A.G.A. Directory of Approved Appliances. No. 336-B equipped with automatic controls with motor gas valve. Available in "A" series with magnetic gas valve control, "S" series with quick acting gas valve control (for buildings equipped with automatic heat control), and "M" series with manual control. Gas ^Burner Specialists offering Engineering Department and Laboratory facilities for Gas Burner problems. 887 Air Conditioning, Automatic Heating Systems THE BRYANT HEATER COMPANY Let (he pup be your furnaceman and weatherman too. 17825 St. Clair Avenue * * Cleveland, Ohio Sales, engineering, and installation facilities for Bryant gas-fixed equipment are available through distributors, dealers and gas companies in principal cities. BOILERS Bryant gas-fired boilers are available for residential, commercial and industrial heating, and for low-pressure steam requirements, in 177 different sizes. With 2 in., 4 in. and 6 in. boilers in either open or enclosed models, for steam, vapor, hot water, Bryant meets every need, including direct and indirect hot water storage heating. Features for economy and efficiency, developed during Bryant's 30 years of manufacturing equipment exclu-' sively for gas, include tubular cast-iron sections, ribbed lower tube, large steam liberating areas, all heating surfaces readily accessible for cleaning: Bryant Controls are used throughout. WINTER AIR CONDITIONERS Bryant gas-fired AC-78 units provide complete Winter Air Conditioning, include heating, humidi fying, cleaning, and circulating. Cast-iron heating sections, unusually large heat transfer area, staggered tubes with maximum scrubbing action, bring high efficiency. Unusually quiet fans of large capacity. Hu midi fying by evaporator pan. Compact, attractive, Bryant Blue Crackle cabinet, using standard Bryant Controls. FORCED-AIR HEATERS Bryant gas-fired forced-air heaters include vertical model as shown at left, and three sizes of horizontal units. The vertical type especially is remarkably compact, thus making it out standing for installations where space is limited. Especially adaptable for multiple installations in apartments or housing groups where tenant control is desired. Cast-iron heating section with chromium alloy heat exchang er tubes brings new efficiency and durability to this type of heater. Every safety protective device necessary to meet all codes is furnished, including high limit control. Completely automatic control provided by dependable, proved, Bryant control equipment, to provide uniform heat without care or attention. Entire unit enclosed in handsome Bryant Blue Crackle finish cabinet, compact and attractive. 888 The Bryant Heater Co. Air Conditioning, Automatic Heating Systems DEHUMIDIFIERS FOR COMFORT AND INDUSTRIAL APPLICATIONS Bryant gas-operated Dehumidifiers employ the exclusive Silica-Gel adsorption method, proved to be simple, compact, and economical for all types of air drying installations. Especially adaptable to industrial requirements, or to comfort dehumidifying for commercial installa tions, stores, restaurants, etc., and where sepa rate control of humidity and temperatures is essential. Two sets of Silica-Gel beds in each dehu midifier, alternately taking up moisture and being activated by a gas burner, provide a con tinuous stream and dehydrated air. * Completely automatic, control, exceptional economy in operation, and good appearance, characterize Bryant Dehumidifiers. . HUMIDIFIERS The new Bryant Humidifier, gas-opera ted, for residential use, delivers warmed and humidified air through one central outlet. It is extremely compact, economi cal to install and to operate, and is equipped with completely automatic con trols. UNIT HEATERS For commercial heating, in factories, stores, garages, restaurants, offices and similar locations, three sizes of Bryant Gas-fired Unit Heaters provide quiet, effi cient, economical service, either for total heat supply, or for auxiliary purposes. DUCT HEATERS l^or service in ducts carrying conditioned air from other central sources, Bryant gas-fired duct heaters are suggested. In a ventilating system, this equipment serves as a gas-fired tempering unit. DUALATORS Bryant gas-fired Dualators, when com bined with high efficiency steam or hot water boilers, bring the added advantages of a warm air distribution system. Circu lation of cold water or pther cooling medium provides for summer cooling. CONVERSION BURNERS Efficient combustion characteristics of Bryant conversion burners make possible their application to any type of central heating plant, to provide automatic gas-fired operation. FLOOR FURNACES For small homes, stores, meeting rooms, and similar installations where circulation is simple, Bryant gasrfired floor heaters bring a new solution to heating problems. CONTROLS . Bryant Controls, engineered exclusively for gas, combine simplicity, compactness, sen sitiveness, appearance, and ease of installa tion and service. See your local Bryant distributor, dealer, or gas company, for complete details on any Bryant equipment. Take your heating problem to Bryant for a modern and * efficient solution^ 889 Air Conditioning, Automatic Heating Systems v DelcO'Frigidaire Air Conditioning, Automatic Heating Systems Delco-Frigidaire Conditioning Division General Motors Sales Corporation Dayton, Ohio PRODUCTS OF GENERAL MOTORS Automatic Heating and Air Conditioning Equipment for Residential and Commercial Applications FRIGIDAIRE EVAPORATIVE CONDENSERS For localities where there is a scarcity of water, or water is available only at high rates, a series of Frigidaire Evaporative Condensers that greatly reduce quantities of water required is available for use in connection with Frigidaire Condensing Units. Frigidaire Evapor ative Condensers are available in 3, 6, 10,20, 30, and 40 tons nominal capacity. Distributors and Branch Offices in Principal Cities FRIGIDAIRE CENTRAL PLANT AIR CONDITIONING EQUIPMENT PRODUCTS--Complete line of air conditioning and automatic heating pro ducts, including: Condensing units, coils, self-contained room air condition ers, self-contained commercial air conditioners, central plant air conditioners, suspended type air conditioning units, evaporative condensers, oil and gas fired boilers, oil and gas fired winter air conditioners, oil burners* oil and gas fired automatic water heaters. Write to Dept. AS, Delco-Frigidaire, Dayton, Ohio, for latest information and detailed specifications, or consult nearest Delco- \ A series of units for duct distribution systems. Available in 6, 12, 21, and 30 tons nominal cooling capacity. Output of any unit may be varied through selection of coil and fan equipment. Water or Freon coils according to choice. May be equipped for heating in addition to summer air condition ing. Can be obtained for horizontal or vertical installations. Frigidaire Distributor whose address is listed in the classified section of your telephone directory. - FRIGIDAIRE SUSPENDED UNITS Designed for use singly or with other units of this type. These FRIGIDAIRE CONDENSING UNITS Frigidaire Condensing Units are built to railroad standards for sturdiness, efficiency and uninterrupted service. In addition, they have been tested under the rigid standards of A.S.R.E. and their ratings CERTI FIED. Complete Certified Ratings may be obtained by writing Delco - Frigidaire, Dayton, Ohio. Following are Certified Ratings of most popular models tested under these temperature condi tions: 1-Saturated refriger ant vapor .40 F, 2-Refriger ant vapor entering compresr sor 65 F, 3-Ambient 90 F, 4Ingoing cooling water 75 F, 5-Outgoing cooling water 95 F. units are particularly suitable to locations where floor space is at a premium and in many cases will provide better distribution of cooled air than will floor units. Only power, refrigerant, and drain connections are necessary at the unit. \Yi to 6 tons. Write for complete information. FRIGIDAIRE REMOTE AIR CONDITIONING UNITS Contain all equipment except condensing unit which is located either in. basement or in nearby room. Available in Yi and 1 ton capacity and can be used either singly or in multiple. These models may also be used for year around service by equipping them with heating coils. Can be used with water or Freon as a refrigerant and equipped with filters and outside air connection if desired. CERTIFIED RATINGS FRIGIDAIRE FREON CONDENSING UNITS (above conditions) Model No. F3E F4F F5G F6H F6J FW2D FW3E FW4F FW5G FW6H FW6J FW70 FW80 FW85 FW9I FW10I Bore Stroke Condenser Cooling 2 cyl. 1V4*2/2 2 cyl. 2'/#*2ye 2 cyl. 2>/i * 2>/fl - 2 cyl. 2/2*3/2 2 cyl. w iy. 2 cyl. P/4*2/2 2 cyl. 2`/kx2>/# 2 cyl. w . m z 3'/2 . 2 cyl. w V* i 3%*3</e 4 cyl. y/rJv` y/, y/t 8 cyl. y/t*y/t Air a . *' " Water Compressor Speed Rpm 475 450 390 380 450 490 590 510 525 490 590 660 510 660 660 660 Capacity Btu per hour Capacity tons 9,310 13,400 15,330 21,200 23,150 7,970 13,810 18,680 27,000 35,000 40,200 60,800 91,500121^500 185,000 244,000 0.77 1.12 1.28 1.77 \ " 1.93 0.66 1.15 \ 1-55 2.25 2.92 3.35 5.06 '7.62 . 10.10 15.42 20.30 Motor Input Kwhr Water Cal per hour 1.2 1.55 1.89 2.79 3.24 0.60 1.11 1.30 1.83 2.58 3.00 4.00 5.92 7.62 11.54 15.40 55.4 101.3 139.0 192.0 243.0 284.0 . 418.0 615.0 841.0 1258.0 1700.0 890 FRIGIDAIRE SELF-CONTAINED AIR CONDITIONERS The Frigidaire self-contained air conditioner provides cooling, dehumidifying, circulating, to which may be added filtering and ventilating with outside air. All equipment including condensing unit, evaporator coils, is contained in one compact unit. Condensing unit either air or water cooled. % ton capacity models for single rooms in offices or homes. A 3 ton capacity model available for larger rooms such as small stores, offices, etc. DELCO OIL BURNER Pressure atomization type. Air supplied at low pressure with Centrifugal Fan. Intermittent or continuous spark ignition. No. 3 Fuel Oil recommended. Most Delco Burners are equipped with re placeable "Rotopower Units." DELCO AUTOMATIC FURNACE (Boiler) Consists of Delco Oil Burner or Delco Gas Burner coordinated with a boiler of special design for steam, hot water or vapor-vacuum heating systems. Unusual economies result from the Im-Pak-Tor type fin construction. Special combustion chamber is water-backed for more efficient heat transfer. . DELCO CONDITIONAL Heats, filters, circulates, humidifies. And for summer air conditioning with special attachment, also cools, dehumidifies, circulates and filters. Fired by either Delco Oil Burner or Delco Gas Burner. Multi-Path method of splitting the air into thin streams results in quicker,' more efficient transfer of heat. Write for complete details. (See also Page 892) l 891 Delco'Frigidaire Air Conditioning, Automatic Heating Systems DELCO OIL BURNER SPECIFICATIONS (based on 110 Volts--60 Cycle AC) Model Gallons OD Per Hour Maximum Capacity-Total Tax (Boiler or Furnace Output) Btu S. H.W. Motor Pump Pounds Weight Gal Strainer Hp Watts Rpm Lift Per Area Net Ship. Hour Sq In. DR1 1.0-1.35 105,600 440 700 1/8 S-P 135 1740 8'0* 13 17 100 132 DR 1.35-2.75 216,000 900 1,440 1/8 S-P 135 1740 8'0* 13 17 100 132 DI2 2.5-7.0 559,200 2,330 3,725 1/6 S-P 160 1735 8'0* 13 36 115 158 D34 7.0-16.5 1,296,000 5,400 8,600 1/3 R-l 415 1750 13'(P 90 49.5 298 385 D44 15.0-30.0 2,880,000 12,000 19,200 3/4 R-I 760 1750 13'CT 90 49.5 383 532 Models available for operation on other cycles, 220 Volts and DC. DELCO OIL FURNACE SPECIFICATIONS Model Capacity Total Tax Net . Gal Oil Per Hour Btu Per Hour Output S HW S HW Overall Dimensions Lgth. Width Height Htg. Surf. Sq ft Cu ft Firebox Volume Height Water Line Steam Water Heater Circu lator Model Flow Vjve DM3 400 640 285 455 1.0 DH3 625 1000 485 765 1.65 96,000 38'/,' 26'/,' 51 Vi* 29 2.9 443/4* 2A* 150,000. 47*,' 33'/,' 54Va' 55.25 4.3 46'// X* 15* 15* 120* 120* DH4 1050 1675 800 1290 2.5 252,000 36*/ 33'/,' 54'/,' 80.0 6.5 46'// X* 22* 125* DU 1400 2200 1080 1700 3.5 336,000 62s/a- 33'// 55'// 104.75 8.7 46'// X 22 125 DL6 1725 2750 1335 2140 4.5 414,000 me 33'/.' 55'/.' 129.5 10.75 46'// 2D 22 125 *Not Standard Equipment. DELCO GAS FURNACE SPECIFICATIONS Model Capacity A.GA. Btu Total Tax Net Input Output Per Hour S HW S HW Btu 80% Eff. Overall Dimensions Htg. Lgth. width Height Surf. Sq ft Cu ft Firebox Volume Height Water Line Steam Water Heater Circu lator Model Flow Valve GH3 625 1000 485 765 187.000 150.000 4234' 33'// 54'// 55.25 4.3 46// X* 15* 120* GH4 1050 1675 800 1290 315.000 252.000 54V/ 33'// 54'// 80.00 6.5 46/,' X* 22* 125* Not Standard Equipment. DELCO OIL FIRED CONDITIONAIR SPECIFICATIONS Hourly Btu Ratings Blower Burner Model Max. Btu Output at Plenum Net Btu Output at Registers Max. Cfm Delivery Unit Fan No. Rpm 2d Size Motor Model Hp Rpm Watts Hp Rpm Watts o.a 3 Net Wt. DA-0 100,000 85,000 1 400 1600 660 2 * N 1/4 S-P 1725 210 DRO 1/8 S-P 1740 \ 135 8' 801. DA-1 135,000 115,000 1 400 1600 660 2 w* \ 1/4 S-P 1725 210 DRF 1/8 S-P 1740 135 DA-2 200,000 170,000 2 400 2400 4 K 1/4 S-P 1725 250 DF 1/8 S-P 1740 150 8' 960 8' 1435 660 DA-3 325.000 280,000 2 335 4000 9 3/4 TC 1710 780 DF-2 1/6 S-P 1740 150 !(/ 2000 590 DELCO GAS CONDITIONAIR SPECIFICATIONS Htg. Surface Sq ft Com. Chamber Vol. Cu ft Input Mode) Btu Per Hour Output Btu Per Hour Registers Btu Per Hour Max. Cfm Cabinet Dimensions Width Lgth Hght Duct Openings Return Warm Air Ceding Height Min. GAO 133,000 100.000 85,000 1600 70 5.5 30* 54'// 46V,' 21' x 253// 25%' * 27'// 6'0* GA1 181,000 135,000 115,000 1600 82 6.4 31'/,' 48' 50* 14' x 28' 18' x 28' 6'0* GA2 267,000 200,000 170,000 2400 112 10,0 53' 64V/ 50* 14'x46' 18' x 46' W GA3 400,000 300,000 255,000 4000 159 23.4 70* 86' 55* 24'x 62* 26' x 62* tiff 892 Air Conditioning, Automatic Heating Systems The Fox Furnace Company Elyria, Ohio Division of American Radiator and Standard Sanitary Corporation Sales Offices: Cleveland, Ouro New York, N. Y. Boston, Mass. San Francisco, Calip. SUNBEAM AIR CONDmONINO Jobbers in principal cities. Engineering layouts provided by factory Sunbeam Oil Fired Air Conditioning Units Series Nos. 200 and 600 Like gas and coal fired Sunbeam Units shown herein, this series is designed to air con dition residences and small stores, churches and other buildings. Each Air Conditioner heats, filters, humidifies and circulates the air in winter and provides circulation of filtered air in summer. Mechanical cooling can be added. Exterior Cabinet--No. 20 gauge furniture steel; modern design; bolts and screws con cealed; finished in two tones of green glossy enamel. Heating Element--No. 7 gauge boiler plate, riveted and welded. Radiator made of No. 12 gauge boiler plate.^ Controls which regulate temperature and Series No. 200 interior view, showing attractive cabinet; integral oil burner; inner casing; heating humidity are furnished. element; blower; motor and filters. Blower and Motor--Blower is of double inlet type with forward curved, closely spaced blades. Moves large volume of air at low speeds. Equipped with self-aligning bearings. Motor is of Capacitor type and is equipped with safety device to prevent damage from overloading. Blower and motor have extra capacity for summer cooling. Humidifier--Either spray or drip type humidifier can be furnished. Spray humidi fier is regulated by a Humidistat. Filters--Sunbeam Filters provide high cleaning efficiency and long life. Are treated .with large amount of adhesive coating without clogging the air passages. Oil Burner--The Series Nos. 200 and 600 Units are equipped with integral co ordinated gun type oil burners that assure high efficiency and economical fuel consump tion. Both Series are, however, available without oil burner. Practically any gun-type burner of the proper capacity can be accommodated. Series No. 200--In this Unit, oil burner is placed inside cabinet as illustrated. Series No. 600--Similar in appearance to series No. 200. Oil burner is installed at the rear of the Series 600 and is located under the smoke pipe where it occupies no usable space. See next page for Capacities and Dimensions. Series No. 720-R This series, which performs the same air conditioning functions as the series already described, is moderately priced, designed for small and average size homes. It is compact and requires little space. Exterior Cabinet--Modern design gives attractive appearance. Die cut and formed parts connected by snug fitting slip joints and the use of 20 gauge steel provide rigid, air-tight construction. Finished in green crystalline baked enamel. Heating Element--Heavy boiler plate steel, riveted and welded. Combustion chamber is of No. 8 gauge steel; radiator of No. 12 gauge. * Series No. 720~R Sunbeam show ing filters. blower and motor. Inner Casing--Galvanized iron. Air circulating between inner and outer casing keeps cabinet cool. Oil Burner--Integral, coordinated burner is of the Rotary wall flame type. Is completely and ingeniously assembled at the factory, assuring correct installation. Equipment--Blower. Motor, Filters, Controls and Humidifiers same as in Series200. See next page for Capacities and Dimensions. 893 ' The Fox Furnace Co. Air Conditioning, Automatic Heating Systems Series Nos. 200, 600 and 720-R--Capacities--Blower-Motor-Filter Specifications toil No. Burner Input Gallons per hour Maximum Btu Cap. at Reg. Blower No. Max. Clm Required at 65 F ' *Approx. Blower Rpm at Vi in. S. P. Dia. of Blower Wheel Motor HP Motor Rpm Number Filters 224 224 224 224 634 634 634 720-R 720-R 720-R 1.2 1.5 1.7 1.8 2.5 3.0 3.5 1 .9 .8 123,000 155,000 176,000 186,000 240,000 285,000 331,000 100,000 90,000 60,000 1-12 1-15 1-15 1-15 1-18 1-18 1-21 1-9 1-9 1-9 1218 1522 1725 1827 2550 3050 3500 986 877 789 482 12* 350 15' 375 15' 380 15* V* 1725 3(16'x 250 H 1725 3(16' x 250 >h 1725 3(16' x 250 V. 1725 3(16' x 250 311 18' 314 18' 266 21', Vi 1725 6(16'x 250 Vi 1725 6(16'x 250 V. 1725 6(16'x 250 655 Vi 1725 2(16'x 250 620 w Vi 1725 2(16' x 250 590 9'/,' '/< 1725 2(16' x 250 Air heated from 65 to 165 F increases 19% in volume. Therefore warm air ducts should have capacity for 19% greater CFM than listed above. fCombustion rate of oil burner must conform to the heating requirements of the installation. Ratings of Nos. 200 and 600 based on oil having a calorific value of 140,000 Btu per gallon. Ratings of No. 720-R based on oil having a calorific value of 136.000 Btu per gallon. Minimum input of burner must not be less than one gallon per hour, on Nos. 200 and 600. or less than .8 gal per hour on No. 720-R. No. 224 634 720-R Series Nos. 200, 600 and 720-R--Dimensions Overall Width 76%' 99%' 64%' fOverall Depth 57%' 64%' 38' Height Height Air Heating Blower Discharge Compartment Compartment Opening 58%' 67' 60* 43%' 51%' 28%' 24' x 26' 30'x30' 18'x 18' Air Intake Opening 13' x 42' 16' x 45Vi" 10* x 2&/z* Approx. Distance From Floor Flue Vent to Center of Size Dia. Flue Outlet Inches 41%' 49%' 23%' 9* 10* 8*- Allow 2 Ft at side of blower compartment for removal and replacement of filter. fAUow 2 Ft in front for opening of doors. tAilow sufficient space in rear for installation of oil burner on series No. 600. Allow 17 in. in rear for smoke outlet on No. 200 and No. 720-R. Sunbeam Gas Fired Air Conditioning Units Series D This series, which performs the same functions as all other Sunbeam Air Conditioners, has the same attractive appearance as the Series 200. All bolts, screws, valves, pipes and wiring are located inside the cabinet out of sight, yet are readily accessible. Exterior Cabinet--No. 20 gauge furniture steel. Modern in design and finished in two tones of green glossy enamel. Heating Elements--Cast iron. Long-lived and leak proof. Provide unusually high efficiency. . Equipment--Blower, Motor, Filters, Humidifiers and Controls same as in Series 200. \ See next page for Ratings and Dimensions. Interior view of Series D showing heating element, burner, ther mostatic pilot, blower, motor and filters. Series M . Interior view of Series M show ing heating dement, burner, valves, inner casing, blower, motor and filters. This series is designed and priced for small and average size homes. It is attractive in appearance and unusually efficient in operation. It is substantially lower in price than the Series D. Exterior Cabinet--Modern design gives attractive appearance. Die cut and formed parts connected by snug 'fitting slip joints and the use of No. 20 gauge steel provide rigid, air-tight construction. Finished in green crystalline baked enamel. Heating Elements--Made of No. 16 gauge steel; unique design provides ample heating surface and long fire travel. . Equipment--Blower, Motor, Filters, Humidifiers and Controls same as in Series No. 200. See next page for Ratings and Dimensions. , 894 The Fox Furnace Co. Air Conditioning, Automatic Heating Systems Ratings--Blower-Motor-Filter Specifications--Series D and M No. A.GA. Btu Btu Capacity Blower Input per Hour at Registers No. Blower CFM at 65 F Approx. Blower RPM at Vi in- S.P. Diameter of Blower Wheel D-2 140.000 (07,100 1-12 1016 401 D-3 210.000 160.650 1-15 1526 344 D-4 280.000 214,200 1-18 2032 300 D-5 350,000 267,750 . 2-15 * . 2540 344 12' 15' 18' 15' Motor (Number HP Filters %2 H3 %4 >/, 4 M-2 80.000 M-3 120.000 M-4 160.000 M-5 200.000 61,200 91.800 122.400 153,000 i-:9 1-12 1-12 1-15 .. 580 : 870 1160 1450 550 380 475 340 9%' 12' 12' 15' % % % H 2 4 4 4 Air heated from 65 to 165 F increases 19 per cent in volume* Therefore, warm air ducts should have capacity for 19 per cent greater CFM than listed above. tSize of filter, 16 in. x 25 in. Dimensions--Series D and M Width of No. . Heating Overall Compartment Depth Width of Height of Depth of Air Overall Blower Blower Blower, Discharge Height Compartment Compartment Compartment Opening Air Intake Opening D-2 44%' 753/6' 58' D-3 56' 763/a' 58' D-4 70%' 79*/a' 58' D-5 82' 76%' 58' 39%' 48%' 65%' 86' 41%' 41%' 41%' 41%' 28' 29' 32%' 29* 16'x22' 16'x34' 16'x45' 16' x 56'/2' 12%' x 35%' !23/s'x44' 12%', 59%' 123/a'x 70' `Allow clearance in rear equal to depth of blower compartment for removal of filters, blower and motor. Allow 24 in. clearance in front of Series D for removal of baffles. M-2 20' M-3 281%' M-4 37' M-5 45%' 66%' . - 54' 69'/$' 54' 69>/2' 54' 73V,' 54'- 32' 40' 40* 48%' 2&Vir 36%' 36%' 39' 26%' 29%' 29%' 333/4' 16*x 14' 16' x 22'A' 16' x 31' J6'*39/2' 10* x 28>/2' 14' x 36A' 14" x 36/2' 16' * 45' `Allow clearance in rear equal to depth of blower compartment for removal of filters, blower and motor. Sunbeam Coal Fired Air Conditioning Units Coal fired models have heavy, sturdy heating elements designed to extract a maximum of heat from the fuel burned. They'are long lived and require a minimum of attention and servicing. The duplex type of grate is standard equipment. Series No. 20 This series meets the demand of the average home owner who desires the benefit of air conditioning and is seeking a moderately priced unit to install in a new home or to replace an inefficient furnace. Features that assure years of satisfactory and healthful service .are incorporated in ' Interior view of Series No. 0 Unit showing filters, blower and this unit. . ' motor. Exterior Cabinet--Modern design gives attractive ... appearance. Die cut and formed parts connected by snug fitting slip joints and the use of 20 gauge steel provide rigid, air-tight construction. Finished in green crystalline baked enamel. Heating Element--Cast iron. Has large area of heating surface. Is long-lived and gas-tight. , Inner Casing--Galvanized iron. Air circulating between inner and outer casing keeps cabinet cool. Blower and Motor--Blower is of double inlet type with forward curved, closely spaced blades.' Moves large volume of air at low speeds. Equipped with self-aligning bearings. . Motor is of Capacitor type and is equipped with safety device to prevent damage from overloading. Blower ana motor have extra capacity for summer cooling. . Humidifier--Either spray or drip type humidifier can be furnished. Spray humidi fier is regulated by a Humidistat. . ... Controls which regulate temperature and humidity are available. Filters--Sunbeam Kilters provide high cleaning efficiency and long life. Are treated with large amount of adhesive coating without clogging the air passages. See next page for Capacities and Dimensions. . 895 The Fox Furnace Co. Air Conditioning, Automatic Heating Systems /UR :am ONING Sunbeam Coal Fired Air Conditioning Unit (Cont'd) Series No. 80 Users throughout the country attest to the long life and high efficiency of this Sunbeam Series. The riveted and welded heating element combined with efficient Sunbeam Filters make the Series No. 80 the cleanest system available. An inner casing prevents heat loss and keeps exterior cabinet cool. Exterior Cabinet--Modern design gives attractive appearance. Die cut and formed parts connected by snug fitting slip joints, and the use of 20 gauge steel provide rigid, air-tight construction. Finished in green crystalline baked enamel. Heating Element--No. 7 gauge boiler plate, riveted and welded. Radiator made of No. 12 gauge boiler plate, welded. Equipment--Blower, Motor, Filters, Humidifiers and Controls same as in Series No. 20. Stoker Fired and Oil Fired Models--The Series No. 50. interior No. 80 is available in specially designed stoker and oil showing blower, motor, and filters. fired models. See table for capacities. Series No. 5500 This new Unit supplies the demand for an air conditioner with a steel heating element--at a low price. .It measures up to the high Sunbeam standards in performance, dura bility and attractive appearance. Exterior Cabinet--Modern design gives attractive appearance. Die cut and formed parts connected by snug fitting slip joints and the use of 20 gauge steel, provide rigid, air-tight construction. Finished in green crystalline baked enamel. Heating Element--No. 8 gauge boiler plate steel riveted and welded. Radiator made of No. 12 gauge steel, welded. Equipment--Blower, Motor, Filters, Humidifiers and Controls same as in Series No. 20. Interior of Series No 6500 showing blower, motor and filters. Capacities--Blower-Motor-Filter Specifications--Series Nos. 20, 80 and 5500 See next page for Dimensions. - Blower No. i ! Diam. of Blower Wheel . Pitch Dia. of Blower Pulley Number Blowers Motor Hp Motor Rpm Number Filter* Btu Capacity at Coal Hand Fired Oil or Stoker Fired Register No. (Approx. tApprox. tCfm Blower JCIm Blower Coal Oil Fired Required Rpm Required Rpm Hand or Stoker at 65 F at /*' at 65 F at >// Fired Fired S.P. S.P. 4420 95.000 108,000 1020 401 1158 430 1-12 12* 12' % 1725 4(20* x 20*) 4820 II 1.000 126,000 1195 430 1356 459 1-12 12* 12' % 1725 4(20* x 20*) 5220 133.000 150,000 1426 459 1618 487 1-12 12* 12' 1 % 1725 4(20* x 20*) 5620 153.000 173,000 1644 487 1865 516 1-12 12* 12* H 1725 4(20* x 20*) Blower No. Diam. of Blower Wheel Pitch Diam. of i Blower Pulley Motor Hp | Number Filters Coal Hand Fired Coal Stoker Fired Oil Gun Type Burner Oil Rotary Burner No. Btu Cap tCfm Btu Cap JCfm Btu Cap (Cfm Btu Cap tCfm acity at Required acity at Required acity at Required acity at Required Register at 65 F Register at 65 F Register at 65 F Register at 65 F 5 >o 5 o 6 2 2280 103.000 2480 118.000 2780 155.000 3080 182.000 3480 222.000 1112 1269 1666 1962 2385 113.000 129.000 169,000 199.000 242.000 1210 1381 1814 2136 25% 117.000 134,000 176.000 207.000 252,000 1260 1439 1890 2225 2705 134.000 153.000 201,000 237.000 288.000 1441 1645 2160 2543 3091 1-12 12* 1-17 12' 1-15 15* 1-18 18* 1-21 21* 12* 1 /4 4(20* x 20*) 17* 1 '/ 4(20* x 20*) 15* 1 M 4(20* x 20*) 15* 1 % 5(16* x 25*) 15* 1 V* 6(16* x 25*) 5520 76.000 815 83.000 888 86.000 924 98,000 1057 1-9 9'// 12* 5522 89.000 956 97.000 1041 101.000 1085 115.000 1240 1-12 17* 12* 5524 104.000 1114 113.000 1213 118.000 1264 134.000 1444 1-12 12* 12* 5527 132.000 1415 143.000 1541 149,000 1605 171.000 1835 M2 12* 12* Vt 2(16* x 25*) A V* 4(20* 4(20* x x 20*) 20*) M 4(20* x 20*) JAir heated from 65 to 165 F increases 19 per cent in volume. Therefore, warm air ducts should have capacity for 19 per cent greater Cfm than listed above. Nos. 2280, 5520 and 5522 are not available in special Stoker-Fired Model. 896 The Fox Furnace Co. Air Conditioning, Automatic Heating Systems Dimensions--Series No. 20 Height No, Overall Heating Width Compart ment Height Blower Compart ment Depth of Blower Compart ment Overall Depth Air Discharge Opening Air Intake Opening Smoke Collar Diameter Approximate Distance from Floor to Center of Smoke Collar 4420 4820 5220 5620 44'/,' 46'/,' 52' 56* 60* 60* 64* 64* 36'/,' 36%' 36%' 36%' 29%' 29%' 29%' 29%' 67%' 71%' 7%' 78%* 20* x 20* 22* x 22* 23* x 23* 24* x 24* 14* x 36i/2* 14* x 361/2* 14* x 361A' 14* x 36'/2* 9* 9* 10* 10* 45%' 453/4* 49%' 49%' -Allow clearance in rear equal to depth of blower compartment for removal of filters, blower and motor. Dimensions--Series Nos. 80 and 5500 Height No. Overall Heating Width Compart ment 2280 2480 2780 3080 3480 73%' 75%' 82%' 91%' 101%' 60* 60* 67* 67* 67* Height Blower Compart ment 36%' 36%' 41' 41' 51%' Width of Blower Compart ment 29%' 29%' 33%' 36%' 42%' Overall Depth 43%' 46%' 51%' 54%' 58%' Air Discharge Opening Air Intake Opening 20* x 20* 22* x 22* 25' x 25* 27'x 27* 32* x 32*5 14* x 36i/2* M* x 36(4* 16' x 45* 20* x 5l'/a* 24* x 55* Smoke Collar Diameter Approximate Distance from Floor to Center of Smoke Collar 9* 9* . 10* ` 10* 10* 41%' 41%' 43%' 44%' 45%' 5520 5522 5524 5527 65%' 69%' 73%' 77%' 58* 58' 58* 61* 28%' 36%' 36%' 36%' 26%' 29%' 29%' 29%' 38%' i' 18'x 18* 20* x 20* 22' x 22' 23' x 23' 10* x 28>/2* 14* x 36i/2* 14* x 36'/* 14* x 361/4* 8* 8* 8* 9* 24%' 24%' 24%' 24' Smoke Pipe Tee extends out approximately 28 in. additional in Nos. 2280 and 2480, and 36 in. in larger sizes. -. Allow clearance at side equal to width of blower compartment for removal of filters, blower and motor. Sunbeam Stoker Fired Air Conditioning Unit Series S ... The New Series "S" is designed for Stoker Firing exclusively. Either hopper or bin feed type stoker can be installed from front, rear, either side or below floor level through openings provided by the factory. The large double radiator will accommodate several months to a full season's accumulation of fly ash without reducing the rated heating capacity of the Unit. Cleanout Collars are at front of radiator. Clinkers are con veniently accessible and can be dropped into clinker pan, located between clinker door and fire pot, to cool. Heating element is constructed of No. 7 gauge boiler plate riveted and welded; radiator of No. 12 gauge steel, welded. Blower, motor, filters, humidi fiers and controls are the same as used with other Sunbeam Units. . Dimensions--Capacities--Blower-Motor-Filter Specifications--Series S 24-S 27-S Distance From Center of Drum To Far Side of Blower Compartment..................... 171/2 150.000 4(20* x 20*) 611/2* 9I' 583/8* 34%* 55* 26* x 26* 16%' x 44%' 43%' 17' x 8%' 4%' 28%' 29%' 29%' 62'%' 23/2 200.000 5(16* x 25*) 67' 98'%' 63%' . 36>%' 56%' 203/a* x 50%' 44Va* 17' x 8>/2* 4%* 31' 313/4* 31%' 67i%* Combustion rate of stoker must conform to heating requirements of installation. Ratings based on coal having a calorific value of 12,000 Btu per pound. LEFT: Interior view of Series 5 showing blower, motor ' and fillers. Bin Feed stoker is in stalled. RIGHT: Heating element show ing Double Radiator; Cleanout Collars; Clinker Pan; Chutes; Chute Extension; HoPPer stoker installed from rear. 897 Air Conditioning, Automatic Heating Systems Electrol Incorporated FINE OIL HEATING EQUIPMENT EXCLUSIVELY SINCE 1918 934 Main Avenue, Clifton, N. J. . Conversion Burners, Boiler-Burner Units, Air Conditioning Units ELECTROL SUMMER AND WINTER AIR-CONDITIONING SYSTEMS Winter Air-Conditioning Direct-Fired Air-Conditioning Unit. Series DF. Designed for new homes or homes being remodeled. Fired by famous Electrol Oil Burner. Heats air and auto matically maintains temperature for which it is set. Cleans the air by means of effi cient renewable type filters. Positively circulates the air with a motor-operated, extremely quiet blower of ample capacity. Blower available in summer for circulation of filtered air. Humidification either pan type or spray type, with automatic control of room humidity. Guaranteed 80 per cent efficient when operated at rated capacities. Enclosed in attractive jacket. Direct-Fired Air-Conditioning Unit. Series DF ' Capacities Btu Model per hour at Bonnet Max. Btu per hour at Grilles Max. Air Temp, at Bonnet Oil Rate Lb . 1 Hour DF0 DFI DF2 DF3 DF4 100,000 135,000 160,000 165,000 235,000 85,000 115,000 136,000 157,000 200.000 145-165 145-165 145-165 145-165 145-165 7.45 8.65 9.70 11.90 14.40 Heating Surface Primary Secondary Total CFM at70F 30 24 54 1000 50 36 86 1450 50 36 86 1650 50 36 86 ' 1850 76 36 112 2450 Air Capacity Fan SP Speed V, 555 V, . 603 V, 500 '/. 513 '/< "428 Motor Hp 1/6 1/4 1/3 1/2 3/4 Economy model. Furnished without burner enclosure, galvanized finish on jacket. Guaranteed 75% efficient when operated at rated capacity. Dimensions Model DF0 DFI DF2 DF3 DF4 Height . Length 48 56'/, 56>/ 561/S 60'/, 71 92'/, 92'/, 92'/, 96V, Width 30 33'/, 33'/, 33'/, 35'/, Outlet Width 21 24 24 24 24 Outlet Length 26 30 30 30 . 32 Inlet Width 20 24 24 24 24 Inlet' Length' 22 ' 24 24 24 28 Approximate Shipping Weight 850 1160 1200 1200 1550 Height of outlet and inlet collars for Duct Connection 1M in. .! .h Gravity Conversion Unit. Series FC. Designed for existing homes. Transforms an old wamFair heating plant into a modern winter air-conditioning system. Blower circulates atr^through efficient renewable filters which remove dust and impurities. Humidification assembly, spray type, located in jacket of furnace, adds proper amount of moisture, regulated automatically by humidistat in living quarters. Blower unit available in summer for circulation of filtered air throughout living quarters. 898 Electrol Incorporated Air Conditioning, Automatic Heating Systems WINTER AND SUMMER AIR-CONDITIONING Split-System Air Conditioning Unit. Series SS. Electrol SS units provide for all phases of air conditioning. The unit can be installed to provide winter air condi tioning, and later cooling and dehumidifica- tion may be added to the same unit without the necessity of changing the cabinet. Both floor-mounted and ceiling-suspended models are available; four sizes of the former, three of the latter, with capacities as shown in the table below. Any Electrol fired boiler with sufficient capacity and of proper design may be used in conjunction with the Electrol Split- System Unit. Specially designed heating and cooling SS--Suspended Type . coils are used to provide rapid heat exchange possible, thus ensuring economical operation. Spray type humidification, automatically controlled by a humidistat located in the living quarters, assures that the proper degree of humidity is maintained at all times. Compact, easily replaceable filters are provided, with ample surface area to remove up to 90 per cent of the air borne dirt, dust and pollen. Completely automatic control, governed by thermostats located in the living quarters is a feature of the SS Unit. ^ The Electrol Split-System permits the use of radiators in rooms such as bathroom and kitchen where air conditioning is not required. S. S. 10 to 15 Suspended type. 55--Floor Type Split-System Air Conditioning Unit--Series SS Capacities Model SSI SS2 SS3 SS4 ssto SSI3 SSI5 Heating Capacity Btu per hour Hot Water at 180 Steam 2 Lb Press. 93,000 170,000 233,000 . 304,000 " 91,800 171,600 246,800 317,900 46,000 66,000 90,000 46,000 66,400 90,000 Air Capacity CFM 1120 2000 2700 3600 500 750 1000 WGS W Vi" /,' VtT V* '// Fan Speed 640 558 656 630 555 600 555 Motor Hp 1/4 1/3 1/2 3/4 1/6 1/6 1/4 Cooling Capacity Btu per hour Cold Water at 50 F 30,0001 . 50,0001 ,, 75,000 f 90,0001 14,000 26,000 35,000 Dir. Expansion (Freon) at 40 F 35,0001 62,0001 , 92,000 f 119,000 1 21,000 V* 31,000 42,000 * Split-System Units should be selected on CFM capacity. E.D.R. is listed for esti mating boiler load only. Heating capacities shown are for four-row coils on hot water and two-row coils on steam, and are based on entering air at 60 deg. Cooling capacities shown are for four-row coils, three-row coils marked*, and six-row coils marked**. Units are equipped with variable speed motor pulleys. Listed air capacities are maxi mum and are based on listed fan speeds with air at 60 deg. SUMMER AIR-CONDITIONING Room Cooling Unit. Series RC. Designed for single rooms in residences, offices, stores, etc., where summer air conditioning only is desired. Circulates cooled, dehumidi fied, filtered air throughout conditioned space. Direct expansion type coil with air cooled condenser. , (See also Page 967) . 899 , Air Conditioning, Automatic Heating Systems Gar Wood Industries, Inc. (WiasW AIR CONDITIONING DIVISION 7924 Riopelle St., Detroit, Mich. Licensed Distributors in All Principal Cities TEMPERED-AIRE UNIT The Tempered-Aire heating and air-conditioning equipment made in five (5) capacities, consists of filters, blower, burner, humidifier, and oil furnace engineered into one compact, coordinated system. Clean, humidified, warmed air is delivered from the unit to the duct system and then uniformly distributed to all parts of the building. Air is cleaned by dry cloth filters and circulated by a multiple-blade blower fan. The heating unit is a down-draft, warm-air furnace equip ped with an integral pressure atomizing type oil burner. The humidifier, located at the top of the unit, is designed integrally with the furnace. Tempered-Aire Ratings and Dimensions No. 102 Btu 1 hour at Bonnet................................. Btu ! hour at Grilles.................................. Air Delivery. CFM..................................... Air Temperature at Bonnet........................ Oil Rate. Gallons 1 hour............................ Heating Surface. Firebox, sq ft.................. Heating Surface, Economizer, sqft........... Total Heating Surface, sq ft...................... Filter Area, sq ft......................................... Motor Horse Power--Burnftr..................... Motor Horse Power--Blower..................... Overall Length, inches............................... Overall Width. Inches................................ 120,000 100,000 1000-1575 175--135 1.20 30 60 90 24 1/6 1/5 96% 40% No. 102A 120,000 100,000 1000-1575 I75-135 1.20 30 60 90 34 1/6 1/5 92% 38% No. 103 165.000, 135,000 1375-2150 175-I35 1.65 33 99 132 43 1/6 1/3 H7% 38 No. 104 225.000 185.000 1875-2950 175--135 2.25 44 132 176 60 1/6 1/2 140% 38 No. 105 300.000 245.000 2500-3925 175M350 3.00 55 165 220 77 1/6 3/4 156% 38 No. 105C 400,000 3000-4500 I85-145 4.00 55 165 220 77 1/4 156% 38 MODEL EW UNIT A complete winter air conditioning unit for moderate cost homes. It comes in one (1) size, with pressure atomizing type oil burner, refrac tory combustion cham ber, star shaped transfer chamber, washable cloth filters, multivane blower and humidifier. RATINGS AND DIMENSIONS MODEL EW Btu 1 hour at Bonnet......................100,000 Btu 1 hour at Grilles......... ............... 80,000 Air Delivery CFM..........................800-1200 Air Temp, at Bonnet....................175 - 135 Oil Rate Gal per hour............................ 1.00 Heating Surface Firebox........... 5.5 Sq Ft Heating Surface Trails. Chamber, 74.5 Sq Ft Heating Surface Total...................80 Sq Ft Filter Area....................................25.5 Sq Ft Min. Width Door to admit unit....... 29 in. GAS FIRED TEMPERED-AIRE Built in a single unit, it provides air filtering, blower cir culation, humidifyi n g and heating. F urnac e is made of heavy gauge cop per bearing steel. Thermostatically opera ted. Safety controls give full protection. Approved by Amer. Gas Assoc. AGA Input, Btu per hour............ AGA Output, Btu per hour......... Grille Delivery Btu per hour....... Air Delivery CFM........................ Filter Surface Sq Ft..................... Blower Motor Size........................ Blower Motor Current Consump. Overall Length. Inches................. Overall Width. Inches.................. No. 90 135.000 101,250 90.000 900-1425 34 1/5 bp 250 Watts 96% 40 No. 120 180,000 135.000 120.000 1200-1900 34 l/5hp 250 Watts 96% 40 900 Gar Wood Industries, Inc. Air Conditioning, Automatic Heating Systems MODEL "R" BOILER-BURNER UNIT A compact firetube steam or hot water heating boiler, with an integral oil burner. Boiler built of heavy rust-resisting boiler plate, electrically . welded. The combustion chamber walls are carried clear to the crown sheet. The result is a considerably higher temperature of fire than is found in the conventional boiler, and better com bustion of No. 3 oil. Since there are no water legs, the bulk of the heating surface is concentrated in the firetubes, or secondary heating surface, resulting in maximum extraction of heat from the hot gas which leaves the firebox and consequent low stack temperature, high efficiency and operating economy. Burner Model Firing Rate--Gal per Hour.................................. Maximum Net Steam Load--Sq Ft...................... Maximum Net Hot Wajter Load--Sq h t.............. Maximum Gross Steam Load--Sq Ft................... Maximum Cross Hot Water Load--Sq ht........... Heating Surface--SqFt.......................................... Overall width--Jacket........................................... Overall Length-Jacket........................................ R500 H 1.65 500 800 750 1200 52 30% 53 R750 H 2.50 750 1200 1125 1800 68 30% 65 R1000 D 3.25 1000 1600 1500 2400 84 37% 59'/. RI400 D 4.50 1400 2240 2100 3360 118 37% 66 RlSOO D 6.00 1800 2880 2700 4320 154 37% 80 VENTILATOR A silent op erating venti lator--attic or commercial use. Ventilator consists of beltdriven propel ler type fan; electric motor with overload protection; metal hous ing; automatic shutter; insect screen; canvas connection and clamps; suspension springs. 8 Sizes: 20 in. to 60 in. CFM: 3500 to 30,000. INDIRECT AIR CONDITIONING EQUIPMENT Made in eight (8) sizes. Consists of a compact cabinet unit containing cloth air filter and vapor mist filter, blower, hu midifying chamber, and indirect, blast heater. While designed par ticularly for use with Gar Wood Boiler-Burner Units (steam, vapor, or hot water), the air con ditioning unit may be used effectively with any adequate existing plant. OIL-FIRED WATER HEATERS Commercial Type--An attractive, quiet operating balanced unit, in 2 sizes. Bums No. 3 fueloil. Fully auto matic. Separate tank. Capacities: 200 and 300 gal per hour 100 F tem perature rise. Over allwidths: 28Mm.; lengths:49in.--61 in. Domestic Types--Model S50 - --coil type heater for use with separate storage tank. Cap. 50 gal per hour 100 F temperature rise. Model S40 has storage tank integral. Cap. 40 gal per hour 100 F ternperature rise. Both j| -I J types have vertical 1 I i rotary burner with J* j S& only one moving EgjssjB part and for use with No. 2 or lighter oil. Model sso Models40 Highly efficient for installation in existing heating plants. Pres sure atomizing type. Simple in design. Han dle No. 3 fuel oil. Sturdy, quite, easily accessible. Fit any shape of firebox. CONVERSION OIL BURNERS Model "W" 41-600 sq ft net steam radiation. Model"K" 41-500 sq ft net steam radiation. Model "H" Up to 625 sq ft net steam radiation. 901 Air Conditioning, Automatic Heating Systems GENERAL |p ELECTRIC COMPANY AIR CONDITIONING PRODUCTS Air Conditioning Department, Bloomfield, N. J. G-E Oil Furnace--Three sizes, LA-3, LA-4 and LA-5 designed for steam, vapor, hot water radiator systems and for indirect heating with air condition ers. Boiler output, LA-3, 417 sq ft steam; LA-4, 555 sq ft steam; LA-5, 1145 sq ft steam. Steel boilers constructed in accordance A.S.M.E. boiler code. Furnaces carry Underwriters' approval. Fully coordinated-boiler, burner, domestic hot water, controls in one enclosed unit made and guaranteed by General Electric. Low standby losses. Auto matic Night and Day temperature control available with all units. G-E Water Circulator available with hot water models. G-E Warm Air Conditioner, Oil Fired--Two sizes, LB-3 and LB-4 consisting of combustion-heat transfer unit, centrifugal fan, humidifier, filters, controls, and necessary air, oil, water and electrical connections, all enclosed in an attrac tive gray cabinet chrome trim. Of direct fired type, develop ed especially for residential air conditioning, it circulates clean, warm, moistened air through ducts. Automatic Night and Day temperature control available with both units. Total output of LB-3, 100,000 Btu per hour, humidifying, 2.5 lb per hour. Total output of LB-4, 133,000 Btu per hour, humidifying, 10 lb per hour. Extremely quiet, electrically welded airtight furnace, no places for gases and odors to escape; flame detector shuts off oil in less than five seconds, eco nomical--burns oil by the exclusive G-E impact--expansion prin ciple; burner nozzle air cooled; sealed-in-steel motor, self lubricated. G-E Gas Furnaces--Designed for steam, vapor or hot water radiitor systems and for indirect heating with air conditioners. Type LM ratings from 320 to 1440 sq ft steam; Type LK ratings from 660 to 1760 sq ft steam; Type LC ratings from 1980 to 9680 sq ft steam. Automatic pressure, low water and temperature limit control. Gas regulation is gas operated to assure positive action. Cast iron sectional boilers meet A.S.M.E. boiler code. Furnaces carry A.G.A. approval. G-E Warm Air Conditioner, Gas Fired--Consists of combustion-heat transfer unit, gas burner, aphonic radial flow fans, humidifier, controls and necessary gas, water and electric connections enclosed in attractive ^cabinet. It is a direct-fired air conditioner developed especially for residential air conditioning which circu lates clean, warm, moistened air through living quarters. Four sizes available: Type LG-li 500 cfm--35,250 Btu/hour; Type LG-2, 1000' cfm--70,560 Btu/hour; Type LG-3, 1300 cfm--105,750 Btu/hour; Type LG-4, 16CK) cfm--141,000 Btu/hour. Automatic water heater available as optional for year 'round domestic hot water. 902 Air Conditioning, Automatic Heating Systems GENERAL Q ELECTRIC COMPANY A.IR conditioning products Air Conditioning Department, Bloomfield, N. J. G-E Unit Room Air Conditioner--Type AF-1-- This unit is designed for comfort cooling applications where cooling, dehumidifying, circulating, ventilating and cleaning of air are desirable. The air conditioner includes a condensing unit, cooling coil, fans, filters, air or evaporative cooled condenser and controls, all en closed in an attractive walnut cabinet. The unit features high cooling capacity, low operating cost, ease of instal lation and pleasing appearance. G-E Central Plant Air Conditioners--A complete line of factory designed and assembled air conditioners for summer, winter or year 'round applications. Type HD-50, 100, 200 and 300 of suspended type include aphonic radial flow fan, filters, humidifiers, cooling coils and heating coils in combination to meet a wide range of air conditioning functions and required capacities. Larger sizes, Type HD-400, 500, 600, and 700 include filters, humidifiers, cooling coils, heating coils, to meet requirements of large, single and multi-zone systems. Type HC Central Plant Air Conditioners are custombuilt, incorporating special arrangements of sub-assem blies to fit the purchaser's needs. G-E Air Circulator--Type HV-1B for attic ventilation, air circulation and exhaust applications. Type HVID-Pedestal mounting for air . circulation. G-E Air Conditioner for Winter --Type HW-1 designed for winter air conditioning of radiator heated homes. Includes filters, humidifier, tempering coil and radial flow aphonic fan. G-E Condensing. Units--Available in sizes from 1 hp through 50 hp. Several aircooled models in small sizes; water cooled models with shell-and-coil and truly cleanable shell-and-tube condensers. Efficient design provides high cooling capacities. Designed especially for air-conditioning application as part of complete G-E air conditioning systems. (See also Pages 1058-1059) 903 *,T Air Conditioning, Automatic Heating Systems Gilbert & Barker Mfg. Company Springfield, Massachusetts New York City Chicago, III. Rochester, N.Y. Springfield,Mass. Pittsfield, Mass. Detroit, Mich. Branch Offices: l&iiMrco Toronto London Paris Vienna Sydney Buenos Aires OnJJBOTNG-ARGONMTIONlNG GILBARCO FLEXIBLE FLAME OIL BURNERS "Gilbarco" Flexible Flame Oil Burners are of the pressure atomizing type, suitable for residential and commercial use in steam, hot water, vapor, or warm air heating systems. Their operation is fully automatic with controls and safety devices integral with the system. Due to the flexibility of the flame, the "Gilbarco" Burner is enabled to more completely fill the fire box with a heat-giving radiant flame. Each "Gilbarco" Burner combines the following definite advantages: (1) Flexible Flame with "Econ O-Flex" controlled combustion--assuring tailor-made application. (2) Forced draft--insuring complete com bustion. (3) Radiant type flame-y-gives great heat Model GB9 output. (4) Constant electric ignition. (5) Separate air and oil controls--insuring complete combustion. (6) Oil filter in oil line--assuring clean oil at all times. (7) Radio interference eliminator. (8) Burner installed outside boiler insures long life, easy inspection and service and general operating efficiency. (9) Quiet operation--no gears, belts or noisy mechanisms. SPECIFICATIONS OF AND CAPACITIES FOR 60 CYCLE MOTOR BURNERS (Write to us for capacities of D.C. and odd cycle motor burners) MODEL NUMBER Mu. oil Capocity per boor. U. 8. CaUooa Total Stan P .{I.Am. (Radlattos, piping, ant pickup) Total Hot Water Rtdbtlaa (Radiation, piping, and pickup) Motor (ttxe) Control* RPM CB1 3.00 1150 IMO Coettaaou* Made tranrformer 1/12 H. P. Stack mounted Protectorday and Tbermpatat 1750 CB2 63 23S0 3760 Cottttauotu electric Made trandorcxr i/a h. p. Stack mounted Protectorday and Thccmnctat 1750 CBS 113) 4400 70*0 CootlaoMi* electric dnile mufonner 1/6 H. P. Protcetarday Pxotectaetat and Tbtnnottat 1750 CB4 153)0 - 6000 MOO Cratinaout two trsarformcr* 1/4 H. P. Ptotectorday Protectostat and Thermostat 1750 CBS . 253)0 10000 163)00 CoBtiaooaa electric two tnoifarmen 1/3 H. P. Ptotectorday Pretectoetat and TtenMUl 1750 GILBARCO HEAVY OIL BURNERS-- Complete Range for Industrial Heating and Power Application GILBARCO SERIES "A6" BOILER BURNER UNITS Three models for both steam and hot water in the " A6'\series which range in capacity from 548 ft to 860 ft of steam radiation (gross) and 876 ft to 1376 ftof hot water (gross). The boiler, especially designed for oil fuel, is of cast iron, which can be molded into effective types of heat-absorbing surfaces. "A6" series models are completely automatic and the high efficiencies which are attained in the boiler are due to the fact that the heat gases are compelled to be in direct contact with the heat-absorbing surfaces at all times. All series "A6' Gilbarco Boiler Burner Units are designed to include: Built-in hot water coil and Aquastat; Low- water Cut-off on steam systems; Insuiat- ing Refractory combustion chamber, Pres- Cutaway view showing Outside view of the " A6" Series GUbareo Boiler Burner Unit. Furnished in two-tone green with chrome trim. suretrol on steam systems; Surface Aquastat on hot water systems. 904 ^tehm o^deofibinl^ trek lighting of burner compart ment. Gauge* easily read through ventilator openings. Gilbert & Barker Air Conditioning, Automatic Heating Systems Unit No. A6--19 A6--20 A6--22 GILBARCO SERIES "A6" RATINGS SQUARE FEET STEAM RADIATION Cross Without Water Coil Net With Coil Net With Special Coil Net SQUARE FEET HOT WATER RADIATION Without Water Coil WHb Coil With Special Coil cTM. Net Net Net DOMESTIC WATER CCKL CAPACITIES GALLONS OF WATER IN THREE HRS. 100*F. Temperature Rise Steam Boiler* it 180*F. Averace Temp. Hot Water Boiler* at 150* F. . Averace Temp. Standard Special Standard Coil Coil Coil 548 3SO 321 291 876 560 539 514 40 80 20 40 700 450 416 391 1120 720 692 674 45 80 224 40 860 S50 515 491 1376 880 8S3 834 SO 80 25 40 SERIES "A6" ^DIMENSIONS nn ._L_. A B c D E| ? C H i E L Mw R ST A6--14 57 H 47M 44H SH liftAt--20 S7H 47K SiA6--22 57 H M 4754 JH SIM 2M SIH >M SIH ISA 8 9 9 ;7H MM 6H 14* S4H 34 tt I6H m. 56 2-2 H 2-3 2-3 4 I3M MM ISH GILBARCO SERIES "BF" BOILER UNITS (Oil Fired) There are five models for both steam and hot water systems in the " BF " series which range in capacity from 780 to 2030 sq ft of steam (gross) and equivalent in hot water (gross). Like the "A6" series the boilers of the "BF" series are of cast iron construction insuring peak efficiency and great durability. The specially designed boiler combines the following important efficiency factors: (1) Extended fin type heat ing surfaces. (2) Low draft loss. (3) Large combustion chamber. (4) " BF " Series Gilbarco Boiler Unit. (Oil Fired) Furnished in twoAone green with chrome trim. Quick steaming. (5) Water-backed combus tion chamber. (6) Ground joints between Showing con struction and gas travel. Gages visible through lou vers in door. sections. (,7), Uniq.ue _gas travel. (8) Positive internal water circulation. (9) Large steam liberati*ng surf*ace. (10) Compact size. GILBARCO SERIES **BF" RATINGS SQUARE FEET STEAM RADIATION SQUARE FEET HOT WATER RADIATION DOMESTIC WATER COIL CAPACITIES. GALLONS OF WATER \N THREE HRS. I00*F. Temperature Rie Grots Net Unit No. BF--3 BF--4 BF--5 BF--6 BF--7 780 1095 .1405 1720 2030 Water Ceil 500 700 900 1100 1300 Coil 428 628 828 1028 1228 Coil 384 584 784 984 1184 1248 1743 2248 2752 3246 Net Without Domestic Water Coil 800 1120 1440 1760 2080 Net With Coil 740 1060 1380 1700 2020 Net With Coil 706 1026 1346 1666 1986 Boilen at IS0*F. Averace Temp. Boilers at 150* F. Averace Temn. With With With Standard Water CoU Water Coil Water Coil Water Coil 100 100 100 100 100 ' 160 160 160 160 160 50 50 50 50 SO- 80 80 ' 80 60 80 Note.--Gross rating is the total output in square feet of radiation at the boiler nozzle. Net ratings represent the allowable standing cast iron radiation which can be connected to each boiler when the domestic hot water load is as shown at the top of each column. No deduction for the hot water coil, regardless of storage tank size, should be made from the net rating, since the maximum load imposed by each coil has already been deducted. Efficiency---Series "A6" Boilers show a test efficiency of 77 percent, Series " BF" (See also Page 906) 905 Gilbert & Barker Air Conditioning, Automatic Heating Systems 80 per cent plus, over-all at rated capacity for contin uous firing. Note--When ordering be sure to specify whether the unit is for a steam or hot water system. SERIES "BF" DIMENSIONS GILBARCO SERIES "F" AIR CONDITIONERS HEAT--CLEAN HUMIDIFY CIRCULATE Gilbarco Series "F" Air Conditioning Sys tems are efficient, dependable and unusu ally economical in operation. They are specially designed for oil fuel and develop a high degree of heating efficiency. The oversized radiator within the furnace, with its long, retarded gas travel insures a great amount of heat with economical fuel con-, sumption. The filtering and humidifying equipment is engineered according to ad vanced principles of this new science-and the fan and motor are of sufficient capacity and durability: to insure many years of efficient service. No. or BotLS* BF-3 No. a* Dociu SccrtoKa BF-4 4 BF-S BF-4 4 BF-7 7 A Si4-8 W 47V V V 16* tOW 3T c w*D e ISH* 31V 14V w V 9W 47V JV 9Hk* souuc*. -- oetj-cumawieu mu. Furnished in tux>~Ume tage green baked cnamcL Burner completely endoted. Detailed construction offurnace and blower-filter unit. SPECIFICATIONS GILBARCO SERIES "F" AIR CONDITIONERS 906 Air Conditioning, Automatic Heating Systems Kelvinator Division of Nash-Kelvinator Corporation SUMMER AND WINTER AIR CONDITIONING Factories in Detroit, Michigan and London, Ontario Factory Division Offices in Boston New York Atlanta Cincinnati Chicago St. Louis Dallas San Francisco Distributors in more than 200 Cities A COMPLETE LINE OF FACTORY-BUILT AIR CONDITIONING EQUIPMENT The Kelvinator line includes perfected equipment for all air conditioning needs, from completely self-contained units for air conditioning a single room or office, to central system equipment for complete-building installations. Throughout this range, Kelvin ator provides equipment that completely conditions the air. Evaporative Condensing Units. Com pletely factory-built in all standard sizes. Unit construction of evaporative condenser saves installation costs. Use of spray discs instead of spray nozzles eliminates need for pumps, saves power costs, and avoids the common cause of service interruptions. Evaporative condenser can be installed in any unused over-head space in condenser or machinery room. It is completely factory- built, assembled, and tested before shipment --mount it in position and connect it and it is all ready for duty. Construction features include; an all- galvannealed steel cabinet with removable panels over a heavy angle-iron frame, which makes the interior easily accessible for cleaning: the quiet-operating, centrifugal- type fan, driven by a fractional horse-power motor, has ample capacity for circulating and cooling; condenser coils are fin type with Kelvinator Evaporative Condensing Unit and 20 hp Compressor. wide spacing that facilitates cleaning; the ^_ brass spray discs which distribute a finely divided shower over the condenser coil, insure a fixed quantity of water at all times without requiring periodic adjustment and cleaning as when a pump and spray nozzles are used. Kelvinator Condensing Units Water-cooled types in all standard sizes. Air-cooled types from to 5 hp inclusive. In 24 years of specialized development and manufacture of temperature control equipment, Kelvinator engineers have pioneered many important developments in condensing unit construction. The Kelvinator refrigerant-cooled head makes possible the use of air-cooled condensing units in sizes up to and including 5 hp. Kelvinator H hp air-cooled conden All water-cooled units have water-cooled compressor cylinder heads which prevent formation of carbonized oil by maintaining the sing unit.. temperature of the cylinder head and valve plate below the carbon ization temperature of the oil. # Large condenser capacities in the air-cooled models make efficient operation possible with high temperature condenser air. Water-cooled models of 10 hp and larger are equipped with shell and copper tube cleanable condensers. The condenser water pass ages are so designed that water pressure drop is kept at a minimum, assuring efficient operation in communities having low water pressures. Kelvinator precision manufacture insures high operating efficiency. 907 s Kelvinator Air Conditioning, Automatic Heating Systems Kelvinator Central System Air Conditioning Unit. Kelvinator Type C Suspended Air Conditioner; condensing unit remote. Central System Air Conditioning Units. Completely-controlled air con ditioning system; with automatic cooling, dehumidifying, filtering, and air distribu tion. Kelvinator heating and humidifying equipment may be installed at any time. Designed, engineered, and completely factory-built and factory tested, for high efficiency and low operating cost. Capacities: 10 to 40 tons I.M.E. per day. Suspended Type Air Conditioning Units. For 0.7 ton to 10 ton installation in locations where floor or room space is limited. Fully automatic control. Com plete cooling, dehumidifying, filtering, and air distribution. Heating coil and humidi fier can be included in sizes of 5 tons and larger. This equipment is designed for in stallation right in the room to be air condi tioned. Eliminates costly duct work; ideal for business firms holding short-term leases. Kelvinator Floor-Type Air Conditioner; condenser remote. Kelvinator Air-Cooled Room Cooler: completely self-contained. Floor-Type Cabinet Air Condition ing Units. For use with Freon or circu lating cold water as the refrigerant. `Heating and humidification for winter air conditioning, and outside-air intake, with filter, can be provided. Capacities: 0.55, 0.80, 1.10, and 1.60 tons. These units, which occupy about the same space as the radiator they replace, and cost little more, afford an ideal method of air conditioning hotel guest rooms, hospitals, office suites, and other existing construction where duct installation ex pense would be prohibitive. Self-Contained Air Conditioners for Single Room Installations. Air-cooled models in H hp and 1 hp sizes. Water cooled models in hp, 1 hp and 1^ hp sizes. Provide cooling, dehumidifying, cleaning, and circulation. Outside air intake standard on air-cooled models, winter-heating coils optional. AH models can be equipped with thermostat for automatic operation. . Kelvinator Room Coolers can be moved to a new location the same as other office or household equipment. 908 Kelvinator Air Conditioning, Automatic Heating Systems Residential Air Conditioning and Automatic Heating Equipment Kelvinator's year 'round residential air conditioning and automatic heating equipment is the result of 24 years of experience in the manufacture of controlled temperature appliances. Developed in the Kelvinator Research Residence, it has been proved in hundreds of Kelvin Homes throughout the country. These homes, whose pre-engineered specifications and construction fundamentals provide new scientific advances in year 'round comfort and household conveniences at the cost of owning and operating an ordinary home, have been heralded by prominent housing authorities everywhere as a major contribution to "The New Mode of Living" for the moderate-income family. The heating function of Kelvinator's year 'round system may be accomplished with oil, gas, coal, or electricity; the cooling function with mechanical refrigeration. Year 'round ventilation is provided by the unique Comfort Damper. Typical Kelvin Homes equipped with year 'round Kelvinator air conditioning. Year 'Round Air Conditioning System-- Ketvinator's residential air conditioning system is of the indirect type wherein the air is heated by a steam coil in the conditioner, the steam for which is sup plied from an automatic boiler. The indirect system was chosen after careful study as the most flexible and satisfactory for year 'round air conditioning. The automatic steam boilers are not only available for supplying steam to the steam coil but also furnish heat to radiators for heating those parts of the house where conditioned air is not required. The illustration above shows the auto matic oil-fired boiler {left), the air conditioner {above at center), and the condensing unit for summer cooling (inside the small room at right). Assembled and cutaway views of Kelvinator resi dential air conditioner. The Conditioner--The conditioner contains a heating coil, cooling coil, filter, humidifier and centrifugal fan. Steam for the heating coil is provided by an automatic boiler, and refrigerant for the cooling coil is supplied by a Freon mechani cal cooling unit. Heating and cooling coils are provided in a variety of sizes to suit all climatic conditions. The attractively finished conditioner is resiliently mounted and is insulated to insure quiet operation. The operation of the conditioner is automatically controlled by the thermostat in summer, and by the thermostat and humidstat in winter. Four sizes with air deliveries up to 2000 cfm provide for . conditioning any size home. Multiple units can be used for zoned systems of large residences. The Comfort Damper--Controlled by the Selector, the comfort damper, a Kelvinator development, permits outside air to be Brought to the conditioner, filtered, and circulated throughout the house at the almost negligible cost of fan operation. In summer, through the introduction of cool night-air and the discharge of warm vitiated air, it reduces the mechanical cooling load and cuts operating costs. During the entire year it is available for purging of the house whenever outside air is required. 909 The comfort damper takes full advantage of the cool ness of night air. y Keloinator Air Conditioning, Automatic Heating Systems Controls--F i nger tip exact selection control is a feature of Kelvinator residential air conditioning. Thermostat and humidstat may, of course, be set to automatically main tain the desired temperature and humidity. Besides these, a conveniently located panel known as the Selector con tains switches by which the Kelvinator Exact Selection Control Panel, Thermostat, and Humidstat. conditions to be maintained may be selected. Simply placing the three allowing the introduction of 100% outside toggle switches in the tip position estab air and the positive discharge of inside air; lishes the system in summer operation; and (4) a position for constant air circu placing them in the down position selects lation. The system is so designed that the winter operation. The rotary switch pro householder may switch back and forth vides for (1) a completely off position from summer to winter or winter to sum for the air circulation system; (2) a mer operation with the Selector, making it position in which the air circulation unnecessary for a service man to be called cycles at the will of the thermostat; (3) the for such purposes. comfort position which controls the com This simplified system provides con fort damper, stopping recirculation and venient control of comfort conditions. Oil-Fired Unit Boilers--The Kel-O-Flame oil-fired unit boilers are provided in a range of capacities from 103,000 Btu/hour to 252,000 Btu/hour to efficiently meet the automatic heating requirements of small as well as large residences. Employing a completely coordinated burner design with a balanced heat-absorbing element, the Kel-O-Flame unit boiler has set a new standard of performance and efficiency. The specially designed burner produces a quiet, non- luminous flame in direct contact with the primary surface of the boiler. Finned secondary heating surfaces extract the remaining usable heat from the flue gases. The Low water line permits its installation in low-ceiling basements. Jacket is thoroughly insulated with asbestos cell. All working parts are easily accessible for adjustment or service. Each unit is complete with fully automatic controls, including a low-water cutoff for steam boilers, safety stack switch, safety limit control, summer hot water con Kel-O-fiame oil fired boiler. trol, and for hot water boilers a circulator relay and flow control valve. Provision is made for automatically sup plying domestic hot water summer and winter. .. As the boilers are entirely factory-built, hazards of field assembly and installation, are eliminated. . Gas-Fired Unit Boilers--Six sizes, for hot water or steam heating, are available, capacities up to 294,000 Btu per hour. Quick steaming is achieved by the use of special venturi mixing throats interconnecting with diamond-shaped horizontal water tubes. ` Heat transfer surfaces are un usually large in proportion to water content of the boiler, frictional resistance within the boiler is materially reduced. Dependable operation of pilots and burners is assured by a special down-draft diverter, which constantly reg ulates the draft through the boiler. An automatic com . bination valve supplies gas under constant pressure whenever the thermostat calls for heat. ' Jacket is fully insulated. Complete automatic control equipment is provided, including a low-water cutoff, automatic electric or gas-failure shut off, and an electric limit control. Kelvinator Gas-Fired Unit ' Boiler. 910 Keloinator Air Conditioning, Automatic Heating Systems Kelvinator Oil Burners Kelvinator conversion oil burners are especially developed to insure quiet, de pendable, and efficient performance in conventional heating plants. : They employ the pressure-atomizing principle. By means of a scientifically de signed turbulator and air deflector, thorough mixture , of the air with the atomized oil is achieved. This results in complete burning of the fuel within the combustion chamber, and makes the full amount of heat available from low-cost, heavy grades of domestic fuel oil. Seven models of burners may be fired at Kelvinator Conversion Oil Burner oil rates from 1.25 to 25 gal an hour with capacities up to 2,270,000 Btu per hour. Kelvinator Goal Stokers Utilizing the proved underfeed principle, Kelvinator Automatic Coal Stokers in troduce important improvements in the automatic firing of bituminous fuels. Gases ordinarily wasted are scientifically released and thoroughly burned over a slow-burning coke fire. Combustion is complete and smokeless. Burner is made of nickel-steel tuyere segments, with special air vents which dis tribute air uniformly to the fuel bed.. A controlled air-damper regulates air flow automatically, and holds the fire down when heat is not required. Coal feed is by a cast, steel tapered Kelvinator Automatic Coal Stoker. worm, full floating in a seamless steel tube. Transmission gears are drop-forged steel, case-hardened and ground, operating in a continuous bath of. oil. An easily acces sible adjustment provides the choice of 5 different speeds. Feed . is intermittent, providing the very necessary poking action in the fire bed. A special coal agitator is available for use with fuels that have a tendency to cake. '' ' 5 _ Construction provides easy accessibility of all working parts for adjustment or service. Coal hopper of smaller, household size models, holds more than a day's supply of fuel. Hopper cover is gas tight, preventing any possibility of blow back of smoke or dust. * . . *- Five sizes of Kelvinator stokers are available with maximum feeds of '35 to 150 lb per hour and capacities of 210,000 to 900,000 Btu per hour. Kelvinator Condensing Unit The Kelvinator condensing unit, for summer air conditioning service, is provided with ac or dc motors. Water- cooled condensers are available in all standard sizes; air-cooled types are provided in sizes to and including 5 hp. Condensing unit capacities exactly match the capacities of the cooling and dehumidifying coils in Kelvinator year 'round air conditioners, insuring high efficiency of operation. The Kelvinator system of auto matically pumping the refrigerant out of the coils after each operation makes possible immediate switch-over be tween cooling and heating, without shutting off or opening refrigerant Kelvinator water-cooled condensing unit for. summer . cooling. -t' . valves. The use of Freon refrigerant meets all code requirements. .. Kelvinator's exclusive construction features and Kelvinator precision-manufacture guarantee maximum operating economy and dependable, trouble-free performance. 911 Air Conditioning, Automatic Heating Systems The Henry Furnace & Foundry Company Manufacturers of MONCRXEF Furnaces & Air Conditioning Systems 3471 East 49th Street Cleveland, Ohio Phone Michigan 9322 Moncrief Aristocrat and "Special" Oil Fired Winter Air Conditioners, made to operate with any standard Gun Type Burner, and Gas Fired Winter Air Con ditioners are available in numerous sizes and capacities. Write for particulars. Aristocrat Oil Fired Air Conditioner "SPECIAL" OIL FIRED AIR CONDITIONERS Unit No. 75 Input Gallons per hour................ - .76 Size of casing: Width........................................... 28" Depth........................................... Height................................... . Blower size................................... 71" >y,no Motor Hp..................................... 1/6 Heating surface--*q in................ 6120 Cfm.............................................. 915 No. filters 13 z 25........................ 2 Btu Del. at Register.................... 75,000 100 1.02 28" 71" 6oy,,' 112 y. 6120 1225 2 100.000 Gas Fired Air Conditioner Approved by American Gas Association SIZES, CAPACITIES--Aristocrat Oil-Fired Units. 'S . Oo <S0.t5S A Casing Dimensions Plenums Warm Cold Air Air B c D 1E G |H J K L M N - 'if -3Co aOS - * CO 0 .8 to t 88125 sty, 603/8 48*/V28 si y. 18 20 28 20 28 125.000 1525 112 150 5iy, 60% 48% 28 5iy. 38% 5% 18 24 28 24 26 150.000 1830 114 175 80% 56% 60% 52% 28 51% 43% 5% 18 24 32 24 32 175.000 2200 114 &200 56% 60% 52%|28 51% 43% 3% 18 24 36 24 36 200.000 2448 114 275 64% 64 59 38 51% 51% 5% 18 30 40 30 40 275,000 3350 2,4 1 1 I Blower | Motor Hp j Sq In. Heating | Surface No. of Filters Size of Filters Shipping Weight (Approx.) Input Gal Per Hour 8925 8925 11088 11088 13248 4 16x25 1240 1.28 4' 16x25 1265 1.53 4 16x25 1365 1.8 4 16x25 1455 2.04 6 16x25 2010 2.8 SIZES, CAPACITIES--Gas-Fired C.B.F. Units. Btu Input Btu at Register Blower Size | Motor Hp 1 No. of Filters | Filter Size Sq In. Heating Surface Gas Line No. of ' Burners Casing Dimensions Plenum Size Inches Warm Cold Air Air Unit No. A B CD EK L M N G-8 75 20 54 VA 13 14 32 16 14 80,000 57,000 no 1/6 2 16x25 G-12 75 26 54 1% 13 19 37. 22 15 120,000 85,500 112 % 3 16x25 G-16 75 34 54 1 % 12 26 34 30 12 160,000 114,000 112 % 4 16x25 G-20 75 41 54 1% 12, 32 34 37 12 200,000 142,500 114 X 4 16x25 G-24 75 49 54 1% 12 40 34 44 12 240,000 171,000 114 % 5 16x25 C-32 75 68 54 lV7 12152 34 60 12 320,000 228,000 214 % 6 16x25 G-40 75 78% 54 1% 12 66 34 72 12 400,000 285,000 214 G-48 75 941% 54 1% 12^80 34 88 12 480,000 342,000 214 % 1 _8 9 16x25 16x25 is epO Q| sj 798 1197 1596 1995 2394 3192 3990 4788 5410 8115 10820 13525 16230 21640 27050 32460 1" 1" 1" 1" 1" ,%' w ,%' 2 3 4 5 6 8 10 12 912 Henry Furnace & Foundry Air Conditioning, Automatic Heating Systems Moncrief Aristocrat Coal-Fired Winter Air Conditioners are made with either cast or steel heating elements, in a wide range of sizes. Equipment includes metal floor, blower with motor, filters, controls, dam per motor, thermostat and Thermo-Drip Automatic Humidifier, duplex roller-bear ing grates--except with triangular grates, at no extra cost (on cast only). If to be used with stoker, grates and controls^ except blower control--may be omitted, stokers being equipped with control. Finegrain crackle finish--green, trimmed with chromium plate. With Cast Heating Element. Unit Size No. Casing Dimensions-- inches A B c D EF Plenum Size Warm Cold air air K LMN Blower Size Motor Hp Sq In. Heating Surface Grate Area Sq In. Cfm Re No. of quired Filters Forced Air Register Btu Coal Hand- Fired Forced Air Register Btu Stoker Fired 4020 66% % 623/. 381/, 28 50% 30 28 30 18 no % 5021 214 967 2 73,800 85,200 4422 4824 6y1o1%% 42% 44% 623/, 62% 38% 401/. 30 3U 50% 503/, 32 34 28 30 32 34 20 20 112 112 y, % 5609 269 1157 6010 326 1330 3 88,300 101,800 3 101,600 117,300 5226 78% 46% 66 44V. 34 503/, 36 34 36 22 112 6753 397 1580 4 120,400 139,000 5628 82% 48% 66 48% 34 503/, 38 38 38 24 114 a 7579 472 1840 5 140,300 162,000 With Steel Heating Element. Blower Size II Motor Hp j Sq In. Heating Surface i Grate Area Sq In. Cfm Required No. of Filters || Forced Air Register Btu Coal HandFired Forced Air Register Btu Stoker Fired Unit Size No. Casing Dimensions--inches A b- c D E F G Plenum Size Warm Cold air air K. L M N 2054 68% 40% 62% 401/, 28 503/, 35% 30 30 30 16 110 2254 /% 44% 62% 40% 30 50% 39% 30 34 34 18 112 2456 M% 46% 66 401/, 34 50% 41% 30 36 36 20 112 2758 74V, 51% 67% 40% 34 50% 46% 30 42 42 20 114 3060 86% 54% 69 48% 38 50% 49V, 36 42 42 24 212 3060J 90% 54% 69 52V, 38 503/, 49% 40 42 42 24 212 3462 90% 60% 71 481/, 42 50% 55% 36 48 48 24 214 3462J 96% 60% 71 54% 42 50% 55% 42 48 48 24 214 V, % V4 V4 V4 % % % 6226 6499 6960 8086 10041 11480 11245 12386 214 269 330 434 552 552 730 730 1070 1232 1424 1815 2240 2362 2800 2895 2 81.600 94,200 3 94,000 108,400 4 108,700 125,500 5 t38,600 160,000 5 >71,000 197,300 5 180,300 208,000 6 213,800 246,700 6 221,200 255,200 Heating capacities are based on a 7 lb combustion rate using 12,000 Btu coal and efficiencies of --65 per cent at bonnet, 85 per cent register for fan coal hand fired--75 per cent at bonnet, 85 per cent at register for oil or stoker fired. If 6 lb combustion rate is desired for prolonged firing period deduct approximately 15 per cent from . forced air Btu ratings. Maximum velocity through filters, 200 feet per minute. The Anthracite Winter Air Conditioner consists of a MONCRIEF Unit and a Miles Combustion Modulator. The outside temperature is correlated with the warm air temperature to affect a Graduated Room Temperature, 68 deg in mild weather and 78 deg in zero weather. Constant Modulated Heat Supply eliminates COLD 70 and complicated control equipment. Write for particulars. ` Note: Made with either the Moncrief Cast or Steel Aristocrat Air Conditioner. 913 Air Conditioning, Automatic Heating Systems Lennox Furnace Go., Inc. Aire-Flo Air-Conditioning Units--Riveted Steel Furnaces Marshalltown, Iowa Syracuse, New York Dealers in Principal Cities LENNOX WINTER AIR CONDITIONING UNITS The Lennox line of warm-air heating and air-conditioning equipment is complete, containing units specially designed for every type of fuel, and sizes ranging from 60,000 to 1,000,000 Btu per hour at the register. All heaters are of the famous riveted, calked steel construction--per manently gas- and dust-tight. Every unit throughout the line is designed to deliver air at uniform temperature and velocity to all warm-air ducts. As a result, these units are unusually easy to balance. Lennox units have long been famous for their high efficiency, quick response to temperature changes and long life. The company has been manufacturing steel warm-air heating equipment for more than 40 years and have pioneered the field of residential forced-air heating. Complete specifications and descriptions of the com plete line on request. LENNOX F3 SERIES OIL AIRE-FLO Exclusive counter-current principle uses full volume of cold air to insulate cabinet and to extract heat from flue radiators. Heat loss through cabinet less than onehalf of 1 per cent. Low stack losses. Inserted steam type humidifier. Large glass filters. Low-speed DWDI blower. Insulating type, pre-cast refractory results in cleaner fire, faster heating and higher efficiency. Heater, filters, blower, humidi fier and oil burner in one attractive cabi- net. Illustration below shows galvanized inner casing which surrounds riveted steel heater. > SJ FRONT ELEVATION Unit Number F3-125-I F3-I25-2 F3-I25-3 F3-200-I F3-200-2 F3-200-3 F3-300-1 F3-300-2 CQ-1701 CQ-1702 Btu at Heating Registers Surface Sq In. 60,000 100.000 125,000 150,000 175.000 200,000 250,000 300,000 75,000 100,000 11,358 11,358 11,358.. M.597 14,597 14,597 17,683 17,683 7,474 7,474 Normal am 1,050 1,310 1,640 1 ;960 2,300 2,620 3,300 3,920 920 1,240 No. and Size of Filters, In. 4-16x20 4-16x20 4-16 x 20 6-16x20 6-16x20 6-16 x 20 9-16x20 9-16x20 2-16 x 25 4-20 x 20 A Dimensions In. B CDE 40 73* 59 40 73* 59 40 an 59 48 83 59 48 83 59 48 83 59 60 104 63 60 104 63 39 47 61 26 33 39 47 61 30 40 F 30 36 LENNOX CO SERIES OILFYRE AIRE-FLO A smaller low-cost oil-fired air con ditioner for the smaller home. Leakproof riveted-steel heater. Large, silent blower. Inserted humidifier. Precast insulatingtype refractory. Blower cabinet can be placed on either side. Burner enclosed. 914 i: L i Lennox Furnace Co., Inc. Air Conditioning, Automatic Heating Systems Unit No. Btu at Register K2-501 K2-52I K2-I521 K2-I522 1C2-2062 K2-2063 70,000 80,000 100,000 125,000 160,000 200,000 Heating Surface Sq In. 7.760 7,760 12,814 12,814 18,623 18,623 LENNOX GAS AIRE-FLO For Natural, Manufactured or Mixed Gas Designed exclusively for gas, with the large amount of heating surface required for this fuel. Highly efficient. A.G.A. approved. The K2-5 series has a large circular radiator completely encircling the combustion chamber. The larger units have two circular radiators. All control valves except main shut-off are enclosed. Each unit equipped with the new Lennox gas burner, external pilot lighter and auto matic safety controls. Blower cabinet can be placed on either side. Cfm Range 500-1000 800-1400 800-1400 1300-2000 2000-2600 2400-3000 Number, and Size of Filters, In. A Dimensions, in. B C D! E F 2-16x25 4-20 x 20 4-20x20 4-20 x 20 6-16x25 6-16 x 25 38 38 45 45 53*/e 53% 45'A 45<A 48JA 48% 47 57 58 58 58 58 63 63 26 . 33 30 40 30 ! 40 30 40 34 > 48 34 48 * 30 36 36 36 43 43 LENNOX C8 AIRE-FLO FOR ALL FUELS These units are designed especially for coal, but are also efficient with other fuels. Riveted-steel heater. Overhead auto matic humidifier. Air-cooled cabinet. Direct-indirect draft. Large silent blower. Larger filter area. .. The QB Series--Not illustrated, also for all fuels, is a lower-priced unit for the smaller home. This unit contains the features usually found in good riveted steel air conditioners. Only slightly lower in efficiency than the C8 Series. Ideal for the small home. Unit No. Btu at Registers . Soft Hard Cas-oil Coal Coal Stoker Grate Heating Normal Area Surface; Cfm Sq In. Sq in. Range Number, Dimensions, In. and Size of Filters A B c D E F C8-2422 110,000 100,000 120,000 318 7,674 1300-2000 4-20x20 40 45% 59 30 40 36 C8-2722 120,000 110,000 135,000 415 8,977 1300-2000 4-20x20 44 49% 61 30 40 36 C8-2761 125,000 115,000 145,000 415 8,977 1600-2300 6-16x25 44 49V# 61 34 48 43 C8-3262 150,000 140,000 170.000 605 10,712 2000-2600 6-16x25 51 59V, 63 34 48 43 C8-3263 175.000 160,000 200,000 605 10,712 2400-3000 6-16x25 51 59V, 63 34 48 43 C8-3582 200,000 180,000 225,000 719 15,333 3300-4000 9-16 x 20 61% 61% 71 36 60 56 C8-352I l 275,000 245,000 325,000 719 15,333 4000-5000 12-16x20 61% 61% 71 36 65 59 SS-800 600,000 720,000 1,000,000 1037 28,728 Special 67* 96* 74V? OBI-220 70,000 60,000 75,000 262 5,438 500-1000 2-16x25 37 38% 56 26 32 30 QBI-242 95,000 85,000 105,000 318 6,684 800-1400 4-20x20 41 42V, 56 30 40 36 QB1-272 115,000 105,000 130,000 415 7,416 1300-2000 4-20x20 44 46% 58 30 40 36 Casing Obround. FOR NEW HOUSE WORK For the smaller better-insulated homes now being built, Lennox also makes a complete line of low-priced equipment for all fuels. Full information on request. Also a complete line of gravity furnaces and burners for all fuels. 915 Air Conditioning, Automatic Heating Systems Lochinvar Corp. 14247 Tireman Dearborn, Mich. T,u' jCoctuttoar u"te," Illustrated below are Lochinvars fully automatic oil-burning air conditioning furnaces and automatic oil burning water heater, priced for the volume market. To the left the model 100-A in attractive green ripple finish of rugged all steel welded con struction assures a large heat output at low cost. A popular model for the smaller home owner is the Junior-Aire. Same construc tion as the 100-A but smaller in size. . The Multiple-stage burner the result of 14 years experience, contains no motor or moving parts. Oil flows by gravity into the burner where it is vapor ized, and together with the oxygen admitted, forms a gas that bums--thus creating an intense heat. The result is high efficiency in the combustion of fuel oil. The Model 100 is a complete Lochinvar fur nace that costs less than an oil burner alone. Famous for its economy of fuel consumption and high heat output. This Lochinvar water heater guaranteed to furnish hot water at H the cost of gas or % the cost of electricity--can be installed anywhere. SPECIFICATIONS Specifications Maximum Oil Capacity ' Model 100-A 1 Gal per hour Junior-Aire 8/10 gal per hour Btu Output Floor Dimensions 110,000 36' x 54W 95,000 . 32' x 53' Write for complete specifications and prices on the Lochinvar line. 916 Model 100 1 gal per hour 85,000 105,000 36" x 41' Air Conditioning, Automatic Heating Systems MEyER Furnace GhMPANy Peoria. Illinois Manufacturers of Domestic Heating and Air Conditioning Units for Coal, Gas and Oil Burning Branches and Distributors Kansas City, Mo. Omaha, Neb. Green Bay, Wis. Pittsburgh, Pa. Philadelphia, Pa. Detroit, Mich. St. Louis, Mo. . San Francisco, Calif. Columbus, O. Minneapolis, Minn. The WEIR Air Conditioner for solid fuels (hand or stoker fired) embodying the famous WEIR Steel Furnace is a complete unit for winter air conditioning, including air cleansing, humidifying and forced circulation as well as heating. Encased in furniture steel with baked enamel finish. Automatic con trols for dampers, blower, humidifier. WEIR Conditioned Air Unit WEIR Gravity Heater Gravity Circulation No. Grate Surface (Sq Ft) Ratio Htg. to Crate Surface Smoke Outlet Di&m. (In.) . Casing Dimen. Round Rect'Iar (In.) (In.) Rated Output At Reg. Pipe Area (Btu. Hour) (Sq In.) Fan Circulation Casing Diraen. (In.) Air Rated Output Delivery at register (CFM) (Btu .Hour) 621 1.26 41.2 9 48 674 1.78 33.9 10 52 628 2.32 29.2 -10 54 630 3*08 633 3.82 26.4 22.7 10 ' 58 to 65 636 4.74 19.4 10 67 540 6.25 19.3 12 544 7.60 18.5 12 47x50 50x52 54x56 56x64 56x66 54,400 73,600 94,100 119,000 138,000 160,000 400 541 47x90 1200 692 50x99 1600 875 54x103 2000 1015 56x110 2300 1180 56x118 2700 60x106 64x114 5000 92,000 118,000 148,000 172,000 200,600 316,000 WEIR Oil Fired - Air Conditioner The WEIR Oil-Fired Air Conditioner does a complete job of winter air conditioning. Designed for oil fuel and forced circulation. Completely self-contained in low compact casing enclosing burner and blower as well as heater and all controls, yet with everything easily accessible. The MEYER Gas-Fired Air Conditioner automatically provides completely controlled winter air conditioning. Effi cient in performance, compact in design, and modern in appearance. Heavy gauge welded steel heating section; die- formed furniture steel casing. A.G.A. approved. No. Input - at Burner (Btu/Hour) Output' at Bonnet (Btu/Hour) Vent Diam. (In.) Dimensions W. U H. (In.) (In.) (In.) Air 1 Delivery Vt In. S.P. (CFM) Size (HP) 125-A 175-A 225-A 200,000 275.000 350.000 WEIR Oil-Fired Air Conditioner 150.000 7 48 65 48 205.000 7 56 65 48 265.000 7 63 65 48 1700 2300 3000 1/4 1/3 1/2 MEYER Gas Fired Air Conditioner E-10 E-15 E-20 E-30 E-45 110.000 165.000 220.000 330.000 495,000 MEYER Gas-Fireii Air ([Conditioner 82.500 123.500 165.000 247.000 371.000 5 32 69 45 6 41 69 45 7 53 69 45 9 69 69 45 10 97 69 45 1200 1800 . 2400 3600 5400 * 1/4 1/3 1/3 1/2 3/4 C-100 C-120 C-150 100,000 120,000 150,000 MEYER Gravity Gas Furnace 75.000 5 38 38 60 90.000 6 42 42 67 112,500 6 42 42 67 Complete descriptive literature, including data on Summer cooling, upon request meyer Gravity Gar Furnace The MEYER Gas Furnace--Efficient--Economical--All Steel, welded heating section, die-formed insulated "casing. A.G.A. approval. 917 Branches &r. Louis Memphis Omaha Minneapolis Salt Lake Crrr Dallas Air Conditioning, Automatic Heating Systems L. J. Mueller Furnace Co. Established 1857 2009 W. Oklahoma Ave., Milwaukee, Wis. Branches Los Angeles Kansas Citt Baltimore Philadelphia Pittsburgh Chicago SERIES "O" OIL-FIRED AIR CONDITIONING UNIT The basic, patented design of this Mueller unit secures a new standard of efficiency and fuel economy. The air passes over heating surface not once, but three times. Velocity and impingement create a rate of heat transfer impossible in previous designs. The silent fan supplies generous volumes of warm, humidified, filtered air to secure uniform temperatures. The Mueller Oil Burner is of pressure atomizing type, specially designed for use with this unit. Details of construction and method of operation of the complete unit are shown at the right. Available in three sizes to handle most residential requirements. CLIMATOR FAN-FILTER UNITS For positive distribution of air in old or new construction, wherever air is to be moved, there is a Mueller Climator Fan-Filter unit available. Fans are designed in accordance with latest aerodynamic principles. Filter area is adequate to handle the air requirements. Fans have ample air delivery capacity for the addition of cooling, if desired. Climator units are available in a range of sizes capable of handling practically any requirement. CLIMATROL AIR CONDITIONING FURNACE Enclosed in the compact, ultra-modern cabinet are the furnace, fan, humidifier and filters, together with controls for automatic operation. Heat is supplied by Mueller gas-fired "HeatSpeeder" sections. The powerful Mueller fan provides positive circulation of conditioned air to all rooms. Cut-away view shows fire travel through one of the sections, also the complete assembly of fan, motor, humidifier, filters and controls. Available in five sizes. 918 L. J. Mueller Furnace Co. Air Conditioning, Automatic Heating Systems Mueller Heaters For All Fuels A Complete Line for All Purposes Return Flue all-cast Fur nace. 18 in. to 30 in. fire- pots, single and double firedoor styles. Available in round, galvanized or square, lacquered casings. Mueller Steel Furnace. Riveted and welded. Extra heavy construction. Burns any fuel. Seven sizes, 20 in. to 34 in. drums. Square or round casing. Gas Era Unit Heater. Floor-mounted or sus pended type. Available in sizes from six to twenty sections, with A.G.A. out put ratings from 216,000 to 720,000 Btu per hour. Gas Era cast iron fur nace. A.G.A. input rating, 65,000 Btu per hour per section. I nsulated, lacquered casing for fan or gravity. Series "E" Gas Era Furnace. A.G.A. input rating, 45,000 Btu per hour, per section. Fan or gravity casing. Muelleraire unit. Gas-fired with fan, filters, and humidifier.5sizes--A.G.A. input ratings, 72,000 to 180,000 Btu. Series "A" Gas Boiler. A.G.A. ratings, 180 to 1,260 sq ft steam; 290 to 2,015 hot water. Series 20 Oil-fired Air Conditioning fur nace. Furnished with or without burner. Practically any burner may be used. Three sizes, from 125,000 to 200,000 Btu per hour at registers. Nos. 93, 94 and 95 cast iron Horizontal Tubular Heaters are especially designed for schools, churches and similar large buildings. Capacities from 1,188,000 to 1,390,000 Btu per hour. Complete catalogs on each of a ve units available upon request. 919 Air Conditioning, Automatic Heating Systems UTICA RADIATOR CORPORATION Utica, NY THE UTICA CAST-IRON CONVECTOR The Utica Convector is designed for installation within enclosures and to heat effectively by convection. The cored' section is ample to assure good circulation and rapid air elimination. The widely spaced fins, integrally cast, will not clog and offer minimum resistance to air flow. Utica Convectors will perform equally well on steam, vapor, vacuum and hot water systems. They are simple in construction, durable and efficient. The Utica Convector Made in 3% in., in., 7% in., and in. widths and in any length above 18 in. in multiples of 5 in. UTICA REDSQUARE BOILERS are stream line in ap pearance and scien tifically designed for efficiency and fuel economy. The 17 Series will carry from 200 to 740 sq ft steam radiation and 330 to 1230 sq ft of water radiation. The 25 Series will carry from 620 to 1240 sq ft of steam radiation and 990 to 1990 sq ft of water radiation. Also available in oil burning types with ex tended jacket. J 7 Series Redsquare Boiler 5 Series Redsquare Boiler Humid-Heet Radiator The HUMID-HEET Radiator furnishes the required amount of radiator heat--and replenishes the air with moisture. Made in a wide range of sizes. Midget Radiators Cut-away view- of Hvmid'-Hcct~ Radiator showing porcelain enameled water wells Midget Radiators--Due to their narrow width (2-tube, in., 3- tube, 4% in.) and sections 1H in. center to center, occupy one-third less space than standard tube radiators. S-Tube Midget 4% in. wide Also Manufacturers of Standard Tube and Wall Radiators 920 Air Conditioning, Automatic Heating Systems UTICA RADIATOR CDAPDRATIDN Utica, NY THE UTICA AIR CONDITIONER For Homes, Small Buildings and Stores Utica Air Conditioner Hydro-Air System The Utica Air Conditioner was de signed by engineers prominently identified with air conditioning since its inception. It is constructed on the Hydro-Air System, which provides operating characteristics and performance similar to the com? mercial installations of fine theatres, audi toriums and restaurants. The Hydro-Air System provides ac curate control of the conditioned air as it leaves the unit. This permits automatic control of the temperature and humidity in the structure. A line of standard package units for various sized jobs giving true air con ditioning in its fullest sense for any type of residence, small buildings or shops, stores, laboratories and offices. A single moving part simplifies the construction and practically eliminates service. The Utica Air Conditioner is ex tremely flexible in its adaptation to operate independent of or in conjunction with any kind of heating system in old or new buildings. Any Utica unit may be installed first as a winter air conditioner and then easily converted into a summer cooling unit; or installed as a year-around conditioner providing heat through ducts or a split system. A true air conditioner at a reasonable price, in package form, requiring only simple, inexpensive installation. The Utica Air Conditioner is proven in perfor mance by numerous installations all over the country in all types of jobs over a period of four years. The Hydro-Air System under which the Utica Air Conditioner is built. Provides thorough washing of the air at all times, thus removing not only dust, dirt, and soot but also Pollen.' UTICA'S HYDRO-AIR SYSTEM WASHES THE AIR. 921 Air Conditioning, Automatic Heating Systems Williams Oil-O-Matic Heating Corporation Manufacturers of Air Conditioning Equipment Bloomington, Illinois Service to Architects and Builders Chicago, III., 641 N. Michigan Avenue New York, N. Y.,'23! Graybar Building For Williams Oil-O-Matic Oil Burner Equipment, see File Index Air-O-Matic Combines Heating and Cooling in One Air-Conditioning System A -- WILLIAMS _ AIRomaTIC The Williams Oil-O-Matic Heating Corporation has developed an outstanding year 'round air conditioning system known as "Air-O-Matic." Low pressure steam, which is usually provided by an Oil-OMatic operated boiler unit, is supplied directly to a copper finned heating coil within the central air distributing unit for heating service, which can be supplemented by direct radiation if desired. Proper provision for the addition of moisture is provided for winter heating service. This same low pressure steam, through an especially developed absorption re frigeration unit, provides the proper degree of temperature and humidity reduction for summer comfort. A change from winter to summer operation can be effected almost instantaneously by means of a master con trol located in a suitable, convenient place. The Williams Low Pressure Steam Absorption Type Unit, the outstanding feature of Air-O-Matic, has been especially developed to meet the particular require ments of air conditioning through years of research in the Williams' laboratories. It affords adequate comfort cooling facilities with unusual advantages of economical operation mechanical simplicity, com pactness and freedom from fire and toxicity hazards. . Both the solvent and refrigerant are newly developed chemicals and are essentially non-toxic, non-inflam mable, non-corrosive to the common metals and chemically stable under all operating conditions. The Air-O-Matic Absorption Unit is designed to operate on a steam pressure of 10 to 13 lb. Other steam pressures may be used, but the capacity will vary with the steam pressure, although the thermal efficiency remains practically constant. The only electrical requirement of the absorption refrigeration unit is that of the motor-driven circulating pump for pump ing the solution through the heat exchanger into the heater. The low power require ments make possible the use of single phase current in the smaller size installa tion, thereby saving the expense of pro viding 3-phase current. The only metal to metal contact of moving parts within the refrigeration unit is between the seal face and seal seat of the solution circulating pump. This seal face operates in a bath of oil, thereby assuring proper lubrication. For all sizes of machines any low pres sure steam boiler of the proper capacity may serve to generate the required steam. Note--A Williams Oil-O-Matic Boiler Burner Unit or other types of automatic heating systems may be used to main tain the necessary steam pressure auto matically. Except where winters are very mild, the steam required for heating, in the average installation, is greater than that required for cooling. Consequently, no additional boiler capacity is required for the opera tion of the absorption unit. Several types of control systems are offered which provide for automatic main tenance of the desired temperature, hu midity, and ventilation. Air-O-Matic may be equipped with either the "cleanable" or "throw-away" type of filters. 922 Air Conditioning, Automatic Heating Systems Williams Oil-O-Matic Heating Corporation Bloomington, Illinois Manufacturers of Automatic and Manually Controlled Fuel Oil Burners Service to Architects and Builders Chicago. III.. 641 N. Michigan Avenue New York, N. Y., 1231 Graybar Building For Williams Air Conditioning Equipment, see File Index A Complete Line Williams Oil-O-Matic offers six Oil-O-Matic bur ner models--a genuine Williams Oil-O-Matic of ideal capacity for every size and type of house for every apartment, public building or commercial structure. Also, the new Williams HP-3 (high pressure) model. New complete boilerburner and furnace-burner, units; a new and revolution ary type of oil-burning automatic water heater; and a new fuel oil-burning range burner for heavy duty ranges are available.. Oil-O-Matic Hot Water Supply A new efficient hot water supply unit made in 3 sizes covering ordinary home use, large home or commercial use, and heavy duty require ment. The Oil-O-Matic oil burner, combustion cham ber, water reservoir, and all automatic controls are com bined in one compact unit. Horizontal tank permits the use of a unique triple flame 0IIC travel; the hot fire travers ing the length of the tank three times before escaping, transfers all possible heat to the water. See specifications lower left. Heating Capacities of the Various Williams Oil-O-Matic Burners _D .2 c c . Model *. "i JZ 6oojf-SP ece TJ `3 Qco^ 2 & X H.P. Gals. Fuel Oil per Oper ating Hour s Cl Mini-* Maxicd mum mum K-150 125 K-3 145 K-4.5 170 K-7 175 J-1800 255 295 HP-3 115 flugh pnssure) 29. 153* m 1/10 1800 30 I3H 20J* 1/1(1 1800 33'/, 203* 223* 1/5 1800 32'/, 22>* 213* 1/5 1800 45 20 24 1/2 1800 50 32 24 1800 30 17 10 1/10 1800 23* 4 8 12 135 IVt 3 4>/2 7 15 25 3 Standard draft pipe 18 in. 12 in length draft pipe optional. Standard electric current is 110-volt, 60-cycie. In case odd frequency motors are used, the maxi mum capacity-of the burner will be reduced in direct proportion to the rpm of the motor. The minimum capacity remains the same. ' Water Heaters WHA* 600 57 223* 28 1/10 1800 WHBf 685 75 23 28 1/1(1 1800 'h WHCt 1385 90 29 34 1/10 1800 \ l>/4 Output: 90 F rise, 60 gal per hour. tOutput: 90 F rise, 120 gal per hour. {Output: 90 F rise, 210 gal per hour. How to Decide Size of Burner For low pressure domestic boilers, 1 gal of fuel oil per hour (140,000 Btu) is re quired for approximately: 300 sq ft of steam radiation or its equiva lent. 480 sq ft of hot water radiation or its equivalent. 70,000 Btu when using hot air furnace ratings. - 24 sq ft steam boiler heating surface (or 2.2 hp). Complete Boiler Burner and Furnace Burner Units Oil-O-Matic burners are also used as an integral part of the following boiler burner and furnace burner units: Abram-Cox Oil-O-Matic American Foundry & Furnace Oil-O- Matic Evans Oil-O-Matic International Oil-O-Matic Kruse Oil-O-Matic National Oil-O-Matic Orr & Sembower Oil-O-Matic Waterman-Waterbury Oil-O-Matic Weir-Oil-O-Matic Horizontal Boiler Burner Unit This unit is a complete Oil-O-Matic product, consisting of a boiler and Oil-OMatic oil burner. It is furnished for both steam and hot water systems. The welded steel tank used meets A.S.M E. code speci fications for operating up to 15 lb. pressure. Underwriters' Listing Underwriters' Laboratories, Inc. list Oil-O-Matic to burn No. 3 fuel oil. Each burner carries the Underwriters' label. Fuel Oil Range Burners Williams Oil-O-Matic fuel oil burner for use in conjunction with heavy duty ranges. Brings oil heat economy to restaurant, hotel, hospital, steamship, dining car, resort and club. The Oil-O-Matic fuel oil range burner is furnished as an integral part of the Oil-O-Matic South Bend Heavy Duty Range. Engineering Service Available to architects. See A. I. A. File No: 30 G-l. 923 Air Fillers The Air-Maze Corporation 813 Huron Road, Cleveland, Ohio ENGINEERS AND MANUFACTURERS OF AIR FILTERS EXCLUSIVELY Direct Factory Representatives in New York, Miami, Detroit, Cleveland, Chicago, Tulsa and Santa Barbara. Distributors in principal cities and towns throughout the United States. During more than a decade devoted exclusively to air filter engineering and manufacturing, a great deal about the control and elimination of dust, pollens and grit has been learned by Air-Maze engineers. Their design and development of a unique type of filter element con struction, embodying distinctive advan tages, has been considered a worthy con tribution to the air filtering science and has resulted in wide acceptance of Air-Maze air filters in all fields of application. uniform in every square inch. For that reason no especially adhesive oil is needed. Efficiency--Tests under varying con ditions, both in laboratories and field operations, show air filtering efficiency of from 98.50 to 99.83 per cent. No Clogging--Because Air-Maze panel filters are easy to completely clean and since the exact density enables uniform deposit of dust, no clogging can occur. Adaptability--In addition to air con ditioning and power equipment installa tions Air-Maze panel filters are effectively used in humidifiers, water eliminator units, paint spray-booths, oil separators, and other applications where specific prob lems and unusual requirements are easily handled by adaptations of the panels. Air-Maze panels will be made to fit frames of existing installations and can be fur nished with locking handles and latches, or with flanged edges and lift handles. 4 in. Thick Panel in. Thick Panel Views showing open end edge of Air-Maze Permanent Cleanable Panel Filters Note Advantages Made Possible by Air-Maze Scientific Construction: Costs Little to Clean--The separating layers and exact spacing of baffles permit free washing action between and around all baffles. Thus, cleaning and oil charging operations may be easily and economically performed. Great Dust Capacity--On the face are coarse baffles exactly spaced, which evenly impinge bulky particles. Progressively inward are finer meshes. Instead of one or two progressions in density there are many; consequently, great dust capacity is possible enabling long operating periods before servicing is required. Vibration Proof--Vibrations in service cannot shake filter media out of position-- the uniform density remains permanently perfect; no replacements are necessary! No Special Oil Required--In Air- Maze each square inch of the panel handles the same amount of air. Properly drained, as directed, no oil will be carried through, since the air velocity is held evenly low and Magnified Section of "Loaded" Air-Maze Air Filter Element. Note that dust has been quite evenly impinged on only one side of the wires. No obstructed spaces can be seen. This feature accounts for the Low Pressure Drop and Non-clogging characteristics of Air-Maze. TECHNICAL INFORMATION Sizes--All sizes and thicknesses are available; two and four inch thick panels are the accepted standard. Installations using large sizes of these permanent panels are surprisingly low in cost. Capacity--Recommended air capacity is 1} to 2}^ cfm per square inch. Thus, the capacity of a 20 x 20 in. panel js 600 to 1000 cfm. Normally, 2 cfm per square inch should be used. 924 Air Filters The Air-Maze Corporation 813 Huron Road, Cleveland, Ohio Resistance--For 2 in. thick panels the resistance varies from 0.089 in. to 0.10 in. HjO when handling 2 cfm per square inch of filter area (288 fpm velocity); and for 4 in. thick filters the resistance varies from 0.121 in. to 0.140 in. H*0 at 2 cfm per square inch (288 fpm velocity); the vari ation being in accordance with the differ ent types of filter media construction available. To obtain specific restriction data write for graph RE-2. Construction--Air-Maze filters are of patented construction consisting of a maze of alternately placed and exactly spaced flat and crimped galvanized wire screens of selected meshes; these are arranged with precision so as to create graduated and progressive density, and to positively embody the baffle impingement principle. The filter element is enclosed in a 16 gage metalescent enameled steel frame having an open end to simplify servicing. EASY TO CLEAN AND CHARGE . . Cut-away View drainage. After cleaning and also after charg ing. set panel on edge, with open end down, to drain for about B0 min. Cleaning--Wash panels in a tank of. any suitable solvent which will cut oil and accumulated matter, yet will not affect the galvanizing. Kerosene may be used or a non-inflammable solution prepared with Air-Maze cleaning powder and water. Important! Be sure that panels are thor oughly drained before charging! Charging--Immerse in oil. Any inex pensive oil of S..4 .. 20 viscosity or heavier is suitable. After complete immersion panel should be removed from charging tank, placed on open end edge, and drained thoroughly. Filter is then ready for service, having the performance and characteristics of a new unit. AIR-MAZE INSTALLATION FRAMES frames assure efficient, attractive installations. Air-Maze panel holding frames are con structed of metalescent enameled heavy gage channel formed steel having rolled front edge and % in. flanged back edge. A thick felt lining on inside of flange insures against air leakage when panels are in place. One frame may be used alone in single panel installations, or a group of many frames may be supplied, fixed together with felt seals between edges; thus a large bank of filter panels may be provided. Every unit is fitted with latches for the locking handles supplied on panels. In determining frame sizes, % in. is allowed over both width and length dimensions of the panel filters. This % in. includes frame edge, clearance and felt seals between edges. . Specify Air-Maze--for all air filter installations and you will be assured of efficient, economical performance. Engineering Service Available--The Air-Maze Engineering Department will gladly offer installation suggestions for special air filter applications. Other Air-Maze Products--In addi tion to the panel types, Air-Maze Corpor ation also manufactures a complete line of circular shaped air filters for use in various Railroad, Industrial and Automotive . applications. Literature Available--Bulletins GPB- 97 and BPAN-86: covering complete panel filter details. Graphs G-ll and G-12: showing results of t'ets mad*e with A. S. H. V.E. Code Test Apparatus.' Folder RR- 27R: describing railroad air filters. Cata logs AUT-37 and NIND-37: covering complete line of Air-Maze. 925 Air Filters American AirFilterCompany Inc. 1st Street and Central Avenue, Louisville, Ky. Representatives In Principal Cities Dust Engineering--Dust Engineering is that branch of applied science which deals with the origin, nature and characteristics of the small solid air-borne particles called "dust," and the development of methods, processes and apparatus for its control or elimination. The American Air Filter Company, Inc., has had an important part in advancing the science of Dust Engineer ing. The efforts of its Re search and Engineering Staff for the past twelve years have been devoted exclusively to the study of dust problems and the development of a complete line of air cleaning equipment for modern air conditioning, building venti lation and the control of pro cess dust in industry. American Air Filter pro ducts, therefore, not only embody the knowledge ac cumulated from years of con stant research and the ex perience gained from design ing, building and applying thousands of air filters, but are backed by ample technical and financial resources to in sure their outstanding posi tion in the Dust Engineering field. Products--American Air Filters are available for every condition, with operating characteristics and efficiencies to suit specific problems. In general, there are two distinct types based upon the "viscous used for the. removal of dust, dirt, bacteria and other foreign matter from the air and are applied to general ventilation, modem air con ditioning, process dust con trol; for air compressors and Diesel Engines; mill motors, turbo-generators and other electrical applications; and for air or gas under pressure to remove entrained oil, moisture and dirt. Air. Filters In Air Con ditioning--Filtered air is today recognized as essential in modern air conditioning. There are other important factors which contribute to our comfort such as tem perature, air movement and humidity, but science today emphasizes the prime neces sity of pure air for health and efficiency. Air cleaners have, of course, always been considered an integral part of large central systems. These are usually of the fully automatic type such as the Multi-Panel filter, illustrated in the accompany ing photograph. There are now available to manufacturers of unit air conditioners moderate priced unit filters such as the Renu filter, the Throway filter, and other types of filters illu strated on this page. The Renu filter is an Airmot Type PL-gt Filter entirely new departure in air filter construction. It con film" and "dry mat" principles. Each type is made in several styles which differ in method of sists of a permanent metal frame provided with a re movable cover and renew able filter pad. The cover operation, servicing, space required and initial cost to meet the various con ditions encountered in air cleaning problems. A dis cussion of various filter types will be found in the Technical Data Section under "Air Cleaners." Air filters are generally Standard Viscous Unit Filter 926 American Air Filler Co., Inc. Air Filters is easily removed without the use of tools, and filter pad can be lifted out and replaced with a new one at very small expense. The Throway filter, as the name implies, is de signed to be discarded after it has served its maximum period of usefulness and re placed with a new filter unit. The Filter pad is enclosed in a perforated cardboard con tainer which makes it pos sible to readily dispose of the dirty filter by burning it. There is probably no sin gle item which costs as little and may mean as much in the design of an air con ditioner as air filtration. These units are furnished in any dimensions or shapes desired--usually in units handling 400 cfm and from 2 in. to 4 in. thick. They are usually made in the following sizes--20 x 20 in., 16 x 25 in. and 16 x 20 in. High cleaning efficiencies can be secured, with a re sistance to air flow ranging from ^6 in. to % in- water gauge. Automatic Self-Clean ing Air Filters--The .American line of automatic air filters is among the most complete ever offered. Prov ed in principle and perform ance by years of actual service. Armored Multi-Panel Filter--Introduces an en tirely new and unique panel construction to further im prove the already outstand ing performance of the famous Multi-panel air filter. The new "armored" panel with its three stages of air cleaning maintains the present high efficiency and normal operating and resis tance of the Multi-panel filter and offers the added advantage of handling ex cessive line concentrations or heavy dust loads without clogging. ., Unimatic Self-Clean ing Filter--Developed es A rmored Multi-Panel Automatic pecially for small air volumes where hand opera tion or push button control is practical. Fills the need for an intermediate filter between manually main tained units and the fully automatic Multi-panel. The Unimatic offers numerous advantages, one of which is the single pass curtain which makes pos sible the use of progressively packed media with its low resistance and great dust holding capacity. Standard Viscous Unit --The American Unit Air Filter incorporates the time tested unit principle of con struction. Each unit con sists of a standard steel frame and interchangeable cell equipped with auto matic latches to facilitate removal for cleaning and recharging. Section of Multi-Panelfilter curtain showing unique construction of new Armored Panel. Dork portion of screen is bakelite-fibre coated. The bright uncoated screen lies immedi ately behind the Armored section of the preceeding panel and provides the second or intermediate stage of air cleaning. The A rmored section is at the bottom of the panel. Airmat Filter Dry Type --The filtering media in this type is the Airmat sheet, a dry filter mat composed of thin sheets of gauzy, cellu lose tissue. The Airmat sheets are supported in screen pockets mounted in a unit frame of box-like con struction. These unit frames can be set up to meet any capacity requirement or space condition. Airmat sheets are renewable--their life depending on the dust condition and hours of service. Airmat filters are used both for comfort and indus trial air conditioning. In the latter field they are particu larly well adapted for the recovery of valuable dusts and forabatingthe dust nui sance prevalent in so many . industrial plants. They are available in two types, the PL-24 as illustrated and the Well Pocket type unit. Unimatic Self-Cleaning Filter Our standard data books and catalogues are in most engineering files or libraries. We will be glad to furnish complete data to engineers or manufacturers. 927 Air Filters Coppus Engineering Corporation 339 Park Avenue, Worcester Mass. MANUFACTURERS OF AIR FILTERS, STEAM TUR BINES, FORCED DRAFT BLOWERS, COOLING FANS "COPPUS AIR FILTERS PASS CLEAN AIR" The Coppus Unit Air Filter (patent No. 2050508 and other patents pending) is of the dry type using as filter material all wool felt. It consists of a distender frame (C, Fig. 2), a filter "glove" (, Figs. 1 and 2) and a retainer grid (B, Fig. 1). The edges of the retainer grid form a reenforced sheet metal box (A, Fig. 1) for protection of the filter element. The edges of the filter glove are reen forced on all four sides assuring an air tight seal against by-passing of dirty air. By tightening the wing studs which hold the distender frame and the retainer grid together, the filter glove is stretched and held tautly inside of the filter box, giving the pockets a tapered shape so essential for an even air flow. This design has the advantage of pro viding an effective filter area entirely unobstructed by wire or screen supports. Cut, Fig. 3 shows the tapered filter pockets on the clean air side. The filter glove can be readily replaced without removing the unit filter from the installation. No aux iliary frames for insertion of the filter cells are required as the completely assembled unit filters can be bolted together to a filter bank of any desired size. Fig. t Specifications Normal Rating: 800 cfm. Resistance when clean: 0.2 in. W.G. Dust Arrestance (cleaning efficiency): 99.61 per cent (Tested in accordance with A.S.H.V.E. Standard Code for Testing and Rating Air Cleaning Devices Used in General Ventilation Work). Dimensions: 20 by $0 in. by in. Weight per unit: 25 1b. Fig. 8 Outstanding Advantages 1. It has an exceptionally high dusfijarrestance. 2. It maintains a high dust arrestance even under diverse conditions of neglect. 3. Its operation is not impaired by atmospheric conditions. 4. It is a Medium Air Resistance Type (Class C) according to the A.S.H.V.E. Code for Air Cleaning Devices. 5. It is easily and quickly cleaned without removing the filter element. 6. Its cost of upkeep is very low because the permanent filter element is reconditioned periodically with a vacuum cleaner. 7. It combines scientific knowledge and practical engineering methods with highest quality of material and workmanship. , Write for Complete Bulletins 928 Air Filters Independent Air Filter Company . 228 North LaSalle Street Chicago, Illinois Representatives in Principal Cities Manufacturers of AIR CLEANING EQUIPMENT for General and Commercial Ventilating and Air Conditioning systems. Advisory Service without obligation "DOUBLE-DUTY" Cross-section through filter. Sludge re moval necessary only every two to six months. Oil never changed, merely re plenished. An Automatic, Self-clean ing, Non-clogging Air Filter for Large Commer cial and Building Instal lations. Basic Principle is that of True Impingement on viscous coated surfaces. Self-cleaning. Dust par ticles are freely and com pletely released when plates are immersed in oil bath. No Oil Entrainment. Oil entrainment is impossible, due to the angular design of the steel louvre plates in the filter curtain. Constant Air Flow--re gardless. of dust content of the air. "KOMPAK" A Dry Fabric Air Filter with Renewable Medium. The KOMPAK affords a maxi mum filter medium surface with in limitations of space available. Normal rating is 600 cfm per unit. At this rating the velocity through the filter material is 223^ fpm, initial resistance 0.15 in.w.g. Each filter unit contains 27 sq ft of fluffy Filter-down fabric. Each unit is 22 in. wide, II in. high and 15 in. deep. Low Velocity through filter fabric results in low resistance and long useful life of the filter medium. Frames are all steel, thoroughly rustproofed. Standard Construction. Sec tional construction is standardized to permit easy installation of any capacity desired. Permo frames are fabricated in vertical sections of the re quired units in height. The illus tration shows a group system of sectional Permo frames. 929 "PERMO PAD" For General Air Conditioning and Ventilating Installations. A fine textured, highly resilient filter, expanding firmly against the frame, providing a perfect seal against air leakage- "PERMO PAD" is self supporting by a built-in metal grilled Overall frame size is 20 x 20 x 6 in. Rated capacity per frame unit 800 cfm. Initial resistance (tandem arrangement) 0.18 w.g. Variety of sizes available for warm air systems and air conditioning units. Air Filters Owens-Illinois Glass Company INDUSTRIAL AND STRUCTURAL PRODUCTS DIVISION Toledo, Ohio ATD FTTTUDC FOR APPLICATION TO RESIDENTIAL, COMMERCIAL and INDUS- AJJa rlLlJC/Ko TRIAL HEATING, VENTILATING and AIR-CONDITIONING SYSTEMS |I `FIBERGLAS" MEDIUM - ADHESIVE-COATED - REPLACEMENT TYPE The Dust-Stop Air Filter con sists of a series of non-combus tible mats of Fiberglas, pro gressively packed--coarse glass fibers of lesser density at the intake and fine glass fibers of greater density at the discharge face. Mats are coated with non evaporating fireproof adhesive having extraordinary wetting power, will retain viscosity under operating temperatures ranging from 15 F below to 300 F above zero, will not flow off or charge the air with molecules. . . Dust-Stop Air Filters are engineered to provide high effi ciency at low cost of installation and maintenance. Efficiency--97 per cent (Tested accord ing to A.S.H.V.E. Standard Code for Testing and Rating Air Cleaning Devices Used in General Ventilation Work). Manufacturers* Acceptance Dust-Stop Air Filters are widely accepted by manufacturers of blowers, gravity and forced warm air heating systems, and air conditioning equipment of all kinds. Special enclosed units are available for con ditioning air for commer cial and industrial air handling problems. Filter Frames Dust-Stop Filter frame assemblies are standard in the units of many manu facturers and are also in stalled by engineers of commercial and indus trial heating, ventila ting and air condition ing. Frame members of cold-rolled steel are assembled vertically or horizontally in combi nations to provide for any cfm and space re quirement. STANDARD SIZES FOR EQUIPMENT* Standard Sizes (Nominal) 20* x 25' z 2' 20* z 20' z 2' 16' z 25' z 2' 16' x 20 z 2' Ratings Cfm 1000 800 800 640 Fpm 300 300 300 300 Resistance Inches Water Gauge 0.095-0.10 0.095-0.10 0.095-0.10 0.095-0.10 VcLoeirr-rm w Mimutc VgLOCITV--RESISTANCE CUBVE Other standard sizes available. Write Owens-Illinois Glass Company for information and data. 930 Air Fillers H. J. Somers, Incorporated Factory and General Office 6063 Wabash Avenue . Detroit, Mich. Somers Washable Air Filter Somers Hair Glass Filters provide everything required in an efficient air cleaning system. Consider these features: High rating for dust, soot and bacteria separation. Require no adhesive, coating or impregnation. Indestructible in normal service. Minimum Low Pressure Drop. Odorless and non-absorptive. Fireproof; Washable; Do not rot nor disintegrate; Permanent. Somers Hair Glass Filters consist of a hot galvanized frame holding galvanized wire cloth packed with hair-spun glass strands. The glass strands are flexible, do not break up and cannot be drawn into air stream. Hair-Glass, being chemically inert, has no facility of absorption; it cannot rust All Welded Vee Type and lasts indefinitely in service. Water either hot or cold may be used to clean it, without impairing its efficiency, These filters eliminate the necessity, the expense and the inconvenience of periodic replacement. Somers Washable Air Filter--All Welded Vee Type--Stock Sizes Frame Size Height and Length In. Frame Depth In. Filter Surface Sq In. 15'h x 24Vl 15*/, x 24>/e 16 z 21!A 16 z 25 16 z 25 16 z 25 16 x 25 ' 16 z 25 l6'/2 x 24'/2 18 x 18 19 x 20 x i9y, 19*/, x 20 mx 19'/l x !9'/2 1% x l9>/2 !9'/2 x 19V* 19V* !9'/i 20 x 25 20 x 30 20 z 20 20 z 30 20 z 20 20 z 20 20 z 20 20 z 20 20 z 20 20 20y, x x 2250'/ ' 3X 3'/.' 3J4 3'/. 3'/, 3% 3% 334 3'/ 334 334 i'A 3 3 3% 2 3 3'/. 334 334 Xf 3 3'/, 2 3 3 ' 3'/. 3'A '3 1023 1110 816 1056 1632 1344 1440 864 800 864 1482 1039 1039 936 1053 480 936 1170 1800 1800 1040 1560 1200 480 840 . 960 , 1320 1560 550 For Average Dry Filter Installations CFM Wet Application where water sprays are applied against filter for hu midifying CFM 1023 1110 816 1056 1632 1344 1440 864 800 664 . 1482 1039 1039 936 1053 480 936 1170 1600 1800 1040 1560 . 1200 480 840 960 1320 1560 550 511 555 408 528 816 672 720 432 , 400 432 741 519 519 468 526 240 468 585 900 900 520 780 600 240 420 480 660 780 275 Frames zinc platedifor 100 hour Balt water spray test. Refill may be inserted if necessary. Quotations and further engineering data, including master holding frame drawings will be sent on request. 931 Air Filters Staynew Filter Corporation Air Filters for Every Purpose 6 Leighton Ave. mm Rochester, N. Y. PROTECTOMOTOR DRY TYPE FILTERS (For removing foreign matter from the air at atmospheric or other pressures, with various types for building ventilation, dust recovery, oxygen chamber and all air cleaning purposes.) Cross Section Showing Panel Unit Construction The fin or V-type construction is used in all Pro- tectomotor dry filters. This basic principle permits (1) a large area of filtering medium to occupy the smallest possible space, and (2) the intake currents to move parallel to the filtering surface at low velocity. Protectomotor Dry Filters require no adhesive material to catch dust--odorless air is assured. Authorities agree that the positive dry filter is most efficient in stopping the smaller air-borne particles. Protectomotor dry filters actually prevent the passage Cross Section of bacteria. of 8 Mulli-VType Cells in V formation EASY TO CLEAN --LONG LASTING Cleaning is easily effected by use of any vacuum cleaner with special nozzle. See illustration below. Protectomotors operate from 3 months to a year without cleaning. Panel units average slightly longer wear than MultiV-Type units--several years at least with out replacement. Panel Units: Consist of Panel Insert and Frame. The Insert is composed of two rows of 60 hollow loops or fins 6 in. deep, formed of rust-resisting embossed wire mesh, supported by a retaining grate of steel or aluminum and similar spacing grate. Each row of fins is covered with a single piece of Feltex Filtering Medium, a felt-like material specially made for the application. Specifications below: Overall Dimensions (Depth less lock ing keys).............................................20 x 20 x 6% in. Size of Insert...........................-........19^ x 19^6 x 6 in. Capacity (average conditions)........................... 800 cfm Area of Filtering Medium.................................. 42 sq ft Linear velocity of air.............................................19 fpm Resistance of clean filter to air flow 0.185 in. water gauge. x Total Wieght..............-...................... ........................ 28 lb Multi-V-Type Units: Filtering medium (closely pressed cotton fibres between two sheets of cotton gauze) is arranged in patented V-shaped pockets in a fibre-board and pressed metal framed These patented cells can be quickly and inexpensively replaced when worn out. Their arrangement makes possible an active filtering surface of 27 times face area. In certain installations the Multi-V-Type is more desirable than the Panel Unit because its construction fits the space better, or because it is lighter in weight per square foot of fil tering area, or for reasons of economy. Com EaseofCleaning plete specifications mailed promptly on request. 932 t Air Filters Staynew Filter Corporation Air Filters for Every Purpose 6 Leighton Ave. Rochester, N. Y. _________ _________________________ PROTECTOVENT Supplies clean fresh air to home or office. Two motor-driven fans, filter, silencer and deflector combined in a practical device with many obvious applications. No draft--no outside noises! Helpful to hay fever sufferers --Multi-V-Type filter medium removes pol len and spores. PROTECTOMOTOR IMPINGEMENT AUTOMATIC FILTER (For efficiently and economicallyfiltering large volumes of air for all ventilating purposes) Dust is removed from the air stream by impingement on two endless revolving curtains. The first curtain passes through an oil bath; the second, which does not pass through the oil bath, prevents any possible oil entrainment in the air stream. This second curtain, being slightly moist from entrained oil, serves as additional pro tection against dust passage. No other filter' has the twocurtain feature. Compressed Air Cleaners Two additional exclusive features are to be noted. One is the compressed air cleaner system (see diagram), of two copper tubes drilled with air jets which blow off excess oil with foreign matter from the bottom of each curtain. The other is the direction of curtain travel. The intake sides of both curtains move downward. Thus foreign mat ter is removed by the oil bath and compressed air before each curtain presents its outlet side, which moves upward, to the air stream. Curtain travel is intermit tent, moving 4% in. during the operation of the mechanism which is approximately 20 seconds each half hour. The mechanism is actuated by a % hp motor with a reliable timing device. Sizes and Capacities Two standard widths are made, 2 ft 9 in. and 4 ft 3 in., ranging in height from 4 ft to 13 ft by 3 in. steps. Capacities are from 2,025 cfm to 20,200 cfm for single units. Almost unlimited capacities may be secured by bolting together units. . Automatic Filter Write for Catalog Mentioning Special Interests PROTECTOMOTORS ALSO MADE FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, TURBO-GENERATORS, AIR TRANSMISSION LINES, ETC. Universal Air Filter Corp 332 West Michigan Street Duluth, Minn. Air Fillers Universal Type C-S Basket Construction Universal Type C-S Sectional or V-type Frame REFILL FILTERS Universal Type C-2 Basket type construction of 3 to 5 baskets (optional) supporting cotton like sheet of filtering media between screens. Baskets are supported in horizontal posi tion by steel frame formed in sections 25 in. x 25 in. Capacity 2000 cfm. Resis tance 0.10 wg when clean. Universal Type E Replacement Filler EFFICIENT--PRACTICAL Filtering media is a cotton like sheet designed to arrest passage of dust, dirt and foreign material from the incoming air quietly and efficiently. No odor added. Filters easily disengaged, media quickly removed. Universal Types C-3 and C-4 Combine low first cost and low upkeep in one filter. By means of wire screens supporting cotton like sheet in zig-zag shape, filtering area is greatly increased. Refilled by removing screens and media from steel frames, inserting clean media between screens and replacing assembly in frame. Type C-3: Capacity 1000 cfm. ' Type C-4: Capacity 750 cfm. Re sistance clean, 0.15 wg. REPLACEMENT FILTER Universal Type E Cotton sheet media with paperboard case fitted to 20 x 20 sectional steel frame. Light, efficient, easily replaced, and completely disposable. Adapted to fit various types of frames now in use. Capa city 600 cfm. Resistance 0.15 wg when clean. 934 Air Flow Regulators Young Regulator Company Department G 4500 Euclid Avenue, Cleveland, Ohio, U. S. A. THE "YOUNG" REGULATOR No. 1--The "YOUNG" Damper Regulator has five important features: (1) It loclb securely. (2) It is. tamper-proof. (3) It gives positive action. (4) It is ornamental,--can be placed on partition walls. (5) It is adjusted and locked with a polygonal wrench or key. Finished in plain, nickel, bronze, or any other desired finish. "YOUNG" REMOTE CONTROL SYSTEM Nos. 700 and 800--The "YOUNG" Remote Control System, a combination of Nos. 700 and 800, is particular ly adaptable for hotels, office buildings, and many other types of buildings for manual control of air conditioning. The damper blades are constructed for diffusion and are placed at an angle in the air stream. The damper is connected to remote control device by a spring wire control--we recommend it being placed in a in. copper tubing. The knob sets damper at any desired position: it is on a 2% in., x 4in. flush plate, and indi cators show position of damper. No. 800 is damper without control. Patents Pending "S "YOUNG" FLUSH CUP REGULATOR No. 200--The "YOUNG" Flush Cup Regulator is used where it is necessary to have regulator flush with the wall. It is operated with a socket wrench. Can be had in concealed type, No. 300. O.D. size in. Finished in bronze or any other finish. "YOUNG" SPLIT DAMPER and CONTROL No. 500--The "YOUNG1 eccentric gear for operating the split Pat. and Pat. Pending damper. Can be used on any split damper. "A" shows friction shoe which will eliminate vibration. The friction shoe has a spring plunger with a rubber tip and will hold the damper in any desired position without the eccentric gear and can be controlled through the grille with a rod. "B" shows eccentric gear for operating split damper and. locking it in position. "C" shows guide for damper blade. The friction damper shoe is No. 501. Split Damper and Control has an 935 i i Boiler Cleanser, Leak Seal, Soot Destroyer The Vinco Company, Inc. 305 East 45th Street New York, N. Y. yiNco VINCO BOILER CLEANSER A positively harmless insoluble powder cleaner for new, remodeled and old heating systems. A unique, scientifically processed compound on a special formula not to be confused with other powder boiler cleaners. CERTIFIES YOIB Bating system `gEBHAIIYIltfl What Vinco Does Vinco permanently removes oil, grease, scale, rust and dirt from the internal surfaces and from the boiler water without the labor of blowing boilers over the top. By this thorough cleansing Vinco stops foaming, priming, surging, and slow steaming. Boiler Cleanser S, S, and 10 lb cans. How Vinco Works Each minute grain of Vinco powder absorbs several times its own weight of oil, rust and dirt. These larger grains of absorbed impurities then settle and are drained through the bottom, according to directions on each can. Our Three-Fold Guarantee 1. Vinco contains no potash, lye, soda of any kind, oil, acid, or other harmful ingredients. 2. Purchase price is refunded if results are not as claimed when Vinco has been used according to directions. 3. Your time, money and comfort are further safeguarded by Our Free Laboratory Service It saves thousands of dollars by analyzing the boiler water before making needless mechanical changes. If desired, the boiler water is again examined after the Vinco treatment is completed, and "certified chemically correct" for boiler operation. VINCO SUPERFINE LIQUID BOILER SEAL A different liquid seal. Unique in that it does not induce priming and foaming. It has no unpleasant smell. Makes speedy and permanent repairs of boiler and heating system leaks. Fine to tighten up new jobs. Directions simple. . DETECTS | istopTleaks Liquid Boiler Seal l qt. cans only Quantities Steam and Vapor Systems--Use 1 quart Vinco Liquid Boiler Seal' to each 6 sq ft grate area. Hot Water Systems --Use 2 quarts Vinco Liquid Boiler Seal to each 6 sq ft grate area. VINCO SOOT-OFF Non-explosive, thoroughly safe. No \ black smoke--no fire hazards. Destroys soot from coal, oil or gas burning heating equip ment. Easier, cleaner and quicker than brush ing. Makes short work of jobs too hard for brush or scraper. Cleans fire pot, flues and chim ney in one simple opera Soot-Off tion. 1 lb cans only. Ask for your copy of the Vinco Manual on the routine care of heating systems. .936 The Vinco Company, Inc. Boiler Cleanser, Leak Seal, Soot Destroyer VINCO SPECIFICATIONS INSIST THAT VINCO BE USED--CORRECTLY--IN EVERY HEATING SYSTEM YOU SPECIFY OR OPERATE. THESE TAGS USED BY BOILER MANUFACTURERS ON ALL THEIR BOILERS Give Proper Specifications for Cleaning All New, Remodeled and Old Steam, Vapor, and Hot Water Heating Systems. (Front of Tag) (Reverse Side of Tag) QUANTITIES OF VINCO (In Pounds) REQUIRED FOR HEATING SYSTEMS Note that quantities are based on actual installed radi ation. not on boiler capacity. CAUTION For Steam or *Also for Hot Water Annually. To Re Vapor Systems To Heating Systems move Rust Scale. Prevent or Cure Maintained at Ap- Dirt and for Priming and proximately 200 (Gravity) Hot Foaming Deg or Above. Water Systems Do oot me is a demising agent soda or any a&ati. vinegar or any add in this trader. DIRECTIONS FDR CLEANING After the system b tested and tight ase the proper quantity of Vinco luted on the reverse side of this tag and follow directions given on each can of Vinco. Satisfactory results wSI be obtained in record time with minimum expense. These tags used by: * American; 'radiator company Richmond Radi atorCompany.Inc pEpTUSVIUefROM$ORKS(pMPANY International Heater Company WATERFILM BOILERS MCOVOtAKO VINCO FOR HOT WATER SUPPLY SYSTEMS Thoroughly safe and effective. Full directions on every can. For systems having: Up to 350 sq ft of radiation____ 3.... ...... - 1M 351 600 " " * " s -----2H 601 " 1100 " " " 0 8-.............._.._.._..4. 1101 * 1400 " a " ____ 10............. . 5 1401 " 1800 " __ __13________-----6H 1801 " 2100 " " " _____15________ -- m 2101 " 2700 " " ....--is .... 9 2701 " 3100 0 " " ____ 20________ ___ 10 3101 " 3700 " " ____ 23________ ----- 11H 3701 " 4200 " " " ____ 26___ ____ ___ 13 4201 " 4600 " " " " _.28... ........ . 14 4601 " 5000 " " " 0 ___ 30. .. . 15 5001 0 5300 " 0 " ..... _31............ ----- 1SK 5301 a 5600 * " * " ____ 32________ ___ 16 5601 " 5900 " * " * -- 33. ____ 16M 5901 " 6200 " " ____ 34____ ___ 17 6201 " 6500 " " " ____ 35_____ __ ------UK 6501 " 6800 " " " .. .. 36..... ........ .. .18 6801 " 7100 " a " " 37 .. ... 18H 7101 " 7400 0 " " * ____.38 ....... .. 19 7401 7700 * " " " ...... .39............ ..... l#K 7701 " 8000 " " " " --.... 40___________ 20 8001 " 8300 " " " " ____ 41________----- 20H 8301 8600 * " " " ____ 42.............. .21 8601 * 8900 " " " .... 43......... -- ._ .21H 8901 " 9200 " " * " ___ 44. --. . .. 22 9201 " 9500 " " " " ....... 4S....... . . ..... 22M 9501 * 9800 " fl ____ 46 ... . ___ 23 9801 10100* " " ' _ 47. ____ . 23K Above 10100 sq ft use an additional pound Vinco for each additional 500 sq ft of actual installed radiation. {In the case of steam heating systems, never blow a boiler under pressure.) VINCO FOR OLD SYSTEMS Annual cleaning of the old heating system adds years of life to the boiler, prevents rust deterioration and saves much fuel and fire attendance. 937 Boiler (Feeders) M-DOIMIMGLL & MILLER Manufacturers of McDONNELL Boiler Water Level CONTROLS General Offices: Wrigley Building, Chicago, 111. Doing oneS^ssJthing ukUi PRODUCTS: Boiler Water Feeders; Combined Boiler Feeders and Low Water Cut offs; Low Water Cut-offs; Combined Low Water Cut-offs and Pressure Controls; Pump Controls: Low Wa ter Alarms: and related equipment. Boiler Water Feeders (Nos. 47, 51 and 53) automatically sup ply water to heating boilers whenever the boiler water level tends to fall to the dan ger point. Their depend able operation is assured by the McDonnell iVo. 47-2 Com bined Feeder ` `cool feed valve" which and Love Water Cut-off with "Quick-HookUp** for automatically fired boilers below 5,000 prevents lime and scale formation at the valve --by packless COn- %SLZSg3iJ.Z same range is identical exceptfortheNo.2cut- s surftch (S. belou,). struction, stainless Steel valves, the Me* Donnell "QuickHook-Up" feature and many other ad vancements that are combined in no other boiler feeders. (See 36-page cata log)Combined Water Feeders and Low Water Cut-offs (Nos. 47-2,51-2 and 53-2) for automatic No. 51-2 Com bined Feeder ally fired boilers, are the same as the Nos. and Low Water Cut-off 47 5J and 53 with for automatically fired -boilers above 5,000'sqft the No. 2 Low Water capacity. No. 51, for Cut-off switch add hand fired boilers, is ed as shown in illus the same exceptfor No. 2 switch. No. S3 and trations. In these No. 53-2 are similar in units the feeder appearance but of takescareofall nor- heavier construction. _ i . for higher pressures TMal operation and (See tables i and 2). the switch merely stands by to cut the current to the firing means in the event of an extreme emergency such as priming and foam- No 3 ^ Water Cut. ing or failure of off Switch used on No. water supply. 47'* No* $1* /Vo. S3,- No. 'TPhLese combined 6H0a-sA hiagnhd9oNUoag. m6c0o-Bn.- feeders and CUt-OIIS tacts and alarm ter"make the boiler minals. Can be fur- water level as auto- J2T,e'y r matic as the firing. Low Water Cut-offs (Nos. 66, 60-A and 60-B) are for automatically fired boilers where the owner is willing to sacrifice the convenience of the combined feeders and cut-offs to se cure a slightly low er price. They will dependably stop the burner when the water level reaches the danger zone, but of course they do not sup ply water to the boiler. Low water cut-offs are also a vailable with ^ simple, com- built-in pressure Control (Nos. 62-A Quick-Hook-Up feature and 62-B). fr boilers of any sise The No. 150 is pr`**"r" up 10 for use on boilers * with pressures up to 150 lb. Itcanbeused as either a low water cut-off, or a combined low water cdt-off, pump control and low water alarm. Service recommendations and typical specifications follow: No. 60-B Low Water Cut-off with Quick-Hook-Up and with No. 2 Cut-off switch (described op posite) --for boilers of any sise; pressures IS to 25 lb. No. 60-A is the same except that it does not fuxee Quick-Hook-Up feature and must be install ed with 1-in. equalising pipes. 938 McDonnell & Miller Boiler (Feeders) SERVICE RECOMMENDATIONS Boiler Size in Square Feet Steam Pressure McDonnell Product to Use Table 1--For Hand Fired Boilers Up to 5.000 Above 5.000 Any size Under 25 lb Under 25 lb 25 to 75 lb No. 47 Water Feeder No. 51 Water Feeder No. 53 Water Feeder Table 2--Water Feeder--Low Water Cut-off Combinations Up to 5.000 Above 5,000 Any size' Under 25 lb Under 25 lb 25 to 75 lb No. 47-2 Feeder-Cut-off Combination No. 51-2 Feeder-Cut-off Combination . No. 53-2 Feeder-Cut-off Combination Table 3--Low Water Cut-offs Any size Any size Any size Under 151b 15 to 25 lb 25 to 1501b No. 66 Low Water Cut-off No. 60-A or 60-B Low Water Cut-off No. 150 Low Water Cut-off Low Water Cut-off--Pressure Control Combinations Any size Under 121b No. 62-A or No. 62-B Com bined Cut-off and Pressure Control . TYPICAL SPECIFICATIONS FOR BOILER WATER FEEDER OR COM BINED FEEDER AND CUT-OFF Furnish and install complete in every essential detail for each boiler unit. Auto matic Boiler Water Feeder--and Low Water Cut-off (if automatically fired)-- equipment as manufactured by McDonnell & Miller, Wrigley Bldg., Chicago. Boiler Water Feeder to be (insert*) of the manufacturer's most improved design, with all working parts isolated from the steam and hot water zone by packless sylphon construction. Float power to be multiplied through a leverage mechanism which contains a self-centering roller di rectly above valve stem. All bearing points, pivots, and levers to be outside of the steam and water zone. Valve cone and seat to be stainless steel, removable and renewable. A strainer to be incorporated in the design and to have a solderless bas ket mounted on a flange for easy removal. Feeder to be installed complete with all piping, valves, fittings, and specialties, as indicated by descriptive diagram in the manufacturer's construction bulletin. Upon completion of the installation, the contractor to place this automatic equip ment in successful operation1, subject to acceptance and approval of the architect's ......................................................... engineer. *If job is hand fired, insert: "No. 47," "No. 51," or "No. 53," as indicated by service conditions in Table 1. *If job is automatically fired, insert: "No. 47-2," "No. 51-2" or "No. 53-2," as indicated by service conditions in Table 2. When combined units No. 47-2, No. 51-2, or No. 53-2 are specified, add the following paragraph to specifications: "Make electrical connections for low water switch to control fuel supply equipment, so that the fuel is automatically shut off by the low boiler water control. Control wiring to be of flexible armored cable. All wiring to meet the requirements of the City Electrical Inspection Department and the National Board of Fire Underwriters." TYPICAL SPECIFICATIONS FOR LOW WATER CUT-OFF Furnish and install on each boiler, in accordance with the manufacturer's instructions, a McDonnell & Miller No. (insertf) Low Water Cut-off, to be float operated and to have packless construc tion. Control wiring to be of flexible armored cable. All wiring to meet the requirements of the City Electrical Inspection De partment and the National Board of Fire Underwriters. No. ISO tlnsert at this point "No. 66," "No. 60- A," "No. 60-B,"or ,.v, . No. 150, as mdi- Combi ne tion Low Water Cut-off, Pump Control and Low Water Alarm built to cated by service con- .... . -- o ditions in Table o. (If No. 62-A or No. .. 62-B is indicated specifications ... Should cover the stand up in high pressure service. Float operates two mercury switches. One closes pump circuit when water level falls: the other cuts burner circuit completes alarm circuit when water level falls to danger zone. Maximum pressure control fea- steam pressure, 150 lb. ture as outlined in the McDonnell Catalog). No. 62-B Low Wa ter Cut-off with built-in pressure control od/ustabte from 1 to 12 lb. No. 60-A is the ' same except that . it does not have Quick - Hook - Up feature and is in stalled with I-in. equalising pipe. New 36-page catalog contains complete descriptions, capacity chart, installation instructions, wiring diagrams, dimensions, etc. - 939 Boilers, Casl-Iron AMERICAN RADIATOR COMPANY .division ofAmerican Radiator & Standard Sanitary Corporation 40 West 40th Street, New York, N. Y. PRODUCTS FOR EVERY HEATING REQUIREMENT AUTOMATIC coal-fired BOILER No. 21 Designed especially for use with mechan ical stokers. Recom mended by leading stoker manufac turers. Can be used with either built in or external water heat er. The hot gases travel four times the boiler's length during which time all heat is absorbed. Available in four sizes. Ra tings:* Steam 510 960 sq ft; Water 815-1535 sq ft. IDEAL ARCO ROUND BOILER A low priced boiler. Uses hard or soft coal or coke. May be easily converted to automatic firing or oil or gas fuel. Machine ground surfaces of doors and sections prevent waste of heat. Ratings:* Steam 200 800 sq ft; Water 320 1280 sq ft. Available in six diameters. IDEAL REDFLASH BOILERS Regular Regular--A prac tical boiler for the average home. Red enamel jacket. Ship ped in sections so that it can be easily in stalled. Multi-ply Asbestocel insulation. Available in five dif ferent sizes. Auto matic Damper Regu lator. Ratings:* Steam 275-10,370 sq ft; Water 440-16,600 sq ft. Special Boiler for Burning soft coal. No, 7 IDEAL BOILER FOR COAL, OIL OR GAS Hand Fired A low-cost uni versal boiler with many high priced features. Gives quick pick up-- low cost heat. Improved flue design utilizes available heat. Precision ground iron-to-iron sec tions. Provision for domestic hot water supply by screwed in Taco Heater. NEW IDEAL ARCO ROUND BOILER A deluxe edition of the old Arco Round. Attrac tive red enamel jacket. New Arco Circulator for quicker pick-up. Precision ground Arco Relief Valve. Sensi tive all-metal Arco Auto matic Regulator. Asbesto cel. insulation. Ratings:* Steam 300-800 sq ft; Water 480-1280 sq ft. ARCOLA Hot Water Boiler for small homes up to six rooms, stores, garages or other small buildings. Needs no basement. Available in three styles: unjacketed, with insulated jacket, and with circu lating jacket. Radiators can be attached to it. Recommended Load--Represents attached load in square feet E.D.R.--including piping-- which may be placed on Boiler in accordance with accepted installation standards for economical operation. 940 Boilers, Cast-Iron AMERICAN RADIATOR COMPANY division ofAmerican 'Radiator &. Standard .Sanitary Corporation 40 West 40th Street, New York, N. Y. PRODUCTS FOR EVERY HEATING REQUIREMENT OIL BURNING BOILER No. 92 Large size automatic oil burning boiler for large homes, apart ments, stores, etc. Ratings:* Steam 1360 2460 sq ft; Water21803940 sq ft at transmis sion rate 4500 Btu/ square foot. Any type burner can be used with it. BOILERS FOR LARGER INSTALLATIONS "Ideal" Water Tube Sectional Boilers--For large buildings and com mercial installations. Sectional construc tion permits easy installation. Available in five sizes from 23 in. to 79 in. Ratings:* Steam 450-15,000 sq ft; Water 720-24,000 sq ft. OIL BURNING BOILER No. 12 Medium size auto matic oil burning boil er. Also equipped with built in hot water sys tem and low water con trol. Asbestocel insu lation of the lining to conserve the heat. Can be used with rotary or gun type burner. Available in four sizes. Ratings:* Steam 510-960 sq ft; Water 815-1535 sq ft at transmission rate 4500 Btu/square foot. sq ft at transmission foot. OIL BURNING BOILER No. 11 Small size auto matic oil burning boiler with built in Taco Water Heater. Equip ped with Detroit Boiler Protector which stops the burner if the water level drops. Available in six sizes. Ratings:* Steam 355-755 sq ft;Water570-1205 :e 4500 Btu/square Recommended Load--Represents attached load in square feet E.D.R.--including piping-- which may be placed on Boiler in accordance with accepted installation standards for economical operation. THE NEW IDEAL FAST VENTING SYSTEM On automatic one pipe steam jobs the New Ideal Fast Venting System speeds heat ing--makes it much easier to balance the job. It consists of the No. 300 Arco-Detroit Multiport for radiators and the No. 861 Arco-Detroit Hurivent for mains. THE No. 300 ARCODETROIT MULTI . PORT At one ounce of pres sure it vents radiators with amazing rapidity. 941 THE No. 861 ARCODETROIT HURIVENT Designed to vent the mains with utmost speed so that the steam can reach the radiators with a minimum of frictional loss. Boilers, Cast Iron AMERICAN RADIATOR COMPANY division orAmerican Radiator & Standard Sanitary Corporation 40 West 40tK Street, New York, N. Y. CAST IRON RADIATORS AND ENCLOSURES CORTO RADIATOR A slender tube radiator which is quick-heating and responsive to varying de mands of comfort. Avail able in 7 heights and 5 widths. Factory tested for 125 lb hydraulic pressure. ARCO RADIANT CONVECTOR Combines the functions of radi ator and convector. Concealed behind an attractive en closure. Five styles of enclosures in any length up to 60 in. Designed for steam, hot water or vapor systems. CORTO HOSPITAL RADIATOR Extremely wide spacing between sec tions allows easy and thorough cleaning. The tubes are smooth with no dust catching edges, no tie rods to collect dirt. ARCO RADIATORS Compact radiators with an output equal to old types of larger radiators. Available in three widths and three heights with 2F6 or 4^ in. legs or for suspension by wall brackets. PEERLESS WALL RADIATOR Especially desirable for commercial installations. Fits into restricted spaces of practically any size or shape, under windows or between them, on walls, ceilings or in skylights.- Available in many sizes. ARCO CONVECTOR Concealed be hind an attrac tive enclosure. Long, specially designed fins heat the air thoroughly. Available in four different widths 3^-9^ in. and the length may be varied by the number of sections. Enclosures to fit every size of convector. VENTO CAST IRON RADIATOR For blast heating and conditioning systems. Rust proof cast iron con struction makes them ideal for use with washed or humidified air. Streamlined studs give positive air wipe. . PERFECTION PIN ARCO PACKLESS VALVES Never leak or need repacking. For steam, hot water, vapor or vac uum heating systems. Five sizes from H to in. For gravity indirect heating with steam or hot water. Threaded nipple or flange and bolt connections. 942 I 'j 1 t \ i j Boilers, Cast-Iron AMERICAN RADIATOR COMPANY division ofAmerican ~Rapiator a Standard Sanitary Corporation 40 West 40th Street, New York, N. Y. PRODUCTS FOR EVERY HEATING REQUIREMENT Arco No. 2001 Equatrol-- Balances radiator output against room temperature to provide an even and continuous warmth throughout the house. New in conception, unequalled in per formance. SCUTTLE-A-DAY A coal burning water heater for small homes, stores, etc. In three sizes with capacities of 75-175 gal. Also The Arco In cinerator which burns the garbage with the same fire that heats the water. Made in 75-110 gal capacities. KOLFLASH COAL WATER HEATER A self contained water heater and storage tank. Galvanized tank is welded to cast iron base and is ex posed directly to fire. Burns hard or soft coal econom ically. Two fuelings a day is average. Removable ashpan. Arco Balancing El bows-- Balances hot water systems by restrict ing the flow with adjust able baffle. With thread ed, or sweat connection in three sizes. From % to ii in. - ARCO HIGH TEST TANK HEATER A water heater for large buildings. Adapted to complete automatic control with hard or soft coal, oil or gas. Hand-fired, will burn without refueling for eight hours or longer. Capacities: Coal 1500-3000 gal; Oil 1520-2520 gal. ARCOLOY RANGE BOILERS AND TANKS Made of the new patented metal --Arcoloy--with appearance and corros.on resistance of copper and the strength of mild steel. Guaran teed for twenty years under normal water conditions. Available in seven sizes: 25-100 gal. NEW IDEAL OIL BURNING WATER HEATER Burns low-priced range oil or distillate. Includes Dome type heater--oil burner-- Detroit Safety float Valve--8 gal oil tank. . OLD LINE WATER HEATER Economical and depen dable to keep larger quan tities of hot water--74 to 880 gal--on tap constantly. Guaranteed for working pres sure of 100 lb. Plant tested 25 lb hydrostatic pressure. EXCELSO WATER HEATER Provides hot water indirectly from steam or hot water boilers. Available with Single, Double, Triple and Dual Coils. Ca pacities up to 3750 gal. IDEAL DOME TYPE WATER HEATER A new cast iron coal burning heater. Made in seven sizes with capacities of 65-250 gal. Plant tested to 315 lb pressure and guaranteed for working pressure of 125 lb. . (See also American Radiator Co. pages 884-885, 1061, and Subsidiaries) 943 Boilers, Cast-Iron Manufacturers of Cast Iron and Welded Steel Boilers, Cast Iron Radiators and Heating Accessories Irvington-on-Hudson, N. Y. Zanesville. Ohio Branch Offices Boston; Philadelphia; Chicago; Queens Village. L. I.; Long Island City, N. V.; Baltimore; Springfield; Lancaster; Pittsburgh; Zanesville; Elizabeth; Geneva. N. Y. Plants Elizabeth. N. J.; Lancaster. Pa Zanesville, Ohio; Geneva, N. Y. AIR CONDITIONING UNIT A complete Winter Air Conditioner, taking place of a radiator. Conditioner has a heating capacity of 80 sq ft. Filter-cleans the air of dust and pollen, then warms, humidifies and circu lates the air. Fan capacity 400 cu ft of air per minute. Each Conditioner Unit will, if room requires it, evaporate up to 12 gal of water a day. Water furnished to Hu midifier from water supply controlled by ball float valve. Equipped with thermostat, automatic current snap-on switch and hand rheostat for fan speeds. Fan can be run indepen dently for Summer circulation. Cabinet finished in burl walnut and velvet black with a touch of chromium. Takes up no more room than grille-enclosed radiator. Fits under average window. Can . be used like a free-standing radiator and either partly or entirely enclosed. Panel Front furnished when completely recessed. No ducts in basement or between wails. No floor registers. No wall grilles.. Capacity and Size Over-all size, 23M x 39M x 13M* 2 Con ditioners ample for 7 or 8 room house. Additional Units can be added at any time by simply replacing a radiator. * MULTIPLE USE FAN COOLER A high efficiency portable unit for offices, hotels, restaurants and home rooms. Also made in a complete equipment package for attic cooling of residences. . For such use, fan draws warm air through grille in upper story hall, forcing it out attic louvre. Heavy warm air accumu lated in the house is replaced by the cooler outside air, reducing temperature in house from 8 to 10 deg. Equipment includes flame-proof vent box trap door, equipped with fusible link. Shuts ti^ht in case of fire and at same time automatically stops fan. When fan not running, trap door closes grille opening, stopping back drafts from attic. Trap door linked with switch to start and stop fan. , Special Package Equipment for outside use on flat roofs. . Capacity and Size Fan made in 3 sizes and capacities-- 30 in..........................7000 cfm 39 in........................10000 cfm 45 in........................14000 cfm 944 Boilers, Cast-Iron Irvington-on-Hudson, New York Zanesville, Ohio There's a Burnham for Every Purpose Catalogs Sent on Request 1--Welded Steel Boilers--Also Three Purpose Welded Steel Boilers. For heating, hot water supply and incineration. Coal or oil. Completely welded for 15 lb working pressure. Multiple shaking grates. Sizes for commercial or domestic uses. Special folder sent on request. 2--Water Tube Boilers for Steam and Hot Water Heating. 17, 21, 27, and 36 in. Double shaking grates, long fire*travel. Steam rating to 9,050 sq ft; for water, 14,480 sq ft. 3--Water Tube Boilers Jacketed in Color. 17, 21, and 27 in. Steel Jacket and 4 ply air cell asbestos insulation. Enameled rich red and black. Jacket goes on after all other set up work. Rating to 5,000 sq ft for steam and 8,000 sq ft for water. 4--Burnham Oil-Burning Boilers. A specific-sized boiler for each specific heat job for use with any standard oil burner. Round Sectional Burnhams in 6 series and 24 sizes. Square Burn hams" in 5 series and 39 sizes. For steam, vapor, or water. 5--Big Twin Sectional Boilers. 50 in. Grate divided for easy shaking; Twin sections, divided down the mid dle. Ratings to 29,200 sq ft for steam, 46,720 sq ft for water. 6--.Tube Type Smokeless Boilers. Bum soft coal efficiently, without smoke. Meet smoke ordinances every where. Similar to (2) above with addition of smokeless feature. 7--Round Sectional Boilers. This boiler made the long fire travel famous. Handled easily. Very large steam dome. Ratings up to 2,080 sq ft for steam 3,440 for water. . 8--High Pressure Hot Water Supply Boilers. Sectional construction. Guaranteed to 120 lb working pressure. Supplies up to 14,000 gal. 9--Junior Hot Water Supply Boilers. Will keep 175 to 700 gal tank always full of hot water. Guaranteed to 120 lb working pressure. 10--Burnham-Taco Tanks. Combining water heater and storage tank in one unit for summer-winter use. Removable copper heating element. Tanks may be galvanized, Everdur or copper. 11--Burnham Slenderized Radiators. Cast iron radiators that occupy 40 per cent less space than ordinary type of same rating. Shorter. Lower. Nar rower. 3-tube type 3}4 in. wide. 4-tube type 4%6 in. wide. 5-tube type in. wide. 6-tube type 6l%$ in* wide. Can be recessed. 12--Fero Tube Radiators. All heights--3, 4, 5r 6, and 7 tubes. 13--Burnham Air Conditioning Units. Do double duty of both heating and winter air conditioning. Units placed in the room. Have no basement equip ment. Take up no more room space than usual grille-enclosed radiator. Entirely automatically controlled. 14--Burnham Air and Vacuum Valves. Full line for radiators, risers and mains. 15--Burnham Radiator Valves. Complete line of heating accessories. Including steel tanks of all kinds. 16--Burnham Flexible Headers. 17--Burnham Unit Heaters. Complete line in modem designs. 18--Burnham Fan Cooler. Portable unit for offices, hotels, res taurants and home rooms. Also com plete equipment package for attic cooling of residences. 945 Boilers, Cast-Iron Crane Co. Manufacturers of Valves, Fittings, Fabricated Piping, Steam Specialties, Plumbing and Heating Materials 836 S. Michigan Avenue, Chicago, 111. Branches in All Principal Cities Write for Catalogs and full information on any materials COMPLETE LINE OF RESIDENTIAL AND COMMERCIAL BUILDING BOILERS AND HEATING MATERIALS Boilers for hot water, steam, vacuum and vapor heating, to burn any fuel--coal, oil or gas. Coal-fired boilers are made both in square sectional and round styles in a complete range of sizes. A special series of sectional boilers is also built for stoker firing. Crane furnishes air conditioning units and split system equipment for all types of residential installations. Crane Radiation includes direct, (legless, bathroom, hospital, wall), concealed, and shielded types of high efficiency and grace ful design. Unit heaters, humidifying radiators, and a complete assortment of valves, fittings and specialties complete the Crane heating line for residential and commercial use. Sustained Heat Boiler BurnerUnit The "Sus tained Heat" principle of design incor porated in this boiler assures high combustion efficiency and low standby loss. Comes complete with oil burner. Basmor Gas Fired Boiler With the famous Butter fly Bunsen-type burner, this boil er develops high efficiency with negligible stand by loss. All types of* gas. Available in both regular and deluxe jacket models. Crane Directed Radiation Invisible low-cost shields direct heat outward into room, equalizing tempera tures, protecting wails and drapes. Crane Coal Fired Boilers Greater "ceiling" heating surface, controlled water travel, and a score of operating refine ments place this boiler on a plane of highest efficiency. 946 Crane Co. Boilers, Cast-Iron EVERY TYPE OF VALVE AND FITTING FOR HEATING INSTALLATIONS Crane Welding Fittings--Uniform thickness in cross-section and radius, with ends accurately beveled. Long tangents facilitate welding in line. Crane Standard Cast Iron Fittings of dense, uniform .metal are made in a wide variety of types and" sizes. Crane Steam Trap--A cast-iron trap of high capacity. Simple working parts. Expels condensate in instantaneous action. Crane No. 512 Gem Union--A ground-joint union with brass to iron seat. No gasket required. Taper threads. .Crane Wedge'Gate Valve (Left)--A brass valve with non-rising stem, stuffing box gland, and disc guides that prevent wear of seating surfaces. Can be packed while wide open under pressure. For steam working pressures up to 125 lb. Crane Double Disc Gate Valve (Right) --A brass valve with rising stem, parallel seats, and wedging device assuring equal bearing on all parts of seat. Can be packed while .wide open under pressure. For steam working pressures up to 125 lb. Crane No. 1168 L. P. Pop-Safety Valve--A side-outlet valve, with brass trimmings, for steam heating boilers. Sturdy, rigid base and ample clearance for tools. When set at a maximum of 15 lb these valves comply with the A.S. M.E. l.p. Heating Boiler Code. Crane No. 984 Air Vent -- An automatic vent to remove air from water mains, hot water heating sys tems and tanks. Operation similar to. the steam trap illus trated above. Simple, low in price. 947 Boilers, Cast'Iron New York, N. Y. Philadelphia, Pa. Boston, Mass. Baltimore, Md. Washington, D. C. Springfield, Mass. Spencer Heater Division Lycoming Manufacturing Company Williamsport, Pa. Sales Representatives Albany, N. Y. Binghamton, N. Y. Buffalo, N. Y. Syracuse, N. Y. Allentown, Pa. Harrisburg, Pa. Chicago, III. St. Paul, Minn. Cincinnati, O. Columbus, O. Dayton, O. Birmingham, Ala. St. Louis, Mo. Indianapolis, Ind. Decatur, III. St. Petersburg, Fla. San Francisco, Cal. Louisville, Ky. Spencer Automatic Magazine Feed Heaters are made in cast-iron sectional types for steam, vapor and hot water heating. Also in steel tubular types for large buildings. There are sizes and capacities to provide economical and convenient heat--safe and sure --for every type of building. The new Spencer Automatic Magazine Feed Warm Air Furnace makes available for property owners the advantages of the Spencer principle of magazine feed, sloping grates, automatic coal action, and low operating cost--for warm air systems of either gravity or forced circulation type. COMFORTABLE HEAT AT LOW COST Spencer Jacketed Healer--L.l. Series Why Spencer Heaters perform so satis factorily can best be explained by a brief inspection of their design and construction. The Spencer principle--as illustrated in the cross sectional view--is simple: Once a day fuel is put into the magazine. It fills the sloping grate to the level of the magazine mouth. The fire bed always stays at the proper level for as fast as fuel burns to ash it shrinks and settles on the sloping grate and more fuel rolls down automatically over the top of the fire bed. Fuel feed is by gravity alone, in just the right amount to keep the fire always burn ing at its most efficient combustion point. This explains why a Spencer Automatic Magazine Feed Heater or Furnace always gives the same uniform, satisfying heat, and burns less coal. These exclusive Spencer advantages are available in all types of the magazine feed heaters and furnaces, either the J and L series cast iron sectional heaters or the W series furnaces burning low cost No. 1 Buck wheat; the C-N series for larger fuels; or the steel magazine feed boilers for larger buildings, also burning No. 1 Buckwheat. Coal - Coke - Gas - Oil--Spencer J and L series heaters, W series furnaces and steel tubular magazine feed boilers are primarily designed to burn low cost No. 1 Buckwheat anthracite and the C-N series Nut or Pea anthracite or coke. If at any time a home owner desires.to burn more expensive fuels--oil or gas-- a Spencer Heater will show an efficiency that is unsurpassed. Thermostats--A Minneapolis Acratherm thermostat and electric damper motor are furnished as optional equipment. Jacketed Covering--Attractive metal lic jackets, are available for Spencer CastIron Heaters. L-l Series Spencer--Sectional View 948 Spencer Heater Division Boilers, Cast'Iron Spencer Magazine Feed Warm Air Furnace Without Casing SPENCER AUTOMATIC MAGAZINE FEED WARM AIR FURNACES Illustrated at the left is the new Spencer Automatic Maga zine Feed Warm Air Furnace, less its galvanized casing. It operates on the automatic magazine feed principle. Once the fuel is in the storage magazine, it feeds over the fire on the sloping grates in just the right amounts for the heat required. Attention is necessary only once a day. Entirely new in warm air furnace design, the Spencer burns low cost No. 1 Buckwheat Anthracite, and eliminates all of the disadvantages of the ordinary type of furnace--no "hot spots," no caulking between sections, no brick lined fire pots, no leaky joints. Assures an air-tight, gas-tight, leak-proof, long life installation. Furnished with attractive metallic casing. Spencer Furnaces are compact, streamlined, and so designed that other air conditioning features can be readily added. SPENCER STEEL TUBULAR MAGAZINE FEED BOILERS For larger buildings we recommend Spencer Steel Tubular Boilers, also of the magazine type, burning low cost No. 1 Buckwheat Anthracite or coke. In the cross section diagram at the right, part of the fire bed is cut away to show the sloping grates and the two magazines filled with fresh coal, ready to feed down automatically of its own weight to the fire. These boilers are built in two vertical sections for ease in handling and instal lation--a great advantage on remodeling or replacement jobs, eliminating necessity of costly tearing out of walls, etc. Combination water tube and fire tube con struction. Built to A.S.M.E. Standards. M Series , Spencer Sled Tubular Magazine Feed Boiler SPENCER STEEL BOILERS For Oil, Stoker, Gas or Hand-Firing For more than 40 years, Spencer has and tubes. Can be furnished with been building, efficient, economical and domestic hot water heating coils, either dependable coal burning boilers. With of the storage tank or instantaneous this background of experience, Spencer type. engineers have developed the Spencer Steel Boiler for oil, gas, stoker and hand firing-- the "C" series for . residential use, and the "Type A" for larger buildings. It is a better boiler, we believe, not only for the property owner, but for the engi neer who specifies it and the heat ing contractor who installs it. The high sustained efficiency of these boilers means adequate heat for a lower fuel cost. De sign is of the three pass type. Combustion chamber is am ply large. Built of best quality open hearth steel boiler plate, C Series Spencer Steel Boiler Type A--Spencer Steel Boiler 949 1 Boilers, Cast-Iron United States Radiator (orporation General Offices: Detroit, Michigan Branches and Sales Offices in Principal Cities Detroit, Michigan U. S.-25 OIL BURNING BOILER Front Extended Jacket Performance Curve CAPITOL FINCAST ENCLOSURES AND CONVECTORS Made entirely of cast iron. Without joints--Cast in one piece. Many lengths and widths. Tappings, top, bottom and ends. Complete choice of enclosures. Finished to harmonize with modern interiors. Output--% of Direct Standing Radiator Load Flue Gas Analysis CO2--12.5%; O2--4.1%; CO--0.0%. CAPITOLAIRE DIRECT FIRED CAPITOL THINTUBE RADIATORS 3-Tube Heights Per Section Heating Surface 19' I.ISqFt 22' !.3SqFt 25' l.SSq'Ft 4 -Tube 19' 1.4 Sq Ft 22' 1.6 Sq Ft 25' l.SSqFt 5-Tube 20* 1.8SqFt 23' 2.1 Sq Ft 26' 2.4 Sq Ft 40 per cent less space needed for these graceful, efficient Capitol ThinTube Radiators. Built to meet a new demand in air conditioning which calls for compactness in floor space. All DeLuxe air condition ing units have the blower built into the ' furnace cabinet. Automatic humidifier of our own design, with all adjustments outside the cabinet, furnished with each unit. Steel wool washable filters supplied with DeLuxe units. 950 Boilers, Cast-Iron United States Radiator (orporation General Offices: Detroit, Michigan Branches and Sales Offices in Principal Cities Detroit, Michigan . CAPITOL RED CAP BOILERS For All Fuels CAPITOL SQUARE BOILERS FOR ALL FUELS "A" Series Ratings in Sq Ft Direct Cast Iron Radiator Loads--Sq Ft Steam-- 575-1450 Water-- 975-2475 280- 655 460-1085 "B" Series Steam--1200-3600 Water--1980-5940 550-2030 910-3350 **C" Series Direct Cast Iron Boiler No. Radiator Loads Sq Ft Steam Water 19-4 300 19-5 350 495 580 20-4 400 20-5 450 660 745 22-4 500 22-5 550 825 910 25-4 625 25-5 675 1030 1115 Capitol Red Cap Boiler design brings the advantages of (1) long fire travel, (2) flue passages that force the hot gases to circulate through every section, ex tracting the maximum heat from the fuel consumed. (3) Deep firepot that provides the extra space needed for better com bustion, and smooth, tapered firepot walls to assure a clean surface for better heat absorption. CAPITOLAIRE CONDITIONING UNIT FOR SPLIT SYSTEMS ' Steam--4700-10,500 Water--7760-17,325 1865-5805 3080-9580 . Illustrated above is a Capitol Red Top Series "C" Boiler. These sectional, cast iron, all fuel boilers can be furnished either jacketed or unjacketed. Sections are con nected with precision-made slip nipples in accurately machined ports and the in dividual sections are ground to permit an iron-to-iron gas-tight assembly. The large, smooth flueways are designed with out sharp turns reducing friction, per mitting unrestricted gas travel. For easy cleaning, all flueways are fully accessible through the large front clean-out doors. Controlled internal water circulation and large nipple ports insure complete sepa ration of water and steam. Capitol Red Top Boilers are heavily insulated against heat loss by a thick blanket of rock wool, reinforced with wire mesh to prevent slip ping or sagging. Capitol Red Top Boilers can be furnished with extra high steel bases to' provide extra setting height or desired additional furnace volume for stoker firing. These bases eliminate the necessity for pitting or building a brick or concrete base. This compact suspended basement type humidifier unit can be installed in new homes, or added to homes which have a hot water or steam radiator system of heating. It is hung from the basement ceiling by means of rubber cushioned hangers. Heating connections are made to the house heating boiler which provides necessary amount of heat for tempering air and evaporation of water. A return air duct carries the air from the living * rooms to the humidifier. After this air is cleaned and humidified, it then passes through supply ducts back to the living rooms of the house. Completely auto matic--by means of a humidity control placed in the living rooms or in the return air duct. . 951 Boilers, Cast-Iron Weil-McLain Company Manufacturing Division: Michigan City, Ind. and Erie, Pa. ` General Offices: 641 W. Lake Street, Chicago NEW YORK OFFICES: 501 Fifth Avenue Prompt Weil-McLaio Boiler and Radiator service is made conveniently available through local stocks carried by Weil-McLain Distributors in most of the important distributing centers. No. 77 All-Fuel Boiler Conversion type boiler with insulated enameled jacket. For hand or auto matic firing. Connected Load Ratings: Steam 410 to 950 sq ft, Water 655 to 1,520 sq ft. Concealed Raydiant Raydiant is a convector type all cast iron radiator made in Concealed, Par tially Exposed and Cabinet Types. Raydiant Radi ators, however, differ from conventional convectors in Square-Type Boilers Sectional boilers for larger installations. Com plete range of sizes. Con nected Load Ratings: Steam 650 to 9,300 sq ft, Water 1,050 to 14,900 sq ft. No. 78 Boiler for Automatic Firing Boiler has insulated en ameled de luxe jacket. Front or rear jacket ex tension available. Con nected Load Ratings: Steam 400 to 1,030 sq ft, Water 640 to 1,650 sq ft. Partially Exposed Raydiant that they supply not only convected heat but also sun-like radiant warmth from their heat radiating "live" panel front. A second important advan tage is their ability to hold heat longer. \ Self-Feed Boiler Magazine type boiler for small inexpensive sizes hard coal or coke. Con nected Load Ratings: Steam 240 to 785 sq ft, Water 385 to 1,260 sq ft. "RO Series" Boiler for Automatic Firing Jacketed and insulated round boiler for small homes. Connected Load Ratings: Steam 420 and 520 sq ft, Water 630 and 790 sq ft. Cabinet Raydiant This helps increase the comfort of (on and off) automatic heating and makes mixed installation of Raydiant and standard . radiation practicable. 952 S-TUBE 6-TUBE Junior Radiators Occupy 40 per cent less space than conventional radiators of same rating. 3-tube, 3% in. wide; 4- tube, 4%e, in.wide; 5-tube, 5% in. wide; 6-tube, 6*^6 in. wide. Boilers, Gas American Gas Products Corporation Division of American Radiator & Standard Sanitary Corporation ' 40 West 40th Street, New York, N. Y. Gas Boilers for Hot Water . . . Steam and Vapor Heating . . . Automatic Hot Water Storage Heaters . . . Air Conditioners . . . Gas Fired Steam Radiators Approved by A. G. A. Laboratory for Steam, Vapor or Hot'Water ' Heating Systems. Ratings Below. Empire Idtai . Standard Ideal Specifications for Empire and Standard Ideal Gas Boilers STEAM BOILERS WATER BOILERS Steam Boiler Number A.G.A. Steam Rating Sq. Ft. Supplies Sq. Ft. Direct c; 1. Radiation No. and Size of Tappings Simply Return In. Water Boiler Number A.GJL Water Rating Sq. Ft. Supplies Sq. Ft.' Direct C. I. Radiation No. and Size of Tappings Simply Return In. O-GS-4 270 O-CS-5 360 O-CS-6 450 - O-GS-7 540 O-GS-^E 255 0-CS-5-E 340 0-GS^-E 425 OCS-7-E 510 0GS-9-E 680 0-GS-1 l-E 850 l-GS-4 610 l-GS-5 - 775 l-GS-6 940 l-GS-7 1105 1-CS-8 1270 l-CS-9 1435 l-GS-10 1600 l-GS-ll 4-GS-6 1765 2000 4-GS-7 2400 4-GS-8 2800 4-GS-9 3200 4-GS-IO 3600 4-GS-U 4000 4-GS-I3 4800 4-GS-15 5600 4-GS-17 6400 4-GS-19 7200 4-GS-2I 8000 4-GS-22 8400 4-GS-25 9600 4-GS-28 4-GS-3! 10800 12000 LGS-33 12800 4-GS-37 14400 4-GS-4I 16000 173 230 289 346 163 218 272 327 436 545 391 497 606 715 826 938 1050 1165 1332 1624 1922 2214 2505 2793 3387 4000 4570 5143 5714 6000 6857 7714 8570 9145 10285 11430 2-2% 2-2$ 2-2% 2-2% 1-3 1-3 1-3 2-3 2-3 2-3 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-6 2-6 2-6 2-6 2-6 2-6 4-6 4-6 4-6 4-6 4-6 6-6 6-6 6-6 6-6 8-6 6-6 8-6 1-1% i-i % 1-1% i-i% 11--11*%/* i-i % 1-1% i-i% i-i% 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-5 2-5 2-5 2t5 2-5 2-5 3-5 3-5 3-5 6-5 3-5 4-5 4-5 4-5 4-5 6-5 5-5 5-5 l-GA-4 l-GA-5 1-GA-6 1-GA-7 2-GA-4 2-GA-5 2-GA-6 2-GA-7 4-GA-9 4-GA-l 1 4-GA-13 l-GW-4 l-GW-5 l-GW-6 l-GW-7 l-GW-8 l-GW-9 l-GW-10 1-GW-1I 4-GW-6 4-GW-7 4-GW-8 4-GW-9 4-GW-10 4-GW-11 4-GW-13 4-GW-15 4-GW-17 4-GW-19 4^W-2I 4-CW-22 4GW-25 4-GW-28 4^W-31 4GW-33 4-GW-37 4-CW-4I 210 280 350 420 420 560 700 840 1120 1400 1680 980 1240 1500 1770 2030 2300 2560 2820 3200 3840 4480 5120 5760 6400 7680 8960 10240 11520 12800 13440 15360 17280 19200 20480 23040 25600 135 180 225 270 270 359 449 539 725 915 1109 631 607 980 1168 1353 1598 1739 1935 2214 2676 3151 3634 4114 4571 5486 6400 7314 8230 9143 9600 10970 12343 13714 14625 16457 18286 2-V/z 2-ll/j 2--1 '/i 1-2/4 1-2/2 1-21/j . 21--22(%4 2-2/2 2-2'A 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-6 2-6 2-6 2-6 2-6 2-6 4-6 4-6 4-6 4-6 4-6 6-6 6-6 6-6 6-6 8-6 8-6 6-6 All Boilers except type 4-G are available in either Standard or Empire Ideal models. (See also Page 886) 2-1/. 2-1(4 2-1(4 2-1/2 '-2(4 1-2(4 i-as 1-2(4 2-2(4 2-2(4 2-2(4 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-4 2-5 2-5 2-5 2-5 2-5 2-5 3-5 3-5 3-5 3-5 3-5 4-5 4-5 4-5 4-5 5-5 5-5 .5-5 ` Boilers, Steel THE BABCOCK & WILCOX COMPANY 85 Liberty Street, Manufacturers of New York, N. Y. Water-Tube Boilers Oil Burners Chain-Grate Stokers Seamless Steel Tubing and Pipe Branch Offices and Representatives in all Principal Cities Type H Stirling Boiler The Babcock & Wilcox Type H Stirling Boiler is a highly efficient unit built for moderate pressures at moderate prices.... and is designed to occupy minimum floor space and head room for the heating sur face required. This boiler is built in four classes and 36 sizes ranging from 691 to 4980 sq ft of heating surface, and can be designed for operation with any fuel and every method of firing. The moderate price is due only to the simplicity of design, efficient production methods and superior shop equipment. , g H eating Surface Floor to Center of M ud Drum , F t. In. 1F lo o r to T o p of I Boiler. F t, In. Size o f Steam O utlet, In. ttin Width of Setting "5 _ e S of Two Single Boilers p. pth In. Boiler, in Ft. In. battery iff- t.e u FD Ft. In. U.COU. 1 1 a691 15-2. 921 in? * H-1 1382 6-0 7-0 8-0 90 1612 10 0 1843 * II 0 2073 * 12 0 2304 " 13 0 11-0 13-0 13-0 17 0 19 0 21-0 23-0 25-0 5-2 14-51/2 13-3'/, *. " ** * *" ** a * *" 5 * *uB " " 877 17-8 1169 1462 H-2 1734 2046 2339 2631 * 2924 * 6-0 7-0 8-0 9-0 (0-0 11-0 12 0 13-0 11-0 13-0 13-0 17-0 19-0 21-0 23-0 25-0 4-9'/. 14-5'/, 13-3'/, "* " ". * ** "* ** 5 " " * " * " 1063 20-2 1417 * 1772 2126 H-3 2481 2833 * 3189 3344 * 389< 4232 60 7-0 8-0 9-0 10-0 II 0 12 0 13-0 14-0 13-0 11-0 13 0 15-0 17-0 19-0 21-0 23-0 25-0 27-0 29-0 4-5'/, 14-% 13-3'/, 5 " * " 6 6 1243 22-8 1661 2073 2491 M HP 2903 3321 3733 4iy 4363 4Q*n * * * 6-0 7-0 8-0 9-0 10-0 11-0 12-0 13-0 14-0 i3-n 11-0 13-0 15-0 17 0 19 0 21-0 23-0 23-0 27 0 to n , 4-1 Vi 14-111 13-3'/, 5 * a ** 6 6 Type H Stirling Boiler tciih Babcock A Wilcox Chain-Grate Stoker The advantages of the Babcock & Wilcox Type H Stirling Boiler may be sum marized as follows: Unusual steaming capacity for the floor space and head-room required. Boilers may be set singly or in battery. Setting heights can be varied to suit any condition of firing. v The choice of three locations for gas exit reduces cost of flues and breeching. Distribution baffles make effective all of the heating surface. Tube renewal is facilitated by correct tube spacing, and a tube removal door. Soot blowers can be readily installed to simplify thorough cleaning of all tubes. A superheater can be furnished with out any change in the standard design or construction. The boiler is supported by a structural- steel framework entirely independent of the brickwork. Ample provision is made for free movement of parts due to expansion and contraction. A complete table of sizes and dimensions, together with pertinent installation data, is contained in a new bulletin which will be sent upon request. Simply ask for Bulletin G-8-B. 954 Boilers, Steel Farrar & Trefts Incorporated Buffalo, N. Y. HEATING AND POWER BOILERS Bison Compact Boilers Bisonette Compact Boilers Firebox Return Tubular Boilers Firebox Locomotive Type Boilers Scotch Marine Type Boilers Vertical Boilers Horizontal Return Tubular Boilers Bison Two-Pass Return Tubular Boilers - Established 1864 STEEL PLATE CONSTRUCTION Storage and Pressure Tanks Receivers, Welded or Riveted Steel Pipe, Welded or Riveted Buoys, Welded or Riveted Condensers and Kettles Smokestacks and Breechings Special Work in Stainless Steel, Everdur, Nickel, Aluminum or Monel Metal The F&T Bison Compact Welded Heating Boiler is more than just another boiler. It has been designed carefully so as to have a large furnace volume, the proper volume of water, just the right amount of steam liberating surface, the correct volume for steam storage and a balanced circulation. The result is a remarkably steady water line--A Balanced Boiler. This boiler requires a minimum amount of floor space and is easy and inexpensive to install. It is reasonable as to first cost and economical in .operation. Construction is in accordance with the A.S.M.E. Code for 15 lb working pressure and boilers are designed for hand firing with anthracite or bituminous coal The Biton Compact or for mechanical firing with oil, gas or stoker. There are various sizes available from 1800 to 35,000 sq ft of steam radiation, all ratings as required by the Steel Heating Boiler Institute. The Bisonette Compact Boiler has the same characteristics as the larger Bison Compact Boiler. It has been designed for installation in large residences and small business establishments where the advantages inherent in a Steel boiler are desired. Firebox Return Tubular Heating Boilers sire Quality Boilers. They are constructed to measure up to the high standards set by Heating Engineers and will give unfailing service under all conditions. Being economical to install and operate, they are highly favored by Architects and Engineers for heating Schools, Hospitals, etc. There are two types of Firebox Boilers, the Up-Draft Type and the Down-Draft Type. Both types are made of welded or riveted construction for heating purposes at 15 Ih working pressure and of riveted construction for power purposes at 100, 125 and 150 lb. working fircbcx Rim Tutnda, Btikr pressure in accordance with the A.S.M.E. Code. Sizes from 1800 to 35,000 sq ft of steam radiation, as rated by the Steel Heating Boiler Institute, are designed for hand firing with coal or for mechanical firing with oil, gas or stoker. The Bison Two-Pass Return Tubular. Refractory Lined Boiler is favored by many Engineers because it Eliminates Water Legs, Flat Sides and Staybolts. This boiler is dependable for long years of continuous and eco nomical operation. It stands up under heavy loads and provides that surplus of power so often heeded. This type of boiler is made of welded construction for 15 lb working pressure and of riveted construction for 100, 125 and 150 lb working pressure in accordance with the A.S.M.E. Code. Boilers are designed for ratings from 25 to The Biton Ttoo-Patt 250 hp and are inspected, tested, and stamped by a repre sentative of a reliable insurance company before shipment. They are furnished for hand firing with coal or for mechanical firing with oil, gas, or stoker.' 955 s Boilers, Steel "Fitzgibbons Boiler Company,Inc. Established 1886 General Offices: Architects Bldg., 101 Park Avenue New York, N. Y. Works: OSWEGO. N.Y. Branches and Representatives in Principal Cities PRODUCTS--STEEL HEATING and POWER BOILERS for all fuels and all heating systems. Capacities to meet requirements of any building. Built and rated according to S. H. B. I. Code. --AIR CONDITIONERS for "SplitSystems" and for Direct-Fired installations in residences of all sizes. "Split-System" Air Conditioners The FITZGIBBONSAIRE combines with Fitzgibbons Steel Boilers for auto matic firing with oil, gas or stoker, to provide: (1) CONDITIONED AIR (cleaned, humidified, tempered, circulated) to all rooms where desired; (2) RADIATOR HEAT to kitchen, baths, garage and other parts through which recirculation is un desirable; (3) YEAR-'ROUND DOMESTIC HOT WATER, without a storage tank. The FITZGIBBONSAIRE JR. Ceiling type unit for combination with oil, gas or stoker fired Fitzgibbons Steel Heating Boiler. Provides moderate cost "Split-System'1 air con ditioning to lower floor, and radiator heat to rest of house, with year-'round tankless domestic hot water. The BOILER-AIRCONDITIONER The same three services as provided by the FITZ GIBBONSAIRE, concentrated in a single compact unit for oil, gas or stoker firing. Direct-Fired Air Conditioners The DIRECTAIRE A new departure in direct-fired conditioners, far ahead of contemporary units in Efficiency, Rugged ness, Durability, Quietness, Cleanability and Appearance. Two models--The ENCLOSING Model (illustrated) which conceals the oil or gas burner; the STANDARD Model for stokers and installations where an enclosing jacket is not re quired. Each model made in 4 sizes--100,000-- 135,000--200,000 and 300,000 Btu at the bonnet. Steel Heating Boilers The OIL-EIGHTY AUTOMATIC--the outstanding residential steel boiler for oil firing. Teams up with any good rotary or gun type burner to form a highly efficient unit. Provides room for burner inside the jacket. Year-'round tankless domestic hot water optional. Ratings, Steam--12 Sizes--425 to 2680 sq ft. The STOKER-EIGHTY--For bituminous stoker firing. Jacketed. Ratings, Steam-- 6 Sizes--485 to 1100 sq ft. The COAL-EIGHTY AUTOMATIC--For anthracite stoker firing. Jacketed. Ap proved by Anthracite Institute. Ratings, Steam--12 Sizes--425 to 2680 sq ft. `The COAL-EIGHTY--For handfiring. Jacketed. Ratings, Steam--400 to 1000 sq ft: The ANTHRA-HEAT--Magazine feed anthracite boiler for small , homes. A. I. Rating--Standing column Water Radiation--300 sq ft. The GAS-EIGHTY--for gas. Jacketed. Ratings, Steam--12 Sizes--425 to 2680 sq ft. 956 Fitzgibbons Boiler Co., Inc. Boilers, Steel FITZGIBBONS R-Z-U JUNIOR Multi-Service Steel Boiler RATINGS, STEAM Coal Burning Type........ 900 to 3200 sq ft Oil Firing Type............... 1100 to 3900 sq ft Stoker Firing Type.........1100 to 3900 sq ft Outstanding Features Tanksaver (optional) supplies year-'round hot water without a separate storage tank. Tankheater (optional) a more efficient in direct water heater. Auxiliary Grate (optional), for refuse disposal and stand-by heating duty in oil fired installations. Com pact, largest size will pass thru a 31 in. door way. Low Water Line, eliminates need for a pit. Jacket (optional), on all types. Descriptive Bulletin on Request FITZGIBBONS Z-U Steel Firebox Boilers Built for 15 lb w.s.p.--A.S.M.E. Code. Up-Draft Type......1800 to 35,000 sq ft steam e-z-u FITZGIBBONS R-Z-U Steel Firebox Boilers The Z-U arranged for rear smoke outlet. Built for 15 lb w.s.p.--A.S.M.E. Code. Up-Draft Type___1800 to 35,000 sq ft steam Smokeless Type.__ 1800 to 35,000 sq ft steam Oil, Gas, Stoker....2190 to 42,500 sq ft steam FITZGIBBONS "F" SERIES Portable Riveted Firebox Boilers Built for 100 lb w.s.p.--A.S.MJE. Code. Ratings, steam--1800 to 15,000 sq ft 600 Series FITZGIBBONS 500 SERIES Portable Welded Firebox Boilers-- ' Return Tubular . Built for 15 lb w.s.p.--A.S.M.E. Code Ratings, steam--3500 to 35,000 sq ft . FITZGIBBONS 700 AND "P" SERIES Portable Riveted Firebox Boilers 700 Series for 15 lb w.s.p.--A.S.M.E. Code. Ratings, steam--3500 to 35,000 sq ft "P" Series for 100 lb w.s.p.--A .S.M.E. Code. Ratings, horsepower--25 to 250. FITZGIBBONS 600 AND 800 SERIES Smokeless Down-Draft Riveted Firebox Boilers Built for 15 to 100 lb w.s.p.--A.S.M.E. Code. Ratings, steam--3500 to 35,000 sq ft 600 and 800 Series Descriptive Bulletins on any or all of above boilers will be mailed on request. Boilers, Steel E. Keeler Company Williamsport, Pa. Established 1864--Offices in All Principal Cities Steel Boilers For Heating and Power Steel Stacks, Breechings and Plate Fabrications Two 100 hp Keeler "CP" Water Tube Boilers in Jersey City Plant. A Few Prominent Users of Keeler "CP" Boilers Abbots Dairies Aluminum Co. of America American Oak Leather Co. Armstrong Cork Co. Bethlehem Steel Corp. Dairymen's League General Electric Co. General Motors Co. General Chemical Co. Hahneman Hospital . Hershey Creamery Co. National Dyeing & Printing Co. Haverford Laundry Pittsburgh Plate Glass Co. U. S. Department of Justice U. S. Steel Corp. E. Keeler Company Boilers, Steel KEELER Type "CP" STEAM GENERATOR (Patent No. 2097268) Keeler Water Tube Boilers are designed to have unrestricted cir culation which permits them to respond quickly to sudden steam demands, and to efficiently de velop high overload capacity. In the Keeler design no group of i tubes or drums is limited to stor age of steam, or to the functions of a feed water heater. The entire boiler is a steam generating unit. Write for Bulletin F-9 Copies of tests showing effi ciencies of 80 per cent and better will be furnished on request. The Keeler Type "CP" Water Tube Boiler Embodies These Important Features 1. It is completely steel encased and insulated. 2. No brickwork required except for front wall and bridge wall. 3. The sides of the furnace are water cooled. 4. Clinkers cannot adhere to sides of furnace. 5. Furnace maintenance costs are reduced to a minimum. . 6. Provides very large capacity in a given space. i 7. Can be operated at high overloads without disturbing water level. 8. Has built-in soot blower. Easy to clean interior or exterior. 9. Made in large range of sizes in pressures up to 450 lb. 10. Units as large as 250 hp can be shipped completely assembled. 11. Units larger than 250 hp are shipped knocked down. 12. Highly efficient with any method of firing. The E. Keeler Company manufactures Straight Tube Water Tube Boilers, both long drum and cross drum types, Curved Tube Boilers, both three drum and four drum types, Return Tubular and Double Duty Fire Tube Boilers for every power or heating re quirement. Two 100 hp Keeler Type "CP" Boilers on One Car. The Keeler Type "CP" Boiler, while built in standard sizes, can be modified so as to meet all practical requirements--to conform with special conditions of installation or- space limitations. . 958 if Keeler Double Duly Boiler Keeler Double Duty Boiler Before Encased Bulletins of Any Type Sent on Request 959 Kewanee B oiler Corp. -______________________________ Boilers, Steel s Kewanee Boiler Corp. 960 K&WANEE. 5?!LER CW9RATI9N Kewanee, Illinois BRANCHES IN 64 PRINCIPAL CITIES Steel Heating and Power Boilers, Water Heating Garbage Burners, Tabasco Heaters and Tanks. Kewanee Firebox Boilers Brick`Set Type KEWANEE STEEL HEATING BOILERS Kewanee offers a dependable line of Steel Boilers built for heating every size building, with high efficiency, burning any kind of fuel. There are 350 standard sizes of Kewanee Boilers most of which are kept in stock, ready for im mediate delivery. Sixty-nine years of intensive study and effort are back of Kewanee Boiler designs. They are all constructed in our extensively equipped factory at Kewanee, Illinois, in conformity with these Codes: American Society of Mechanical Engineers for construction, and for rating with the Steel Heating Boiler Institute Simplified Practice. Keuianee Welded TyPe C Boilers The Kewanee series include: Heavy Duty Riveted Firebox Types: 1,840 ft to 48,500 ft. Brickset and portable settings, Updraft and Downdraft Smokeless Furnace, Single-pass tubes for rear smoke outlet; Two-pass tubes for front smoke outlet. Welded Boilers: 8,800 ft to 48,500 ft. Direct Draft or Smokeless Arch with Corrugated Crown Sheet. Rear Smoke outlet and Weld+Rivet for front Smoke outlet. Kewanee Smokeless Boilers Portable Type Residence Steel Boilers: S80 ft to 8,984 ft. Square and Round Type "R" with and without Jackets and Hot Water Heating Coils for Storage Tank or Instantaneous flow. SPECIFICATIONS--BRICK-SET AND TYPE "K" PORTABLE UP-DRAFT BOILERS Table for two aeries of Boilers lists maximum dimension only. Kewanee Residence Square Type R Boilers Boiler No............ ........................... .. 3 45 6 8 9 10 11 12 13 14 15 17 18 19 3K 4K 5K 6K 8K 9K 10K UK 12K 13K 14K 15K 16K 18K 20K 20 Rated Steam Capacity: Coal.. ............................... Sq Ft Oil, Gas or Stoker............. Sq bt Width and Length ... In. x Ft In. Overall Height..............................In. Height of Water Line.................In. Approximate Weight: Coal___ Lb Oil..........Lb 1240 1380 1800 2200 3000 3500 4000 4500 5000 6000 7000 8500 10000 12500 15000 17500 20000 1770 2020 2190 2660 3650 4250 4860 5470 6080 7290 8500 10330 12150 15160 18220 21250 24290 30x9-10 36x3-10 36x10-4 36x11-10 42x11-4 42x12-10 48x11-10 48x13-4 48x14-10 54x15-3 54x17-9 60x17-0 60x19-6 66x19-6 72x19-6 72x164) 72x18-0 59 65 65 65 71 71 77 77 77 63 83 93 93 99 105 107 107 52 3500 55 3900 55 oo 55 4700 58V, 5700 58/a 6400 61 7000 61 7600 61 8200 66 9500 66 75 75 80 85V, 10700 12600 14500 17600 20700 2% 3130 3550 3800 4200 5100 5800 6400 6900 7400 8600 9700 11500 13300 16100 19100 17700 20000 Rated Capacity for Water Boiler is 60 per cent greater than Capacity for Steam Boiler. SPECIFICATIONS--SMOKELESS DOWN-DRAFT BOILER 376 _377 378 379 380 381 382 383 384 385 386 387 388 389 390 Rated Steam Capacity: Coal............................................................Sq Ft Oil. Gas or Stoker..................................Sq Ft Width and Length............. In. x Ft In, Overall Height...................... In. Height of Water Line...................................... In. Approximate Weight: Coal........................... Lb Oil..............................Lb 3500 4250 42x8-3 80 70 6800 6200 Boiler No...................................... 576 577 4000 4860 42x9-3 80 70 7500 6900 4500 5470 48x8-7* 86 73 8100 7400 5000 6080 48x9-5 86 73 8600 8000 6000 7290 54x11-2* 94 78 10000 9100 7000 8500 8500 10330 54x12-11' 60x12-8* 94 101 78 85 11100 13600 10100 12500 10000 12150 60x14-9 101 85 15300 14100 12500 15180 66x14-1! 107 a 16500 15000 18220 66x17-4 107 a 18900 17500 21250 72x16-5 113 2% 21200 20000 25000 30000 24290 30360 36430 78x17-0* 78x20-7* 84x19-11 115 115 125 95 25100 95 29500 a 23200 27500 31500 SPECIFICATIONS--PORTABLE UP-DRAFT BOILER 578 579 580 480 581 481 582 482 583 483 584 484 585 485 586 486 587 487 588 488 589 489 35000 42500 84x22-8 125 35200 590 490 Rated Steam Capacity: Coal....................................Sq Ft Oil, Gas or Stoker......... Sq Ft Width and Length .In. x Ft In. Overall Height..........................In. Height of water Line............ In. Approximate Weight: Coal. Lb Oil..'Lb 3500 4250 42x8-7 80 70 6100 5500 4000 4860 42x9-61/, 80 70 6700 6100 2773 774 775 4500 5470 48x8-10 86 74% 7300 6600 5000 6080 48x9-6/2 86 74% 7900 7100 6000 7000 8500 10000 12500 15000 7290 8500 10330 12150 15160 18220 54x11-5 54x13-11/2 60x13-4'/2 60xI5-5/2 66x 15-6</j 66x18-01/2 94 94 101 101 107 107 81 ' 81 86 86 89 89 10200 11400 13300 14800 17300 19700 9300 10400 12200 13600 15800 18100 17500 21250 72x17-0 113 96 22000 20300 20000 24290 78x17-7* 115 97 24200 22300 25000 30360 78x21.3'/, 115 97 29400 26400 SPECIFICATIONS--TYPE "C" WELDED BOILER 776 777 2777 778 779 780 2778 2779 2780 781 2781 782 2782 783 2783 784 2784 785 2785 786 2786 787 2787 788 2788 30000 36430 84x20-7 125 109 32300 30200 789 2789 35000 42500 84x23-4 125 109 36100 33800 790 2790 Rated Steam Capacity: Coal.........................Sq Ft Oil. Gas or Stoker. Sq Ft Width 8c Length, In.xFt in. Overall Height............... In. Height of Water Line. .In. Approximate Weight: 700 Series, Coal .... Lb 2700 Series, Coal... .Lb Oil..................................Lb 2200 2600 3000 3500 4000 4500 5000 6000 7000 8500 10000 12500 15000 17500 20000 25000 30000 35000 2680 3160 3650 4250 4860 5470 6080 7290 8500 10330 12150 15180 18220 21250 24290 30360 36430 42500 36x5-10 36x6-4 36x6-10 36x7-8* 42x7-10* 42x8-6* 42x9-2 48x9-4} 48x10-7 54x9-11 54x11-2* 60x11-6* 66x12-3* 72x12-1* 72x13-4* 78x14-9* 84x14-2* 84x15-11* aa 99 99 IO8V2 112 118 118 122 135 135 85 65 94 95 101 101 103 114 114 3400 2900 3900 3800 3300 4400 4300 3700 5000 4800 4100 5500 5300 4600 6000 5800 5000 6500 6300 5400 7500 7200 6100 8400 8100 6900 9700 9400 6000 MOOO 10600 9100 12900 12500 10700 14900 14400 12300 16600 16100 13800 18400 17900 15400 22000 21200 18100 252Q0 24400 20900 264Q0 27500 23400 Boiler Series 1773-1790 for Oil, Gas, Stoker; Series 2773-2790 for Anthracite; Series 7L73-7L90 Hi-Firebox for Stoker, 2680 Ft to 42500 Ft. SPECIFICATIONS--RESIDENCE SQUARE TYPE R BOILER ROUND R Boiler No.......................................... 742 743 745 746 747 748 734 735 736 1737 Kewanee Round "R" Rated Steam Capacity: Coal.Sq Ft Oil. Gas or Stoker........... .Sq Ft Width and Length..............] n. x In. Diameter.................................. Overall Height....................... Height ot Water Line.......... Approximate Weight: Coal ....Lb Oil.. ....Lb Standard Jacket, Crated ....Lb 790 1000 1350 1600 1780 1960 840 1120 1470 1900 2160 2380 32x39* 32x45* 32x45* 32x51* 32x57* 32x63* 59% 48 2150 1900 205 59% 48 2360 2060 225 70% 58% 2800 2500 175 70% 58V, 3050 2730 190 70% 58V, 3300 2920 200 70'/, 38V, 3550 3125 225 370 400 70 54% 44 880 800 Boiler No., Square "R" Oil or Gas................ 83R1 83R2 83R3 83R4 83R6 410 560 540 680 900 23 26 26 55% 59% 44 46 61 49 1040 1280 920 1130 1400 190 215 83R7 TSRT 3&4 and Square Type "R" Residence Heating Boilers for all fuels. , Standard snug fitting jackets or Regal, Regal-Square styles for completely enclosing burners are available for Round "R" and 83R. Hot Water Copper CoiL 65-75 gal comes Rated Steam Capacity.... Sq Ft 901 1105 1326 1513 2091 2363 2652 2924 with Round "R". \ Approximate Weight with Jacket... l.h 1600 1800 2000 2200 2800 2900 3100 3300 Boiler Series 1742-1748, 1734-1737 for Oil, Gas or Stoker; 2742-2748, 2734-2736 for Anthracite. Kewanee Round Capacities up to 720 may be ordered for Kewanee Indirect Hot Water Heating Coils for Type C, Square and Round "R" Boilers; 140 sizes, 65 to 4500 Gal. l`R" Boiler Rex Square Jacket Square and 83R Boilers. Kewanee Round "R" Boiler Boilers, Steel vctu m* Boilers, Steel \ UNION \ L.BOILERS,J Union Iron Works Erie, Penna. Representatives in All Principal Cities KNOCKED DOWN HEATING BOILERS NO BUILDING CHANGES ARE REQUIRED FOR REPLACEMENT WORK The Union heating boiler is a knocked down water tube cross drum boiler. The design is similar to Union high pressure cross drum boilers for industrial power plants, adapted to the requirements of heating service. As these boilers are shipped knocked down, the largest piece will go through the usual door or building opening and it is unnecessary to provide special openings or alterations, such as ripping out walls, to place them on the foundations. No electric welding is required in the field for assembly, as these boilers are put together with an ordinary tube expander. For replacement work, Union water tube heating boilers provide extra furnace volume, increased efficiency and excess capacity without requiring larger space or building changes. Brick base used on all sizes above No. 100 inclusive. Stack Height--1 Boiler--Ft. Ins. Heigh*--Grates to Tubes--Inches Boiler Humber - 20 30 40 50 60 70 80 90 100 120 140 160 180 200 4298 5684 7196 8512 9870 11298 12866 14126 169)2 19670 22442 25326 26096 5219 6902 8738 10336 11985 13719 15623 17153 20536 23885 27251 30753 6877 - 9094 11514 13619 15792 18076 20585 22601 27059 31472 35907 5821 8350 11043 13980 16537 19176 21950 24996 27444 328S7 38216 43601 44956 54590 307 ' 406 514 608 705 807 9)9 1009 6-5 *4 3-3 6-6*4 4-3 6-9*4 7-9*4 4-1C 50 6-9*4 50 8-714 50 9-9*4 5-5 9-11*4 10-2*4 11-3*4 11-9*4 12-3*4 130*4 5-11 6-S 6-5 611 13-8 6-11 6-1 24 6-6 6-1 24 6-6 6-3 24 &8 60 60 24 24 6-11 71 7-3 30 7-9 7-3 7-4 30 \ 30 7-9 8-11 9-6 36 9-5 36 36 36 10-6 lU'O 7-2H 4-0 2-6 1-3 7-24* 4-0 3-6 1-3 1AM 40 4-1 1-3 7-8W 40 4-1 1-3 7-94* 50 4-1 1-3 8-8 M 50 4-6 1-3 60* 5-6 4-6 1-3 8-9*4 50 1-3 11-2*4 11-1*4 11-6*4 11-8*4 imo*4 5-6 6-6 6-6 6-6 50 50 5-6 60 b-U 4-2 4-2 4-4 23 23 23 23 24 26 26 . 26 4a S-8 6-3 6-5 60 70 70 7-6 7-6 7-8 8-2 1-4 1-4 1-7 1-lC 20 20 20 20 2-4 2-S 2-6 3-6 4-1 4-1 4-1 4-6 4-6 50 5-0 50 5-6 60 60 10 14 16.33 18.37 20.41 22.5 24.75 27.5 27.5 32.5 33 35.75 66688888 333 4 4444 8 .4 6 6 1-2 1-2 1-2*4 1-2*4 1-3 1-3 2-2 2-2 2-2*4 2-2*4 2-2*4 2-2*4 20 22 24 26 28 30 30 32 36 18' 20 22 24 26 28 28 30 36 JO 45-0 45-0 600 600 650 70-0 700 750 750 800 900 28 26 55-0 30 28* 55a 34 36 32 . 34 700 700 38 36 750 42 40 800 42 40 800 44 42 850 44 8SO 48 50 S2 900 100-0 100-0 56 54. 56 115 14C IK. iac 20C 22C 23C 2a 22( 24( 26C 5800 6388 682C 850C 9322 104a 10961 1143C 13271 1433( 16636 176a 19898 460 952 6900 7800 57C 65C 69( 71( 75C aa BRICK BASE REC UK 850C 125( 1040C 1385 153( 1140C 1264( 1681 134a 187C uia 187t i6oa 221C 175a 224! 200a 243C 2652 2121C 238a 2o50 21 21 21 21 22 24 24 24 37*4 37*4 37*4 37*4 39*4 39 *4 20 30 40 SO 60 70 & 90 100 120 W0 160 962 Boilers, Steel Waterfilm Boilers, Inc. Main Office and Factory 154 Ogden Avenue, Jersey City, N. J., U. S. A. KOVEN WATERFILM BOILERS STEEL FLASH TYPE BOILER FOR AUTOMATIC FIRING The Koven Waterfilm Boiler is of the flash .'type, stabilized--by a distinctive Koven design. It heats quickly, cools slowly, cuts fuel costs--in some instal lations as much as 50 per cent. In addition to the usual water jacket used on the ordinary type of boiler, Koven Waterfilm Boilers are equipped with heat generators or boosters which absorb heat from the combustion chamber--heat which is available before the boiler water becomes entirely heated. Because of this operating principle Waterfilm . Boilers are not only economical to operate but will furnish heat immediately whenever desired. Koren Waterfilm Boiler with Oil Burner and Hot Water Equipment. Waterfilm Boilers for domestic service are equipped with a properly designed water tank and heating coil, and will supply plenty of hot water in year 'round service. Built by Koven--welded steel construction--boiler, tank and burner enclosed in a beautiful de luxe cabinet. Domestic sizes range from 500 ft to 1400 ft E.D.R. SECTIONAL SERIES FOR APARTMENT HOUSES AND INDUSTRIAL SERVICE The Koven Waterfilm Boiler is con structed in sectional design for use in apartment houses and industrial plants. This design also is a steel flash type boiler. Being of sectional construction it will readily pass through a 2-ft door --eliminates the necessity for rigging or building alterations. The Patented Koven Booster design insures fast steaming--steams with only a small percentage of its water at the boiling point, a feature especially desirable in large-volume heating service. Sizes range from 1500 to 20,500 ft, E.D.R. Koven Sectional Waterfilm Boilers for Large-Volume' Heating Service. Complete details and Catalog sent promptly upon request. 963 Burners, Oil Automatic Burner Corp. 1823 Carroll Avenue Chicago, Illinois Domestic Oil Burners -- Range Burners Water Heaters -- Special Products ABC Oil Burners are built in five models in the rotary atomizing type and four sizes of pressure atomizing burners. Capacities range upward to 27 gal per hour. All models are listed as standard by the Underwriters Laboratories and approved by the fire prevention bureaus of principal cities. Well over 100,000 ABC Oil Burners have been manufactured and sold since 1920, through franchised dealers. AH ABC Rotary burners have the famous MISTOLATOR atomizing device. Sizes, capacities and specifications given below. SPECIFICATIONS ROTARY PRESSURE Model Gal Oil per Hour Max. Capacity Sq Ft Net Standing Steam Water Model GalOil Max. Capacity Sq Ft Net Standing Steam Water H1 2 500 800 Pl-1 2.0 500 800 H2 4 1000 1600 Pl-2 3.5 900 1440 E3 3 800 1280 P-ll 11.0 3000 8000 E 4 7.5 2000 3200 P-27 27.0 8000 12800 E 5 15.0 4300 6880 W 3.5 900 1440 MANUFACTURER'S DIVISION In addition to.their regular ABC line, the Auto matic Burner Corporation, builds oil burning devices used as standard equipment by more than thirty manufacturers of furnaces, boilers, ranges, circulating heaters, etc. Some of these are among the largest and' most famous in the country. In order to serve them properly special facilities and special techniques have been developed to aid manufacturers in the design and production of their units. Modem research labora tories and an expert engineering staff assure manu facturers of a co-operation which is unusual both in quality and degree. A^field engineering staff goes far towards solving the manufacturer's field problems. Specially designed and built domestic oil burners as well as range burners are among the products of this division. RANGE BURNERS -- WATER HEATERS In addition to its complete line of special burners for manufacturers, the Automatic Burner Corporation manufactures an equally complete line of conversion stove burner units and kerosene burning water heaters. The capacities range from to 5 pints per hour in the conversion burner line. The water heater line is made up of side arm heaters for installation under the standard type of coil water heaters, which are usually gas fired. The Automatic Burner Corporation welcomes in quiries from architects, engineers, contractors and manufacturers of heating equipment. ' 964 Burners, Oil OIL BURNERS Kleen-Heet, Inc. 1823 Carroll Ave. Chicago, 111. Domestic Oil Burners -- Range Burners -- Water Heaters Kleen Heet Oil Burners are built in a complete range of sizes and capacities up to 27 gal oil per hour. Each is of the pressure atomizing type, electrically operated and ignited. Each of the four models has been approved by the Underwriters Laboratories and by fire preven tion bureaus in principal Cities. Sold and serviced through franchised dealers and distributors throughout the country. Each model equipped with the famous Kleen Heet GOVERNOIL nozzles, engineered and built in our own plants. UNIQUE MECHANICAL FEATURES Kleen Heet, a true pioneer in the industry, has developed and built into these latest models, valuable and exclusive features. The Kleen Heet OIL-AIRATOR, a balanced and syncronized combination of air spinner, choke ring, and nozzle, produces the MULTIFLEX flame ... a feature giving installing engineers a choice of 72 different flame shapes and sizes in order to produce more perfectly fitting flames. Resulting operating efficiencies are unusually high. SPECIFICATIONS Model Gal Oil per Hour K.U KU2 904 805 820 W 2.0 3.5 4.0 12.0 27.0 3.5 . Maximum Capacity Sq Ft Net Standing Radiation Steam . 500 900 1000 3200 8000 900 Water , 800 1440 1600 5120 12800 1440 RANGE BURNERS--WATER HEATERS Kleen Heet Incorporated manufactures in addition to this regular line, a complete line of conversion range burners as well as a line of side arm water heaters, designed for installation under the ordinary coil water heater. Capacities in the conversion -range burner line range from }/i pint to 5 pints of kerosene or range oil per hour. The water heater units are for domestic use only and burn up to one pint of range oil per hour. All items in the line are approved by the Underwriters Laboratories. _ Kleen Heet Incorporated welcomes inquiries from architects, engineers, contractors and manufacturers of heating equipment. 965 Burners, Oil Branford Division of Malleable Iron Fittings Company Dept. 41, Branford, Conn. Oil Burners and Boiler Burner Units Branford Burners have earned a high reputation for low maintenance cost during the past 15 years. Finely built and engi neered, designed with exclusive features, the Branford has progressed steadily on its ability to give service above the ordinary. MODEL F The Branford Model F is designed for the average size home with capacities from 200 to 750 sq ft radiation of steam. It is readily adaptable to steam, hot water, vapor and warm air furnaces. Includes features found only in the highest priced burners. Economical in price and opera tion. BOILER BURNER UNIT Efficient and economical burner for steam, vapor, hot water, warm air. Capa cities 500 to 1700 sq ft of steam. Boiler built to A.S.M.E. standards. Compact, heavy, corrosion resisting steel, electro welded. Two-pass tubular. Heavy steel casing, baked enamel finished chromium trim. Completely equipped. MODEL A -The Model A DeLuxe Branford Burner heads a .line of fine burners. Capacities to 1,000 sq ft of steam radiation. Adjustable flame. Full floating motor, Branford RotoFlex principle. All parts accessible. Ex clusive performance proved features. . MODEL E Similar in design to the Model A, but of larger size and capacities up to 2,500 sq ft of steam radiation. MODEL D For the installations requiring larger capacities, the Model. D provides up to 7,500 sq ft of steam radiation. Built for long, hard service and low'cost operation. Branford Model F Branford Boiler Burner Units Branford capacities and models cover all heating requirements, are especially desirable both, to the dealer and owner. 966 Branford Model A Burners, Oil Electrol Incorporated FINE OIL HEATING EQUIPMENT EXCLUSIVELY SINCE 1918 934 Main Ave., Clifton, N. J. Conversion Burners, Boiler-Burner Units, Air Conditioning Units Electrol Oil Burner " QtdcCAlKlecMc ' ELECTROL OIL BURNER, Famous for nearly 20 years for dependable economical operation in any boiler or furnace. Curved air chamber produces rotating air and ball-shaped flame. Built-in Master Control, a safety operated by clean air only. Continuous electric ignition. Cut-Off Valve at Nozzle. New parts fit any existing models--eliminating obsolescence. Burns low cost fuel oil. One moving part. Simple, rugged, fully automatic. SummerWinter Domestic Heater. Made in three models TCV-TUV-TM. The first two for domestic use, the last for commercial use. The vertical mounting of the motor, fan housing and oil pump, makes possible the use of the TCV and TUV Burners with jacketed boilers and furnaces. They embody all the unique Electrol features. Model Size TCV TUV TM Gal Hour Capacity E.D.R. Min. Max. Steam Water 1.0 3.5 200-1100 350-1800 2.0 8.5 600-2800 1000-4500 8.0 24.0 2500-10000 4000-16000 Dimensions in. Lgth Wdth Hght 21 %, 213/4 19% 20V4 21 V> 21H 48 24% 25 Electrol Conversion Oil Burners should be selected to heat a boiler to its full rated capacity, regardless of the load that may be connected to the boiler. Electrol-American, Series A complete automa- No. EA 6 Heating Unit ic: boiler-burner unit for the moderate-sized home. Boiler of cast iron construction. Specially designed heat absorbing surfaces. Biltin-Taco Water Heater, capa city 40 gals. (100 gal heater can be supplied). Includes safety controls; Low Water Cut-Off, safety valve and pres sure limit switch. Boil Cap. No. of Installed Boiler Radiation Lb Oil Gal D.H.W. Three Steam Water Hours Over-all Dimensions In. L wH EA6-1 355 570 8.5 EA6-2 435 695 10.3 EA6-3 515 825 12.1 EA6-4 595 950 13.5 EA6-5 675 1080 14.9 EA6-6 755 1205 16.3 40 40 40 40 40 40 47* 29% 54% 5094 29% 54% 5454 29% 54% 5794 29% 54% 6154 29% 54% 6494 29% 54% ertrim: water column, com bi nation pressure and vacuum gauge on steam boil ers, altitude gauge and EA 6 Unit *100 gal at extra cost. thermometer on hot water boilers. Fired by Electrol Model TCV Burner. Burns low cost fuel oil. Heavily insulated, sound-proof jacket. finished in beige enamel. Burner, smokehood, water heater and controls completely enclosed. Electrol-Kewanee Acompieteboil- Heating Unit er-burner unit consisting of (1) exclusive design, horizontal, welded copper bearing steel firetube boiler; (2) Electrol oil burner mechanism; and (3) domestic water heater. Induced draft, low stack temperature. 80 per cent over-all efficiency. Cap. No. of Installed Revile Radiation Lb Oil Cal D.H.W. Three Steam Water Hours Over-all Dimensions In. LWH EX-5 500 800 11.5 EX-10 850 1350 19.4 EX-15 1150 1900 27.4 50 47V2 34 55% 80 60'/2 34 55% 100 75 34 55% ' (See also Pages 898-899) 967 Burners, Oil S. T. Johnson Co. 940-950 Arlington Avenue, Oakland, California Branches:--San Carlos, Cal.; San Francisco, Cal.; Sacramento, Cal.; 401 N. Broad St., Philadelphia, Pennsylvania. Founded in 1904, S. T. Johnson Co. is one of the oldest and largest manufacturers of oil burning equipment and offers a RNEI 56 complete line from small domestic to large industrial units, with manual or full automatic ignition and control, burning from the lighter fuel oils to the heaviest grades ... it includes combination oil and natural gas burners, burners with Low Fire Starting and Modulated Firing accessories, the Laddi Du-all Boiler-Burner unit and the air-conditioning, ventilating and heating unit, "Selectair." . The company provides complete engineering and technical service for assistance in the solution of heating and air-conditioning problems. Representatives in principal cities throughout the world. JOHNSON COMMERCIAL TYPE ROTARY OIL BURNERS (Capacities up to 41,700 sq ft steam radiation or its equi valent). The three commercial types of Johnson Rotary Oil Burners are of the same basic construc tion, consisting of motor, fan, housing and firehole plate, con centrically mounted in a com pact unit . . . easily installed on any make of boiler. Exact amount of air necessary for perfect atomization is supplied by motor-driven fan and ad justed by butterfly valve. Complete combustion of cheap er grades of fuel oil is accom plished by the Johnson method of centrifugal atomization. An oil-air ana water separating tank prevents foreign matter entering the fuel. TYPE 30-AV AND 30-AVH FULLY AUTOMATIC The 30-AV uses up to No. 5 Dimensions and Capacities of Types 28, 30AY and 30AVH Burners Burner Size No. 2Vl Capacity Steam Radiation Sq Ft Min. 825 Max. 2775 Boiler Hp Rating 20 Gallons Oil per Hour Size Motor Hp Min. Max. 2 7H Lb Approximate Shipping Weight' 28H 30AV 30AVH 220 275 285 A 14 Dimensions in inches . ' B CDE F 13 *A 694 17 15 3'A MOO 6950 50 3 15 >A 250 300 320 1654 isy. ioy. 8% 171/2 151/2 4'/i 2775 13900 100 6 30 Vi 400 470 505 17 m 13 954 21 191/4 5'/, 5550 27800 200 12 60 2 475 540 575 21'/z 21'h 13 11 24 20 3<% 8325 41700 300 24 90 525 575 625 2l'/2 l\'h 13 11 25 201/2 * Boiler output. Type 28 Burner available without built-in pump in same capacities. 968 S. T. Johnson Co. Burners, Oil fuel without pre-heating. Johnson-built vis cosity compensating control valve furnishes constant flow of fuel to burner, regardless of fuel temperature or viscosities and without excessive pressure on lines or undue strain on pump or motor. The 30-AVH is designed for efficient use of heavy No. 6 fuel oil. Fundamentally, this is the standard 30-AV burner with equipment for pre-heating the fuel. Type 28 Semi-Automatic Burner, manually ignited, is made for heating boilers up to 41,700 sq ft of steam radiation or 300 boiler horsepower. Built in five sizes, with built-in oil pump, and five sizes for use with separate oil-pumping equipment. Fuel oils (pre-heated when necessary) as heavy as No. 6 may be used. `Laddi' Du-All combination boiler-burner unit for small and medium-sized homes, is fully automatic, odorless, quiet and troublefree. It furnishes heat or domestic hot water or both in combination at low cost. Made in 'Ijiddi' Du-All three sizes: 100,000, 120,000 and 140,000 Btu per hour output. These units rest on the floor. Diameter at base is 24 in. on all three sizes while heights are 4J^ ft, 5 ft, and ft respectively. Specifications: Vertical % in. copper-bearing steel boiler shell electrically welded, tested to 150 lb hydrostatic pressure. Horizontal firebox with pre-cast refractory combustion chamber; seamless extra heavy copper-bearing steel fire tubes; reversible chimney connector for either top or back connection. Complete ly insulated with mineral wool. Heavy steel enameled jacket. Johnson Type B or BH burner. Electric ignition or combination electric-gas ignition. Each unit complete with necessary controls. Burns either Diesel fuel oil or No. 3 standard. Each unit fully assembled and tested at factory before shipment. Air-Conditioning Unit "Selectair" combines in one compact unit every feature desired by home-owners, architects and engi neers for economical heating, air-conditioning and ventilating the modern home. Supplies year-'round hot water for domestic use. Forced circulation of air for summer needs. Equipped with Johnson "Bankheat" Pressure Type Burner. "Seleclair" Capacities and Dimensions of SELECTAIR Units Size Max. Rating* Cu Ft Air No. btu per hour V. s. P. 1 125,000 1,485 2 200,000 2,320 3 300,000 3.300 Heat Exchanger Size Stack Oil Rate Btu per hour Connection Cal per hour 105,000 166,000 235,000 . ' 8* r 1 to V/4 V/4to2 2 to 2'/, Cabinet Width 27" 31' 33" Dimensions Length Height 60' 54' 69' 63' 86' 69' Total output includes steam to heat exchanger,.heat for domestic hot water, and heat available for installed radiation if used. Burner (Oil), Accessories Preferred Utilities Manufacturing Corp. 33 WEST 60th STREET NEW YORK, N. Y. BOSTON SALES OFFICE 839 BEACON ST. The "PREFERRED UTILITIES" are Air Conditioning Controls Anti-Hum Valve Anti-Syphon Valve Bake Ovens CO, Analyzer Combustion Chambers Commercial Ranges Commercial Range Burner Condensate Control Double Tapped Bushings Draft-A-Justors Draft Gauges Economizer Flame Mirror Floatless Low Water Cut-Off Flush Fill Bores Foot Valves Heavy Fuel Oil Metering Valve Heavy Fuel Oil Strainer Heavy Fuel Oil Thermometers Heavy Fuel Oil Valve Ignition Torches Industrial Furnace Insulating Cement Joint Seal Multiple Boiler Control Nitralloy Nozzles Observation Ports Oil Pipe Dope 100% Automatic Damper Pressure and Vacuum Gauges ' Recording Thermometers Refractories and Cements Smoke Control Stack Thermometers Steam Line Oil Heaters Suction Line Extension Flange Suction Line Valves Syphon Breakers Tank Sludge and Transfer Pump Three Wire Armored Cable Vent Protectors Vented Fill Caps Water Level Control Yacht Hot Water Heater PREFERRED DRAFT-A-JUSTORS Listed as standard by the Underwriters' Laboratories, Inc. Hundreds of thousands in use. Holds the draft constant in the fire box. Scientific draft control for Small Draft the smallest to the largest jobs. Stove, domestic, A-Juster and commercial sizes from 4 in. to 24 in. in diameter. Industrial sizes from 30 ft x 30 ft to 5 ft x 12 ft. Large Draft A-Jusler THE PREFERRED FLOATLESS LOW WATER CUT-OFF Listed as standard by The Underwriters' Laboratories, Inc. . Conforms to A. S. M. E. Boiler Construction Code. - Low Water Electrode Assembly FEATURES OF THE PREFERRED FLOATLESS LOW WATER CUT-OFF Unaffected By Sludge. . Fully Electric. Positive Snap Action. Simple To Install. Priced Right. No Parts To Replace After It Has Acted. * Instantly Returns Automatic Heating Equipment To Operation When Safe Water Line Is Restored. 970 Cooling Towers The Cooling Tower Company, Inc. 15 John Street, New York, N. Y. Representatives in Principal Cities Manufacturers of Atmospheric Cooling Towers, Spracoolers, Forced Draft and Induced Draft Cooling Towers, Spray Nozzle Cooling Systems, Spirodome and Impact Type Spray Nozzles, Louvered Spray Fences, and Indoor Type Cooling Towers. Atmospheric Cooling Towers Mechanical Draft Cooling Towers The amount of water circulated per square foot of active horizon tal area (area of one deck) affects the final temperature to which an atmospheric cooling tower will cool. Frame--Steel or timber diagonally braced for wind thrust, with load safety factor of 4. Our towers have passed the acid test of all recent cyclones. We fabricate, erect, and guarantee forced and induced draft cooling towers of any capacity from one ton up, for in door or outdoor use. Special Balke type filling provides for thorough mixing of air and water, resulting in efficient cooling. Spray Nozzle Systems Walkway and Ladder--Provide easy access to distributors. " . Distributing System--Sprinkler type of patented construction. Guaranteed free from plugging. Secondary Distributors--Prevent un necessary icing of tower during winter use. Decks--Patented sections; rigid align ment; warping or distortion prevented; uniform distribution of water; properly spaced. .Louvres--Wood or corrugated metal. Securely fastented; rigid construction. Collecting Basin--8 in. deep, extends 1 ft outside tower footings; fitted with discharge flange, suction head and strainer. Lumber--California redwood or Louisiana cypress. Substructure--Designed and furnished on request. Guarantee--A curve guarantee for our standard atmospheric towers to show temperature reductions effected at various loadings per square foot of active horizon tal area. All curves based on wet bulb tem peratures taken with sling psychrometer. Type A Spracoolers For use where cost will not permit a standard deck type cooling tower and space will not allow a spray pond to be installed. Wood or steel con struction, light in weight, equipped with an efficient nozzle distributing system. We make two types of spray noz zles--Impact spray nozzle which throws a flat, fan-shaped spray cloud--Spiro dome spray nozzle producing a high conical spray cloud suitable for general installations. Either type may fit requirements and our Engineering Department will submit proposals covering the best type for a particular purpose. Outstanding features of our spray pond systems are: (1) Non-clogging nozzles. (2) Freedom from interruption of opera tion. (3) Automatic drain and flushout valve. (4) Well designed spray fence for protec tion against spray dirt. Indoor Cooling Towers For indoor Installations of one to forty tons capacity. Available in commercial type or quiet rating. Steel shell, Balke type wood filling, drift eliminators, float valve, access door. Easy to erect, economi cal to operate. Low pumping head. Ship ped complete or knocked down. 971 / Cooling Towers Binks Manufacturing Co. Plant and Executive Offices 3114-3140 Carroll Avenue, Chicago, 111. Branch Offices Cleveland. Ohio..............................1120 Chester Ave. Detroit, Mich............................. 2832 E. Grand Blvd. Los Angeles, Calif...................... ...... 239 W. 15th St. Milwaukee. Wis.......... ....................743 N. Fourth St. New Orleans, La____ _______________329 Balter Bldg. New York, N. Y.................................128 Lafayette St. Philadelphia, Pa................................ J2016 Market St. Pittsburgh, Pa...906 Chamber of Commerce Bldg. San Francisco, Calif ............... 923 Harrison St. Windsor, Ontario, Canada Representatives in Principal Cities COOLING TOWERS--SPRAY NOZZLES--COOLING PONDS-- SPRAY PAINTING EQUIPMENT "Binks" Atmospheric Spray Cooling Towers "Binks" Atmospheric Spray Cooling Towers are made in a wide range of sizes to handle capacities from 5 to 1200 gpm. They are used and recommended for all types of industrial water cooling work and are suitable in the standard sizes for refrigeration plants ranging from 2 to 240 tons and for Diesel engine plants ranging from 30 to 3600 hp. The towers consist of a heavy shop welded copper-bearing steel frame, genuine wrought iron manifold with welded feeder arms and bronze nozzles. All metal parts are hot dip galvanized after fabrication. , Louvres consist of clear all heart redwood or galvanized steel, to suit requirements. Due to standardized construction features "Binks" Atmospheric Spray Towers may be quickly erected on the job, for either ground or roof installation from a simple elevation print fur nished with each unit, without skilled factory supervision. . All bolts and nuts for assembling are cad mium plated, louvres being inserted to the tower frame in slip fit louvre retainer channels requiring the use of no bolts, nuts or any other fastening. There are more than 2000 "Binks" Atmospheric Towers now in operation. "Binks" Indoor Forced Draft Cooling Towers "Binks" Indoor Forced Draft Cooling Towers are made in standard sizes from 5 gpm up to and including 300 gpm. They are extensively used for the cooling of jacket water for Diesel engines and large ca pacity air compressors, for condensing water for refrigeration ma chines and various in dustrial processes. This type of equip ment is exceptionally well adapted in loca tions where outdoor mounting of towers on building roofs would be extremely costly due to piping the installation to and from the tower. These units may be conveniently placed adjacent to the process with provision being made for fresh air inlet to the tower, such as open doors or windows, whereas the saturated air is conveyed to the outdoors through a duct. " Write for Complete Catalog and Prices on any `' Binks' ' Equipment in which you are interested. 972 Binks Manufacturing Co. Cooling Towers Diagrammatic sketch of Binks Type " K" Tower . "Binks" Spray Nozzles Mode in all types for every cooling and industrial need "Binks" Type "K" Induced galvanized steel of heavy gauge, complete Draft Towers with 34-in. pans, and are shipped knocked down with complete assembly drawings t The "Binks" Type "K" Induced Draft Towers are designed for outdoor mounting either on ground or building roofs and are for field installation which can be accom plished by ordinary labor. 1 made in sizes from 25 to 2000 gpm capacity. They are extensively used for all industrial Spray Painting Equipment water cooling requirements and standard sizes are suitable for refrigeration work ranging from 6 to 600 tons and for Diesel engine service from 90 to 6000 hp. Fan assemblies are mounted to top of tower directly connected to geared head motors which are splash, moisture and weatherproof. Capacities of fans from 3200 to 96,000 cfm, depending on tower size, and are extremely quiet in operation, drawing air upward through tower from open louvre sections at bottom. This principle of mechanical draft tower con struction eliminates wind noises in the casing and is representative of one of the . most efficient mechanical draft towers made. They are constructed entirely of Consult Binks for any Spray Painting or Finishing Needs. Spray guns of all types. Compressed air supply systems. Compressed air cleaning systems. Spray booths and exhaust systems. Water wash spray booths; for reclaiming porcelain enamel; also for synthetic enamel and other materials. . Paint supply systems: individual pres sure tanks or pipe line circulating systems. Conveyor systems for handling items to be sprayed. Complete accessory equipment for the finishing department. 973 Cooling Towers The Marley Company 1915 Walnut St., Kansas City, Mo. Representatives in Principal Cities Manufacturers of: Marley Patented Spray Nozzles, Spray Towers, Spray Deck Towers, Spraycoil Towers, Forced Draft Towers, Spray Ponds, Louvre Fences and all Accessories, Atmospheric Heat Exchangers. Marley Patented Spray Nozzles-- Furnished in a wide variety of sizes and capacities for service with spray ponds, cool ing towers, air washers, brine lofts, aerators, etc. Marley nozzles are of the centrifugal type with a long whirl chamber, free, non clogging passages and no moving parts. The large venturi inlet is so designed as to impart the proper water whirl, producing a full free break-up at discharge orifice with minimum friction loss. Marley Bulletin No. 59. Marley Atmospheric Spray Towers-- Cast iron louvre posts, slip fit redwood louvres, ex tremely effec tive downspray distribu tion system plus standard ization of de sign, are a few of the out standing fea tures of this type of Marley cooling tower. Completely shop fabricated and correctly engineered, these towers provide a water cooling unit of rugged construction, good efficiency and low maintenance at mini mum cost. Marley Bulletin No. 81. ` Marley Spray Ponds--Group castings, joints and bolts eliminated, friction loss reduced by Marley tapered pipe. Positive break-up, improved distribution and effec tive operation under low pressures pro vided by Marley patented spray nozzles. Wide capacity ranges obtained by varying nozzle sizes and spacings. Marley BulletinNo. 56. Marley Small Series Forced Draft Towers -- F urnished with steel shells and basins for indoor or out door operation. Completely shop fabricated for field assembling. These towers meet such requirements as complete elimina tion of drift, posi tive cooling per formance regardless of location, extreme thermal efficiencies and quiet operation. Marley Bulletin Marley Standard Forced Draft Towers--For all service requirements and ca pacities. Made of wood or steel. Features include zig-zag elimina tors, mul tip1e banked spray filling, double casings in wood towers, cast iron bell inlet fan rings, adjustable pitch fan blades, flexible and independent operating control of both water and air. Marley Bulletin No. 85. Marley Small Spray Nozzles--Two piece nozzles with removable base plugs {right) are especially designed for brine spraying, air washing, etc. Humidifying nozzles (left) produce a fine mist easily absorbed by air. Made of bronze. Easily taken apart. 974 Expansion Joints Adsco PRODUCTS for STEAM SERVICE American District Steam Company North Tonawanda.N.Y. IN BUSINESS OVER SIXTY YEARS Branches and Agents in Principal Cities PACKLESS, U-RING TYPE JOINT A compact, fully guided, packless joint with steel body and fully enclosed expan sion element for high pressures and high temperatures. Requires no servicing. The element is a series of welded U-rings of stainless alloy steel. Particularly adapt able where space is limited. Pressures to 300 lb and temperatures to 750 F. Write for Bulletin No. 35-50G. Packless, U~Ring Type RED DIAMOND BRAND CASING Combined conduit and; insulation for underground steam or hot water lines, made of kiln-dried, wire-bound, strong wood staves with a waterproof covering. It is good for 25 or more years of efficient service as proved by letters from satisfied users. Easily and quickly installed. Write for Bulletin No. 35-65G- ADSCO VERTICAL STEAM TRAP A float type steam trap with or without thermostatic air by-pass for vacuum ser vice to 15 lb pressure and gravity service to 125 lb pressure. The cover with all working parts can be removed without disturbing the piping connections. The trap is equipped with a reversible valve and reversible seat of stainless alloy steel. Write for Bulletin No. 35-85AG. ADSCO HEAT EXCHANGERS Made in various sizes and capacities to heat of cool water, oils, other liquids or gases according to expert engineering specifications. Simple in design, sturdy in construction, dependable and economi cal in operation. Available in U-tube or straight tube types of heaters, condensers, condensate coolers or special units. Write for Bulletin No. 35-75AG, 35-76G. ROTARY CONDENSATION METER - Rotary Condensation Meter Measures steam consumption by meter ing condensate from heating systems or industrial equipment. Accurate within 1 per cent and factory tested to 150 per cent of rated capacity. Compact, easily cleaned, tamper-proof and equipped, with non-fogging counter mechanism. Counter reads directly in - pounds. Suitable. for vacuum or gravity service. Available in' 7 sizes from 250-12,000 lb per hour capa city. Write for Bulletin No. 35-80G. . ' {See also Page 1052) 975 y-' Expansion Joints E. B. Badger & Sons Co. Engineers and Manufacturers 75 Pitts St., Boston 271 Madison Ave., New York Representatives in Principal Cities PRODUCTS and SERVICES--Corrugated Copper and Stainless Steel Expansion Joints, Pipe Bends, Chemical Apparatus, Copper and Sheet Metal Work; Engineers on Process Work. BADGER "PACKLESS" CORRUGATED EXPANSION JOINTS Expansion joints of the corrugated type have been used for many years to relieve strains, to absorb vibrations between con nected equipment, and to compensate for changes in lengths of pipe-lines due to temperature differentials. They protect equipment, eliminate costly shutdowns and prevent loss of materials flowing through the pipe-lines. The name BADGER has been known to industry since 1841 and for over 50 years has been closely identified with the early development and continuous manufacture of the corrugated "packless" type of ex pansion joint. So much so, in fact, that industry today speaks of and frequently specifies this joint as the "Badger Type of Expansion Joint". But during the past 50 years, requirements in industry have changed. They have become more and more severe. Pressures have been in creased; likewise, temperatures. Corrosion and other factors have entered into the expansion joint problem. Being engineers as well as manufacturers, E. B. Badger & Sons Co. recognize the importance and effect of these changes and maintain a competent engineering staff to study them. As a result of these many years of study and of the many improvements brought out, Badger Engineers have consistently broadened the use of the "packless'' corru gated type of expansion joint. BADGER joints are designed and manufactured to meet the most stringent codes. Wide Range of Traverses, Pressures and Temperatures By varying the number of corrugations, BADGER Packless Expansion Joints can be made to take care of a wide range of traverses--from fractions of an inch up to 6 in. single and 12 in. double. An impor tant feature is that for each size the grad uations in traverses form a straight line. . The step-up is uniform. Standard joints are made to care for pressures ranging from vacuum up to 300 lb. Special joints are made for higher pressures. Standard Joints are made to operate in temperatures ranging from sub-zero to 900 F. .* Flexible The BADGER Packless Expansion Joint is readily flexed, reducing the thrust on adjacent equipment or fittings to a mini mum. In the case of copper joints, less than 200 lb per inch of diameter is needed to completely compress the joint; with stainless steel, less than 300 ib. Other metals are in proportion according to their ductility. Compactness and Ease of Installation The outside diameter of the joint proper is about that of a flange. This compact ness is particularly advantageous when the installation is in cramped quarters or in trenches or tunnels. The corrugated type of expansion joint is as easily installed as any flanged or welding-end fitting. Advantages of Using BADGER "Packless" Joints The BADGER Packless Corrugated Ex pansion Joint provides these installation, operating and maintenance economies: Packless The flexing member is formed from a single tube which eliminates the necessity of packing and the servicing of packing. This is particularly advantageous in under ground installations because with this type of joint the expense of manholes can be eliminated. Engineering and Development The BADGER Packless Expansion Joint as manufactured today is the result of many years experience with expansion joint problems and of constant effort to make the packless corrugated joint more economical and efficient. The three most recent developments by Badger Engineers are: (1) perfectipn of scientifically con trolled heat-treatment throughout all stages of manufacture; (2) perfection of the Directed Flexing Design; and (3) development of Stainless Steel Joints. 976 Fans Autovent Fan & Blower Company 1809-23 N. Kostner Ave., Chicago Illinois FANS--BLOWERS UNIT HEATERS Autovent "31" Series Propeller Fans-- Will not churn air or overload the motor. Especially recommended for economical ven tilation. Ruggedly constructed. Capacities from 500 to 38,000 cfm. Write for bulletin No. 200. Acid-Moisture Proof, Explosion Proof Fans--Wherever acid fumes or excess moisture laden air exists, the Acid-Moisture Proof Propeller Fans equipped with fully enclosed motors and fan wheels with Bakelite coating (or of special construction) are recommended. Wherever explosive gases and chemical fumes must be removed, VaporExplosion Proof Propeller Fans (underwriters label "Class 1-group D") with fan wheels of copper, brass or other non-ferrous metals must be installed. Write for bulletin No. 201. AUTOVENT "31 SERIES" PROPELLER FANS Constant or Two Speed--Alternating Current--Multiphase-- 220 or 440 Volts--60 Cycle Size Type I6HMN lOHMR I8HMN I8HMR 20HMN 20MHR 24MHL 24HMN 30HML Motor HP 1/8 1/5 1/8 1/4 1/4 . 1/4 1/6 1/4 1/4 Cfm Max. 1700 1950 2350 2950 3450 3550 3850 4500 6000 Appr. Rpm Max. 1140 1725 1140 1725 1140 1725 850 1140 850 Appr. ShpgWt. Lb 64 66 77 90 115 115 145 150 210 Size Type Motor Hp 30HMN 36HMT 36MHL 42HMT 48HMT 54HME 60HME 72HME ' V<Ai >A 1.0 I'/z 2 2'/z 3 Cfm Max. 7600 10000 12500 13500 18900 21500 25600 38000 Appr. Rpm Max. 1140 690 850 . 690 690 575 480 480 Appr. Shpg. Wt. Lb 220 335 390 510 650 1200 1500 "BW" (Bucket Wheel) Propeller Fans--A slow speed operating fan. Provides efficient ventilation for unlimited uses, from 500 to 40,000 cfm. Sturdily constructed, minimum power, available at low, quiet operating speeds. Write for bulletin No. 202. Autovent Uniblade Volume Blowers--Motor driven--universal discharge, for fume hoods, chemical labs, processing, drying, forced draft, etc. .Handles low volumes of air at medium pressures. Wheels range from 6 in. to 11 in. dia.--same design as heavy duty blowers. Can be mounted on floor, wall or ceiling. Direct Connected Blowers for general ventilating applications, available in wheel diameters up to 25 in. Bulletin No. 300. Forward Curve Belt Driven Blowers No. 301. Autovent "V" Belt Driven Unit Blowers--Forwardly curved blade type with smooth air flow and quiet bearings. Motor mounted on steel pedestal, integral with blower housing, making a compact unit. Air delivery can be decreased or increased if desired. Interchangeable motors. Sturdily constructed of sheet steel, rolled lock seams. Write for bulletin No. 300. Backward Curve Belt Driven Blowers No. 302. Autovent Super-Type Steam Unit Heaters--This suspended type heater forces air circulation and directs warm air to lower part of room. Heating element of flat copper fins, attached to seamless, drawn copper tubes. Tubes run vertically for perfect drainage. No welded or brazed joints in coil or header. Fans have non-overloading power feature. Motor furnished to requirement. Write for bulletin No. 101. 977 * American Goolair Corporation COOLING AND VENTILATING FAN SYSTEMS 3604 Mayflower Street, Jacksonville, Florida PRODUCTS Silent Reversible Belt Drive Cooling and Ventilating Fans for homes, stores, offices, factories, etc. Quiet, high speed direct drive fans. Fans ifferentiate dearly D between cooling and venti lating. Cooling requires complete air changes as rapidly as every half minute to every minute and onehalf; ventilation requires air changes only every two to five minutes, depending on the building. Coolair has pioneered home cooling by air circulation. One of the outstanding advantages of COOLAIR ventilating fans is that they will deliver large quantities of air under free delivery with small horsepower and, consequently, low operating cost. Elimination of costly and unnecessary duct systems will often more than pay for the COOLAIR equipment. It is impor tant to provide ample exhaust and intake opening to avoid re stricting the air volume. Net free air passage area should never be less than area of fan. For maximum quietness free area should be enough larger than fan to assure a grille velocity of not more than 750 fpm. Typical Codair Home Cooling and Ventilating Installation Standard Type--Front Vie*.e Diameters Six to Nine Feet Performance Data on Segued Description COOLAIR Belt Drive Fans meet the ventilating and cooling requirements of any size building. They are just as efficient when blowing in as when exhausting. The V-belt drive permits use of standard electric motors operating at the most efficient speed, and easily replaced in event of motor trouble. Slower speed motors are costly, difficult to replace and less efficient. With simple exchange of a motor the COOLAIR unit can be converted from a silent, slowly turning residence unit using a small motor, to a high speed industrial unit using a large motor. With a reversible motor, air can be blown into or exhausted from the building at will. Air can be pulled from the cool side of the building in the morning and the fan reversed when the sun moves to the opposite side in the afternoon. 9?8 American Coolair Corporation Fans . Performance Data--Coolair Belt Drive Fans Fan Size Hp Watts per Hour RPM Cu Ft Air per Min . ' Type " B"--Front View Diameters 16 in. to 6S in. Over-All Dimensions (In.) Size 2B 2%B 3B 3%B 4B 4'/2B 5B *6 7 6 9 Height and Width 30% 36% % 49 55% 61% 67% 75% 87% - W% 112 Depth 12 12 12 16 17% 18% 16% 28 34% 34 34 2B 2%B 3B 3%B 4B 4%B 5B "% t% '/4 t 3$ ft M tt y. tH t% tt Vs ttl t% 4.* t Vs tti ttl'/2 % t% t< m% tt2 *% ti ti% tt2 tt3 190 230 300 420 570 800 300 420 570 600 1085 420 570 800 1060 1450 570 800 1085 1450 570 800 1085 1450 1900 800 1085 1450 1900 2850 427 582 413 460 507 663 305 340 385 448 529 268 290 350 392 489 259 277 306 369 194 225 260 286 329 195 211 251 277 324 3250 4450 5750 6400 7000 9200 7800 6700 9800 11000 13500 11200 12100 14600 16300 20400 15800 17000 18800 22500 17000 19700 22700 25000 28000 23000 25000 29600 32800 38000 Standard type frames. Note: Depth Approximate. Very quiet. fQuiet. ttlndustrial. Data in accordance with Standard Code Test. American Society of Heating and Ventilating Engineers. Advantages (1) Low initial cost. Great air delivery per dollar of power. (2) Economical operation. Use of a small motor at the most efficient speed. (3) Quiet performance. Great volumes of gently moving air without objectionable noise or drafts. (4) May be equipped with reversible motors to exhaust or blow in at will. (5) Air volume controlled by means of two-speed pulley on smaller units. (6) Rubber insulated motor support. Adjustable to belt tension. (7) Equipped with SKF ball bearings in dustproof, grease-packed housings. (8) Easy to install. The steel blades and frame are durable, yet light in weight (9) Standard motors; Enclosed when specified. No vent holes are necessary to keep them cool. (10) Blades are individually mounted, inexpensive to replace. . (11) Type "B" units, when .equipped with ball bearing motors, are suitable for operation in any position. (12) Blades of Type "B".belt drive units are non-overloading. (13) Residence units are light, spring suspended for ultra-quiet operation. . Coolair Direct Drive Fans Codair. Direct Drive--16 in. to 64 ,n- > ' Data on Bequest Covered by U. S. Patent No. 1,855,660, designed for maximum air per horsepower with minimum noise. .. ; Type "B" Direct Drive COOLAIR Fans are made in four sizes. At 1200 rpm for residence kitchens, small stores, etc. At 1800 rpm for cooling, drying; for removing dust and fumes. 'Motors totally enclosed, long service types. The 1/6 hp and larger are ball bearing, will operate in extremes of position, temperature and humidity. Cushion mountings. Coolair Residence Unit and Spring Suspension covered by U. S. Patent No. 1,992,112.. 979 Fans Bayley Blower Company 1817 S. Sixty-Sixth Street Branches in Principal cities Milwaukee, Wis. Builders of Heating, Ventilating, Cooling, Purifying, Humidifying and Air Washing Equipment; Exhaust and Drying Apparatus, Mechanical Draft and Blast, Fans and Blowers of all Types Bayley Plexiform Fan: Is a multi-blade fan for supplying air for heating and ventilating systems, manufacturing processes, atomizer requires very little attention, and will operate successfully under low water pressure. The orifices are large and this atomizer, unlike high pressure nozzles, cannot clog. drying systems, forced and induced draft sys tems. It is suitable for handling high or low temperature gases at medium or low pressure. Will deliver maximum quanti ties requiring minimum space with great economy. This is a distinct Bayley product, high class material and workmanship, properly designed to avoid excessive vibration and overstressing of parts. Inlets and outlets are properly sized for maximum delivery and maximum efficiency. Fans are fur nished in single or double width of any required arrangement and with sleeve or anti-friction bearings. Bayley Chinook Heating Sections: The Chinook sec tion is used with blast heating, venti lating and drying systems, and is suit able for high or low pressure steam cir culation. The base is divided into two chambers. Steam enters (see cut) thel lower chamber, ris. ing through ^-in. pipes located within the 1^-in. pipes leading from the upper* chamber. Condensation takes place in Aeroplex Fan: the larger pipes, the water falling into the . Is of high speed design with self limiting power characteristics. Application parallel to the Plexiform Fan. Highly efficient and quiet in operation. Bayley Exhausters and Pressure Blowers: upper chamber and draining away through the return outlet. The Chinook can be repaired in the middle of the bank without breaking steam connections or taking down a section. Shipped assembled in smaller sizes, and Type "B" exhaust fan knocked down in the larger units. May is for heavy duty, hand be installed in horizontal or vertical ling refuse from industrial position. and textile plants. Type "SE" is used in handling Bayley Chinookfin Heating Sections: smoke, fumes and dust Are the same design as the Chinook laden gases. Type "H" Heaters, using heavy gauge copper fin for high-pressure work. tubes. As compared with Chinook it is These units are highly efficient and of much lighter and occupies less space. high class design'and workmanship. Bayley Plexfin Unit Heaters: Bayley Turbo Air Washers, This unit in Humidifiers and De-Humidifiers: corporates The Turbo Atomizer used in the Chinookfin radiation and Plexiform or Bayley Washer pro Aeroplex fans. The fan assem duces a bly including steady, fine top plate and spray. Water motor is re at low pres movable as a sure is deliv unit for main ered to the The Bayley Turbo Air Wother Show tenance and center of a ing Turbo Atomizer and Eliminator inspection. The heating element is a re rapidly re movable unit. Casing all welded extra volving cone-shaped rotor provided with heavy gauge. This is an exceptionally atomizing pins set in its periphery. This . high grade unit at a moderate price. 980 Fans Buffalo Forge Company 450 Broadway, Buffalo, N. Y. Branch Offices Aluany, N. Y.......... ..... .................611 Standard Bldg. Atlanta, Ga..... ,,724 First N.a.t.ional B-an.k.B..ld.g. Baltimore, Md____ 404 St. Paul St. Chicago. Ill............ ...... .......20 North Wacker Drive Cincinnati, Ohio.... . ..................6.2...2 Broadw.avy Cleveland, Ohio............................ ......418 Rockefeller Bldg. Dallas, Texas....................................Tower Petroleum Bldg. Davenport. Iowa--D. C. Murphy Co., 305 Security Bldg. Denver, Colo.--Hendrie & Bolthoff Mfg. & Supply Co., 1635 Seventeenth St. Des Moines, Iowa--D. C. Murphy Co., 214 Old Colony Bldg. Detroit. Mich.--Coon DeVisser Co., 2051 W. Lafayette Blvd. Greenville. S. C.._..........210 Franklin National Life Bldg. Houston, Texas...................................... _ 312 Caroline St Indianapolis, Ind..............................1441 No. Delaware St Kansas City, Mo..................... ................-_428 Dwight Bldg. Kitchener, Ont., Canada-- Canadian Blower & Forge Co., Ltd Knoxville, Tenn.--C. F. Sexton...........,,.702 Empire Bldg Los Angeles. Calif..................... 708 Pershing Square Bldg. Melrose. Mass....................................................486 Main St Minneapolis, Minn.................................. 619 Foshay Tower Nashville, Tenn.--Southern Sales Co., 117 Fifth Ave. South New Orleans, La.--Devlin Bros:.......1003 Maritime Bldg. New York, N. Y......................39 Cortlandt Bldg., Room 1110 Philadelphia, Pa............................ ........... _703 Cunard Bldg. Pittsburg, Pa..... ........................................... 431 Fulton Bldg. San Francisco, Calip.--Moore Machinery Co., 550 Fifth St St. Louis, Mo--..................................................1598 Arcade Bldg. Salt Lake Citt, Utah.................... Salt Lake Hardware Co. Seattle, Wash........ .........................................o50 First Ave. South Toledo, Ohio.... ........................ 1922 Linwood Avenue Tucson, Abiz.--Tidmarsh Engineering Co., P. 0. Box 2425 Washington, D. C.--820 Woodward Bldg., 15th and H Sts., N. W. Wilkes-Barre, Pa.--Power Engrg. Corp., 517 Brooks Bldg. PRODUCTS: Heating and Ventilating Equipment including: Unit Heaters, Multiblade Fans, Pipe Coil Heaters, Buffalo Air Washers, Buffalo Unit Air Washers, Buffalo Unit Coolers, Drying Equipment, Mechanical Draft Fans, Air Preheaters, Exhaust Fans, Blowers, Dust Collectors, Disc Fans, Spray Nozzles. "Buffalo" Ventilating Fans No matter what type of fan your work calls for, there is a "Buffalo" Fan of that type, of the right size; quiet, efficient, practical. Write for our fan catalogs. Breezo Ventilating Fans Breezo fans provide efficient, inexpensive ventilation on any job where they may be used to exhaust into the open. Made in sizes from 8 in. to 36 in. in diameter. "Buffalo" Comfort Conditioning Cabinets -for cooli n g and heating. Heating coils are two-row copper fin type ca pable of heating from 70 F to 135 F with 2 lbs. steam. Cool ing capacities--from 3 tons up. "Limit-Load" Conoidal Fans with Silent Floating Base The "Buffalo" "Limit-Load" high-efficien cy, non-over loading venti1 a t in g fan mounted on the silent, float ing fan base eliminates all motor and fan vibration. "Buffalo" Unit Heaters Gas Units: Made in suspend ed and floor types. All models equip ped with full auto matic safety fea tures. Provide clean, silent heat at moderate cost. Steam Units: Both suspended Steam Unit and floor type units are available in a large range of capacities. "Buffalo" Unit Coolers Suspended Type: Quiet unit coolers for use with cold water, brine, methyl chloride or Freon. Com pact, simple, inexpensive. Floor and Flat Sus pended :. Available for same kinds of refrigerants, but with larger capacities. "Buffalo" Air Washers "Buffalo" Air Washers are in use in thousands of buildings, many for more than 30 years. Bulletin 480 gives details. 981 Champion Blower & Forge Co. Manufacturers and Engineers Plant and General Offices: LsUlCRStCr, Pa. Manufacturers of Blowers, Ventilating Fans and Exhaust Fans for Air and Material; and Blast Gates Fans Type "SE" Electric Driven Fans These Fans are built for direct connection to Motor, with Adjustable Motor Base, quiet oper ation, large volumes, low outlet velocities. Type "S" Belt Driven Fans Built in all standard arrangements with Ball Bearings or Ring Oil Bear ings, suitable for V Belt Drive. Type"BC" Backward Curve Fans Designed for higher speeds, furnished in any arrangement. The capa city characteristics show a flat horsepower curve. Type " C " Single and Double Width Forward Curve Blast Wheels We are well equipped to build these Wheels in quantities for Oil Burner, and Stoker Manufacturers as well as Manufacturers of Air Conditioning and Ven tilating Equipment. Fans DeBothezat Ventilating Equipment Division American Machine and Metals, Inc. Executive and Sales Offices: 100 Sixth Ave., New York, N. Y. Factories: EAST MOLINE, ILL. Branch Offices and Agents in All Principal Cities Type II. Disc Pressure Fan. 24 in., z/i hp, lilfO rpm, 6170 c/m against Yi * static pressure. Bifurcalor. Efficient unit for use where fumes of excessive temperature, corrosive or explosive character, are to be removed. Motor outside air stream. Fans and Blowers are guaranteed to have non-over loading power characteristics. Complete operating safety under varying working conditions. Disc Pressure Fans--Three types: H for high static pressures; HL, for moderate; and L for low--designed to meet all pressure-volume requirements efficiently. Sizes from 8 in. to 10 ft with a wide range of rpm. "Selective Series" bulletin SS101 contains complete technical data and instructions for selecting from over 200 units the proper fan for your particular requirements. Giant Fans^-all diameters from 5 ft to 10 ft. May be supplied with directly connected motor, chain or V-Belt drive. Widely used on Forced and Induced Draft Cooling Towers. Bifureators--for use wherever gases are injurious to motors. Can be placed horizontally or vertically in straight duct without introducing right angle turns in the duct. No troublesome extended shafts, flexible couplings or bearings. Motor located outside air- stream assuring safe, care-free operation. ' Duplex Rotation Impeller Blowers--Efficient units consisting of two disc pressure fans rotating in opposite senses, so designed that rotational losses are completely eliminated. Direct drive by Duplex Rotation motor; ball bearings used throughout. Ideal for installation where large volumes of air are desired at low tip speeds. Vari-Speed Belt Driven Fans--25 per cent variation of speed provided by manual adjustment of motor pulley. Fan and motor are mounted as unit by mounting ring. Quiet in operation, rugged in construction and economical in power con sumption. Type "S" Double Width Belt Driven Fans Built in sizes up to 60 in. Wheel for Ventilating and Air Conditioning. Type "CEM Electric Driven Fans For use in Forced Draft and small venti- taring work. Built in sizes up to and including 18 in. dia. Wheel. 982 Two-Stage Duplex-Rotation Impeller Blower, with port of housing cut away to show construction. Large volumes of air against high static pressures at low tip speeds. Extremely high efficiencyover entirerangeofoperation. 983 Vari-Speed Belt Drive Fan. Fan. and motor mounted integrally. Fan speed may be adjusted to meet varying operating conditions. Fans ILG Electric Ventilating Company Propeller Fans, Blowers, Unit Heaters, Air Conditioning Equipment 2880 North Crawford Avenue, Chicago, 111. Sales Representatives in all Principal Cities ILG SELF-COOLED MOTOR PROPELLER FANS Used everywhere for removal of foul air, fumes, heat, etc. Features include: the patented Ilg self-cooled motor, dynamically balanced, vibration-free, bucket-type wheel, and a strong onenameplate responsibility. Motor, wheel and frame are all Ug-built. The self-cooled motor design com bines the low operating cost of the open motor with the protection of the fully enclosed motor. The fan action draws clean air through vent pipe from out side; circulates it through motor (follow the arrows) and exhausts it. The Ilg motor stays clean, cool. Ilg fan sizes range from 12 to 72 in. in A.C. and D.C. Ratings are in accordance with the Standard Test Code of the A.S.H.V.E. and the National Association of Fan Manufacturers. OTHER ILG PRODUCTS Jig Universal Multiblade Blowers--Type B Universal Blowers combine compactness, quietness and efficiency. Motor is recessed in side of blower, requiring no separate base. Multiblade wheel is mounted on motor shaft. There is no inlet bearing. Available also for belt drive. Capacities 1750 cfm to 70,000 cfm, single and double width. Ilg Type "B" Volume Blowers--A new design in small volume, low pressure blowers. Light weight, quiet running. Dynamically balanced multiblade wheel is mounted on motor shaft. Motor - and steel housing are supported by cast-iron base. Universal discharge. Available in 11 capacities, 180 cfm to 2100 cfm. Ilg Type "BC" Universal Blower--Motor load remains constant over unusually large variation in air volume and static pressure. Type "BCM comes in direct connected drive (left); also>belted drive with ball bearings (right). Blower wheel has back ward curved blades riveted to side and back plates. Universal discharge. Available in 11 sizes. Ilg Unit Heaters--Steam and Electric--Copper tube and fin construction and enclosed self-cooled motor. Ug-built throughout. For steam or hot water. Tested with 500 lb hydrostatic pressure. Available in 67 capacities; also, Ilg electric unit heaters for all electric operation, available in 20 sizes. Ilg Cooling and Air-Conditioning Units-- Self-contained Ilg Spot Koolers in ^ ton coolingcapacities with water or air-cooled compressors. Also central unit systems using floor cabinet or ceiling suspension units with remotely located com pressor. For cooling, dehumidifying, and recircu lating. Also, for heating and humidifying. 984 Fans Akron, O. Albany. N. Y. Atlanta, Ga. Baltimore, Md. Boston, Mass. Buffalo, N. Y. Camden, N. J. Chicago, 111. Cincinnati, O. Cleveland, O. Columbus. O. Detroit. Mich. El Paso, Tex. Greensboro. N. C. Hartford. Conn. Indianapolis, Ind. Kansas City, Mo. Little Rock, Ark. Los Angeles, Cal. Louisville, Ky. Milwaukee, Wis. Minneapolis, Minn. B. F. Sturtevant Co. Hyde Park, Boston, Mass. Sturtevant PLANTS LOCATED IN Camden, N. J. Hyde Park, Mass. Framingham, Mass. Sturtevant, Wis. Galt. Ont. Berkeley, Calif. The Cooling and Air Conditioning Corporation Division of B. F. Sturtevant Company Montreal, P. Q. Newark. N. J. ' New York, N. Y. Phoenix, Ariz. ' Pittsburgh, Pa. Portland, Ore. St. Louis, Mo. San Francisco. Cal. Seattle, Wash. Spokane, Wash. Springfield, Mass. Syracuse, N. Y. Salt Lake City. U. Toledo, O. Toronto, Ont. Washington, D. C. A. M. Lockett & Co. New Orleans, La. Houston. Texas Dallas, Texas HYDE PARK . BOSTON, MASS. Atlanta Camden Chicago Greensboro Los Angeles New York DATA ON HEATING, VENTILATING, AIR CONDITIONING AND VACUUM CLEANING EQUIPMENT FOR ARCHITECTS, ENGINEERS, CONTRACTORS The publications listed below have been prepared to aid the architect, engineer and contractor in the selection of proper equip ment for industrial, public, and private buildings of all types and sizes. If you do not have all of these publications in your file we will gladly send copies upon request. MISCELLANEOUS HEATING AND VENTILATING EQUIPMENT Catalogue No. 377 Unit Ventilators. _ 395 Rexvane Speed Heaters (Floor type unit heaters). 396 Speed Heaters (Suspended Type Unit Heaters). . 345 Carbon Monoxide Asphyxiation and Its Prevention. 399 Blower Wheels (For oil burners, etc.). , COOPERATION AIR CONDITIONING EQUIPMENT -Sturtevant Engineers, located at each of the offices listed are always ready to co operate with architects, engineers and con tractors in the selection of equipment Catalogue No. 295 Air Washers. AC 101 Industrial Air Conditioning. 398 Comfort Air Conditioning. suitable for any prospective installation. 378 Filticooler (Compact, high ef ficiency air washer. For filter VENTILATING FANS ing, washing, humidifying, cool ing, dehumidifying. Used prin Catalogue No. cipally for public buildings and 271 Multivane Fans (Forwardly curved factories). blade type). 401 Railway Air Conditioning. 381 Silentvane Fans (Backwardly 424 Fans and Air Washers for curved blade type). Theatres. 414 Rexvane Fans (Radial blade type). 425 Air Conditioning Distributors 332 Ventilating Sets (direct motor- Handbook. driven centrifugal type fans for ventilating small rooms. Capaci ties: 80 to 1600 c.f.m.). 400 Direct-connected Fans and Blowers (Propeller Fans; Window Fans for kitchens and offices; Centrifugal Fans from 80 to 6460 c.f.m.; Portable Gas - Engine - Driven VACUUM CLEANERS Catalogue No. 397 Central Vacuum Cleaning Systems (Commercial Buildings). " . 368 Industrial Vacuum Cleaning Systems. . Fans;.Coal Burning Blowers; Forge Blowers; Dust Blowers). 422 Roofvane Ventilators. 373 Vortex Furnace Cleaner. . - . 413 "Vortex" Portable Vacuum Cleaners. 985 / Fans The Torrington Mfg. Co. 50 Franklin Street, Torrington, Conn. Manufacturers of All-Aluminum Blower Wheels and Disc Propeller Type Fan Blades. Air impellers for every purpose. Single Inlet Blower Wheel Pat. 1,700,017 Double Inlet Blower Wheel Pat. 1.700.017 Special Design Blower Wheel ' Cup Type Blower Wheel Pals. 1.518.765 and 1,616,060 ` {Produced under license from American Blower Co.) . Torrington Aluminum Blower Wheels produce the smooth, quiet per formance which is essential in modern heating and air conditioning units because the unique patented construction breaks up resonance and minimizes noise. Made of aluminum, they resist corrosion and their light weight facilitates quick starting (as in automotive pistons)--saves power. Every wheel is perfectly balanced by hand, given a running test and packed in a specially designed carton for protection in transit. Bulletin lists 31 sizes of single inlet single width and 31 sizes of double inlet double width wheels, including guaranteed capacities for each. Also gives detailed dimensions for all wheels and table of dimensions for housing scrolls. We do not manufacture housings. Sizes 3 . in. ^o 15 in. diameter in all standard widths. Special Design--for unit type air con ditioners. 2 sizes only. Design is of double inlet type with a center spider plate to which hub is attached. Blades, in addition to being riveted to inlet rings, are held rigidly in their proper position by the channel shaping of the inlet rings which closely fit the blade feet. Made of aluminum or steel, cadmium plated. No. SD 5 in. diameter x 4 ^ in. width--36 blades. No. % SD 5% in. diameter x 6% in. width--45 blades. Bulletin gives performance curves, also details of wheel dimensions and table of dimensions for housing scrolls. Torrington Cup Type Wheels--T'he one piece ^up construction is economical for production and the design is efficient and sturdy. Ideal where maximum air delivery and minimum power is required for small diameter wheels. Used for auto mobile heaters and windshield defrosters, small hair dryers, hand dryers, ice box and refrigerator circulators, window venti lators, exhausters and wherever small blower units are used. Made for either clockwise or counter clockwise rotation, of steel or aluminum, in the following sizes: ,. 3 in. diameter x 1^6 in* blade width 4 Yi in. diameter x 2^6 n- blade width 4^ in. diameter x 3 in. blade width 5 in. diameter x 2} in. blade width 5 in. diameter x 3 in. blade width Also made in double width wheels. 986 The Torrington Mfg. Co. Fans MDISTCCRAT are beautiful, * _ _--ATVjQuin Propeller fbnBbdn ornamental, ultra quiet, modern as the year 1938. Designed for free air applications (desk fans, air circu lators, etc.) Perform well at moderate pressures. Used for window ventilators, unit type air conditioners, unit heaters, refrigeration devices, etc. Blades are hand set for alignment, statically balanced and packed in special containers for protection in transit. Clockwise rotation only. Alu minum alloy blades, steel center, any finish. Bulletin gives detailed dimensions and guaranteed performance curves re corded under NEMA code tests at various speeds. De Luxe Model--The round, convex centerplate adds to the beauty of this ultra quiet blade which will improve the appearance of and help to sell your unit. Sizes 10 in., 12 in. and 16 in. Standard Model--Same as DeLuxe Model but with blades mounted on a conventional type of spider instead of round center disc. A sturdy and beautiful blade which has withstood extreme labora tory breakdown tests. Priced lower than DeLuxe Models. Sizes 8 in., 10 in., 12 in., 14 in. and 16 in. Larger sizes will soon be marketed. A T ITT^RAT tor aut heat- /1U I Blades ^rs, windshield defrosters, etc., have been standard ever since these devices were first marketed. Made in sizes 3 in., 4 in., in., 5 in., 5J4 in., 5J4 in., 6 in., 6}^ in., all four blades, also 7 in. 5-blade, in one piece of cold rolled steel or aluminum with brass hubs, com plete with set screw. J4 in. bore is stan dard. Either clockwise or counter clock wise rotation (expressed when looking at air delivery side of fan). White nickel is standard finish for steel blades. Bulletin gives complete specifications and ratings. Torrington Paddle Type Blower Wheel (Small sizes only)--For automobile heaters and windshield defrosters, small hair dryers, ice box and refrigerator circu lators and many other purposes where moderate air deliveries and inexpensive wheels are required. Made in either steel or aluminum. * Sizes--2 in. diameter x 1 in. width 2x/i in. diameter x ljf6 in. width 3 in. diameter x lJ4e in. width Bulletin gives complete dimensions, suggested housing designs and capacity rating tables. Airistocrat DeLuxe Model Airutocrat Standard Modd Pais. B.07g,SSt and .0X1,707 A utocrat Fan Blade Paddle Type Blower Wheel Every Torrington fan has resulted from scientific research and development under experienced engineers in a laboratory fully equipped for the study of aerodynamics. . Other new Torrington models are under development. Get on our mailing list and you will be kept informed on important new fan developments. * 987 Fans Branch Offices in Principal Cities L. J. Wing Mfg. Co. 59 Seventh Avenue, New .York, N. Y. Factory: NEWARK, N. J. Wing Featherweight Unit Heaters--Floodlights of Heat Located near the ceiling or roof, they prevent accumulation of hot air in the upper spaces thereby avoiding costly waste of heat. They project the air, com fortably warmed, to the working area where the heat spreads to every point. Vertical downward discharge from multiple outlets ' at proper velocity assures even distribution. The lightness of the units permits their suspension directly overhead in any location. Furthermore, one large WING unit with multiple discharge takes the place of several one-direction heaters at less cost for units, piping, wiring and installation. There is a type for every condition from low ceilings to installations as high as 55 ft. They use the WING Featherfin Heating Element described below. Bulletin H-6A. Wing Revolving Discharge Featherweight Unit Heaters Operate on an entirely new scientific principle of heating that projects uniformly and comfortably warmed air to the walls and remote corners of the plant. Elim inate uneven heating encountered where equipment obstructs the flow of heat from a fixed discharge. These heaters have been giving entire satisfaction in some of the most trying situations, as on fruit piers where even temperatures are essential--where "hot" spots would be disastrous. Bulletin H-6A. Wing Featherfin Heating Sections For heating air for any purpose by steam or hot water. The WING Featherfin Heating Element is extremely light in weight. It is of the fin-and-tube ex tended-surface type, and offers very low re sistance to air flow. Its hairpin shape avoids expansion and contraction strains. Each tube is easily replaced in case of accidental damage. Sections available for any final air temperature with any steam pressure. Used separately for any heating purpose and in DM/ Winn Faihtrfin WING Unit Heaters. Tested at 1000 lb pressure. Heating Element thawing Bulletin H-6A. Compression Union Tube WlNG VARIABLE-TEMPERATURE HEATING SEC- Variable-Temperature Heating Section. Connedum tions permit precise control of air temperature without by-passing and without throttling steam. No freezing. Bulletin VT-2. , Wing Garage Heaters For effective and economical heating of garages. Sometimes cut heating costs in half. Bulletin G-J. Wing Door Heaters For instantaneously heating inrush of cold air at large doorways of industrial buildings. Bulletin D-l. 988 L. J. Wing Mfg. Co. Fans Wing Utility Heaters A lightweight sus pended unit heater for delivering heated air in one general di rection. Has the same powerful fan and rug ged heating element as WING Feather weight Unit Heaters. This is the latest refinement of the original horizontal light weight heater which , was developed by WING. Bulletin U-4.. Wing Industrial Fog Eliminators Eliminate fog, odor and fumes in dyeing, bleaching and finish ing plants, creamer ies, pasteurizing, bot tling, canning and packing plants, chem ical works, paper mills, steel pickling plants, etc. No ducts are required. Bulletin PE-12. Wing Featherfin Process Heating Units For man ufactur ing pro cesses such as drying, aging, etc., re quiring the recirculation of the heated air. Motor or turbine located outside air cur rent. Bulletin P-2. Wing-Scruplex Safety Ventilating Fans A propeller type fan that will deliver air against static pressure, quietly and efficiently. Moves the air for ward in straight lines with minimum eddy. Capacities to 100,000 cfm. Bul letin F-6. Wing-Scruplex Exhausters For economically moving air wherever ducts are used. It combines the efficient WINGScruplex Propeller Fan with a housing which places the motor entirely outside the air duct. Motor and drive remain cool and clean and are easily accessible. The powerful WING-Scruplex Fan delivers high air volume with low power consumption against any pressures for which duct systems should be designed. V-belt or direct drive. Light, compact and easy to install. Bulletin E-70. Wing Motor-Driven Blowers jfor low-pressure heating boilers and small power boilers. Increase boiler capac ity, permit close con-1 trol and allow use of lowest-cost fuel. Fully enclosed, dustproof motor with speed regulator and automatic controls. Bulletin M-76. Wing Turbine-Driven Blowers Increase boiler capacity, main tain constant steam pressure and permit com plete combus tion of low-cost fuels. The ex haust steam, free from oil, can be used for heating or pro cesses. Bulletin T-97A. Wing Type^ COM. Blowers (High Static Pressures at Low Speeds) Efficiently produce high static pressures at low speed. Equipped with constant-speed motor and built-in damper, permitting variation of air delivery over a wide range-with decreasing horsepower. Ideal for many ventilation appli cations and for forced draft for boilers. Bulletin CO-2. 989 Heaters, Unit Airtherm Manufacturing Company 1474 South Vandeventer, St- Louis, Mo. THE ENGINEERED LINE OF UNIT HEATERS AIRTHERM IMPROVED UNIT HEATERS Backed by the experience of thirty years in unit heater con struction, the new Airtherm line represents a great advance in unit heater construction. Many new and exclusive fea tures have led to the instan taneous acceptance of this line by important industries. High quality materials, sound engineering principles, advanced construction meth ods, all combined with modern styling, have resulted in a product of unquestioned merit. Study all unit heaters before you buy. Your choice will be Airtherm. The Airvector (above) Airtherm's latest contribution to the propeller fan type unit heater field. Many exclusive features, including ribbed "Sound-Proofed'1 Cabinets, "No Pendulum Action" method of motor mounting, modern styling, and other exclusive features. Complete range of sizes for any job. The Airheator (right) Airtherm's blower fan type unit heater for floor or ceiling mounting. Available in a variety of assemblies, welded construction, quiet oper ation, and high efficiency. Airtherm Unit Heaters are the choice of leading engineers. The Airblanket (left) An outstanding innovation in unit heater con struction and performance. The Airblanket is now being used where ceilings run as high as 70 ft, and has shown amazing performance under every circumstance. Investigate the Airblanket for any job over 18 ft ceiling, or any other instal lation requiring absolute control of warm air discharge. Write for Catalog A-37. 990 Heaters, Unit Fedders Manufacturing Co. HEAT TRANSFER SPECIALISTS SINCE 1896 57 Tonawanda Street, Buffalo, N. Y. Branches and Representatives in All Principal Cities Unit Heaters, Air Conditioning Surface and Unit Conditioners, Unit Coolers, Commercial and Household Refrigeration Equipment Fedders Unit Heaters Handsome monopiece steel cabinets, quieter operation, nigged heating elements, rubber mounted motor and fan assemblies and a com plete range of sizes with constant and multiple speed, standard and explosion-proof motors provide the correct answer to exacting com mercial and industrial heating requirements. Capacities range from 75 to 1300 E.D.R. as listed below. Patents 1.970,105, 2,025,426 FEDDERS ALL SEASON UNITS FOR AIR CONDITIONING A complete line of All-Season Unit Air Condi tioners complete with any combination of cooling and heating coils, humidifiers filters and blowers, ready to connect to refrigerant, cold water, steam or hot water supply. Cooling capacities from one ton up, heating capacities up to 2200 E.D.R. Available for floor or suspended instal lations. Write for Bulletin AC-201. FEDDERS AIR CONDITIONING SURFACE Complete lines of all-copper cooling and heating coils, factory engineered and manifolded for vcorrect distribution of cooling and heating medi um. Engineered and cataloged on a package basis. Write for Bulletins. Fedders HighCapacily Thermostatic Expan-sion Valves for Air Conditioning. Patents: l 74,681 1,987,948 B,011,879 FEDDERS SERIES 73 UNIT COOLERS Series 73 Unit Coolers are built for comfort cooling and com mercial refrigeration. Handsome cabinets, non-rusting through out, all-copper cooling element, complete with motor, fan and Fedders Thermostatic Expansion Valve. Write for Bulletin. y991 Heaters, Unit McCord Radiator & Mfg. Co. Heating and Air Conditioning Division Detroit, Michigan UNIT AIR CONDITIONER A new develop ment to heat, cool and condition stores, large offices and small fac tories. Cooling capacity 5 tons with 45 deg water; heat capacity 77.000 Btu per hour. Two 2 speed squirrel cage fans; silent vibrationless motor; washable spun glass filters. Smart modern design cabinet of chrome trimmed lacquer over bonderized steel. VERTICAL TYPE UNIT HEATER Developed to simplify the pip ing layout on high and wide build ings. Warm air taken from top of building is re heated and dis charged downward into working area. Adjustable deflector outlets provide ef ficient distribution in any direction, re quiring fewer units.- Capacities from 115.000 to 250,000 Btu per hour. Totally enclosed ball-bearing motor. UNIT HEATER r Advanced de sign permits rear entry of inlet and outlet, eliminat ing unsightly con nections and re quiring small head room. Wide . range of output-- Capacities from ' 20,000 to 500,000' Btu per hour. Quiet, totally enclosed motor. Beauti fully designed welded steel case with rounded corners, stainless steel mouldings and baked crystal enamel finish. CENTRIFUGAL BLOWER HEATER For use wher ever a large vol ume of air at low face velocity is required. Cap acities 120,000 to 900,000 Btu per hour. Extremely quiet with large volume of air. Low speed, large diameter fan may be used with any type of duct construction or with hood as illustrated. OTHER McCORD PRODUCE'S McCORD CENTRIFUGAL BLOWER UNIT HEATER--for use where ceiling suspension units are not desirable, particularly where ceilings are high. Floor or wall mountings. McCORDFIN BLAST HEATING AND COOLING UNITS--in con- t venient standard sizes. Solid copper and bronze, solder dipped, protected against corrosion and electrolysis. Greater efficiency due to perfect metal to metal contact and reduced air resistance. McCORD SUSPENSION TYPE AIR CONDITIONING CONVECTORS--modern attractive design, sturdy construction, efficient operation. McCORD CENTRAL SYSTEM AIR CONDITIONERS--complete units for in- stallations requiring 3 to 24 tons cooling and 160,000 to 500,000 Btu per hour heating. McCord maintains one of the best equipped heating transfer laboratories in the industry. McCord's 34 years of experience and progressive engineering will help you maintain your reputation. . For engineering recommendations, catalogs, and prompt quotations, write McCord Radiator & Mfg. Co., Detroit, Michigan. * 992 ( j 1 Heaters, Unit Modine Manufacturing Co. 17th and Holburn Streets, Racine, Wisconsin Branches in All Principal Cities MODINE UNIT HEATERS Application-- Not only success fully used for indus-. trial, garage and similar space-heat ing applications, Modines are ideally suited also to show rooms, stores, oil stations, churches, school rooms, resi dential recreation rooms, etc. They have also effected important econom ies in the drying of paint, leather, en amels, paper, wood, etc., by speeding up and bettering the drying process. Exclusive features that not only make the Modine a better unit structurally but assure more effec tive, economical dis tribution of heat :(1) Expansion Bend, given each tube of the condenser before entering lower head er, provides for free expansion, thus eliminating strain from being trans ferred to header tanks. (2) Velocity Gen erator for redirecting and controlling the heated air strearrvassures greatest possible Unit Heaters--Capacities and Dimensions __ (In Inches) Mode! No. Over Depth all width Less Height Motor E.D.R. C.F.M. Motor R.P.M. 76 126 152 161 204 238 275 352 440 542 620 710 903 1163 1300 1545 2015 id/, 16 18 18 16 18 22'A m 23 26'/, 26'/, 30V, 34*/, 30'/, 31% 9V, 13 15 15 15 15 18 18 18 22 22 22 26 26 26*/, 521/. 56'/, 5*/, 8 8 8 8 8 9 9 9 9 9 9 id/, 10'/, 8 11 II 76 126 152 181 204 238 275 352 440 542 620 710 903 1163 1300 1545 2015 187 456 540 770 735 731 1052 1425 1320 1710 2140 2230 3000 4050 5010 5400 6540 1550 1590 1590 1140 1140 1140 1140 1140 1140 1125 1120 1120 1125 1110 1125 1125 1110 All above models are available with variable speed motors. Units for hot water application also available throw consistent with comfortable heating. (3) Direct Pipe Suspension facilitates horizontal redirection of the heated air stream, permitting full 360 deg rotatability. Also means easier installation at less cost-- no brackets, pipe rods or straps being nec essary. Write for Unit Heater Catalog 137. MODINE BLAST HEATERS Made in over 250 sizes, types, and ca pacities to meet the specific demands for heat transfer service. Outstanding fea tures are: (1) Expansion Bend--Allows each tube to expand and contract indi vidually, eliminating expansion strain. (2) AH steam carrying passages are cylin drical for greatest possible strength. (3) From inlet to outlet condenser is of copper or copper alloy construction. (4) Copper fins are bonded metallically to tubes to prevent reduction of original heat transfer capacities. See Catalog No. 337. MODINE COPPER CONVECTORS The new Modine Copper Convector furnished in four types, Concealed, Re cessed, Floor and Wall Cabinet, is de signed for use on steam, vapor, vacu um or hot water systems. Styled for beauty of line and proportion, the en closure is adapted to easy color appli cation. Interchangeable, die-cast grille segments in four patterns make it possible to design a grille which will harmonize with any interior. Grilles also available in plated finishes.--Bulletin 237-B. MODINE COOLING COILS For use in connec tion with central sys tem cooling and air conditioning plants, Modine Cooling Coils, Cold Water Type, are installed in conjunction with a blower fan and duct work. Adaptable where cold water or non corrosive brine is used as the cooling medium.--Catalog 537. OTHER MODINE PRODUCTS Modine also offers complete lines of Unit Coolers and Air Conditioning Equipment. Data will gladly be furnished on request. 993 Heaters, Unit The Unit Heater and Cooler Co. Wausau, Wisconsin Offices in Principal Cities MANUFACTURERS OF THE GRID UNIT (patented) AU-cast aluminum "fins*' bonded to cast high-test iron core. No soldered, brazed, or expand ed joints -- no unions--no seams --fewest connec tions possible. Typical Installation of Grid Unit Heater GRID UNIT HEATER DATA Model No. Dimensions Inches A B C D' Face Area Sq Ft Motor Hp Rpm Vol at Capacities 5 Lb Steam 60 Air Approx. Shipping Pipe Sizes Fan Btu Final Temp. Weight Supply Return 1000 16 12% 9% 16 0.85 1/20 1700 578 29,400 107 90 i%" i%n 1200 18 14% 11% 17% 1.04 1/20 1700 711 46,000 119 120 i%" i%" 515 22 18- M% 20 1.67 1/10 1750 1290 59.600 102 180 i%" i%" 1500 22 18 11% 20 1.67 1/10 1750 1450 77,500 109 210 i%" i%" 1520 27 18 11% 20 2.2 1/10 1750 1700 104,000 113 250 i%" i%" 520 27 23% 11% 21% . 2.8 1/6 1150 2500 102,300 97 280 2" i%" 2000 27 23% 11% 21% 2.8 1/6 1150 2500 148,000 114 320 2" i%" 2025 32 23% 11% 21% 3.6 1/6 1150 2875 177,000 115 370 2" i%" <. 94525 32 28% 11% 2B 4.5 1/2 1150 4200 166,400 390 2" i%" 2504 32 28% 11% 23 4.5 1/4 1150 3200 210,000 118 400 2" i%" 2500 32 28% 11% 28 4.5 1/2 1150 4200 225,000 108 440 2" i%" 2530 36 28% 11% 28 5.3 1/2 1150 4650 282,000 115 500 2" i%" 530 38 33 13% 29 6.5 1/2 1150 5300 260.500 105 600 2%" i%" 3000 38 33 13% 29 6.5 1/2 850 6350 341,000 109 690 2%" i%" 3000 38 33 13% 29 6.5 1% 1150 8100 394.000 104 725 2%" i%" 'Varies with type of motor. GRID UNIT HEATERS ARE NOT AFFECTED BY ELECTROLYTIC ACTION No leaks--no breakdowns. Low maintenance expense. More air changes per hour. Positive "directed" heat. Lower outlet temperatures. Larger air volume. . Reduced fuel cost. Applicable to either low or high steam pressure lines. Send for Bulletin on Units not listed above. 994 . Heaters, Unit YSUING RADIATOR Lom/mniu Offices in all Principal Cities * R3Citl6t WiS- Model "5/4 " Unit Heaters Eva porators AIR CONDITIONING UNITS Made in four . physical sizes for homes and indus trial applications. Unit Heaters--A new complete line, 28 sizes sus pended units--constant or variable speed motors. Unit Coolers and Evaporators for use with water, brine.or any common refrigerant. Cooling Coils with con tinuous tubes or removable headers for use with water or brine. Streamaire Convec tors--A complete new line, six distinct types of en closures. "FH" Unit Heaters-- Ten models, high capaci ties for industrial applica tion. Blast Units, Commer cial Heat Transfer Sur faces for heating, cooling or air conditioning. ' Cooling Coils Streamaire Convector Blast Units--Commercial Units 995 Model "FH" Unit Heaters Healing and Cooling Surface (Fan System) Aerofin Corporation 410 So. Geddes Street Syracuse, N. Y. Aerofin Standardized Light-weight Heat Exchange Surface Branch Offices CHICAGO. NEW YORK, PHILADELPHIA, DETROIT, ATLANTA, DALLAS Aerofin is the modern Standardized Light-Weight Encased Fan System Heat ing and Cooling Surface originated by Fan Engineers to meet the present and future requirements of this highly specialized field. All Standard Aerofin Units are furnished as completely encased Units, ready for pipe and duct connections. The patented casings are built of pressed steel and are exceptionally strong and rigid, protecting the Unit from all the strains of pipe connections and expansion or con traction in service. The casings are flanged on both faces, top and bottom, and template punched for bolting together adjacent Units, or for duct connection. so arranged as to absorb all expansion and contraction strains. Headers--Cast bronze or aluminum. Tubing--% in. O.D. copper,, admiralty or aluminum. Joints--Where admiralty or copper tubes are used together with bronze headers tubes are brazed to headers using Mueller patented joint. Where both aluminum tubes and headers are used tubing is welded to headers. Casings--Copper, aluminum or gal vanized iron. Design--Units are constructed with headers on opposite ends making possible installation of units with tubes horizontal or vertical. Aerofin Corporation Heating and Cooling Surface (Fan System) Fig. 3 High Pressure Aerofin: (Fig. 3) Aerofin is of the continuous tube design being recommended where extremely high pressures of steam are used. Headers--Pressed steel. Tubing--1 in. O.D. Copper, aluminum or admiralty. Casings--Copper, aluminum or gal vanized iron. Fig. 6 Narrow Width Aerofin: (Fig. 5) recommended for water cooling or for flooded Freon systems. Made in straight tubes only with headers on opposite ends, joints between headers and tubing being brazed. Construction similar to Flexitube Aerofin. Fig. g \ Fig. 1 Flexitube Aerofin: (Fig. 1) supplants the original non-corrodible Low Pressure Aerofin. Flexitube Aerofin is distinguished from all other developments by its off-set tubes, Universal Aerofin: (Fig. 2) is dis tinguished by its "S" bend construction of tubing, the units being designed with steel headers on opposite ends;' the ends of the "S" bends being connected thereto by compression nuts, the bends taking care of the expansion and contraction of the tubing. This type of surface is recommended where close control is desired. Headers--Pressed steel. . Tubing--1 in. O.D. Copper, admiralty or aluminum. Casings--Copper, aluminum or gal vanized iron. 996 Fig. 4 Booster Aerofin: (Fig. 4) is of the continuous tube design and is recom mended where small volumes of air are used, or where it is designed to raise the air temperatures in branch ducts, etc. Headers--Cast iron. Tubing--% in. O.D. Copper or alumi num. Casings--Copper aluminum or gal vanized iron. Aerofin Encased Rooster Units: (Fig. 4). For horizontal or vertical air flow. Six sizes, 150 to 1624 cfm. For either horizontal or vertical air flow. Fig. 6 Aerofin Continuous Tube Water Coils: (Fig. 6) are designed for air cooling by circulating cold water through the Aerofin and air over the extended fin surface. These units can be made for either horizontal or vertical air flow. Tubes and fins are made of copper, com pletely tinned with a permanent metallic bond between fin and tubes. Headers are made of one-piece cast bronze and casings of heavy galvanized iron or copper. Every unit is tested to 1000 lb hydro static pressure. 997 Aerofin Corporation Heating and Cooling Surface (Fan System) Fig. 7 Fig. 9 Aerofin Cleanable Tube Units: (Fig. 7) for cooling only ami all made with headers removable so as to permit of cleaning out tubes. Recommended for use where sediment or scale forming chemicals are present in the cooling water. Headers--Cast iron. Tubing--Copper or admiralty. Casings--Copper or galvanized iron. Aerofin Direct Expansion Units: (Fig. 9) Centrifugal Header Type--Re commended where control of rows in direction of air flow is not required. Advantages: Weighs but 9 to 16 per cent of same equivalent cast iron surface and occupies one-third of the space. Eliminates expensive foundations and building re-inforcement. Can be suspended from roof beams or trusses if necessary. Aerofin Sizes Aerofin Direct Expansion Units: (Fig. 8) Row Control Type--Recom mended for use where cutting on or off rows of tubes in direction of air flow is desired. Suitable for use with Freon or Methyl-Chloride. Flexitube: 13 standard lengths, three widths, one and two rows deep. Narrow: same as Flexitube. Universal: 17 standard lengths, two widths, one and two rows deep. Continuous Tube: 13 standard lengths, three widths, 2-3-4-5 and 6 rows deep. Cleanable Tube: 17 standard lengths, one width, 2 and 4 rows deep.- Direct Expansion: Row Control- 11 standard lengths, 3 widths, 1-2-3 rows deep. Face Control--11 standard lengths, 3 widths, 2-3-4-5-6 rows deep. Centrifugal Header--11 standard lengths, three widths, 2-3-4-5-6 rows deep. Steel Supporting Legs: 18 in.- and 24 in. high. Punched same bolt hole centers as standard casings. Quickly attached. No other foundation required. Sale: Aerofin is sold only by manu facturers of nationally advertised Fan System Apparatus. List upon request. Write Syracuse for Heating Bulletin G-32; Direct Expansion Bulletin DE-34 on refrigeration type units; Continuous Tube Bulletin C. T. 34 for Water Cooling Coils; or pamphlet on Cleanable Type Aerofin for cooling. 998 Healing and Cooling Surface The G & O Manufacturing Company 138 Winchester Avenue New Haven, Connecticut G0 SQUARE FINNED TUBING STRAIGHT LENGTHS--U-BENDS--CONTINUOUS COILS RADIATING ELEMENTS FOR ALL HEAT TRANSFER PURPOSES THE use of Individual fins results in high efficiency in heat transfer from primary tube surface to secondary fin surface. Fins of any size or shape may be obtained giving any desired proportion of primary and secondary surface. A square fin has about 30 per cent greater surface than a round fin of a diameter equal to one side of the square. Individual fins permit of any fin spacing: also, of using fins in groups at intervals along tubes. - .. A--Generous Fin Collar provides large contact area between Tube and Fin. B--Tube expanded against Fin Collar; insures mechanically tight joint, made permanent by bond of high tempera ture alloy--perfect thermal contact. C--Free air=flow passages; non-clogging. Standard Sizes Fin Surface O.D. Fin Spacing at Tube Size per Linear Inch Foot >/.' s/.' . vf 1' q. '/' rU l'/2* r'd. iy*' *q. W *q. 6 . 0.80 sq.ft. 6 - 0.60 sq.ft. 6 1.55 sq.ft. 6 2.40 sq. ft. 6 : 4.00 sq. ft. G & O Finned Radiation Coils for all industrial applications are available in a wide range of sizes for high and low pressure operation. Universal U-10S / ' , High Pressure No. 10 Send for Catalog 999 Heating and Piping Systems, Industrial GRINNELL COMPANY. Heating, Industrial and Power Plant Piping, Fittings, Hangers, Valves, Pipe Bending, Welding, Piping Supplies, Etc. Executive Offices: Providence, R. I. Albany, N. Y. Atlanta, Ga. (Plant aod Foundry) Auburn, R. 1 (Plant aud Foundry) Baltuiobb, Md. Boston, Mass. Bufpalo, N. Y. Cbarlottb, N. C. (Branch) Cbicago. III. (Branch) .Cincinnati, Ohio Offices, Plants and Branches Cleveland, Ohio (Branch) Columbia. Pbnna. (Plant) Columbus, Ohio Dallas, Texas (Branch) Detroit, Mich. Kansas Cut, Mo. Long Island City, N. Y. (Branch) Milwaukee. Wis Minneapolis. Minn. (Branch) Newark, N. J. New Orleans, La. New York. N. Y. Philadelphia, Pbnna. (Branch) ` Pittsburgh, Pbnna. , Providence. R 1. (Plant and Foundry) Rochester. N Y St. Louis, Mo. (Branch) St. Paul, Minn. (Branch) Warren, Ohio (Plant and Foundry) GRINNELL COMPANY OF THE PACIFIC Los Angeles. Cal. (Branch) Oakland, Cal. (Branch) San Francisco. Cal. (Branch) Seattle, Wash. (Branch) Montreal, Qua. (Branch) GRINNELL COMPANY OF CANADA, LTD. Vancouver, B. C. (Branch) Toronto. Ont. (Plant and Foundry) Oshava. Ont. (Foundry) Winnipeg, Man. PRODUCTS AND SERVICES-- Complete Service on materials-.to Specification on Power Plant Piping, Industrial Piping, and Industrial Heating Systems; Prefabricated Pip ing including Pipe Cutting and Threading, Pipe Bends, Welded Headers, Welded and Welding Fit tings, Lap Joints and the Grinnell line of products for Super Power. Grinnell Equifio Valves For Forced Hot Water Heating Grinnell Equlflo Valves for forced hot water heating systems; Grinnell Adjustable Pipe Hangers and Sup ports; Grinnell Cast Iron and Mal leable Iron Pipe Fittings; Grinnell Malleable Iron Unions; Grinnell Weld ing Fittings; Grinnell Thermoliers (Unit Heaters); Grinnell Thermofin (Convectors); Thermoflex Traps and Heating Specialties. Also Humidifying Systems; Con stant Level Size Circulating Systems; Piping for acids and other special materials. Malleable Iron, Brass, Bronze and other Castings; Brass, Cast Iron, Wrought Iron and Steel Pipe; Seam less Steel Tubing in Iron Pipe Sizes. Valves: Check, Globe, Pressure Re ducing and Regulating, Quick Open ing, Safety and Y. Automatic Sprinkler Systems; Stand Pipes; Underground Supply Mains; Hydrants; Fire Pumps; Pressure and Gravity Tanks. Grinnell "Junior" Automatic Sprinkler Systems for Basements and other hazardous areas of Dwellings, Small Apartment Buildings, Schools, Churches, Stores, etc. Equifio Valve The designing of forced circulation hot water heating systems is so simplified by the Grinnell Equifio Valve that they can be laid out and installed as easily as vapor or steam systems. This valve consists of a regular type packless radiator valve with a cartridge or tube made up of a series of orifices and baffles capable of setting up any required frictional resistance. This method of establishing any desired resis tance does away with elaborate calcu lation of pipe sizes. Grinnell guarantees perfectly balanced circulation to each and every radiator where these valves are installed throughout the system. Equifio Data Book sent to interested parties. For Data on Thermoflex Traps and Heating Specialtiesf see page 1110 1000 Grinnell Company, Inc. Heating and Piping Systems, Industrial 7HERMOLIER Patented THE GRINNELL UNIT HEATER De Luxe, Industrial and Factory Types-- 125 Lb W.S.P. Industrial Type Thermolier is a ruggedly built unit heater whose efficiency and dependability have been proved by actual performance in field service. Thousands of them are installed in industrial buildings and commercial structures of all types of occupancy. Thermolier has 14 points of superiority, the most outstanding of which is the internal cooling leg built right into the unit, an exclusive Ther molier feature. See drawing below. Radiation is from brass-finned seamless copper U-tubes rolled into a cast-iron tube sheet. No solder is used for strengthening joints and there are no flat horizontal surfaces to catch dirt. Units may be controlled manually or automatically, singly or in groups. Installation and piping are extremely simple and inexpensive^ hence the unit may be moved from one THE THERMOLIER INTERNAL COOLING LEG ACCOMPLISHES A RESULT SUCH AS IS DIAGRAMMATICALLY ILLUSTRATED HERE ERMOSTATIC TRAP UNIT HEATER location to another at small cost if found desirable on account of changes in building or occupancy. The complete line includes 22 Models in DeLuxe Type, and 30 Models each in-Industrial and Factory Types. Thermoliers provide maximum distribution of heat without objectionable drafts. Specifications Fan--Grinnell special of rugged construction. Motor--heavy duty, oversize, enclosed, moisture-proof. Housing--Art Metal Slate gray finish with chromium trim on DeLuxe'Types. Copper on Industrial Type with rubbed lacquer finish; steel on Factory Type finished in gray duco. Frame--Heavy pressed steel, providing rugged support for motor and fan. Special Features--Adjustable swivel hanger rod couplings; louvers rigid, but easily adjustable: integral cooling leg insuring perfect drainage through one thermostatic trap for pressures up to 25 lb. For pressures not exceeding 125 lb, a thermostatic trap of proper construction can be used and should be attached directly to the unit. CAPACITIES 60 F Entering Air Temperature--2 lbs Steam Pressure Mode] No*. 20 20L . 25 25L 30 30L 40 40L 45 45L Btu per Hour 35,000 26,900 40.500 30,900 47,800 35,200 69,400 53,300 81,200 62,600 Model Nos. 50 50L 60 60L 65 65L 70 70L. 80 8QL Btu per Hour 90,70067,100 104,800 77,700 129 500 110,100 142,000 117,000 164,600 139;300 Model Nos. 90 90L 100 I00L no II0L 140 I40L 180 I80L 1001 Btu per Hour 189,200 151,600 234,000 196,000 259,000 211,600 320,000 271,000 368,000 294,000 Data Book cover ing other pressures and temperatures, dimensions and complete installa tion information on application: Address Grinnell Company, Inc., 277 ..West Exchange Street, Providence, R. I. s Grinnell Company, Inc. Heating and Piping Systems, Industrial GRINNELL ADJUSTABLE PIPE HANGERS AND SUPPORTS One of the chief advantages of Grinnell Adjustable Hangers is that they permit adjustment of pipe lines after installation, thus obviating the necessity of tumbuckles or the removal of hangers. Their time and trouble-saving qualities during installation are equally exceptional. Below are shown a few Grinnell Hangers and Supports of par ticular interest to heating engineers. Send for Hanger Catalogue showing complete line. Fig. No. 101 Solid Ring Adjustable Swivel Rings (Patented) These Malleable Iron Adjustable Swivel Rings can be used with Coach Screw Rod or Machine Threaded Rod in connection with practically any type of Ceiling Flange, Expansion Case, Insert, etc. Adjustment of at least 1in. is secured by turning Swivel Shank. Swivel Shank automatically locks, preventing loosening due to vibration in the pipe line. ' The Split Ring permits adjustment either before or after Ring is closed. A wedge type pin is loosely but inseparably cast into the hinged section for fastening this section after pipe is in place. Fig. No. 104 Split Ring Fig. No. 174 ' Swivel Pipe Roll Adjustable Swivel Pipe Rolls (Patented) An adjustable type of pipe roll using a single hanger rod. Swivel Shank allows vertical adjustment and automatically locks, preventing loosening from vibration. CB-Universal Concrete Inserts (Patented) Made of air furnace malleable iron, in one body size, to take a special removable nut, tapped for % in., yi in., % in. or AZ in. rod as required. Nuts automatically lock by means of V-type teeth on both insert and nuts. Fig.N0.t8t CB-Unitersd Insert GRINNELL WELDING FITTINGS 90" Elbotp. Long Turn Grinnell Welding Fittings are made from Seamless Steel Pipe or tubing and possess the same physical characteristics as stan dard, extra strong and o.d. steel pipe or seamless steel pipe of comparable size. They can be used under the same con ditions, pressures and temperatures as the pipe itself. Welding faces for all plain circum ferential Butt Welds are scarfed or beveled to the regulation 45 deg. angle with Ag in* square end on inside of fitting. Angles of bevel other than 45 deg. can be furnished on special orders. Wtiding Ouild Welding Tee Lop Flanged Wddino Neck . 1002 ' Threaded Outlet Heating and Ventilating Units John J. Nesbitt, Inc. Holmesburg, Philadelphia, Pa. * 11 Park Place, New York City Manufacturers of THE NESBITT SYNCRETIZER Heating and Ventilating Unit, sold by John J. Nesbitt, Inc., and American Blower Corporation; NESBITT HEATING SURFACE with Steam-distributing Tubes, sold by leading manufacturers of fan-system apparatus; WEBSTER-NESBITT UNIT HEATERS (for details see page 1127), distributed in the U.S.A. by Warren Webster & Company. The Nesbitt Syncretizer Series 400 The last word in heating and ventilating units for schoolrooms, offices, etc., where the continuous introduction of outdoor air is desired. Made in three types or cycles of control, to circulate all outdoor air or varying percentages of outdoor air. Fully automatic. Doubly controlled by a room thermostat and the Nesbitt Air-Stream Minimum Temperature Control, to pre vent drafts and overheating and to har monize (syncretize) air-stream and room temperatures. Available in models to deliver from 750 cfm to 1560 cfm, ane mometer rating^ Modem in appearance; quiet; economical. Nesbitt Syncretizers may be installed for today under conditions which require all outdoor air, and the cycle of control adjusted for tomorrow when conditions permit recirculation of room air. Nesbitt Syncretizers are sold by Ameri can Blower Corporation, as well as by Nesbitt representatives. For engineering data, get Publication No. 225; for "The Story of Syncretized Air," Publication No. 226. Nesbitt Series B Thermovent For Large Interiors For heating and ventilating auditoriums, gymnasiums, assembly halls, and similar gathering places, there are the Nesbitt Series B Thermovents, in capacities of from 2000 cfm to 6000 cfm, anemometer rating--Publication No. 227. Nesbitt Heating Surface with Steam-distributing Tubes Copper tube and fin heat transfer sur face perfectly adapted to close, continuous automatic control with modulating steam valves. Revolutionary steam-distributing tubes within the condensing tubes carry the steam equally to all parts of the section, thus assuring UNIFORM discharge tem peratures, even under throttled steam supply; eliminating temperature stratifi cation; preventing tube freezing without preheaters; giving ideal system results. The man above is holding a steam-dis tributing tube from Nesbitt Surface. Strong and lasting, built to withstand test pressures up to 200 lb gauge. Avail able in cased or uncased units of many sizes and capacities, to meet every need. Sold by many leading manufacturers of fan-system apparatus (list upon request). Send for Publication No. 229 which con tains full particulars and engineering data. 1003 Heating and Ventilating Units The Herman Nelson Corporation General Offices and Factories at Moline, Illinois Sales and Service Offices in all Principal Cities Heating and Ventilating Equipment for Schools and Industrial Plants Herman Nelson Air Conditioners for maintaining comfortable and healthful conditions in school class rooms consist of heating element, filter, cabinet, air intake, fan and motor unit and two sets of dampers --all designed and arranged to pro duce efficient heating and venti lating at low cost. One Herman Nelson Air Conditioner is all that is normally required. in a classroom. Other Herman Nelson equipment especially designed for large rooms, auditoriums and gymnasiums is available. Herman Nelson hijet Heaters The Herman Nelson Corporation manu factures a complete line of hijet Unit Heaters in two types, propeller fan and blower, hijet Heaters provide low cost heat and ideal working temperature for all types of industrial and commercial build ings. Dependability and efficiency proved by actual performance in thousands of installations. Suspended Type .Available in eight sizes, each with single speed, two speed or three speed operation on single phase 25, 50 and 60 cycle, 110 or 220 Volt current. Also for single or multi-speed operation on 115-130 or 230-260 Volt direct current. Three phase motors for larger models for 25, 50 or 60 cycle, 220 or 440 Volt current. Type D Available in ten models. Each model in two depths, 21 and 32 in. The 21 in. unit can be furnished with two, three or four fans, and the 32 in. unit with two or three fans. High or low capacity heating element available. Furnished normally with direct connected motors, but equip ped with V belt drives if desired. CATALOGUES AVAILABLE on both Herman Nelson Unit Ventilators and Unit Heaters. For Complete Information and Specifications Write to THE HERMAN NELSON CORPORATION, MOLINE, ILLINOIS. 1004 Heating and Ventilating Units The Herman Nelson Corporation General Offices and Factories at Moline, Illinois Sales and Service Offices in all Principal Cities Complete Line of Automatic Heat and Air-Conditioning Equipment Ok Oil Burning Air Conditioning Furnace Features induced draft and extra long flue passages with fins spaced logarith mically for eco nomical operation. Thermal damper control prevents de livery of cold air to rooms. Four sizes. Conversion Oil Burner "Prize-winning design incorporates many ex clusive features to pro vide low cost operation with high heating ef ficiency. Fully en closed. Four sizes. Oil Burning Boiler Efficient oil buming mechanism operating as a com ponent part of boilej-burner unit providing depend able operation. For steam or hot water. Six sizes. Gas Burning Air Conditioning Furnace Induced draft mechanically pro vides air for com bustion and positive discharge of spent flue gases regardless of natural draft conditions. Three sizes. Oil, Coal and Gas Furnaces provide for the simple addi tion of summer air conditioning. Automatic Stoker Oil motor trans mission. Extra heavy sectional tuyeres and worm. Automatic shut-off,. no sheer pins. Three sizes. Coal Burning Air Conditioning Furnace Heavy welded and riveted heating element and radia tor. Sturdy con struction assures long life. Three sizes. Self-Contained Cooling Unit % ton capacity. Di mension: 31% in. x 30 in. x 15% in. Reciprocating type Freon compressor. Attractive appearance. Year Around Air Conditioning Units These units are used with radiated heat systems (steam or hot water) to provide winter and/or summer air conditioning in stores, offices or homes. Type Y For residential use. Suspended from ceiling to con serve space and simplify duct con nection. Two sizes. Type X For commercial installation. Fur nished for floor or ceiling mounting. Durably construc ted to provide q uiet, trouble-free opera tion. Three sizes. CATALOGUES AND FOLDERS Available. For Complete Information and Speci fications Write to THE HERMAN NELSON CORPORATION. MOLINE. ILLINOIS: 1005 Heating Systems (Hot Water) Bell and Gossett Company 3000 Wallace Street Chicago, 111. HOT WATER SYSTEMS AND SPECIALTIES B & G INDIRECT WATER HEATERS FOR STEAM AND VAPOR SYSTEMS Ratings below are based on 100 deg rise in three hoars with boiler water temperature of 1*0 deg or more - Description SINGLE COIL all sizes. Uuplex apartments and small buildings. DOUBLE COIL For larger apartments, garages, medium sized factones and office buildings. TRIPLE COIL bor heavier requirements. HORIZONTAL TUBE Heaters No. Capacity Gallons Max. Length Inches Max. Shell Coil Shipping Width Openings Opening* Weights Inches Inches Inches Pounds 30 30 n% 5)6 1 % 40 40 12% 5% 1 % 52 52 14% 5% 1 % 70 70 16% 5)6 1% % 90 90 18% 2% 1% 1 100 100 20% ?'/. 1% 1 120 120 22% 2% 1% 1 150 150 25>/. 2'/. 1% 1 12 13 15 18 40 44 47 52 160 160 12 11% 200 200 14% 11% 300 300 19% 11% 400 400 25% 11% 500 500 27 11% 600 600 21% 153/4 800 800 25% 153/4 1000 1000 29'/. 15% 1200 1200 46% 17 1600 1600 53% 17 2000 2000 61% 17 2 2 2 2 2* 3 3. 3 4 4 6 1% 1% 1% 1% 1% 2% n 3 3 3 61 72 100 120 210 234 250 217 238 260 B & G TANKLESS HEATER This B & G Tankless Type Heater has been designed to fulfill a need for a heater of unusual capacity that could be installed in boiler rooms lacking space for storage tanks. For all Steam, Vapor and Hot Water Heating Boilers Series Number 12 16 20 30 Coil Openings % % %% Shell Openings r 2%' 2y%' Boiler Water Capacities 180 F 200 F 212 F 110 175 225 145 246 305 175 300 375 250 430 516 Length 32" 36' 36' 48* Diameter 12' 12' 12* 12* Shipping Weight Pounds 106 119 132 172 B & G THERMO-VOIR The Thermo-voir eliminates the need for constantly maintaining heat in the boiler, as required by the ordinary in direct heater. The water stored in the reservoir absorbs heat from the boiler during "off" periods of the burner, there by reducing stand-by loss to a minimum. It permits the boiler to cool off almost completely if there is no demand for hot service water. For the first time, modern boilers with small water content and large heat absorption can be economically used to indirectly heat Domestic Water. . in., B & G MONOFLO FITTINGS The Monoflo Fitting makes a one-pipe hot water heating system truly practical. This device, when installed in place of the tee at each radia tor's connections to the main, diverts hot water to the radiator and re: turns cooled water to the main. It assures correct distribution of water in either gravity or mechanically circulated systems. Sizes l in., in.. 2 in., 2)^ in., 3 in. 1006 Bell and Gossett Company Heating Systems (Hot Water) Size No. Inches 1 1% 1% 2 2% 3 L.D. 3 B & G BOOSTER Face To Face Dimensions Inches Pipe Size Inches Motor Hp 110 Volt 60 Cycle Delivery i Approx. Gallons 1 Shipping per | Weight Minute ; Pounds 8% 8% 8% 8%9% 9'/* 12 1 flanged 1V* Hanged V/r Hanged 2 flanged 2`/? Hanged 3 flanged i flanged 1/6 1/6 1/6 1/6 1/4 1/4 1/3 20 i 57 30 j 68 48 70 ! 70 72 100 78 115 i 82 147 | 136 B & G FLO-CONTROL VALVES Easily opened for gravity circulation by merely .turning with the fingers the external wing extension of the valve stem. STRAIGHTWAY PATTERN 1 in. 1% in. 1% in. 2 in. 2% in. 3 in. Conn's Weight Screwed 2 ends 5 1b Screwed 2 ends 5!b Screwed 1 end Manged 1 end 17 lb Ranged 2 ends 25 lb Ranged 2 ends 33 lb Flanged 2 ends 56 lb Conn's Weight Screwed 2 ends 41b ANGLE PATTERN Screwed 2 ends 41b Flanged 2 ends 171b Flanged 2 ends 23 lb B & G TRIPLE DUTY SYSTEMS A combination of B & G Booster, B & G Flo-Control Valve and B & G Indirect. Heater, with the proper electrical controls comprises a B & G Triple Duty System. D & T SIMPLEX AND SELF-FILLING "TANK-IN-BASEMENT" SYSTEMS *3= tostsi7 D & T Simplex System consists of an air-tight D & T Compression Tank, No. 600 Valve SQ Simplex Volte D & T Simplex Relief Valve and D & T Unit which performs the double duty of Vacuum Breaking Valve. Capacities up relieving excess pressure and keeping the to 4500 sq ft of radiation. system filled with water. Capacities to Self-Filling Air-Cushioned Tank Equip 4500 sq ft of radiation. Tanks can be in ment consists of a D & T Compression stalled either on floor or exiling. Tank and a D & T No. 500 "All-in-One" B & G THERMOCHEK B & G NO. 3 Controls automat DUAL UNIT ically the temperature A Relief-ReducingValve of hot water storage at moderate cost. Body tanks heated by in and all parts exposed to direct heaters. Pre water are bronze. Extra- vents lime and sediment forma large chemically treated tion in the heater coils. Sizes composition diaphragm. in. and 2 in. 1007 Heating Systems (Hot Water) Taco Heaters, Incorporated 342 Madison Avenue, New York TACO HEATERS, Inc. offers a complete line of water heating specialities for domestic hot water supply on steam, vapor and hot water boilers. Also specialities for hot water heating systems, including Taco Circulator, Tank-in-Basement System, and fittings for one-pipe systems. TAGO-ABBOTT SYSTEM For Domestic Hot Water Supply on Steam and Vapor Systems makes possible efficient year * round operation of a steam or vapor heating boiler to supply Domestic Hot Water. This patented System provides for automat ic control of the heating boiler in such a manner that when the room temperature reaches the desired point, control of the firing device is transferred from the room thermostat to an aquastat --operated by the water in the boiler. This aquastat controls the boiler water at a sufficiently high temperature to heat the do- Domestic Taco c Tankless Taco No. 14 mestic water without producing heat in the radiators. CAPACITIES, DIMENSIONS AND SHIPPING WEIGHTS OF TACO HEATERS Size of Taco A .Gallons in 3 Hours Heated Sq. Ft. Hot from 40 F to 140 F Water Radiation Below Water Line On . Below* On** fBoiler Boiler Water from Water at 160 to 212 F 190 F Steam Water of 0 Lb Line Gauge Boiler at Pressure 212 F Steam of 0 Lb Gauge Pressure B C DEF Size of Taco G Pipe Connections Boiler Conn., In. Tank Conn.,1 Height, In. Diameter. in. Shipping Weight. In. H 1\1 K. 1 L DOMESTIC TACO 00 0 30 1 IA IB 2 2A 2B 2C 3 3A 30 00 30 40 15 20 0 30 50 20 30 30 40 52 30 to7o5 30 40 50 1 65 IA 66 30 to 40 125 82 40 to 52 150 50 60 to8o5 IB 2 100 175 75 125 2A 120 225 90 150 2B 144 82 to 100 275 105 175 2C 160 100 to 120 300 120 200 3 200 120 to 144 375 150 250 3A 1 1 I 1 1 iy. iy. 1i1y1%/.. 2 >? % V, 8/2 8y. 5% 5% % 10 y. 12 Iff y. 15 >/l 1 14 Wi 1 l6'/2 1 18% 4 1 21% 7Vi I l9'/2 9 VA iy. 21V. 26 9 9 10 10 12 14 18 22 27 31 34 50 65 80 M 60 M 75 M 100 M 125 M 150 M 200 . 250 300 400 500 600 800 120 to 185 150 to 220 200 to 300 250 to 360 300 to 430 400 to 570 450 600 750 900 1200 1500 MULTI-COIL TACO 210 300 M 60 2 250 400 M 75 2. 320 500 M 100 Z'A 420 600 M 125 2% 500 800 M 150 3 640 1000 M 200 3 !% II i% |3% 2 3% 2 15% 2% 16 2% 20% 9% 9;/e . 12 12 'Va 14% 75 84 . 120 140 205 255 Based on 120 F inlet temp, to heater and 160 F outlet temp. Based on 140 F inlet temp, to heater and 180 F outlet temp. tYeara of experience affirm our conviction that for best results a liberal size Taco should be selected. Installing a slightly larger Taco than is absolutely necessary makes possible lower aquastat setting and consequent fuel saving. This more than pays for the slightly additional initial cost. TANKLESS TACO Nos. 14, IS, 16, and 18 Tankless Taco No. 14 recommended for 1-2 baths; T. T. No. 15 and No. 16 for 1-3 baths; T. T. No. 18 for 2 - 4 baths. Write for complete information. .. Taco Tempering Valve is available in following sizes H. 1. IK. IK and 2-in. 1008 Taco Heaters, Incorporated Heating Systems (Hot Water) TACO TANKS Galvanized (copper bearing steel) 300 lb test pressure; 127M lb working pressure. CODDer. Monel Metal nr Rvprrflir 5fiA lh iMt nrMClir* 1 HRIX IK nrnririna nriu-cnra Capacity, Size Gal In. 40 16x48 52 >6x60 66 18x60 82 20x60 100 22x60 120 24x60 144 24x72 180 30x60 Tank Conn., In. 6-1 6-1 6-1 6.P/2 +!% 6-15? Gauge Metal Galvanized Shell Head IOg^-% l0ga--^4 IOg*--!6 9ga--& 7 ga.-K 7 7ga.4& 7 ga.-K 7ga.4& 7a.4ia 3g*--y. 3 ga.-y4 3g;>-% Unit Heating Surface. Sq Ft In. 6 6 6 71/2 7% 7Vi 9 13% 2 2 2 2 2 2 2 3 Capacities, Gallons in 1 Hour Heated from 50 to 150 F Below Water Line Boiler Water at 212 F Boiler Water at 180 F Heated 50 to 180 F Steam 0 Lb Gauge 1 Pressure Shipping Weight, Gal vanized 80 40 80 40 80 40 too 50 100 50 100 50 120 60 180 90 120 167 120 190 120 21! 150 260 150 301 150 389 180 444 270 590 TACO SPECIALITIES offer a complete line for gravity and forced circulation one and two-pipe hot water heating systems. The Taco Hy-Duty Circulator makes it possible by high efficiency to take full advantage of small pipe sizes. It delivers 20 gal per minute against a 10 ft head, equivalent at 20 deg temperature drop, to 200,000 Btu. Taco also offers a complete line of circulators of standard performance. Other Taco specialities for hot water heating systems include Taco-Flow- Check, Taco Relief and Reducing Valves, Taco Expansion Tanks, and Taco Venturi Fittings. "TACO-ONE** VENTURI SYSTEM--for one pipe hot water heating is recommended for both new and renovation work because of its simplicity--and saving of labor and material costs. Even and quick distribution of heat are among Taco Hy-Duly Circulator its important advantages. This system is a combination of Taco Hy-Duty Circ,,1'>tor, Taco Venturi Fittings and other Taco Heating Specialities. The Taco Venturi fitting connected to return branch from the radiator creates a suction effect on water within the radiator. Supply branch to radiator is connected to main by regular tee. KEY -'TACO-ONt'VtlTTUAI FITTING -*TACO-Oe' HY-DUTY CIRCULATOR With Taco-One Venturi Sys tem, the efficiency of the com bination of the Taco Hy-Duty -'TACO-ONE'CHECK VALVE Circulator and the Taco Venturi fitting makes it pos sible to meet the vast majority of installation require ments with a single circuit of pipe. With most jobs, totalling less than 1000 sq ft of radiation, main length not over 125 ft and not more than 12 Venturi Fittings, only a single circuit with in. Venturi Fittings and main is required. F 11C AA rtf f*lrtl 11. 1*.. .. n1. a f ' I "-- ma If. _ A _ -- I _ .f * . ,t , , Maximum Radiation FOR VARIOUS 6.T.U. EMISSIONS ANO WATER TEMPER ATURE5 150 too t+o 6.T.U. 6TU 0.7.0 1T5* ZOO* tis* WATER WATER WATER Maximum LENGTHSf LONGEST CIRCUIT IN FEET Maximum NUMBER OF Size Of VENTURI MAIN SUES TACO FITTINGS HY-ourr TO BE USED CIRtULATW ON SYSTEMS SINGLE DOUBLE CIRCUIT CIRCUIT Size Radiator OF BRANCH VENTURI AND RISER FITTINGS PIPE SIZE ONE CIRC DOUBLE CIRCUIT CIRCUIT TRUNK CIRCUITS SEE NOTE`A' Maximum Amount of RADIATION PER VENTURI FITTING FOR VARIOUS B-T.U EMISSIONS AND WATE R TEMPERATURES SINGLE T0TALTWO RA0S RADIATOR ABOVE tfMN OR AD0VE MAIN ONE BELOW RAIN ISO zoo 2+0 ISO 200 2+0 BTU 6 T.U 6.T.U BTU. 6.T.U. BXU nv ieo* ZIS* nr 2W US* 500 375 300 100 IV 12 I2-KRC1& r IV r . V T5 56 46 60 45 38 1000 1000 750 750 (.25 St 5 125 125 IV 12 12-motc UV IV IV IV* v IV 12 12-ferqrc IV IV IV IV* w Vlm 1O0 75 62 eo 60 50 VC ISO 112 94 120 90 7S 1000 750 625 <50 IV 12 i2-mcuc IV 2* IV IV.W vr too 75 62 eo 60 50 1000 750 625 150 IV 12 12-mcttti IV 2- IV IV .w VC ISO 112 94 120 90 T5 Where supply and return branches to radiators exceed 8 ft 0 in. in length, branch size should be increased one size beyond those shown. For most installations not more than one half of total job should be installed below main, and in no case should branches to radiators below main exceed 9 ft 0 in. in length. Care- must be taken in installing radiators below main on two-circuit jobs. For such installations, it is suggested that full information be sent to Taco Heaters, Inc., for layout. ` 1009 x Heating Systems (Hot Water) H. A. Thrush & Company Peru, Indiana Service and Sales Offices in Principal Cities THRUSH FLOW CONTROL SYSTEM Thrush Flow Control System of Warm Water Heating is more com pletely automatic than . was ever before offered for residential heating. The illustration shows the ten Thrush devices which make up this system. 1. Thrush Flow Control Valve. 2. Thrush Water Circulator. 3. No. 4 Thrush Differential Pres sure Relief Valve. . 4. No. 12 Thrush Pressure Re ducing Valve. ' 5. Air-tight Thrush Pressure Tank. 6. No. 5K)1 Thrush Radiant Heat Control. 7. No. 198 Thrush Relay Trans former. 8. No. 203 Thrush Modulating Boiler Water Temperature Con trol. . 9. Special Combination Thrush Gauge and Thermometer. 10. No. 75 Thrush High Pressure Relief Valve. Thrush Flow Control System assures a continuous flow of radiant heat, reduces fuel consumption and provides domestic hot water for bath, kitchen and laundry the year around as a by-product. On new work it permits^the use of small pipe and valves which completely offsets the cost of the Thrush equip ment. . Thrush Water Circulator Class FC Flow Control System--Flow Control Valve and Circulator Only Description Up to Up to Up to Up to Up to Up to Up to 300 sq ft 500 sq ft 800 sq ft 1000 sq ft 1500 sq ft 2500 sq ft 5000 sq ft No. No. No. No. No. No. No. Valve.................. 114 l' I14A 1/4* 115 IVi' 115 IVi' 120 2* 125 W 130 3* culator................ 14 1* 14 1' I4A I*// 15 l% 15 1'/>' 22 2' 23 y Class FCC Flow Control System-- Complete Circulation, Temperature and Pressure Control No. Valve.................. 114 1' culator................. 14 1* No. No. No. No. 1I4A l%* 115 IVi' 115 l*/2* 120 V No. 125 2*/2* No'. 130 y 14 1* I4A W 15 IVi' 15 I'/i' 22 2' 23 y Relief Valve........ 4 Valve................... 12 Thrush Pres. Tank. D Vf 4 >/.' 12 0 Vf 4 Vf i2 1 Vf 4 y.' 112 '/,' 4 >/' 212 Vf 4 Vf 12 3 y4* 4 Va* Vf 12 Vf 2-No. 3 Heat Control.... 201 i hrusb Modulating 201 201 201 201 201 201 perature Control. 203 1 hrush Kelay 1 runsformer................. 198 203 198 203 203 203 203 203 198 198 198 198 >98 1010 Heating Systems (Hot Water) H. A. Thrush & Company Peru, Indiana Service and Sales Offices in Principal Cities Sizes and Capacities Thrush Flow Control Valves No. 114 II4A 115 120 125 130 Size r I Vf 2i'"/2' wy Connection Screwed Flanged Hanged Flanged Flanged Hanged Radiation Capacity 500 sq ft 1000 sq ft 1500 sq ft 2500 sq ft 5000 sq ft | Shipping Weight 1 3 lb 1 16b : 171b 191b 26 lb :1 391b Sizes and Capacities Thrush Water Circulators No. Size 14 1* Screwed I4A 1*4* Hanged 15 l */i" Hanged 22 1~ h ianged 23 y h Ianged Motor 1/10 hp 1/10 hp 1/8 hp 1/6 hp 1/4 hp Gallons Delivery 25 per min 35 per mm 50 per min 75 per min 140 per min Radiation Capacity 500 sq ft 800 sq ft 1500 sq ft 2500 sq ft 5000 sq ft Storage Tank Capacity 750 gal 1000 al 1500 gal 2000 gal 3000 gal End to End Dimensions 8%* 9*4* 10*4* IO>/8' II'/j' . Use next size larger Circulator for conversion jobs. Capacities of Circulators equipped with standard 110 volts. 60 cycles, single phase, a-c motors. No. 4^ No. 4 Thrush Differen tial Pressure Relief Valve provides absolutely safe re lief of excessive pressures. No. 201 Thrush Radi ant Heat Control auto matically controls circula tion of water so that warmth of radiators is constantly maintained. No. 12 Thrush Pressure Reducing Valve automati cally fills system and main tains proper amount - of water at all times. No. eos Thrush Modulating Boiler Water Tempera ture Control automati cally raises or lowers water temperature to meet the demands placed on the heating system by changes of outdoor temperature. 1011 No. 198 Thrush Relay Trans former for use with low Voltage No. 201 Thrush Radiant Heat Control. S'. Instruments The Bristol Company Waterbury, Connecticut ' Branch Sales and Service Offices Akron, Ohio Birmingham, Ala. Boston, Mass. Chicago, III. Detroit, Mich. Los Angeles, Cal. New York City Philadelphia, Pa. Pittsburgh, Pa. San Francisco, Cal. St. Louis, Mo. Seattle. Wash. The Bristol Company of Canada, Ltd., 64 Princess Street, Toronto, Ontario Bristol's Instrument Co., Ltd., North Circular Road, London, N.W. 10, England A COMPLETE LINE OF INSTRUMENTS FOR CONTROLLING, RECORDING AND INDICATING TRADE-MARK BRISTOL'S REO. U. 6* PAT. OFPICS FLOW METERS, ELECTRIC AND MECHANICAL For indicating, recording, automatically controlling, and integrating flow of steam, air, gases, liquids. Electric Flow Meters telemeter measurements of flow any dis tance up to several hundred miles. Catalog No. 1050. Recording and Indicating Resis tance Thermometers: For securing, at a central point, readings of a number of temperatures at distant points. Catalog No. 1451 and Bulletin No. 997. DIRECT READING RELATIVE HUMIDITY RECORDER - Shows trend of hu midity condition. No calculations or humid ity tables needed. Re quires no water, no fan. Portable, corrosion-re sisting case. Catalog No. mo. Right: Thermo-Humidigraph, Model 4069 Electric Flow Meter, Model M 1040 M Recording Pressure Gauge. Model 40M Mechanical Flow Meter, Model 1140MF RECORDING PRESSURE GAUGES For securing con tinuous records of pres sure, vacuum or liquid level for steam, air, gas, liquids. For ranges from full vacuum to 12,000 lb per sq in. Catalog No. 1014- WET- AND DRY-BULB PSYCHROMETER Records wetand dry-bulb temperatures in kilns, drying rooms, air ducts. Self-contained and distance types:* Mois ture-, fume-, and dust-proof case. For wall, and flush panel mounting. Cat alog No. 1250.. Wet- and Dry-Bulb Psychrometer, Model 4S40M Recording Ther mometer. Model S40M RECORDING AND INDICATING THERMOMETERS Recording Ther mometer: For all commercial ranges from 60 F below to 1000 F above zero. For wall, flush or panel mounting. Cat alog No. 1250. INDUSTRIAL STEM THERMOMETERS Plain or red background. With fixed thread, union connection or socket design. Straight form, or near oblique, right side and left side angle formsT Also portable stem thermometers with ring top, ring handle top, or adjustable stem handle forms. Fenestrated guard or plain bulb. Catalog No. 1250. 1012 . ,, . Instruments Consolidated Ashcroft Hancock Co., Inc. Bridgeport, Conn. BRANCHES IN PRINCIPAL CITIES Makers of AMERICAN INDUSTRIAL INSTRUMENTS--Since 1851 Manufacturers of Indicating and Recording Gauges; Gauge Testers; "lP' Gauges; Draft Gauges; Indicating and Recording Thermometers; Tachometers; Dial Thermometers; Pressure and Temperature Controllers; Electric Temperature Controllers; Pop Safety and Water Relief Valves; Steam Traps; Engine Indicators; Counters; Absolute Pressure Gauges. Also manufacturers of Bronze. Cast Steel and Forged Steel Valves, Locomotive and Engine Room Clocks; Barometers; Mercury Column Gauges; Steam Whistles; Hydraulagraphs; Gauge Boards. Ashcroft American Gauges--Ashcroft American Gauges are made in all sizes from 2% to 12 in., for pressures from 8 oz to 25,000 lb and also for vacuum. Cases are cast-iron or cast brass. The move ments are Heavy Duty and all bear ings are Monel Met al. Write for Cata log No. A-59. Also Duragauges --accurate to within_H of 1%. Stainless steel movement. In Phenol Cases in 4x/i in., 6 in. and 8% in. dial sizes. For Mercury Pressure and Vacuum Gauges, "U" Gauges, Draft Gauges and Mercurial Barometers, write for Catalog B-59. Recording Duragauges--Recording Duragauges are made for all pressures from 15 in. of water to 10,000 lb and for vacuum. They are made in one size only to accommodate a 10 in. chart, having an effective scale width of Z% in. The case is Die Cast with a dull black hardrubber finish and with either bottom or back connection. The pen-arm is made of non-corrosive Monel Metal and is of the inverted type. Operating instructions are lithographed on the chart plate so that they cannot be lost. Write for Cata log E-59. American Air Duct Thermometer-Designed especially for both warm and cold air ducts. Fitted with chromium plated frame, glass front. Fur nished with 9-in. or 12-in. scale graduated 0-160 F. Write for Catalog F-59. American Recording Thermometers-- Made for recording temperatures from minus 40 to plus 1000 F or equivalent C. Very flex ible connecting tubing up to 200 ft. One size to ac commodate 10 in. chart, with an effective scale width of Z% in. Same case as for the American Recording Gauge, so that all instru ments are uniform in ap pearance when mounted on Gauge Boards. Write for Catalog H-59. American Dial Thermometers--Ameri can Dial (mercury-filled) Thermometer has the accuracy of the standard glass tube thermometer and the reading convenience of a dial face. Entire working mechanism is made of steel, meaning long life. Six sizes, ranging from 4H in. to 12 in. diameter dials. Furnished with rigid connection or flexible capillary tubing up to 200 ft. For temperature ranges from minus 40 to plus 1000 F. Write for Catalog G-59. American Precision Temperature Controllers-- Self-operated. For regulating temperatures from 2 0 to 475 F. For hot water service tanks, water heaters, etc. Size of valve must be speci fied. Write for No. 2200 Bul letin. Instruments Illinois Testing Laboratories, Inc. 422 N. LaSalle Street, Chicago, Illinois TESTING ENGINEERS AND MANUFACTURERS "Alnor" Indicating Pyrometers--Portable and Wall Type. "Alnor" Sur face Temperatures, "Alnor" Distant Reading Resistance Thermometers, "Alnor" Pyrometer Controllers, "Alnor" Velometers--Air Velocity Meters. Instruments Leeds & Northrup Company General office and works: 4941 Stenton Avenue, Philadelphia, Pa. Boston Cleveland Hartford Chicago Detroit Houston Branch Offices: Los Angeles Pittsburgh San Francisco New York St. Louis Tulsa RUGGED, NULL-TYPE INSTRUMENTS THAT ARE RELIABLE Fig. 1--Showing Tube Type Velometer with No. SSSO Angle Jet taking air velocity of grille. . Fig. --Showing Tube Type Velometer with No. 31^25 Duct Jet taking readings directly in the duct. Duct Jet furnished standard 18 in. or 36 in. long. Other lengths available on special order. "ALNOR" VELOMETER The Instantaneous Direct Reading Air Velocity Meter The Velometer is a direct reading instrument which gives accurate and instantaneous readings of the speed of air measured in feet per minute. The indicator or meter is housed in an attractive black Bakelite case in. x 5% in. x 2% in. and weighs approximately 2 lb. ... .. The movement consists of a swinging vane to which the indicating pointer is attached, control hair springs and a magnetic damping system. The air which enters the port or jet of the instrument exerts an impact or pressure on the vane which causes it with the pointer to deflect across the scale and is read directly in feet per minute velocity. No mathematical calculations or stop watches are necessary to determine the velocity reading as the pointer indications are a direct measurement of air speed. While the Velometer is offered in three types, the Tube Type is by far the most popular. This type uses attachments called jets for most of the velocity readings. The style of jet to be used depends on the requirements or purpose for which it is used. Ranges--Standard Range 0 to 300 fpm low scale, 0-3000 fpm high scale 0 to 2 in. static or total pressure. Other ranges available up to 18,000 fpm velocity and 20 in. pressure. No. 2215 Averaging Jet--This jet is offered for obtaining velocities of ordinary duct openings or grilles. With this jet, average velocity readings over a 4 in. circle can be quickly obtained. No. 2220 and No. 2240 Jets--These jets, angle and straight, have small orifices to give spot velocities over a in. diame ter. The Velometer with these jets pro vides accurate spot velocity readings of irregular shaped or slotted openings or other small velocity streams, locates leaks in duct systems and other similar service that would be difficult by other means. No. 2425 Duct Jets--These jets are offered for direct velocity readings in ducts. The Duct Jet is, in effect, a double jet using two tubes and two meter fittings. With this jet, static pressure is balanced out or subtracted from total pressure and the net result or velocity pressure is read directly on the scale of the Velometer in feet per minute. Thus no calculations are neces sary. Inch marks are provided on the jet for the convenience of the user. No. 2460 Static Pressure Jet--This jet provides direct readings of static pressures of ducts, plenum chambers or pipes in inches of water. No. 2485 Total Pressure Jet--This jet gives direct readings of total pressure, in inches of water. Inch marks are provided on this jet to enable the user to place the jet at the desired distance in the duct. Write for Complete Folder 1014 Model S Micromax Recorder Records from 1 to 16 points on a single stripchart. Extremely open record. Can operate signals. (About l/loth size) ' Model R Mieromaz Recorder Records 1 or points on a roundchart. Has extremely readable diaL Can operate signals. (About l/16th size) Switchboard Indicator Hand-operated. Can be connected through selector switches to any number of points. (About l/10th size) Electrical Thermometers for Air Conditioning Electrical Instruments for the Heating Plant No method for measuring temperatures fits the specific needs of air conditioning as does the three-lead null-type resistance thermometer method. It is independent of distance and disregards all tempera tures except those right at detector loca tions. The detectors (resistance thermo meter bulbs called Thermohms), can be placed anywhere--in rooms, air ducts or water lines. They are connected by simple electrical wiring to instruments at a central location. Instruments may be: Micromax Recorders, Model S for up to sixteen Thermohms; Micromax Model R, for related pairs such as wet and dry bulb; indicators with switches for any number of Thermohms; or indicating and recording combinations. The facts needed to operate a modern heating plant so as to save fuel, to protect equipment, and to operate efficiently at varying loads are provided reliably by rugged L&N instruments. Readings can be indicated or recorded or both. Re corders can be equipped to operate signals or alarms that warn the operator of extreme conditions. In some cases the instruments control automatically. Micromax Model S provides a per manent record of conditions at from 1 to 16 points on one wide-scale chart. Micro max Model R concentrates on conditions at one point, provides a permanent record, and has a giant indicating dial that can be read at a glance. The switchboard in This equipment is fundamentally re liable. Instruments and Thermohms are highly responsive, yet rugged in construc tion. A complete system is easy and economical to install, regardless of dis tances. It is easy to operate and demands minimum maintenance. Thermohms and instruments are interchangeable, and can be replaced without disturbing wiring or returning anything to the factory. dicator provides intermittent checks on conditions at one or several points. In the heating plant, L&N measuring, signalling or controlling equipment is used for: Metermax Combustion Control. Furnace Pressure Control. . Smoke Density Analysis. . L&N Resistance Thermometers make it possible to operate efficiently; to main tain comfort or correct process atmosphere constantly ... so that maximum return is realized on the conditioning investment. J-N-225(2) Flue Gas Analysis (Percent COj). Flue Gas Temperatures. Steam and Water Temperatures. Boiler-Furnace Temperatures. Electrolytic Conductivity of Water. 1015 Instruments The Liquidometer Corporation 38-16 Skillman Ave. Long Island City, N. Y. Tank Gauges, Liquid Level Controls Remote Reading Thermometers ADVANTAGES OF LIQUIDOMETER AND LEVELOMETER TANK GAUGES (1) Accurate check on liquid deliveries and consumption provided. Correct inventory constantly available. (2) Inaccurate and dangerous "gauge sticking" or "taping" methods elimi nated. (3) Tanks can be gauged without loss of pressure or vacuum. (4) Overflowing of tanks--and consequent losses eliminated. (5) Extra handling of liquids in many instances saved. (6) Costly shut-downs due to lack of fuel prevented. (7) Approved by Underwriters Labora tories, for gauging hazardous liquids-- fire and labor hazards cut down.- LIQUIDOMETER--THE 100% AUTOMATIC READING TANK GAUGE Liquidometers are self-contained. Large clock-faced dials provide completely automatic readings without the use of pumps, valves, elec- . trical energy, or other outside source of power, and they are not affected by specific gravity differences. They will gauge practically any liquid that will flow, light or heavy. Used on fuel oil tanks in residences, apartments, public buildings, indus trial plants, U. S. Army and Navy air and water craft, on freight and passenger vessels, and for other liquid gauging requirements. Direct Reading Models are used where remote reading is not required. On this type, the dial indicator is located on the tank itself, and a metallic bellows is used to seal the indicator from the tank, thus preventing escape of liquid, gas or pressure. Models are available to automatically control pumps, motors, signals or other devices for maintaining desired minimum or maximum liquid levels. LEVELOMETER TANK GAUGES (HYDROSTATIC) Levelometers utilize the principle of hydrostatic balance between the head of liquid to^be measured and a dial indicator--there is no liquid in the indi cator to expand or contract and create error. Dial indicators have large graduations and figures and, if desired, one dial indicator can be arranged to gauge a group of tanks. In this instrument the tank liquid traps and com- Ifn'Modcl presses air in an "air chamber"--the pressure de e meter pends upon the height of liquid in the tank, and this Master Model pressure is transmitted, through tubing to a metal Leveiometer bellows in the indicator unit; the slightest movement of the bellows operates the dial indicator. As air is required to insure correct readings, a manually operated pump is generally supplied, but, where compressed air is available, a valve may be substituted for the pump, thus providing a continuous reading gauge. Levelometers are made in a number of different models to suit various tank capacities and desired dial calibrations. Models for tanks under pressure also are available. We will welcome the opportunity to make recommendations for perplexing liquid level gauge problems. 1016 Instruments The Palmer Company Main Plant: 2506 Norwood Ave., Cincinnati (Norwood), Ohio Canadian Factory: The Palmer Thermometer Co., Ltd., King and George Sts., Toronto Manufacturers and Originators--"Red-Reading-Mercury" Thermometers 1 11U1\1 VIVID 1 D1\0 .rvuvuig auu Air-Conditioning with "Red-Reading- Mercury". Industrial style Thermom eters with 7 in., 9 in. and 12 in. case. Straight and various Angle styles. With Fixed thread, Union, Separable-socket or flange fittings. Standard ranges: --20 +120 F and +30 +240 F. Other ranges furnished. Guar anteed Accurate, strong and durable. With the RED column, these thermometers are very easy to read. For genuine, select ed-tubes, be sure to specify PAL- i M ER' thermo meters on your No. 827 next order. Psychrometers M. wnw 1UC1 UIUlllC ICIO Every engineer should carry this accurate type thermome ter around at all times. Handy and easy to read, with the RED column. Standard ranges: --30 +120 F. 0 +220 F. Can be furnished in maximum-registering style also. Wall Thermometers Can be used inside and out doors. This style made of bronze castings with white duco finish. Also furnished in chrome finish. With the RED column, it can be seen at a great dis tance. Other styles made. Has a graduated, accurate scale. For testing moisture in the air. Necessary on every Air-condition ing job. Pocket style, with Laboratory Ther mometers leather case. Wet and Dry bulb guaranteed accurate. For tests to be made at any time, these ther No. 18*40 Can be carried around to mometers are very valuable. make tests at any time. ROUND or LENS glass. From After the instrument is 6 in. to 16 in. length. Also longer swung, the temperature can lengths. All ranges furnished, be read at once because of with the RED column. Made the RED column in each of selected glass. Every ther tube. mometer PALMER furnishes is Aspirating Psychrometer No eieo a,n,In,cecall,ecdu artUnUd tureatieud so as not also furnished, with electric Thermometer to change with age or use. It operation a__n_Jd _all_s_o batter.y npa^,yrsr to kb,u,.y, thke,, kb-e_si-t. style. When you buy PALMER thermometers, you get selected glass tubes, which show a bright RED column. Only pure mer cury is used. The RED column is accomplished by reflection. Patented by Palmer. Specify PALMER "RedReading-Mercury'' Ther mometers when you want a good reliable thermometer. Precision Thermometers Have on hand a reliable test ther mometer in Fractional Divisions, so as to make very close and accurate tests. In }/& deg, H deg and 3^o deg divisions. With Test Certificate. Easy to read with PALMER "RedReading-Mercury" feature. The mer cury thermometer with a wide RED column. jivrowpjAWOTga;m u iw w a g ta ra No. 14200 Write for FREE catalog. Repairs Repairs to all makes of ther mometers with "Red-Read ing-Mercury" at no extra charge. 1017 A trial order will convince you! No. 1004* Instruments *laAjlor InAtm/nwni CornpxmieA Rochester, N. Y., U. S. A. IN CANADA--Taylor Instrument Companies of Canada. Ltd., Toronto NEW YORK CHICAGO BOSTON PHILADELPHIA PITTSBURGH CLEVELAND LOS ANGELES INDIANAPOLIS SAN FRANCISCO ST. LOUIS CINCINNATI TULSA DETROIT ATLANTA MINNEAPOLIS Manufacturing Distributors in Great Britain, Short & Mason, Ltd. London Taylor Instruments for Indicating, Recording and Controlling Temperature, Pressure, Humidity, Flow and Liquid Level Taylor Industrial Thermometers--with new "BINOC" Tubing --This line of thermome ters includes many styles and scale ranges with *leader bine in the same case an electrically - operated temperature controller with an indicating ther mometer. One tube sys tem operates both units. bulbs for every applica tion. Suitable for air ducts, kiln temperatures and oven tem peratures. But these thermometers con tain a new and radical develop ment of tremendous importance The New Taylor "Fulscope" Recording Controller--An air-operated controller that gives practi cally any character of process control, regardless of time lag in apparatus. --"BINOC" Tubing. This newly Available for controlling temperature, designed and optically correct pressure, humidity, rate of flow, liquid glass tubing assures an ease of level. Where reading that has been generally extreme load lacking in industrial thermome changes or ters. "BINOC" Tubing more badly balanced than doubles the angle of vision' operating con within which readings can be ditions exist, made. Because of the patented the Taylor Triple-lens construction, its * ` D ub l-Re broad, contrasting mercury col sponse Control umn can be read easily and ac Unit" is the ' curately with both only positive eyes at close range means of main and also at greater taining con than normal dis trol-point. tances.' Bore reflec Writefor tion is absent. literature. Taylor Record ing Thermome ters--Temperature ranges and time re quirements vary greatly in heating and ventilating work. Taylor Re corders are made in needed scale ranges and time periods. These instru ments are beautiful and efficient, par ticularly adapted for heating and air con ditioning applications. They may be had for surface or flush mounting. The polished flanges make an effective panel board installation. Taylor Electric Contact Tempera ture Control--These instruments com* New Taylor Indicating "Fulscope" Controller--For those control applica tions where a highquality air-operated controller is desired for close and sensi tive regulation, but a record is not required, this instrument is available for temper ature, pressure, flow and liquid level. TaylorType-P Controller--A compact and very sensitive air-operated con troller, ideal for airducts, air-washing machines, cooling rooms and similar applications. 1018 Taylor Instrument Companies Instruments Taylor Self-Acting Temperature Con troller -- Adapted for use on hot-water storage tanks, etc. It requires no auxiliary motive power, such as compressed air, to open and close the steam valve. The valve can be closed at any desired temperature, or a throttling action can be obtained. Not practicable on pipe lines having steam pressure over 125 lb. Taylor HamptonModel Humidi- guide (DirectReading)-^. hygro meter giving direct humidity percent ages, in a smart modern case suita ble for home, office or public buildings. Finish is rich brown. The Permacolor Thermometer is filled with non-fad ing, easy-reading red liquid. Taylor Dial Thermometers for air ducts or any application where it is desirable to have temperature readings at some distance from the thermometer bulb, as in a central con trol room. Can be read at a glance as easily as a steam gage. Taylor Sling Psychrometer--The advantage of this form of Wet- and Dry-Bulb Hygrometer over the stationary form is the facility with which tests caii be made and the accuracy of the readings obtainable, as in whirling the bulbs they are subjected to perfect circu lation. Consists of two ac curate etched stem ther mometers mounted on a diecast frame, with the bulb of one covered with a wick to be moistened. These thermometers have scales of 0 to 100 F, gradu ated in deg divisions. A copper case protects the tubes when not in use. Taylor Anemometer--This instrument is ideal for measur ing air velocities with the fan revolutions indicated on the dial. Available in various models for a wide range of air speeds and registration limits. Taylor Re cording Hy grometer-- This instru ment records both wet- and dry-bulb tem peratures on the same chart in different colored inks, making com parison very easy. Type shown above with motor-driven fan for con ditioned rooms or passages in which circu lation is poor. Can be supplied without' fan for installations where circulation across bulb is good. Taylor Humidiguide--A hand some small hygro meter for the wall of the home, office, school or other building where a neat, easy-reading and inexpensive instrument is de sired. It is selfcontained, requir ing no charts or separate tables. Frame is Ma hogany Bakelite. For complete information on above inr struments and others designed for heating, ventilating and air conditioning, send to any of the offices listed on the previous page for new Taylor Catalog Number Five. 1019 Instruments ' =fVaA OAUOC CO. = (jn &AdicaJnfyxinxL %u&idmq, fyeMuM, Qajuqjt&. 44 B E AV E R STREET NEW factory tiudsviue Ptnnsylvania RANCHES- NEW TORE-CH1CAOO FHIlAOtlfHIA IOETON CLEVilAN D OETROIT ST. LOUIS HOUSTON SEATTLE LOS ANOELIS ONTEAV YORK U. S. GAUGES--U. S. Gauges are made in all sizes from 2 to 12 in. inclusive for pressures from 1 lb up to 50,000 lb, and for vacuum. Cases may be cast-iron, cast brass, drawn steel and drawn brass for wall mounting or flush mounting. For severe service long wearing hardened steel or bushed movements may be supplied. For service on Steam Heating Systems-- Steam Gauges . . . Compound Pressure and Vacuum Gauges . . . Retard Gauges . . . Compound Retard Gauges . . . Steam Gauges with Internal Siphons. For Hot Water Heating Systems-- Altitude Gauges . . . Tank-in-Basement Gauges . . . Altitude and Pressure Gauges . . . Combination Altitude Gauges, and (a) Bimetal Thermometers, (b) Glass Tube Thermometers, (c) Vapor Tension Distance Type Thermometers . . . Glass Tube Hot Water Ther mometers. U. S. RECORDING GAUGES--U. S. Recording Gauges are made in 8J^, 10 and 12 in.-sizes for pressures from T lb up to 50,000 lb, and for vacuum. Cases may be cast-iron or cast brass for wall mounting or flush mounting?' Pen arms are made of non-corrosive metal. Especially designed clock movements are used. Charts can be furnished for customary time periods.. ' U. S. DIAL THERMOMETERS--U. Si Dial Thermo meters are of the vapor tension type with open scale reading in the central and upper portion of the scale. Cases may be cast-iron, cast brass, drawn steel or drawn brass for wall mounting or flush mounting. Supplied in all sizes from 2 to 12 in. inclusive, for temperature rangesifrom 40 E to 800 F. Furnished with rigid connection bulb or with flexible capillary tubing up to 100 ft long. 1020 Insulation Aluminum Aircell Insulation Co. Curtis Bldg., Detroit, Mich. Supplied in sheets, rolls, and made-to-size packs to suit all applications. Licensed under Patents: 1,75 7,479--1,890.41 8-- 1,984,174. others pending. REFLECT-O-CELL is the successful production of insulating material inher ently incorporating the Dewar Principle of insulation as exemplified by the Dewar flask (Vacuum or thermos bottle). Sound scientific measures are therefor embodied in providing a thermal seal. REFLECT-O-CELL combines the rec ognized insulating properties of aluminum foil with the established thermal charac teristics of uniform still air spaces formed by corrugated insulating paper. The benefit of the metal and paper combination is mutual: the paper offering a convenient and efficient form for applying aluminum foil as thermal insulation while the metallic protection of aluminum furnishes construc tion permanence to the Hermetex insu lating paper. The unique design of REFLECT-OCELL permits both surfaces of the foil to function as heat barriers, resulting in economical insulation through the form ation of multiple spaces faced on one side with a metallic heat reflective surface. Supplied in conveniently scored con tinuous roll sheets it is installed in struc tural spaces, or, in packs, can be applied to any construction. Ease of application, low cost, light weight and high efficiency are responsible for the wide acceptance of REFLECT-O-CELL in the production of insulated busses, trucks, and house trailers by General Motors Truck Corp., Ford Motor Co., Fruehauf Trailer Co., Covered Wagon, Palace Travel Coach, and others. Similar satisfactory insulation service has been rendered in residences, industrial buildings and processing equipment. Thermal Efficiency determined at the University of Detroit under humidity conditions prevailing in actual use--0.27 Btu for a single layer. Moisture Sealing which effectively reduces summer dehumidifying load ana winter humidifying requirements by pre venting vapor pressure losses. Windproofing all studding spaces similar to metallic window weatherstrip effect. Soundproofing provided by high hys teresis air cell construction. Easy to Install with a uniformity which insures continuous service by stap ling into studding through flanged edges. Low in Cost because it is ideal com bination of large production materials instead of costly processed natural sub stances or waste by-products. Light Weight of 38 lb per 1000 sq ft gives low heat storage and instantaneous insulating action. Especially indicated for exposed appli cation to eliminate air-conditioning shock and to reduce cooling load. Samples and data mailed on request. Single layer wall application. Also installed in two layers 1021 Insulation Alfol Insulation Company Incorporated 155 East 44th St. New. York, N. Y. Agents in Principal Cities INSULATION for INSULATION for Fans Turbines Blowers Dehumidifiers Pumps Air Conditioners Ducts Boilers, Pipes, etc. Houses, Buildings, etc. At temperatures up to 1250 F. ALFOL PAT. IN 34 COUNTRIES Refrigerators Refrigerator Cars Refrigerator Trucks Refrigerator Boxes Refrigerated Rooms etc. Ships Ovens Ranges Tanks Stills - Alfol consists of single or multiple sheets of pol ished pure aluminum foil installed between wall studs, furring strips, ceiling joists or roof rafters. When heat tends to flow through such insulated structures, 95 per cent of radiant heat is reflected back toward its source. In summer, stifling outdoor heat is driven off. In winter, practically all sup plied heat is retained in the house where it is needed. The reflection of heat is a revolutionary principle in insulation engineering which has won wide spread recognition and acceptance by engineers and scientists throughout the world. Alfol is now extensively used by many of the largest manufac turing and industrial plants, U. S. Navy, and others, as well as in houses and buildings of every kind and size. Alfol will save up to 75 per cent or 80 per cent of the heat loss that would occur through an uninsulated house. It consequently costs less to heat an Alfol insulated home. Many owners report over one-third saving in fuel costs. Alfol is installed only by Authorized Applica tors. All work is done in strict accordance with Alfol Standard Speci fications. . Alfol Insulation Company, Inc. Insulation Data on Heat Savings Effected by Alfol Construction Wood Stud Wall--4-in. studs................................ 8-in. Brick Wall--Furred....................................... Open Attic Floor.................................................... Wood Shingle Roof (no lath and plaster)............. Concrete Roof--6-in.- slab--suspended ceiling.... Slate. Tile or Composition Shingle Roof (no lath and plaster).......................................... Heat Transmission Btu/Hour/Sq Ft/F Not Insulated 0.25 .30 .62 .46 .35 .56 1 layer ALFOL o.n .12 .13 .13 .13 .15 2 layer ALFOL 0.09 .09 .10 .09 .10 .11 Heat Transfer * Stopped ... % 1 layer ALFOL 56% 60 79 72 63 73 AlJoL 64% 70 84 81 72 81 These Coefficients have been determined in accordance with the method employed in The A.S.H.V.E. Guide, and are based on new insulating value of aluminum foil tabulated in National Bureau of Standards Letter Circular No. 465, June 4, 1936, which contains the latest available data on the insulating value of aluminum foil. ALFOL ADVANTAGES UNAFFECTED BY DAMPNESS Alfol is non-porous, has no capillarity, cannot absorb moisture. Moisture infiltration in nonmetallic insulations increases conductivity frequently as much as 50 per cent. Such variations cannot occur in Alfol. INSULATING EFFECT Transmittance coefficients (see table above) are determined from tests made on actual wall sections insulated with Alfol. They accurately measure Alfol's insulating effect including the heat loss through and around studs, joists, rafters, etc. Where published coefficients of materials are based on 12-in. by 12-in. panel tests . . . materials preheated, in "bone dry" condition and at specified densities . . . they do not include the heat loss at studs, nor the effect of moisture infiltration, variation in density, thickness, etc. Many noted authorities on heat transfer recognize that the performance of Alfol in actual use is difficult to surpass. FIREPROOF, CLEAN, AND SANITARY Negligible heat-storage capacity. Alfol preheats or cools in approximately one-fourth the time re quired for other insulations. Being metal, Alfol is clean. It repels vermin; prevents bacterial growth. Alfol metal-jacketed pipe lines Trained mechanics unreel sheets of Alfol 09 needed. These compact rolls cause no dust, dirt or tcaste. This Alfd-insulaied ceding is equiva lent in insulating effect to a solid concrete ceiling dab 8ft thick. ' Aluminum Foil Does.Not Tarnish 1022 Insulation (Cor) Armstrong Cork Products Company Building Materials Division Lancaster, Pennsylvania Albant Atlanta Boston Buffalo Charlotte Chicago Branch Offices Cincinnati Cleveland Columbus Dallas Des Moines Detroit Houston Indianapolis Jacksonville Kansas Crrr Louisville Milwaukee Minneapolis New York Omaha Pittsburgh Rochester St. Louis Distributors Appleton, Wis. Northwestern Asbestos & Cork Insulation Co. Baltimore, Md.__ ___________ ___ ___John R. Livesey Boston, Mass____ _________ ___T. R. Nunan Company Charleston, W. Va.______Capital City Supply Company Cleveland, Ohio____________ Clark Asbestos Company Denver, Colo....-Stearns-Roger Manufacturing Company Eau Claire, Wis--------------------- Horel-George Company Evansville, Ind_____ Tri-State Asbestos & Magnesia Co. Jamestown, N. Y____ Laco Roofing & Asbestos Company Joplin, Mo__ ______ ___ ______ Joplin Cement Company Little Rock, Ark__ Fischer Cement & Roofing Company Los Angeles, Calif.________ Van Fleet-Freear Company Manitowoc, Wis. Northwestern Asbestos & Cork Insulation Co. Memphis, Tenn............................. ...Grant Brothers, Inc. New Orleans, La..H. T. Steffee Oklahoma Crrr, Okla_____ Kelley Asbestos Products Co. Philadelphia, Pa. ________ ____ ___John R. Livezey Portland, Oregon ...................... Asbratea Supply Company Providence, R. I..._____Jthode Island Covering Company Richmond, Va__ John R. Livesey San Angelo, Texas___San Angelo Building Materials Co. San Francisco, Calif__ _____ Van Fleet-Freear Company Seattle, Wash.............................Asbestos Supply Company Spokane, Wash.Asbestos Supply Company Springfield, Mass.-__________ Johnson Asbestos Company Springfield, MoSouthwestern Insulation Company Tacoma, WashAsbestos Supply Company Terre Haute, Ind________ _____The Hartmann Company TuiA, Okla_____.___ Kelley Asbestos Products Company Washington, D. C.~.................. ....................John R. Livesey Wichita, KansLudeman Insulations Company For detailed technical information, samples, and descriptive literature, ask any office or representative. PRODUCTS--Armstrong's Corkboard, Armstrong's Cork Covering, Arm strong's Vibracork, Armstrong's Corkoustic, Armstrong's Temlok, Armstrong's Temcoustic, Armstrong's Insulation Sundries. a Corkboard Sizes and Thicknesses Armstrong's Corkboard is furnished in rigid boards 12 in. x 36 in., 12 in. x 32 in., 18 in. x 36 in., 24 in. x 36 in., and 36 in. x 36 in., in several thicknesses: 1 in., 1H in., 2 in., 3 in., 4 in., and 6 in. Insulating Efficiency The thermal conductivity of Arm strong's Corkboard, depending on the density, is 0.27 to 0.29 Btu per hour, per inch thickness at 90 F mean temperature (U. S. Bureau of Standards). The value of adequate and efficient insulation is covered in the text section of this book (Chapter 5) and the tables on pages 104 to 116 indicate the savings which can be effected by using 1^ in. or 2 in. of corkboard in standard wall and roof con struction. The reduction in heat loss amounts to from 50 per cent to 75 per cent. This means that an adequate thickness of corkboard .oh walls and roofs reduces the heat wasted, and, therefore, the heat re quirements of the house by 25 per cent to 40 per cent. Air Conditioning . An adequate thickness of corkboard in sulation is essential for any air con ditioned room or structure. Insulation reduces the amount of heating or re frigerating equipment required to produce desired temperatures and aids economical control of humidity conditions. The insulation of air conditioning equip ment assures economical and efficient operation by minimizing refrigeration losses. De-humidifying chambers and ducts as well'as pumps and brine storage tanks may be insulated with Armstrong's Corkboard or Cork Lagging. DI Corkboard Armstrong's DI Corkboard is recom mended, for the insulation of ducts where the problem is to prevent condensation. Where refrigeration, must be conserved, the insulation should be standard'cork board in heavier thicknesses. Armstrong's DI Corkboard is furnished in sheets 12 in. x 36 in. x ^ in. It is 1024 Armstrong Cork Products Company Insulation (Cork) factory-coated on one face with a water proof mastic finish. It is exceptionally flexible, which makes it easy to shape to the sharp curvatures encountered in duct work. This insulation can be cut with a sharp knife and applied quickly. DI Corkboard can be erected in a waterproof adhesive or in hot asphalt. Cork Covering Armstrong's Cork Covering is made of pure cork in sizes to fit all standard pipe sizes. The inside surfaces of each piece are machined to assure an accurate fit, free from moisture-catching air pockets. Cork covering is rigid and will not sag. Thick nesses are: Ice Water (1.20 in. to 1.93 in.); Brine (1.70 in. to 3.00 in.); and Special Thick Brine (2.63 in. to 4.00 in.). Armstrong's Fitting Covers are designed to fit accurately standard ammonia and extra heavy fittings, both screwed and flanged, of all types. They also are rigid and join the sections of cork covering so as to provide continuous, dependable insu lation. The economies resulting from the application of Armstrong's Cork Covering to all cold lines repay the cost of the insu lation and assure additional refrigeration savings. Vibracork The elimination of noise and vibration transmission is of primary importance in air conditioning work. Armstrong's Vibra cork, made in two densities, is ideal for this purpose. It does not take a set, is not affected by atmospheric moisture, and will not deteriorate in service. Vibracork may be used to isolate a floating foundation or applied directly between the machine's bedplate and the floor or foundation. Products--Information Additional Armstrong insulating and acoustical products especially suited to heating, ventilating, and air conditioning work include: Armstrong's Corkoustic Armstrong's Temlok Armstrong's Temcoustic Armstrong's Insulation Sundries For aid in the solution of any technical problems involving insulation, isolation, or acoustical treatment and for literature and prices, get in touch with an Armstrong district office or distributor or the Armstrong Cork Products Company, Building Materials Division, Lancaster, Pa. Density 1025 Insulation (Corlj) Cork Insulation Company, Inc. 155 East 44th Street, New York, N. Y. Factory: Wilmington, Delaware Boston, Mass. Chicago, III. Los Angeles, Calif. Branches Philadelphia, Pa. San Francisco. Calif. Represented by Corinco Insulation Co., Inc. Seattle, Wash. St. Louis, Mo. Washington, D. C. CORINCO PRODUCTS Insulation Corkboard Acousticator Cork Pipe Covering Cork Lagging and Discs Cork Tile Flooring Marine Corkboard Isolation Corkboard INSULATION Proper and efficient insulation for in dustrial or domestic purposes demands a material with a low conductivity factor. Cold storage equipment is vitally de pendent on the efficiency of the insulating material used. Corinco Corkboard and Corinco Cork Pipe Covering afford positive protection from refrigeration loss * for Freezers, Cold Rooms, and for Cold Pipe Lines. AIR CONDITIONING With the rapid increase in the use of Air Conditioning equipment, it has be come more and more apparent that a proper insulating medium is necessary for the ducts, pumps, and other cold equip ment. Corinco Corkboard . is ideally suited for efficient and economic cover ing of this equipment, greatly reducing heat loss and preventing the formation of condensation. CORINCO CORKBOARD CORINCO ISOLATION CORKBOARD Corinco Corkboard is manufactured in sheets 12 x 36 in. and 24 x 36 in., in thick nesses of 1,. 2, 3, and 4 in. Its low conductivity factor, and its high resis tance to moisture and fire make it an ideal insulation for cold storage and other low temperature installations. For effective control of machinery noises and vibrations, Corinco Isolation Corkboard has proved successful. It is available in boards 12 in. wide by 36 in. long by 1, 1J4, 2, 3, or 4 in. thick. To meet specific requirements the boards are manufactured in several densities classified according to the weight per board foot. CORINCO CORK PIPE COVERING Corinco Cork Pipe Covering and Fittings are available in three standard thicknesses--Ice Water, Brine, and Special Thick Brine. They are made to fit snugly around the pipe and fittings, thus precluding the possibility of mois ture and frost forming within the covering. This assures long life and efficient opera tion. . . CORINCO ACOUSTICATOR The adoption of noise control is becom ing more widespread with the growing realization that the workers' efficiency is greatly increased in quiet surroundings. Theatres, auditoriums, and broadcasting studios, as well as industrial plants, have turned to Corinco Acousticator for def inite noise control. . For the insulation of large pipe lines and - cylindrical tanks, Corinco Cork Lagging is used. For other information and engineering services, write to Cork Insulation Co., Inc., 155 East 44th Street, New York City. 1026 Insulation (Cork.) Mundet Cork Corporation 65 S. Eleventh St. insulation division Brooklyn, N. Y. Manufacturers of Corkboard, Cork Pipe Covering, Compressed Machinery Isolation Cork, Natural Cork Isolation Mats, Cork Tile, Cork Bulletin Board, and all kinds and varieties of Cork Specialties. Albany, N. Y. Atlanta, Ga. Chicago, III. Cincinnati, Ohio Mundet Branches Dallas, Texas Los Angeles, Calif. Detroit, Mich. Memphis, Tenn. Houston. Texas New Orleans, La. Kansas City, Kans. No. Cambridge (Boston), Mass. Philadelphia, Pa. St. Louis. Mo San Francisco Calif Baltimore, Md_________ Buffalo, N. Y...... .. ........ Charlotte, N. C............ Cleveland, Ohio.... Richmond, Va Hartford, Conn_______ Minneapolis, Minn___ Nashville, Tenn______ Mundet Agents __The McCormick Asbestos Co. Norfolk, Va.. ----------------- F. H. Gaskins Corp. ...........,,.Cbxtoo Asbestos Co. ......... ..............-_C. R. Howard C. S. Rees .............Virginia Insulation Co. Oklahoma Crrr, Okla ..Standard Roofing & Material Co. Portland, Oregon__ .... -Pacific Asbestos & Supply Co. Salt Lake City, Utj .Louis A. Roeer ........ The Hartford Cement Co. Seattle, Wash_______ ...Pioneer Sand & Gravel Co. Asbestos Building Materials Co. Tulsa, Okla__________ ...Standard Roofing & Material Co. ,,_John Bouchard & Sons Co. Utica, N. Y___________ ---------------- George Weisenberger Engineering and Specification Service Our engineering department is at the service of Architects and Engineers at till times to assist and advise in the prepara tion of specifications pertaining to cork. This service is also available to any one who has a cold insulation or a vibration isolation problem, and is rendered without obligation. Our complete catalogue is filed in Sweet's Architectural Catalogue, and will be sent on request. It is replete with valuable information and data that should always be within reach of every specification writer whose field touches our products. Mundet Contract Service We contract for the erection of our products. In this way we may be certain that our material is installed in accordance with best established practice. This gives a definite advantage to an owner, in that divided responsibility for a given instal lation is eliminated. No contract in volving cork is too large, too small or too far away. All materials and workmanship are unqualifiedly guaranteed. lines. The three thicknesses in which it is manufactured make it suitable for pipes carrying sub-zero to 50 F temperature. The pipe covering comes in sections 36 in., long. A complete line of standard covers is available in the three thicknesses. Mundet Cork Vibration Isolation The transmission of machine vibration can be easily and permanently prevented by the use of Mundet cork isolation. The machines commonly associated with the heating and ventilating industry are best isolated with Mundet Natural Cork Isolation Mat. This form of isolation is fabricated from blocks of pure cork. These blocks are held together within a rigid steel frame or bound with asphalt paper applied with hot asphalt top and bottom. Steel bound isolation mat is Mundet "Jointite" Corkboard Mundet V Jointite" Corkboard is 100 per cent pure cork, fabricated in accor dance with the U. S. Government Master Specification, and is unsurpassed in its Above ii ehoten a Steel Bound Mundet Natural Cork Ieolation Mat. Note the natural cork Urine trilhin the steel frame. field. It is used for all cold insulation services and for acoustical correction. We manufacture only one grade of corkboard. Mundet "Jointite" Corkboard is sold in the standard 12 in. x 36 in. sheet. Stand ard thicknesses are in., 1 in., lJ<j in., 2 in., 3 in., 4 in. and 6 in. usually used under exposed mounts, .and asphalt paper bound isolation mat, under concrete foundations, of the envelope type. Mats are constructed to fit under any type of machine foundation. For loads exceeding 2,000 lb per square foot, we manufacture Mundet Machinery Mundet "Jointite" Cork Pipe Covering Mundet11 Jointite" Cork Pipe Covering is the complement of Mundet "Jointite" Corkboard and is used for all types of cold Isolation Cork, which is a board form of compressed granulated cork and comes in three densities. Both types of isolation are furnished in 1 in., l}4 in., 2 in., 3 in., 4 in. and 6 in. thicknesses, depending on class of service. 1027 Insulation The Philip Carey Company Manufacturers of Heat Insulation and Asbestos Products Lockland, Cincinnati, Ohio Atlanta, Ga. Baltimore. Md. Birmingham. Ala. Boston, Mass. Buffalo, N. V. NC.Charlotte, Chattanooga, Tenn. Sales Offices Chicago. III. Cincinnati. Ohio Cleveland. Ohio Dallas. Tex. Detroit. Mich. Indianapolis. Ind. Jacksonville. Fla. Knoxville, Tenn. Los Angeles, Cal. Louisville, Ky. Memphis, Tenn. Minneapolis, Minn. Nashville, Tenn. Kansas City, Mo. New York, N.Y. Norfolk, Va. Philadelphia, Pa. Pittsburgh, Pa. St. Louis, Mo. Seattle, Wash. Washington, D.C. Wheeling, W. Va. Standard 1 in. and in. thick Careyduct sections with core extended. Careyduct fittings are made from standard sections of duct, and may be made in the field with compara tive ease. A simple mitre cut plus a few standard accessories make a complete fitting. Prefabricated fit tings may be ordered from the fac tory if desired. Careyduct is a new prefabricated insulated duct built entirely of as bestos. The double layer construc tion consists of an inner core of hard, rigid asbestos, and the outer jacket is made of multiple layers of a fine corrugated asbestos structure. The combination results in great strength and is an excellent insulator. The broken joint assembly method practically eliminates leaks that are Standard 90 deg Elbow assembly. Left: Core opened to show duct vanes. Right: The completed fitting. commonly found in metal con struction. The standard sizes of Careyduct are designed so that a combination of smaller sizes will exactly nest in a larger size. All tees and take-offs are Two standard 90 deg Elbows nested in a larger standard section to form a tee. a combination of ells and straight duct. Grilles and dampers are installed according to the accepted standard practice. Carey duct gives high insulating value. It materially reduces the transmission of extraneous and equipment noises. The cost of Careyduct is slightly higher than well constructed metal duct, and is decidedly lower than properly insulated metal duct. For more detailed information and prices, write for illustrated catalog. 1028 Insulation The Relotex noRPQHATiQN 919 N. Michigan Ave., Chicago, Illinois Mills: MARRERO, LA. AND METUCHEN. N. J. Boston, Mass. Minneapolis, Minn. Philadelphia, Pa. Denver, Colo. New York, N. Y. ' Cleveland, Ohio Sidney, Australia Paris, France London, England Builds CJEILOTEX *BRAND INSULATING CANE BOARD Los Angeles, Calif. St. Louis, Mo. Seattle, Wash. Portland, Ore. Spokane, Wash. Tacoma. Wash. Buenos Aires. Argentina Durban, South Africa Protects - Insulates - Decorates - Subdues Noise Building Board Lath Vapor-seal Sheathing Finish Plank Tile Board Adhesives Hard Board Tempered Hard Board Green Tempered Hard Board Black Tempered Hard Board Tempered Concrete Form Board Panel Board Studio Board Hardboard Tile (Tempered) Roof Insulation Vaporproofed Low Tem perature Insulation Ferox Insulating Protection Course Insulation Blocks Ornaments and Mouldings Utility Board Texboard Traffic Board Promenade Traffic Top Mil-flor Traffic Top Cemesto Thermax C-X Wallboards G-X Rock Wool Products Celotex Cane Fibre Insulation In the manufacture of Celotex, long tough fibres of bagasse (cane) are properly refined, thoroughly sterilized, effectively waterproofed, firmly felted and securely interwoven to produce large boards of maximum strength consistent with the light weight necessary to - assure high heat retarding value. Careful technical control assures uniform high quality. . The thermal conductivity of Celotex is 0.33 Btu per hour per square foot per 1 F per inch thickness (based on a mean temperature of 70 F.) Tests conducted at Armour Institute of Technology and other recognized laboratories confirm this figure. The Celotex Corporation maintains an Engineering and Research staff which is available for all types of insulation investigations. Engineers are invited to address their problems to The Celotex Corporation, Chicago, III. Celotex Vapor-seal Insulating Sheathing A sheathing that has wide acceptance because it provides unusual advantages for use on outside walls under any type of exterior. Designed to meet the advancement of modern building construction. All surfaces and edges moisture proofed with a coating of special asphalt . . . One side additionally treated with a bright aluminum compound as an added vapor-seal--this side is applied facing the studs and interior... Coated on the surfaces-- not integral--no impregnation--thus main taining full insulating efficiency . . . Dry Rot and Termite Proofed by the exclusive Ferox Process (patented) . . . Greater rigidity and bracing strength than ever before . . . Backed by Celotex written 10 POINT Life-of-Building Guarantee. Same thickness as the wood sheathing it replaces--1 in.--S2S to 25/32. 4 ft wide; 7 ft, 8 ft, 8)4 ft, 9 ft, 9)4 ft, 10 ft and 12 ft long. 1029 The Celotex Corporation Celotex Cemesto Insulation Celotex Cemesto is composed of genuine Celotex Cane Fibre Insulation Board core with a surface coating of 34 in. asbestos cement board adhered to one or both sides with a strong, moisture-proofed, highly vapor-resistant cement. It forms a rigid board de signed to assure permanent insulation and resistance to fire, moisture and weather. It is used as a wall, ceiling, or roof deck in interior or exterior construction, and is recom mended for homes, pavilions, cabins, garages, filling stations; vent ducts, spandrels; steel frame buildings and hangars. The standard insulation value of Celotex, 0.33 Btu per inch, is maintained in Celotex Cemesto. It is recommended for insulation where the temperature is not constantly in excess of 200 deg--it is not, however, a high temperature insulation. The Celotex core in Cemesto is Dry Rot and Termite Proofed by the exclu sive (patented) Ferox Process and the hard asbestos cement coating provides permanent mineral protection which neither rusts nor decays. Celotex Cemesto is sawed, drilled, and otherwise handled with ordinary tools. It may be painted if desired or used in its natural light grey finish which provides a smooth surface with excellent light reflecting qualities. Celotex Cemesto is surfaced on one or both sides and comes in sizes 4 ft wiae; 4 ft, 6 ft, 8 ft, 10 ft and 12 ft long; Yz in., \ Yz in., 1^ in. and 234 in. thick, when surfaced (SIS) on one side; and in., 134 in., in. and 234 in. thick when surfaced (S2S) on both sides. Thermax Structural Insulating Slab A-fire-resistant insulating slab suitable for wall sheathing--partitions, ceilings and load bearing roof decks. Thermal con ductivity is 0.458 Btu per hour, per square foot, per degree Fahrenheit, per inch thickness. It provides an excellent plaster base; and when used over large auditor ium spaces, the under side is often left exposed for acoustical treatment. Ther max is manufactured of clean shredded wood fibres bound together with fireresistant cement. It is nailed, sawed or set in masonry walls, by ordinary me chanics with ordinary tools. Standard sizes: 1 in., 2 in:, and 3 in. thicknesses in slabs 20 in. x 48 in. and 20 in. x 64 in. --also 20 in. x 32 in. in 3 in. thickness only. A pplicalion of Thermax Structural Insulating Slabs. 1030 The Celotex Corporation Insulation Celotex Roof Insulation Selected to insulate wood, concrete, steel, unit tile or poured gypsum roof decks under average conditions. Size 22 in. x 47 in. Full 34 in. thick. Also furnished laminated in thicknesses, 1, 134 and 2 in. Used to prevent ceiling conden sation and conserve fuel; also to prevent excessive expansion and contraction of concrete roof decks. Makes possible a reduction in the size of heating plants. Celotex Vaporproofed Low Temperature Insulation Waterproofed and vaporproofed low density insulation for low temperature require ments. Coolers (beer, meat, creamery, etc.,) Fruit and Vegetable Storage Rooms, Packing Plants, Fur Storage, Air-conditioned Spaces, General Cold Storage Rooms and Freezers. Each block enrobed in a sealed odorless membrane. Ferox Treated. Con ductivity 0.30 Btu per inch. Sizes: 12 in. x 36 in., 18 in. x 18 in., 18 in. x 36 in., 9 in. x 36 in. Thicknesses: 1 in., 134 in., 2 in. or any multiple of 34 in. Celotex Building Board The original cane fibre insulation. Suitable for general use where an insulating board is desired. Can be beveled, paneled, grooved or painted to provide attractive walls that insulate. Neutral tan color. Double surfaced--one side smooth sanded, the other a tapestry-like texture. 34 in. and 1 in. thick. Sizes: 4 ft wide and 4 ft, 5 ft, 6 ft, 7 ft, 8 ft, 8% ft, 9 ft, 934 ft, 10 ft and 12 ft long. Backed by Celotex written 10 point Life-of- Building Guarantee. " Celotex Insulating Lath A natural bond for plaster ... a con tinuous surface eliminates lath marks and reduces cracking ... beveled edges to reinforce plaster (patented) . .. tests prove a bonding power of 1,000 lb per square foot. Shiplapped joints (see diagram). Size: 18 in. x 48 in.; 34 in., 24 in. and 1 in. thicknesses. Backed by Celotex written 10 point Life-of-Building Guarantee. CELOTeK Plaster III Celotex Insulating Tile and Finish Plank Tile Board and Finish Plank--For beveled square edges; otherwise the same attractive wall and ceiling treatments . . . as Type Double-A. Type Double-A joint may be applied over existing plaster or as 34 in. thick only, and 1 in. thick on special a new finish. Neutral tan color or several order. Sizes range from 12 in. x 12 in. to pleasing tints on reverse side that simplify 24 in. x 48 in. Celotex Finish Planks, 34 decoration. Type Double-A joint permits in. thick. Sizes: 6 in. to 16 in. wide; 8 ft alternated surfaces if desired. Type A, to 12 ft long. Backed by Celotex written furnished 34 in., 24 in. and 1 in. thick, has 10 point Life-of-Building Guarantee. C-X Rock Wool Products Effective insulation made from molten rock. Incombustible, vermin proof and per manent. Rock Wool Batts 15. in. x 23 in; Prepacked Batts 9 in. x 15 in; Paper Backed Batts 15 in. x 23 in. and 15 in. x 48 in.; Pads 9 in. x 15 in.; Paper Backed 2 in. Batts 15 in. x 23 in. and 15 in. x 48 in. Loose and Granulated to spread between ceiling joists also available. The Ferox Process All Celotex Cane Fibre Products are manufactured under the exclusive Ferox Process (patented) and therefore effectively resist damage by Fungus Growth, Dry Rot and Termites (White Ants). It is not a surface treatment--it is integral--in soluble in water--non-volatile--odorless-- permanent. 1031 Insulation (Weather Strips) Chamberlin Metal Weather Strip Co., Inc. General Offices, Detroit, Mich. Factories, Detroit, Mich., Peru, III. Atlanta. Ga. Baltimore, Md. Boston, Mass. Buffalo, N. Y. Chicaco, III. Cincinnati. Ohio Factory Sales--Installation Branches Cleveland. Ohio Dallas, Texas Denver, Colorado Detroit, Mich. Indianapolis, Ind. Kansas City. Mo. Los Angeles. Cal. Louisville, Ky. Milwaukee, Wis. Minneapolis, Minn. Newark. N. j. .New York, N. y Philadelphia, Pa. Pittsburgh. Pa. Portland, Ore. St. Louis, Mo. San Francisco, Cal. Washington, D. C. CHAMBERLIN HEAT-SAVING PRODUCTS Weather Strips, Calking, In-Dor-Seals, Insulation and Insulate-Windows. Weather Strips Modern weather strip service, in which engineers and architects can have greatest reliance, is one that can responsibly fulfill conditions of a contract. For problems of infiltration or circulation of air, gases or mixtures, leakage of rain, filtration of dust, sand or soot--there's a Chamberlin Weather Strip remedy regardless of cli matic or construction conditions. Particu larly helpful to the engineer is the know ledge that the job can be entrusted, regardless of location, to a Chamberlin Factory Branch employing experienced mechanics. Modern problems of heating, venti lating and air conditioning can be ap proached with utmost confidence in this field with the aid of Chamberlin's proven 45 years of experience and specialized training. Write for A .I.A. catalog of standard details and specifications. Consuit nearest branch for equipments, sur veys, quotations. Calking Chamberlin Plasti-Caik is essential in the sealing of construction joints in wood, metal, glass, stone, tile, concrete and brick. It is waterproof, permanently elastic, non staining and noncorrosive. It provides durable adhesion and will not sag, pucker, or shrink under extremes of heat or cold, dryness or moisture. Chamberlin PlastiCalk is specially prepared with porous pigments capable of retaining oil indefi nitely, and does not contain tar or asphalt. Supplied in various colors. It is all impor tant that a calking compound be specified thoroughly on the basis of .stringent physi cal properties. Such specifications will be furnished upon request. Calking applied with hand tools. hand or power gun. Automatic Door Bottoms In-Dor-Seals eliminate under-door drafts and heat, losses in rooms adjacent to cold areas, corridors and halls--as in a sleeping room door--virtually an "outside" door at night when windows are open. They are used to light-proof X-Ray and dark rooms; to sound-proof private offices, studios; laboratories; to resist room-toroom circulation of odors, fumes and dust. 1032 raised the instant door opens. Insulation Chamberlin Metal Weather Strip Co., Inc. General Offices, Detroit, Mich. Factories, Detroit, Mich., Peru, 111. CHAMBERLIN HEAT-SAVING PRODUCTS Weather Strips, Calking, In-Dor-Seals, Insulation and Insulate-Windows. Rock Wool Insulation Having an average conductance coef ficient of 0.24 to 0.27 Btu, Chamberlin Rock Wool is one of the most efficient insulations available today. Long in fibre and clean of "shot", it insures effective . insulation with low density and light weight. It is available in several forms adaptable to both new and existing con struction--in blowing, commercial or loose wool fibres; in wall-thick or 2 in. thick batts, with or without vapor-proofing coverings. Among its physical properties Chamberlin Rock Wool averages 38 per cent silica, 32 per cent lime and only 0.04 per cent sulphur. Its loss on ignition is less than 0.1 percent. Wherever pos sible pneumatic application, by means of such , modern high-powered and efficient transient units as illustrated, is preferable. Here again, the engineer will do well to consider the value of faithful, responsible performance in the art of application-- the hidden factor that means so much in obtaining the utmost efficiency from insu lation. Insulate-Windows In addition to other major heat loss controls, Chamberlin has developed a pro duct that reduces 40 to 60 per cent of the heat loss of glass in standard window con struction. Thousands of Chamberlin InsulateWindow (registered tradename) units have been applied to wood and metal windows in existing.-builciings, including offices, banks, residences, etc.--they are not double glazed units. They are single glazed and custom made to supplement existing win dows of practically any type. Depending upon characteristics of the areas and sash to be "insulated," Insulate-Windows are hinged, stationary or sliding. They are framed with a patented rolled section of antique-finished, cold-rolled bronze em bodying ingenious features of mechanical glazing in place of putty. Chamberlin "insulation'* of windows is a high grade, mechanical service involving design and installation of durable, secondary window units, readily accessible for cleaning and removal when necessary--no interference with sash operation or ventilation. Insu late-Windows provide a year 'round heat stop that gives practical relief without the technical difficulties involved in doubleglazed windows. Typical Chamberlin Insulation unit. Equipped with powerful,gas-powered,pneumatic blotter capable of pro jecting granular grade "A" rock wool a minimum dis tance of more than 00 ft throug'i a large rubber hose. At right-- near view of insulated" residential metal casement windows. Chamberlin Insu late - Windows on outside. Below-- battery of InsulateWindows showing how they can be hinged. AU 5 units can be unlatched from within the room by simply opening the two casement venti lators. 1033 Insulation Ehret Magnesia Manufacturing Go. Valley Forge, Pa. DURANT PRE-SEALED INSULATED PIPE SYSTEM The Modern Way to Insulate and Protect Underground and Outdoor Piping. (Hot and Cold) Explanation Durant Pre-Sealed Insulated Pipe Sys tems have been in successful use in the far west for fifteen years. A great many instal lations have been operating under a variety of conditions which have proven beyond any doubt that the system is thoroughly reliable. The absolute pro tection of the pipe and insulation against moisture and soil conditions has solved the problem which has bothered engineers. The Ehret Magnesia Mfg. Co. obtained an exclusive control of the manufacturing and sales rights. A new department was built at Valley Forge and equipped with the most modern equipment to properly produce Durant Pre-Sealed Insulated Pipe. This department is now in active produc tion ana many installations have been fur nished all of which are giving satisfactory service. The most carefully designed and con structed systems for protecting under ground piping have frequently caused serious trouble due to leakages with not only great impairment to the insulation and the pipe but to loss of efficiency in the operation of the lines. The same has often been the case with outdoor pipe lines exposed to the elements. Here the old method of wrapping on roofing materials has usually been ineffective, for no matter how securely applied the action of wind and weather eventually causes cracks and looseness with resulting damage to the covering and pipe. The Durant Pre-Sealed Insulated Pipe system completely overcomes these difficul ties in an effective and permanent manner. Not only did the Durant Pre-Sealed Insu lated Pipe system overcome the engineering difficulties of protecting the pipe lines but it greatly simplified the installation as the sections of treated pipe are delivered to the job as entirely complete.units, only joint and fitting connections being necessary in the field. Description Solid Asphalt Shell--A special grade of pure high melting point asphalt -is melted and cast around the pipe, or in sulation, which results in a seamless and jointless coating which will be forever a; permanent resistance to the entrance of moisture or infiltering air. Jackets ac curately spaced around the pipe, or in sulation, insure uniform thickness of the asphalt layer. These jackets are left in place and protect the surface from me chanical damage in shipping and handling. Thickness of Asphalt--The layer of asphalt can be applied in any thickness. For insulated piping in underground con ditions a 1-in. thick coat of the asphalt is recommended, and ordinarily supplied. For insulated piping with outdoor con ditions a thickness of J-in. is usually sufficient. Where uninsulated piping is to be protected from the corrosive action of the soil and from electrolysis there should be a surface seal consisting of a J-in. thickness of the asphalt. Perfectly Sealed Connections--The method of treating joint and fitting con nections, as described on the next page, actually extends the asphalt shell along the entire pipe system in an absolutely seamless manner. Any Kind, Size and Length of Pipe-- There is no limit in size or length of pipe which can be given the Durant treatment and any specified type of pipe can be used. However, ordinary stock lengths will be supplied unless special lengths are ordered. Curved or bent pipe can be treated in the same manner as straight pipe. 1034 Ehret Magnesia Manufacturing Co. Insulation Insulation Material--^Engineers re cognize the durability of 85 per cent Magnesia and that it is a yardstick of thermal efficiency because it is practical both for low temperature piping and for piping having temperatures up to 600 F. Therefore Ehret has selected 85 per cent Magnesia as the ideal product to incor porate in the Durant Pre-Sealed Insulated Pipe System. Thickness recommendations of the 85 percent Magnesia will depend on the service and the conditions. Discussion The reasons for the effectiveness of the Durant Pre-Sealed Insulated Pipe method in protecting pipe and insulation are ob vious. Asphalt is well known to be absoutely impervious to the passage of moisture or air through it. The dense, jointless casing of asphalt thoroughly and per manently prevents water and air from penetrating through. This not only insures against deterioration of the pipe and insula tion, thus preventing losses in the line, but the perfect surface air seal actually increases the overall efficiency. The asphalt protection will not crack from the pressure of the soil and it is sufficiently ductile to follow any possible movements of the pipe line. There are no cemented joints or seams which might crack open and leak. The insulation and the protective coat ing are applied at the factory under most favorable conditions. This is in great contrast to the difficulty experienced in separately installing the pipe, insulation and surrounding protection in the field. This is especially true for underground installations where the work must be done at the bottoms of narrow, deep and often muddy trenches with questionable results. Durant Pre-Sealed Insulated Pipe is delivered to the job in complete pipe lengths (approximately 20-ft sections). The only work to be done in the field is to make the joint and fitting connections. For underground work the trench can be narrower and shallower than for a conduit or tunnel for the same size pipe. The running length of the trench need only be wide enough to accommodate the treated pipe. Only at connections need any greater width be used to allow for a man to work in. The Durant Pre-Sealed Insu lated Pipe rests directly on the bottom of the trench and no greater depth is necessary to allow for crushed stone and underdrain tile. The back filling can be accomplished in one operation as the soil can be settled into place by Hooding with water. This eliminates the necessity of the men re turning at a later time to add earth to the sunken surface. Installation After the connections are made and tested, insulation is applied of the same type and thickness as on the adjacent pipe, after which the necessary jackets are placed in position and the melted asphalt poured in. The following illustrations indicate the simple manner in which this is done. Specie! Durant joint casing in place ready for Asphalt. Asphalt poured in slot--a perfect seal. Insulation The Eagle-Picher Lead Company General Offices: Temple Bar Building, Cincinnati, Ohio Offices In AU Large Cities EAGLE EAGLE HOME INSULATION Eagle Insulation for homes is a fluffy, woolly material spun from mineral rock. In both granulated form for pneumatic application and in bat form, it is extreme ly lightweight, non-corrosive, fireproof. According to U.S. Bureau of Standards tests, Eagle Insulation in applied thickness of ZYz in. has a thermal conductivity rating of only 0.074 Btu at 103 F. (Over all conductivity is considerably lower.) Fuel Savings Up to 40 Per Cent Water Repellent Samples of Eagle Insulation exposed to completely saturated atmosphere for 100 hours gained less than 0.2 per cent in weight due to moisture absorption. This is important. Insulating materials which absorb water soon lose much of their in sulating efficiency. Being made of mineral wool, Eagle Insulation contains no vegetable matter to attract insects or pests. It is rotproof Eagle Insulation literally "seals" furnace --will not deteriorate. It passes the most heat inside the home. Records show that severe settling tests. fuel savings run up to 40 per cent of the season's total. In summer, Eagle Insula tion keeps homes up to 15 deg cooler than outdoor temperatures. Reduces Fire Hazard Type H-l. Applied Pneumatically In granulated form, Eagle Insulation is blown into hollow spaces between wall studdings and between joists in the attic floor by a special pneumatic process. No Unlike many insulating materials which are described as "fire-safe" or "fire-resis tant", Eagle Insu lation is absolutely building alterations are necessary, whether the structure is of frame, brick veneer or stucco construction. Work is done by skilled licensed contractors. fireproof. It will not burn. Fire haz ard is greatly re duced. Hollow spaces in walls, which ordinarily act Type H-3. Bats for New Construction Eagle Insulat ing Bats are rec tangular pads 15 in. x 18 in. or 23 as flues once a fire starts, are com pletely filled with a material that even a blow torch can not ignite. Eagle Insulating Wool easily blown into spaces between wall studdings The Bureau of Buildings of the City of New York has given full approval to use in. x 3% in., de signed to fit snugly between studding and joists. Irreg ular spaces around doors and windows filled by cutting bats to exact size. Eagle wall-thick bats quickly installed in new construction of Eagle Insulation where fire-retarding is required under the Building Code and the Data and Specifications Multiple Dwelling Law. Also approved For complete specifications and tech by Underwriters' Laboratories, Inc. as nical data on Eagle Home Insulation; see being a non-conductor of electricity. Sweet's Architectural Catalog. EAGLE INDUSTRIAL INSULATION The Eagle-Picher Lead Company manu factures a varied line of insulating products effective for a full range of temperatures. Eagle Super t466" Plastic Insulation provides remarkable heat-saving efficiency for temperatures as high as 1800 F. Trowels easily on all large or irregular surfaces. 100 lb covers 60 sq ft 1 in. thick. Eagle Blanket Insulation is Eagle Insulating Wool felted and secured be tween metal fabrics. Easy to cut and fit. Other products include Eagle Insutseal (waterproofing cement), Eagle "33" Ce ment, Eagle "99" Finishing Cement, Pipe Covering and Blocks, Insulating Wool. For specifications and technical data on Eagle Industrial Insulation, see Sweet's Engineering or Power Plant Catalog. 1036 =TMs^ Insulation . General Insulating & Mfg. Company Engineering Offices and Main Plant: Alexandria, Indiana Executive Offices: St. Louis, Missouri Branch Plants: Dover, N. J. Dubuque. Iowa rock WOOL INSULATION Gimco Sealal Bats complete ly fill empty spaces between studdings and joists. Fur nished either with or without waterproof paper backing. Gimco Sealal Rock Wool Bats--Gimco Rock Wool Bats are made from long, tough rock wool fibres specially annealed by a patented process. More than 90% of their volume is tiny air cejls . . . which provides extra insulating effect. Installed 3Ys in. thick Gimco's conductivity is only 0.067 Btu per hour per sq ft for that thickness. Gimco provides full "wall-thick" protection . . . keeps inside temperatures as much as 15 deg cooler in summer and pays for itself out of winter fuel savings. Gimco is as fireproof as the rock itself, resists moisture, and will not decay, pack down or dust out. Gimco is as permanent as the house, and offers no attraction to vermin or termites. Gimco Bats are Self-Supporting--Gimco bats need only to be pushed between studdings or joists. Their own natural resiliency holds them permanently in place without additional support. Application costs are thus cut to a minimum. Gimco Insulation for Present Homes--Gimco in granu lated form can easily be blown into empty wall and ceiling spaces. It makes a permanent "wall-thick" insulation, and can be installed in any home, regardless of age, size or type of construction. For complete details, write for new book on home insulation. Specifications--Gimco Sealal Bats can be obtained either with or without waterproofed paper backing. They are made in three sizes: (1) 15 x 18 in. x wall thick; (2) 15 x 23 in. x wall thick; (3) 15 x 48 in. x wall thick. Ten small bats insulate approximately 20 sq ft of wall or ceiling area; 10 medium size bats insulate approximately 25^$ sq ft; 10 large bats insulate approximately 55 sq ft. Present homes are easily and quickly insulated by blowing Gimco Rock Wool in empty wall and ceiling spaces. In sures a thick, protective blanket of uniform density. GIMCO ROCK WOOL PRODUCTS FOR INDUSTRY Flexfelt Blankets--Efficient and adaptable rock . wool insulation for boilers, heaters, furnace breachings, hot tanks and other industrial equipment. Standard sizes: 2 ft x 4 ft and 2 ft x 8 ft. Special sizes are also made to order or as planned by our engineers from pur chasers' equipment drawings. Gimco Flexfelt Pipe Coverings--Flexfelt coverings are suited for every type of pipe insulation . . . hot water, steam process, cold water and refrigerant lines. They are made in a variety of sizes and styles, each individually designed to do an efficient insulating job. Gimco No. 320 Insulating Cement--For monolithic insulation of heating boilers, pipe settings, etc. Also used for finishing over blanket type insulation. Coverage: 50 sq ft., 1 in. thick per 100 lb. Free Construction and Engineering Service--Gimco engineers, backed by years of research in our own laboratories, render prompt and efficient service in helping you solve insulation problems. Quotations and suggestions on any job (temperatures up to 1500 F) will be gladly given. 1037 Insulation The Insulite Company Executive Offices: Minneapolis, Minnesota Factories: International Falls . Minnesota Kyml, Finland INSULITE Stocked by Dealers in All Principal Cities Throughout The World Insulite Wood Fiber Insulation Board Products Insulite, the original wood fiber in sulation board has been specified by engineers and architects for 24 years--used for exterior sheathing or interior finish, duct lining, and for other thermal insu lation and sound control work. Surface textures: fine screen one side and burlap one side. firmly locks the sheets together between supporting members, thus providing a rigid, level base for the plaster. Thick nesses: H in., M in., 1 in. Size 18 in. x 48 in. Tile--Available in both Ins-Light and Graylite with burlap and fine screen tex tured surfaces. Tile is beveled on all four Ins-Light Building edges of both sur Board--This board faces, and is available is of a natural light color with high lightreflecting value. Thermal Conducti vity: 0.33 Btu/hour/ square foot/inch/F based on a density of 16 lb per cubic foot. in two types of joint: B-B (Butt joint), V-W (interlocking). Both types are rever sible, making it pos sible to reverse the tile and expose either Thickness: H in., surface. Thicknesses: H in., 1 in.; sizes up to 4 ft x 12 ft. in., 1 in.; in sizes 12 in. x 12. in. to Graylite Build . ing Board--Made from the same wood fibers as Ins-Light, Above: Insulite Building Board, applied with metal toashert and screw* being used to insulate air ducts in air conditioning installations. 24 in. x 48 in. Plank--Available in both Ins-Light and but during the manu Graylite with burlap facturing process each fiber is coated with asphalt which adds to its strength and fine screen tex tured surfaces. Plank has the interlocking and moisture resist V-W joint and is ing qualities. Ther mal conductivity: 0.35 Btu/hour/ square foot/inch/F. beveled and beaded both long, edges on each side. Plank is Ins-Light LokJoint Lath--An reversible so that either surface may insulating plaster base, fabricated from Ins-Light Building Board. Has pat ented "Lok" that Above: Ins-Light and Graylite Tile and Plank senes os ike interior finish in o modem sales room. be exposed. Thick ness: % in.; in sizes 6 in. to 16 in. wide and 8 to 12 ft long. Bildrite Sheathing Bildrite Sheathing, although made from the same wood fiber stock used in other Insulite products, is an outstanding, new building material development. Treated by a patented integral asphalt treatment during the manufacturing process, it provides several times the bracing strength, greater resistance to moisture, and more insulation than that afforded by ordinary wood sheathing, and it builds a knot and crack free wall at less cost. To assure rapid and proper application, each large sheet 25/32 in. thick, and in sizes up to 4 ft x 12 ft, is plainly marked for proper alignment and spacing of nails. Thermal conductivity: 0.36 Btu/hour/square foot /inch/F. 1038 I The Insulite Company Insulation Ins-Light Roof Insulation Ins-Light Roof Insulation is made from the same wood fiber as standard Insulite. It can be used over any roof construction. The standard size is 22 in. x 47 in., for convenient handling, and with either offset or square edges. Furnished in thick nesses of H in., 1 in., 1)4 in., and 2 in. Conductivity 0.32 Btu/hour/square foot/ inch/F. Graylite Roof Insulation Graylite Roof Insulation is a new and improved product, exclusive with Insulite. Treated with an asphalt emulsion during the process of manufacture* it provides those qualities of greater resistance to moisture and greater durability so desir able in roof insulation, combined with an ideal base for bonding to the roof deck and to the roofing. Furnished in full )4 in. thickness and in multiples of )4 in* up to 2 in. with either square or offset edges. Size: 22 in. x 47 in. Insulite Hardboard Products Tough, durable grainless boards with hard, smooth, surfaces in various densities, and sizes up to 4 ft x 12 ft: DualBoard--H in. thick; golden oak brown; has lowest density of all HardBoard products. DeLuxe DualBoard--^ in. thick with smoother surface and greater density than DualBoard. HardBoard--Ho in., H in., H6 in., H in., He in., golden oak color; much greater density them DualBoard. Tempered HardBoard--Same thick nesses as HardBoard; burl walnut color; extremely high density. PanelTile--Same as Tempered HardBoard except that it is scored in 4 in. squares to simulate tile. Insulite Sealdslab Fabricated from special low density board, each block of Sealdslab is " sealed dry" with a Hz in. impregnation of a specially developed asphalt which insures an effective seal against moisture absorp tion after Sealdslab is asphalt coated or dipped during application on the job. The factory primed surfaces also insure an excellent bond for subsequent asphalt coatings. Available in same sizes and thicknesses as Ins-Light Cold Storage Insulation. Sealdslab is especially adapted for use in frcczers;meat, beer and creamery coolers; milk cooling tanks; fruit and vege table storage rooms and general cold storage rooms. Applying Insulite Roof Insulation Ins-Light Cold Storage Insulation Cold Storage Insulation is a low density Insulite product which has found a wide acceptance for use in refrigerator cabinets, refrigerator cars, ice houses, storage plants, breweries and other places where low temperatures are maintained. The ther mal conductivity is 0.29 Btu/hour/square foot/inch/F and is available in eleven standard sizes and in thicknesses of 1 in., 1)4 in., 2 in., 3 in., and 4 in. Insulite Fiberock Insulite Fiberock insulation is a rock wool product, treated for moisture resis tance, with a low percentage of shot and with sufficient resiliency to prevent it from settling. Conductivity: 0.26 Btu/hour/ square foot/inch/F. Available in six forms: Loose. Fiberock--A fluffed form of rock wool insulation for hand packing in walls. Granulated Fiberock--A granular form of rock wool which can be con veniently poured into place. Usually used over ceilings. . Fiberock Plain Batts--Rock wool in batts 15 in. x 23 in. to fit snugly between studs and joists, requiring no special fastening. Thicknesses: 3H in.; 2 in. Fiberock Paper-Backed Batts--Rock wool in batts lined on one side with water proof asphalt saturated kraft paper, which is flanged on long edges of batt for securing to studding. Sizes: 15 in. x 23 in.; 15 in. x 48 in. Thicknesses: 2 in.; wall-thick. * Fiberock Pads--Rock wool in batts 15 in. x 9 in., wall-thick. Pre-Packed Wool--Loose rock wool pressed and cut into units 15 in. x 9 in. and packed for shipment in layers roughly 2 in. thick. Insulation Insul -Wool Insulation Corp. General Offices, Wichita, Kansas Branches in Principal Cities Manufacturers and Distributors of Insul-Wool Insul-Wool is a fibre insulation of the "fill" type--made of wood pulp, a natural insulating material. By the exclusive "Insul" method the wood pulp is converted into a loose fluffy substance which, when installed in a building, forms a soft heat-resisting blanket having millions of tiny air cells cap able of resisting passage of either heat or cold. UNIFORMITY OF PRODUCT Only one grade of Insul-Wool is made and every "run" is tested at the factory to insure uniformity of product and unvarying high quality. It is free from grit, silicon particles, or "shot." FIRE PROOF AND VERMIN PROOF A special "Insul" method of chemical treat ment makes Insul-Wool thoroughly vermin proof and fire proof. It has been approved by the National Board of Fire Underwriters. Insul-Wool Applied over Ceiling "INSUL" SERVICE Insul-Wool is distributed and installed only by specially trained men--direct factory re presentatives or men in the organizations of the largest insulation material dealers through out the United States. ADVANTAGES OF INSUL-WOOL 1. It is made from wood pulp, a natural insulating material. 2. Chemical treatment makes Insul-Wool safe under all conditions and hazards. 3. Approved by the National Board of Fire Underwriters. 4. Its light weight of 2.5 lb to the cubic foot adds very little load to the ceiling rafters. - 5. Does not pack or settle and outlasts the building in which it is installed. 6. Economical to install. 7. Cuts fuel costs and reduces Summer temperatures, indoors. 8. Meets U. S. Government requirements on Federal Construction with a thermal ' conductivity of 0.25 Btu per hour, per square foot, per degree Fahrenheit, per inch thickness. * Analysis of Insul-Wool in Terms of Commercial Thickness Material INSUL-WOOL Commercial Form Comm'l Thickness Inches Wood Fiber-Loose Type. Fire proofed and Germ proofed. I 4. D. WL Per cu. ft 2.25 lb C. Conductivity 0.25* 0.067** Kansas City Testing Laboratory. Inc., November 27, 1935. **J. C. Peebles, Armour Institute of Technology, April 8, 1937. ' Complete data on Insul-Wool Insulating Product will be sent upon request. 1040 Insulation International Fibre Board Limited Sales Offices OTTAWA--MONTREAL--TORONTO--WINNIPEG Administrative Offices and Mills; GATINEAU, QUE. London Office THE TENTEST FIBRE BOARD CO. Ltd. W. C.Astor House. Aldwych, London, 2., England Tempest insulattWg wall board TEN/TEST is a manufactured lumber made from spruce fibres, solidly pressed under hydraulic pressure into a strong, homogeneous board. The fibres are chemi cally treated and water-proofed during process of manufacture, until the insula tion is non-hygroscopic, free from capillary attraction and moisture-resisting in service commensurate with the maximum degree of insulation obtainable. . Official Tests Conductivity. TEN/TEST has a con ductivity of 0.33 Btu per hour per square foot per degree fahr. per 1 in. thick. Authority: Professor E. A. Allcut, M. Sc. M. I. Mech. E. Mem. A.S.M.E. Professor of Applied Mechanics, University of Toronto. Tests performed by Hot-Plate method. Mean temperature 47.8 deg. Tensile Strength 228 lb per sq in. Tests made on in. board cut to strips 1 in. wide and tested in a Riehle Tensile Testing Machine, the grips being 2 in. apart. 228 lb is-the mean average of seven series of tests. Transverse Strength (equal deflec tion) is 28.4 lb. Test made on Jfs in. board, 6 in. wide, 18 in. long, on 12 in. centers, and load being applied to breaking point. Plaster Bonding Strength 2163 lb per sq ft. Brown and scratch plaster coats were applied to standard jf* in. board, and the pull registered in an Olsen Testing Machine. Authority: Columbia University Testing Laboratories, New York. - TEN/TEST Products TEN/TEST Insulating Building Board. Standard insulation for use as exterior sheathing, interior finish; between walls and under floors for sound deadening. Standard Industrial Insulation for refrig eration and the prevention of condensa tion. Manufactured in convenient sizes: 4 ft wide and up to 17 ft long, H in* to 1 in. thick. TEN/TEST Notch Board Plaster Base. Insulating plaster base having tongue and groove interlocking joints. Provides an effective bond with plaster without use of metal lath at joints. Sizes: 16 in. wide; 32 in. and. 47% in. long. Thicknesses from % in. to 1 in. TEN/TEST Roof Board. An effective roof insulation. Manufactured in two sizes: 1 x 4 ft and 2 x 4 ft. Thicknesses from % in. to 1 in. TEN/TEST Ashlar Block (Acousti "A"). For interior decoration and acoustical correction. Absorbs 35 per cent of incident sound at a frequency of 512. Can be supplied in a variety of designs and sizes to harmonize with any decorative treatment, allowing the archi tect much freedom in design and finish of churches, auditoriums, theatres, etc. Ashlar Blocks have bevelled edges, standard or to suit, can be left in the natural color or tinted as desired. TEN/TEST Moulded and Shiplap Edge Wall Panels. Conceals joints and provides excellent decorative treatment. Featured in widths of 11 in. to 47% in., lengths up to 12 ft. Moisture Resisting. TEN/TEST, after complete immersion in water for 24 hours, registered 37.5% increase in weight. Note.--Authority for tensile strength, transverse and moisture tests; J. T. Donald & Co., Ltd., Chemical Analysts and Engineers, Montreal, Que. TEN/TEST Mouldings. An effective trim and finish for joints, corners, etc. Available in widths of % in. to 10 in. and lengths up to 12 ft. HYDRO/TEST. Water proof, insula ting building board, designed particularly for low temperature requirements. 1041 Johns-Manville Executive Offices 22 East 40th Street, New York, N. Y. Offices in All Large Cities Insulation Johns-Manville Home Insulation J-M Home Insulation consists of special grades of rock wool for retarding heat flow through walls, ceilings and floors of frame houses and all types of buildings. J-M Home Insulation is remarkably effective in providing year-around comfort --keeping homes up to 15 deg cooler in summer--reducing fuel bills up to 30 per cent in winter. It is permanent, fireproof, and will not support vermin. Furnished in three forms: Type A for existing con struction; Types B and C for new homes. Blown Method--Type A Type A Rock Wool is blown pneu matically into the spaces between studs in outer walls and between rafters or joists in roofs or attic floors. Insulation thickness in walls corresponds to stud depth, ap proximately Z% in.; density does not exceed 10 lb per cubic foot. This type of insulation is installed by J-M Approved Home Insulation Contractors, who are equipped with the necessary apparatus and trained crews. Home Insulation--Types B and C Type B Home Insulation is furnished in the form of resilient, prefabricated batts, of uniform density and full stud thickness, in sizes 15 in. x 23 in. and 15 in. x 48 in., designed to fill completely the width between studs, joists or rafters spaced 16 in. center to center. Heavy waterproof paper, affixed to the batt surface toward the occupied portion of Applying J-M Home Insulation baits in new home the building, protects the rock wool from the excess water in fresh plaster and also improves the handling qualities of the batts. The side-flanges, fastened to the supporting framework, hold the batts firmly in place in ceiling or roof construction. Insulation in odd-shaped spaces is secured either by application of pieces cut from the batt, or by the use of Type C, which is furnished in pieces 8 in. x 15 in., full stud thickness, without the waterproof paper backing. Write for Details For complete information on J-M Home Insulation, write for Brochure HI-18A. J-M Insulating Board and Insulating Lath Johns-Manville furnishes a complete line of Insulating Board, .Insulating Lath and Roof Insulation Board in standard sizes and thicknesses. These materials are thoroughly efficient, with high insu lating value and great structural rigidity. J-M Airacoustic Sheets for Lining Air-Conditioning Ducts J-M Airacoustic Sheets, for duct linings of air conditioning systems, are rigid, fire proof, highly sound - absorbent and mois ture-resistant, with a surface which will not materially increase friction losses in the duct system. Write for DS Series 275. 1042 Johns-ManviUe Insulation Johns-Manville Pipe and Boiler Insulation supplied in sections to fit straight runs of copper pipe or tubing with the following outside diameters: yg in., l/i in., in., in., 1J6 in., in., 1% in., 2J-6 in., 2% in., 3Jji in., 3% in., 4)4 in., 5J6 in., and 6J4j in. J-M Asbesto-Sponge Felted Pipe Insulation . Recommended on all high pressure steam piping at temperatures up to 700 F where insulation may be subjected to rough usage or where maximum efficiency and durability are desired. Furnished in 3-ft sections up to 3 in. thick. J-M Pre-Shrunk Asbestocel Pipe Insulation J-M Superex Combination J-M Pre-Shrunk Asbestocel Pipe Insulation J-M Pre-Shrunk Asbestocel is a radically improved insulating material for hot water or low pressure steam piping, which, since it is made of moisture-proofed asbestos paper, offers positive protection against shrinkage troubles. Supplied in canvas, asbestos paper or aluminum finishes. All types furnished in 3-ft sections in standard thicknesses of 2 to 8 plies, each ply approximately in. thick. J-M 85% Magnesia Recommended as the most efficient in sulation of the molded type for tempera tures up to 600 F. Pipe insulation is furnished in sectional or segmental form for all commercial pipe sizes, in thick nesses up to 3 in. Blocks are 3 in. by 18 in. and 6 in. by 36 in., flat or curved, from H in- to 4 in. thick. J-M Pre-Shrunk Wool Felt Pipe Insulation Due to its Dual-Service Liner--an asphalt-saturated felt--J-M Pre-Shrunk Wool Felt is equally effective and durable on either hot or cold water service piping. By the use of waterproofed felts, shrinkage troubles have been minimized. . Supplied in two finishes, the regular canvas and a smooth, dull-coated alumi num. In either finish, it is furnished in 3-ft sections in thicknesses of in. % in., 1 in.. Double in., and Double % in., for pipe sizes from in. to 5 in. Can also be Superex Combination Insulation (an inner layer of high temperature Superex and an outer layer of 85% Magnesia) is recommended where temperatures exceed 600 F. Superex and Magnesia are both furnished in sectional and segmental pipe covering, arid in block forms. J-M Improved Asbestocel Sheets and Blocks Asbestocel Sheets and Blocks are used for insulating warm-air ducts, flues, heater casings and fan housings in the ventilating system. Temperature limit 300 F. Fur nished 6, 9, 12, 18 and 36 in. wide by 36 and 72 in. long, from l/i in. to 4 in. thick. J-M Rock Cork Sheets and Pipe Insulation J-M Rock Cork is made of rock wool and a moisture-proof binding ingredient molded into sheets for insulating refrigerated rooms and air conditioning ducts; and into sectional pipe insulation with an integral waterproof jacket, for all low temperature service. It is strong, durable, and will not support vermin. Because of its unusual moisture resistance, its high insulating efficiency is maintained indefinitely. Furnished in sheets 18 in. by 36 in., in lJ4, 2, 3 and 4 in. thicknesses; also 18 in. by 18 in. by 1 in. thick. In pipe covering form, in ice water, brine and heavy bribe thicknesses, for all commercial pipe sizes. Details on Request Write for complete information on any Johns-Manville insulating material. 1043 New York Insulation The Ruberoid Co. INSULATING PRODUCTS Executive Offices 500 Fifth Avenue, New York, N. Y. Chicago Divisional Offices Boston (Millis) Erie Baltimore Mobile The desire for increased efficiency of heating equipment as well as the need of fuel conservation prompts the engineer to seek the product that provides him with the most economical operating plant. The following Ruberoid Insulating Products are tabulated to enable you to choose quickly the one for the correct purpose. Greater detail and description are provided in the Ruberoid-Watson Catalog on "Heat or Cold Insulating Products," which will be sent on request. Product Temp. Limit Suggested Use Hi-Temp Pyrfelt Aristo Sponge Felt 85% Magnesia Imperial Watcocell Supercell Air Ceil Woolfelt Anti-Sweat Frost-proof to 1600 F to 1000 F to 750 F to 750 F to 600 F to 500 F to 350 F to 350 F to 350 F to I80F to 120 F 30 F to 100 F Protective inner layer for low temperature insulations. Breechings and flues -- withstands vibration. Superlative efficiency particularly on oil refinery lines. For vibrating pipes and underground insulation -- excellent efficiency. Combined efficiency and reasonable cost -- General use in industrial work. For temporary lines that require efficiency and constant removal of insulation. For a low-cost, medium pressure industrial steam line. An efficient and economical residential insulation. Standard insulation for residential pipes. For cold and hot water lines. _ For cold water lines to prevent condensation. To prevent freezing in circulating water pipes exposed to cold. Air CtU Pipe Covering--A low-cost insulation for resi dential use. Woolfelt Pipe Covering-- For the insulation of pipes carrying hot or cold water-- also prevents condensation under normal operating conditions. Sheet and Block Insulations All of the above products are also made in sheet and block form to whatever thickness may be required. Standard sizes are usually 6, 12,18 or 36 in. wide x 36 in. long. In this form they are used for in sulating flat or irregular surfaces, such as tanks, breechings, furnaces, etc. Insulating Cements For the finishing of sheet and block insulation and the insulating of irregular surfaces, such as valves, unions, flanges, etc., the Ruberoid-Watson line of insu lating cements is complete. This group of plastics not only uses as its base asbestos, but also takes advantage of such excellent natural products as magnesium, mineral wool and Vermiculite. Asbestos Cements--Factory Prepared --Grades 203, AA, A, HF. Asbestos Cements--Mine Run-- Grades 115, 214. Magnesia Cement--85% Magnesia. High Temperature Cement--Grade H.T. Mineral Wool Cement--Grade R-W. Vermiculite Cement--Grade A-il. 1044 The Ruberoid Co. Insulation RU-BER-OID Insulating Products for Residential Use Genuine RU-BER-OID Rock Wool The insulating material for supreme satisfaction as a residential insulation is Rock Wool. Its fluffy, fibrous texture produces its high efficiency. It is flexible in that it permits use in many forms and fills in all spaces. It is fireproof, resists vermin, and neither deteriorates nor rots. For comfort, fuel saving and all 'round economy, RU-BER-OID RockWool is the product to recommend and use. Pre-formed Fabricated Rock Wool Kraflined Giant Bats 9 in. x 15 in. Wall Pac pads assure uniform density for sidewalls. studdings, rafters, beams, etc. It provides assured covering capacity and nominal labor for applying. Packed in cartons, easily handled. 20 pads, the contents of one carton, are capable of insulating 20 sq ft including studding. Shipping weight 20 lb. RU-BER-OID Rock Wool Fill Insulation (loose rock wool) Ideal for insulating a new residence. Each bat is backed with a moisture-re sistant paper that acts as a barrier against moisture penetration and assists in holding the bat in place due to the flaps on either side. Made in either wall thickness or 2 in. thick. Size 15 in. x 48 in. Packed 5 per carton which weighs 45 lb; 2 in. bats packed 8 per carton. Standard Bats These are either Kraflined or without the moisture-resistant paper backer as may be desired. Furnished in two thick nesses, wall thick or 2 in. Size 15 in. x 23 in. which permits use in either studding, 16 in. centers or 24 in. centers. Kraflined Standard Bats packed 8 per carton; with out waterproof backer, 7 per carton-- Shipping weight 25 lb. 2 in. thick packed 12 per carton, weighing 30 lb. Wall Pac Pads RU-BER-OID Rock Wool is put up in a small pad 9 in. x 15 in. approx. 3 in. thick. It is not as stiff or rigid as the pre-fabricated bats, but it is a refined method of using loose wool for packing between There are occasions when a fill insulation is the desirable type to use, but in the majority of cases, the pre-fabricated bats or Wall Pac Pads assure more efficiency and can be installed with less labor. RU-BEROID Loose Rock Wool is clean, long fibred and easily handled. It can be fluffed up to apply at a density of about 8 lb per cubic foot and cover about 17 sq ft of area including the studs, per 35 lb bag when used to a thickness of about 3% in. Granulated Rock Wool . For use in blowing into sidewalls or attic spaces in existing homes or for pouring between ceiling beams, Granulated Rock Wool is provided in bags containing 35 lb. It is in pellet form averaging from the size of a pea to a marble. In this form it is very flexible, providing all the advantages of a rock wool product. It can be packed to any density of from 4 lb per cubic foot to 10 lb, depending on the desire of the applicator, although for the maximum efficiency, it is recommended at a density of 8 lb per cubic foot which gives a gross covering capacity per bag of about 18 sq ft 3 in. thick. 1045 1 Insulation The Pacific Lumber Company PALCO WOOL INSULATION 100 Bush Street San Francisco 59 E. Van Buren St. Chicago 700 So. La Brea Ave. Los Angeles 122 East 42nd St. New York WHAT IT IS PALCO WOOL is a loose fill insulating ma terial made from the bark of the Redwood tree, the protective covering of the world's oldest living thing. It is highly refined into an insulating material of light weight wiry fibres of springy resilience. Recent im provements in manufacturing have made it clean, dustless and lighter in weight. In practical use PALCO WOOL has proven to be ideal for all types of construction, large or small, where resistance to conduc tion of heat is required. It is continuously efficient and reasonably priced, thus assuring economical performance. USES PALCO WOOL is suitable for any type of domestic or commercial construction, in fact every place where an insulating material is required to effectively resist the transmission of heat. INSTALLATION Approximately 1 lb of PALCO WOOL is required per square foot of 4 in. thickness. It is easily put in place by hand. Between 100 and 150 lb can be applied per hour per man. It comes in bales weighing approxi mately 100 lb. Size 24 in. x 24 in. x 26 in. Send for Data Folder and Sample Send for "Comfort that Pays Its Own Way," new 16-page folder with compara tive data charts and complete information on PALCO WOOL. 8 PROPERTIES that make it AN IDEAL INSULATION 1. Thermal Efficiency: The estab lished conductivity of PALCO WOOL is 0.255 Btu per hour per sq ft per inch of thickness per degree F difference in tem perature by the Flat Plate Method. 2. Non-Settling: The fibres of PALCO WOOL possess such resilience that no set tlement in a wall can occur under the most severe conditions of vibration. 3. Moisture Resistant: The fibres of PALCO WOOL are entirely lacking in capillarity, and have little attraction for moisture, enabling it to remain dry and efficient when in use. 4. Permanent: The inherent anti septic qualities of PALCO WOOL make the existence of fungus impossible. The fibres retain their resilience indefinitely. 5. Vermin Proof: PALCO WOOL is distasteful and repellent to rodents and insects. 6. Fire Resistant: PALCO WOOL will not readily support combustion and is fire resistant. 7. Odor Proof: PALCO WOOL is odorless itself and does not absorb or give . off odors. 8. Economical: PALCO WOOL is light in weight and low in density, offering exceptional thermal efficiency per dollar invested. 1046 Insulation The Standard Lime & Stone Company 1888 - Golden Anniversary - 1938 First National Bank Building Baltimore, Md. Manufacturers of Capitol Rock Wool Insulations Representatives in all Principal Cities The Standard Lime and Stone Company, prominent in the building materials industry since 1888, manufactures Capitol Rock Wool Insulations, and produces crushed stone, all types of lime, fluxing stones, Capitol Portland Cement, etc. A new manufacturing technique produces a refined, longer, lighter, more flexible fibre--a more effective form of Rock Wool. Prefabricated Batts and Grade "A" Blowing Fibre (granulated) are widely used types of Capitol Rock Wool. Efficiency of Capitol Rock Wool The chart shows the comparative thicknesses of. various materials to give equal insulation efficiency. Transmission of both heat and sound is virtually eliminated by the effective tiny dead air cell structure of Capitol Rock Wool. Wall in new construction--shows vaporproofing membrane over Capitol Rock Wool Batts. CAPITOL ROCK WOOL BATTS A Distinctive Product Improvement --Solves Important Problems Moisture-proofed. The processing of Capitol Rock Wool Batts gives the fibres a moisture resisting characteristic. Mois ture from wet plaster, etc., penetrating from the structure interior is stopped by an effective vaporproofing membrane, applied over the surface of all Batts. Moisture is turned back inside the building to be ex hausted by normal ventilation. Vaporproofing Membrane. Tested membrane of enough length to protect the exposed surface of the Batts is enclosed separately in each carton--17^ in. wide to make tacking in place a quick, easy job, and giving a smooth, continuous mem brane-protected surface without any open horizontal joints between batts. Cuts Costs. The Capitol Rock Wool Batt is semi-rigid. Batts are one size, 15 in. x 24 in. Because of their size and stiffness, they "spring fit" between framing members spaced either 16 in. or 24 in. on centers. They cut readily to fit irregu lar shaped spaces. . Two Thicknesses. Wall-thickness, for maximum efficiency; also 2 in. thickness. Insulating Efficiency. Capitol Batts are carefully fabricated for uniform density and high insulating efficiency. Fire Protection. All Capitol Rock Wool Products assure fire protection. Also sound and vermin proof. Permanent. Once installed behind the plaster base, the Capitol Batts and the vaporproofing membrane give lasting protection to the home or building--a permanent investment that pays for itself. Capitol Rock Wool in Existing Homes Capitol Rock Wool Grade "A" Blowing Fibre is pneumatically introduced into the wall air spaces of homes already built, whether the construction is shingle, clap board, brick veneer, stucco or half- timbered. "Blown" installation is the same for any type of construction and is per formed by franchised blowing contractors, operating in accordance with Company' specifications and whose work is subject to Company inspection. Installation leaves no telltale marks. `- Capitol Rock Wool in New Structures, New homes or buildings are generally insulated at the time of erection by placing Batts between the studding and roof rafters. Many new structures however, are effectively insulated by installing Grade A Blowing Fibre after the scratch coat of plaster is applied. Send for catalogs and samples of Capi tol home and industrial insulations. "Look for the Capitol Dome on each carton--on each bag** 1047 s Insulation United States Gypsum Company 300 W. Adams Street, Chicago, 111. Sales Offices In Principal Cities Insulating Building Board Insulating Lath Metal Reinforced Insulating Lath Insulating Tile PRODUCTS Insulating Plank Insulating Mouldings Roof Insulation Asphalt Coated Sheathing Strip Wool Bat Wool Junior Bat Wool Granulated Wool RED TOP INSULATING WOOL Description Red Top Insulating Wool is an extremely light, fluffy mineral fiber insulation--a fireproof material. The nature of the raw materials used, particularly as to purity, permits accurate manufacturing control--the product is uniform and consists of snowy white, longfiber wool. It contains no "shot" or non insulating materials that add weight. Red Top Wool is springy and resilient --it will not mat. Low Thermal Conductivity The heat conductivity of Red Top Insullating Wool (1-J4 lb density) is 0.266 Btu per inch thickness, per square foot per hour, per degree Fahrenheit difference in temperatures. (Tests by Professor Peebles, Armour Institute of Technology). Unusually high in insulating efficiency, it is outstanding when, as customarily used, it is wall thick (4 in.). So used its rating is 0.066. Light Weight (Density) In its standard density, Red Top Insu lating Wool weighs but 1-^2 lb per cubic foot. Types The types of Red Top Insulating Wool are illustrated in this page, showing its adaptability. Applying Red Top Strip Wool between studs. Strip Wool has a waterproof paper backing with a B in. flange for nailing to studding. Used as shown-it Prevents the entrance of moisture into the insulation. Method of applying Red Top Bat Wool between rafters or studding. Insulation Western Felt Works 4029-4117 Ogden Avenue, Chicago, 111. LARGEST INDEPENDENT MANUFACTURERS OF FELT New York Cleveland Boston Detroit Branch Offices St. Louis Cincinnati Los Angeles San Francisco Denver Philadelphia Manufacturers and Cutters of Wool, Hair and Jute Felts WESTERN FELT WORKS, as a leading manufacturer and cutter of FELT, operates a thoroughly modern mill and completely equipped cutting department. Com petent and up-to-date research' and laboratory technicians are available at all times without obligation, to anyone whose field touches our products. AVAILABLE IN ROLLS, SHEETS OR CUT TO SPECIFICATIONS--Western Felt products are used most commonly in heating, ventilating and air conditioning installations for eliminating noise transmission and as an insulation against heat losses and cold penetration. WESTERN FELTS FOR SOUND CONTROL--Noises created by the operation of air conditioning equipment must be entirely eliminated at their source or neutralized and deadened during their course of travel through the air ducts. For such purposes Western Felts are especially adapted for lagging on air ducts, where it does triple duty--as a sound deadener of noises caused by the air conditioner itself--by preventing noises originating outside the system from being transmitted via the air ducts--and, because of its low rate of thermal conductivity, it serves as an insulation against heat losses through the duct structure. CUT TO REQUIRED SHAPES AND SIZES--Western Felts serve efficiently, as shock pads under such machinery as oil burners, stokers, fans, blowers, pumps, etc. Western Felts used in this manner counteract destructive vibrations and the resultant noises which would otherwise pass through air ducts to the various rooms. OTHER USES FOR WESTERN FELTS--Fabricated of wool, hair, or jute, Western Felts are available for a wide variety of other uses, such as weatherstrips, anti-squeak strips, insulation material, gaskets, washers, packing material, floor pads--in sheets, rolls or cut to special requirements. Important is the use of felt strips as a dust seal between the room register and wall. APPLICATION OF WESTERN FELT--Strength of fibre, flexibility and easy working characteristics of Western Felts make them simple to handle. Flat surfaces or irregular contours are easily and quickly covered at low labor cost. Write for free samples and further information describing the use of Western Felts for air conditioning units, or other purposes. Blowing Red Top Wool into Brick Veneer Wall 1048 Red Top Junior Bats are easily and quickly installed. Showing how Western Felt is used as mounting material at base of motor and blower units to reduce vibration and subdue noises. Insulation The Zonolite Company General Offices: 5905 Second Blvd., Detroit, Mich. Mines: Libby, Montana Manufacturing Distributors Dominion Insulation Ltd. 57 Bloor Street Toronto, Ontario. Canada Hill Brothers Chemical Co. 2159 Bay Street Los Angeles. Calif. Hinman Asbestos Corporation . Corner Fifth & Binney Sts. Cambridge, Mass. C .Zonolite Insulation o 5000 Manchester St. Louis, Missouri Honbywill and Stein, Ltd. 15 Regent Street London S.W.1, England Zonolite Corp. of Michigan . 5905 Second Blvd. Detroit, Michigan. George Karsch 720 Eye Street Sacramento. Calif. The Zonolite Co. Libby, Montana James Keeth East 1827 Sprague SDokane, Wash. Western Mineral Products Co. 2602 Ed Creighton Ave. 1720 Madison St., N.E. Omaha, Nebraska Minneapolis, Minn. Co.Gypsum Lime & Alabastine ' Calgary, Canada Winnipeg, Canada ZONOLITE INSULATION FOR HOMES Zonolite is a micaceous, non-metallic mineral insulation (aluminum magnesium silicate) expanded many times through a special process by the application of in tense heat. It insulates both by its multi ple dead-air cell construction and by its bright reflective surfaces. Zonolite offers "three-way" heat control, for it is an efficient, permanent barrier to the passage of heat by conduction, convection or radiation. The density of Zonolite is uniform, tamper-proof. Its insulating "value is the same in the walls or on the ceiling as when it left the factory. Zonolite cannot be "fluffed" or stretched when being installed: it flows evenly, filling every nook and corner with a "tailor-made" insulation of high efficiency. -Easily Applied Zonolite is easily installed in attics by pouring directly from the bag. No ma chinery is required for putting Zonolite between walls as it pours easily and fills completely with a constant and uniform density. Zonolite is sold in 4 cu ft bags and weighs approximately 6 lb per cubic foot. These bags provide the following coverage, in cluding joists or studs, 16 in. on centers: 3 in. thick 3% in. thick 4 \n. thick 5% in. thick 17H sq ft 14)^ sq ft 13 sq ft 9 sq ft Your local Zonolite Representative will gladly furnish estimates for installation costs on all thicknesses of Zonolite, Insu lation. Properties of Zonolite Insulation Zonolite Insulation is ALL-MINERAL --ROTPROOF and FIREPROOF; VERMIN-PROOF--rats, mice, termites or insect larvae will not eat it or nest in it; SOUND ABSORBING--tests by V. O. Knudsen, acoustical authority, show Zono lite to be high in sound absorption and sound insulation; LIGHT-IN WEIGHT-- approximately 6.1b per cubic foot; DI- 1050 The Zonolite Company Insulation ELECTRIC--a test by J. C. Peebles,' Armour Institute of Technology, showed that 20,800 volts were required to puncture a one-inch layer of Zonolite between oneinch brass balls; SAFE TO HANDLE-- no danger of silicosis, lead poisoning, sores or boils; CHEMICALLY INERT--tests of every description prove Zonolite will not deteriorate in any way or affect any material with which it comes in contact; ODORLESS--will not absorb or give off odors under any conditions. Zonolite forms a THICK insulation; is approved by leading air conditioning firms for use with their units. ZONOLITE - ASPHALT ROOF BLOCK . A durable roofing, weatherproof throughout its thickness, and an efficient insulation. (Thermal conductivity: 0.38 for the minimum applied thickness of in.). Not penetrated or affected by hot moppings; insulating value is the same in application as in laboratory. Elastic . . . will take up expansion, contraction, or uneveness in the roof deck without crack ing or forcing out the asphalt between the blocks. Economical to Apply. Three plies of roofing felt are usually ample for any job. No special precautions, either before or during application, are necessary to pro tect the insulation from the weather. Rotproof, waterproof, verminproof and highly fire resistant, Zonolite-Asphalt Roof Block is an ideal insulator for all types of roof decks. It is available in 12 in. x 24 in. blocks of any desired thickness from \ in. up.. noise, thereby allowing the use of a smaller duct to carry a specified volume of air. They are absolutely verminproof, rotproof, and fireproof, inside and out. Will withstand excessive vibration and high air pressures. Made exclusively by local sheet metal shops licensed by The Zonolite Company. ZONOLITE INSULATING PLASTER Insulates and Plasters in One Job An all-mineral plaster, extremely light in weight and uniform. Insulates effec tively against passage of heat and trans mission of sound. Fire resistant, easy to handle and spread. The elastic nature of the Zonolite ingredient permits expansion and contraction after application, thus adding permanence and strain resistance to the plaster, and reducing cracking. By applying Zonolite Insulating Plaster as brown and scratch coats over any plaster base, an unusually fine foundation for finish coats is provided. ZONOLITE INSULATING CEMENT A 100 per cent mineral product, Zonolite Insulating Cement is ideal for insulating tanks, boilers, etc., where the insulation must stand temperatures up to approxi mately 1000 deg. Its base is Zonolite, which accounts for its light weight and unusual efficiency. Has pronounced sound absorbing qualities as well as high thermal insulating properties. Zonolite Insulating Cement adheres well to any clean metal, concrete or tile surface. Can be reclaimed simply by adding water. ZONOLITE AIR DUCTS (Patented) Sound Absorbing and Insulated Entirely new in both concept and design, Zonolite Air Ducts are formed of heavy, specially-designed wire mesh. Directly to this mesh is applied Zonolite Insulating Cement--a thermal and sound insulator of great efficiency. No inside lining is necessary. The result is a duct which prevents condensation, minimizes drag, and absorbs sound at the rate of 1.5 deci bels per foot of duct. (Duct size: 91A in. x 1134 in.). Zonolite Air Ducts (Patented) permit increasing air velocity with no increase in ZONOLITE CONCRETE Proper mixtures of Zonolite and Port land Cement make excellent roof insu lation and roof saddles--all in one product. Zonolite Concrete has also proved itself as an ideal floor fill insulation where temperatures do not exceed 400 F--for instance, paint drying ovens. ZONOLITE INSULATED REFRACTORY Zonolite combined with high tempera ture cement and refractory 'material is extensively used in oil burner combustion chambers, soaking pits, large annealing ovens and industrial uses up to 2500 F. Write your nearest Manufacturing Disti jutor for full Details and Specifications 1051 Insulation, Underground Apsco PRODUCTS for STEAM SERVICE American District Steam Company North Tonawanda.N.Y IN BUSINESS OVER SIXTY YEARS Branches and Agents in Principal Cities Conduit with Asbestos Insulation ADSCO-BANNON TILE CONDUIT For Underground Pipe Lines A vitrified, salt-glazed, separable tile conduit, with or without base drain, com bining strength, durability and simplicity in connection with one or more bare or insulated pipes in underground steam or hot water lines. It provides high insu lating efficiency in a conduit that can be installed at small labor cost and is adapt able to varied installation conditions. Semi-steel pipe supports are held in fixed position on reinforced conduit sections. They do not pierce the conduit wall and are suitable for use with sectional molded insulation or filler insulations, particularly ADSCO-Corning Filler Insulation. Write for Bulletin No. 35-67G. Conduit with ADSCO-Corning Insulation INTERNALLY GUIDED JOINT An internal guide ring provides full guiding for entire travel of the slip, limit stops prevent overtravel of the slip in either direction. No metal to metal con tact against polished slip surface. Small over-all dimensions make it suitable for use in restricted spaces. Pressures to 300 lb and temperatures to 750 F. Write for Bulletin No. 35-30G. .. Internally Guided Joint INTERNALLY-EXTERNALLY GUIDED JOINT Internally-Externally Guided Type A completely guided slip type joint. Both ends of slip guided throughout entire length of ti^vel by an internal guide ring and an external guide in hood. Slip cannot pull out of body. No metal to metal con tact against slip surface. Pressures to 300 lb and temperatures to 750 F. Write for Bulletin No. 35-20G. PISTON-RING EXPANSION JOINT Piston-Ring Type Joint Piston rings in the guide ring attached to the inner end of the slip hold the line pressure, enabling the joint to be unpacked and repacked under full operating pressure without interruption to service. A fully guided joint for pressures to 400 lb and temperatures to 750 F. Slip cannot pull out of body. Write for Bulletin No. 35-15G. (See also Page 975) 1052 Insulation, Underground BALTIMORE H. W. Porter & Co. INCORPORATED Newark, New Jersey WASHINGTON RICHMOND CHARLOTTE Description--Therm-O-Tile is a com plete conduit system for the permanent support, protection, and insulation of underground pipe lines. The tile is made 6 in. to 24 in. in diameter and with five different size base tiles, producing twentyseven different conduit cross sections. waterproof fibre filling may be used for insulation, as the insulation space is kept dry at all times, by the internal drain. For single or double pipe lines, sectional insulation of economical thickness is recommended; for multiple pipe lines,, a filler type of insulation is usually more economical in first cost. Waterproofing-- Under normal soil conditions, this conduit is waterproof. If marshy ground or partially submerged conditions are encountered, the conduit may be made completely waterproofed by the use of membrane waterproofing applied under the slab on a sub-base and carried completely over the tile envelope. Efficiency--The degree of thermal efficiency secured depends upon the type and thickness of insulation used. This conduit, due to its sealed air chambers in the tile and dry insulation space, adds to the normal efficiency of the insulating material on the pipe lines. Foundation--The base of the system is a thick concrete slab poured directly in the trench bottom, reinforced with steel when installed over a filled or boggy ground. Drainage--The drainage system of the conduit is entirely internal, open to in spection at manholes, and of ample ca pacity to keep the pipe space dry at all times without any possibility of becoming clogged with silt or vegetation. Pipe Support--All pipes are supported on cast-iron adjustable supports resting directly on the concrete base independent of the tile envelope. Accessibility--All piping is installed before tile is placed, giving complete ac cessibility for welding, testing and insu lation. Pipe fitters work on concrete slab walkway. Strength--Due to immovable concrete base and arch construction of extra heavy tile members, conduit will sustain any roadway traffic load usually encountered without extra reinforcement. Insulation--In this conduit, either sectional pipe covering or Thermobestos Pipe Supports Single or Double Pipe Line* Using Sectional Pipe Insulation. ' Multiple Pipe Line* Utinq Filler Type Insulation. Therm-O-Tile is also sold and installed locally by Johns-Manville Construction Units. 1053 Insulation, Underground. The Ric-wiL Company Agents In Principal Cities Established in 1910 CONDUIT SYSTEMS FOR UNDERGROUND STEAM PIPES Union Trust Bldg., Cleveland, Ohio--New York, Chicago, San Francisco Conduit--Standard conduit is vitrified salt glazed tile or cast-iron with Loc-liP Side Joints, bell and spigot type, lined or unlined. Tile in 24 in. sections, sizes 4 to 27 in. inside diameter. A Super-Tile con duit to support any average traffic load is also available. For extra heavy duty under railroads or where conduit is subject to extreme loads, Ric-wiL is made of castiron in 2 or 4 ft sections. Where reduced labor cost is not essential, Ric-wiL Uni versal Type System is recommended (details on request). Base Drain--Standard Base Drain is vitrified salt glazed tile for tile conduit and extra heavy tile or cast-iron for the castiron conduit, in 24 in. lengths. Made in three sizes to support and drain properly all conduit sizes. Pipe Supports--Standard pipe sup ports will carry from one to five or more pipes and are ordinarily spaced 12 ft apart. They are strong, made of cast-iron, rustproofed, and interlock with the base drain foundation, imposing no load on the con duit itself. No movement of pipes can disturb them. Special pipe supports avail able for different conditions. Information on request. Insulation--Ric-wiL Dry-paC Water proof Insulation is high-grade long fibre asbestos processed so that it is permanently water repellant. Of unusually highefficiency and great natural strength, it will not slump away from pipes and is non corrosive. Sample will be sent gladly for testing. Ric-wiL No. 11 Insulation (same as Dry-paC except non-waterproof) or sectional pipe covering can also be fur nished. For lined conduit, diateomaceous earth mixture is molded and keyed inside the tile. Accessories--Shutter sleeves, filter cloth, asphalt joint cement, water-proofing compound, manhole covers, and other accessories will be furnished as desired. Engineering Service--Full coopera tion with architects and engineers. In stallation supervision if desired. Technical Data--Tabulated Steam Heating Rates, Test Reports, Service Detail Bulletins, Catalog Bulletins, Central and District Heating Bulletins and Archi tects and Engineers Detail Sheets available upon request. Ric-wiL Unit Steam Main, o prefabricated. ready-to-imiaH unit, ft long, including conduit {Armco Iran), pipe, insulation, and acctstoriet. Ideal for speed and economy on district heating projects. 1054 Insulation, Underground Underground Steam Construction Co. 75 Pitts Street, Boston, Mass. PRODUCTS--Engineering and Contracting of Steam Line Installations. Underground Steam Conduits. USCCO PRE-CAST CONCRETE CONDUIT This unit marks a long step forward in the economics and mechanics of laying under ground steam lines. Its Outstanding Features Are: Strength resulting from flat reinforced bell; from the longitudinal joints, and from the fact its sections are 4 ft long, reducing the usual number of joints necessary. Shape which allows 12 per cent greater inside capacity than circular conduit of like diameter. This permits larger pipes in a given size conduit and more room for drainage, pipe supports and rolls. Ease of Installation resulting from the fact that all top and bottom halves mate. Bottoms may be laid for any distance, the piping installed and then the tops brought up and laid. This speeds up the work and protects idle halves from damage. They can be stored away from the job. Materials are high strength cement with suitable aggregate, amply reinforced with wire mesh. Pipe Supports are of cast-iron and quickly installed. They may be placed anywhere in the conduit. The weight of the pipe holds them in place. ' Joints may be of any standard accepted brand of jointing compound or they may be of standard Portland cement mortar. 1055 / Insulation, Underground A. Wyckoff & Son Company Elmira, N. Y. Send all inquiries to our only Office and Factory--105 Home Street 1855-1938 WYCKOFF celebrates its 83rd Anniversary and introduces a NEW EVER LASTING Underground Redwood Steam Pipe Casing Specified by Architects and Engineers, Installed by Leading Contractors Unlined Redwood Casing Showing Socket End Extra Heavy Shell Unlined Underground California AU Clear Heart Stock Redwood Casing. Tin Lined Redwood Casing Showing Tenon End Extra Heavy Shell Tin Lined Underground Casing for Steam Pressures over 6 lb made of All Clear Heart Stock California Redwood Made of California Redwood staves (no knots or sap) wound with heavy galvanized wire, covered with a tough, practically indestructible coating of Montezuma Asphalt. Redwood is impervious to water, insects, worms and ro^, gives decades of economical service under the most trying conditions. Wyckoff casings have an enviable record of durability in service as insulation for underground steam or hot water lines and the frost-proofing for exposed pipes. They cannot shrink, swell or warp, and will "stay put" for years. Made in 2 in., 3 in., or 4 in. thick shells with tenon and socket joints in lengths up to 12 ft. Immediate shipment from stock. Write for details and prices of this unique type casing, advising kinds and sizes of metal pipes to be covered. (We also manufacture all clear Redwood Pipe for water supply lines, chemical lines, fume stacks, etc., in pressures up to 172 lb. Sizes 1 in. and up. Lengths to 12 ft.) - 1056 Motors Century Electric Company 1806 Pine Street, St. Louis, Mo. Offices and Stock Points in Principal Cities Y%MULTISPEED MOTORS to 200 Horse Power Press the Button--Change the Speed . . . Especially adapted to meet the variable or con stant speed requirements of Fans, Ventilators, Refrigerators and similar apparatus where adjust able speed change is a requirement . . . Built for 2, 3, 4 or more speeds--automatic, push button or manual control . . . Wide or narrow speed ranges, such as 1800/1200 or 1800/600 down to 900/450 rpm (60 cycle) . . . Conventional open or splash* proof type . . . Special speed combina tions are also available . . . Ball Bearings or phosphor bronze sleeve bearings. CENTURY MOTORS For Compressors, Pumps, Fans, Blowers, Refrigerators, Stokers, Oil Burners Type of Motor Horae Power Starting Range Duty Remark* Applications SINGLE PHASE MOTORS FIS--Brush-Lifting 1/8 to 40 Heavy BR--Brush-Riding 1/6 to 1/4- Heavy CPH--Cap. Start and Run 1/8 to 10 Heavy CSH--Cap. Start 1/8 to 3/4 Heavy Low Starting Current, High Starting Torque Short Annual Service Characteristics High Starting Torque Piston ot Plunger Pumps. Refrigerators. Stokers. Compressors, etc. High Starting Torque CSN--Cap. Start 1 to 10 CPX--Cap. Start and Run 1 to 10 Medium Light High Starting Torque Must be Loaded to at Least 50 per cent Capacity Fans (Belted or Direct Connected) Centrifufugal Pumps, etc. SP--Split Phase SP--Split Phase 1/20 to 1/3 1/20 to 1/3 Medium Light Unrestricted Starting Current, Special Serv ice. High Torque Restricted Starting Current. General Pur pose Oil Burners, Unit Heat . era. Blowers, Fans, Small Tools, etc. POLYPHASE MOTORS SC--Squirrel Cage SCN--Squirrel Cage _ 1/8 to 600 71/2 to 200 Medium Medium Normal Starting. Current Normal Torque Lower Starting Current than SC Normal Torque - General Purpose Motors. SCH--Squirrel Cage AS--Automatic Start 3 to 200 1 to 60 Heavy Heavy Low Starting Current High Starting Torque Lower Starting Current than SCH High Starting- Torque Refrigerators. Piston or Plunger Pumps. Com pressors. etc. SR--Slip Ring DM-DN-R Shunt Wound Constant Speed DM-DN-R Compound Wound Varying Speed DN-R Shunt Wound Adjustable Speed 1 to 350 Heavy For Frequent Starting and/or Speed Control Fans, Blowers. Centrif ugal Pumps. Com pressors, etc. DIRECT CURRENT MOTORS 1/20 to 300 1/12 to 300 1/2 to 200 Torque is limited only by Commutation. A Direct Current Motor has ample Torque to start any load that it can carry when up to speed. Starring Current is limited by Controller to about 150 per cent of full load current for light starting torque re quirements with corresponding increases in current for increased starting torque Fans, Blowers, Centrifugal Pumps, Machine Tools, etc. Reciprocating Pumps, Com pressors and Machines with Flywheels, etc. Fans. Blowers, Machine Tools, etc. Quiet Starting--Quiet Running--Remarkably Free from Vibration--Keep Themselves Clean Inside--Easy to Keep Clean Outside--Harmonizing Appearance--Century Squirrel Cage Polyphase Motors are Especially Adapted to all types of Air Conditioning Equipment. . 1057 Motors and Controllers GENERAL ELECTRIC COMPANY SCHENECTADY, N. Y. SALES OFFICES. WAREHOUSES. SERVICE SHOPS urn DISTRIBUTORS i* PRINCIPAL CITIES For Code Wire, Conduit Products, Wiring Devices, Insulating Materials, etc.. Address--APPLIANCE AND MERCHANDISE DEPARTMENT, BRIDGEPORT. CONN. HEATING, VENTILATING, AND AIR-CONDITIONING MOTORS Wound-rotor quiet-operating induction motor on sound-isolating base. Type MB Capacitor fractional-horsePower motor. Type KC The complete line of motors manufactured by the General Electric Company offers you a motor with electrical and mechanical characteristics best adapted to your com pressor, fan, or pump application. The most frequently used applications are listed below. Complete information on other types of motors, vertical, enclosed, etc., with various electrical and mechanical modifications, may be obtained from our nearest sales office. ' ... A complete line of motors, designed and tested especially for quiet operation for use in schools, hospitals, commercial buildings, and also a complete line of special sound- isolating bases for these motors are available when using V-belt drive. Application Fan* and Centrifugal Pumps Reciprocating Pumps ana Compressor* Small Direct Connected Fans - Belted Fans. Centrifugal Pumps Pumps. Compressors. Fans SOME G-E MOTORS AND THEIR USES Speed Type Winding Type Horsepower Range Classification Constant or Adjustable Constant or 3-Speed Constant or Zpeed Multispeed Shunt B & CD Compound - B & CD Resistance Split Phase KH Reactance Split Phase KX Low Torque Capacitor High Torque KC \ KC Capacitor KC Repulsion Induction SCR ' Squirrel Cage K or KB (Low Starting Current) KF 1/8-200 I/8-M0 1/40-1/3 I/6-I/3 1/50-10 1/4-10 1/8-10 1/8-10 1/4-1000 7l/r-75 Direct Current Single Phase . Alternating Current Reciprocating Pumps and Compressor* (High Starting Torque) KG 3-100 Polyphase Alternating Current Pumps. Compressors, Fans " Constant or Adjustable Constant Wound Rotor Synchronous M & MB TS i/HOOO 25-2000 This Company will gladly assist in the solution of any electrical problems in relation to heating and ventilation 1058 Motors and Controllers GENERAL. ELECTRIC COMPANY SCHENECTADY, N. Y. SALES OFFICES, WAREHOUSES. SERVICE SHOPS and DISTRIBUTORS in PRINCIPAL CITIES For Code Wire, Conduit Products, Wiring Devices, Insulating Materials, etc., Address--APPLIANCE AND MERCHANDISE DEPARTMENT, BRIDGEPORT. CONN. CONTROL FOR HEATING, VENTILATING, AND AIR-CONDITIONING MOTORS The General Electric line of standard control offers manual or automatic equipment for com pressors, fans, or pumps driven by any type motor which you require, providing full protection for your motor, especially those listed on the pre ceding page. . For special applications General Electric con trollers can be designed to meet your exact requirements. The following is a list of typical control equip ment applicable to all motors listed on the preceding page: CR7107 controller (cover removed) for use with multispeed Squirrel cage motors Full-voltage automatic starters with thermostatic control for fans, or pumps. Automatic reduced- or full-voltage starters for synchronous motors driving compressors. Manual or automatic speed-regulating controllers for wound-rotor motors driving fans. Manual full-voltage starters for pump motors. Manual speed-regulating switches for small capacitor, motors driving fans. Electrically operated valves. ACCESSORIES Thermostats. Float switches. Indicating Push buttons. CR7006--full voltage mag- netic switch for use with in- Auction motors ' CR1061 fractional-horsepower motor starting switch for wall mounting CR7764 Speed regulating controller for wound rotor motor {cover removed) Motors and control of one manufacture insure perfect operation, simplify installation and insure good service for the entire installation. This Company will gladly assist in the solution of any - electrical problem in relation to heating and ventilation See also pages 90S and 90S 1059 Motors The Ohio Electric Mfg. Go. 5906 Maurice Ave., Cleveland, Ohio Motors ^ to Hp, 870, 1150, 1750, and 3500 Rpm--also 2-speed. The greater part of our production is motors of special types to meet the particular requirements of the appliances or machines for which they furnish power. Ohio Motors are extensively used for Compressors, Pumps, Fans, Blowers, Oil Burners and Stokers. Rigid Base Type Designed in the modern mode, with flowing lines and rounded contours, eliminating all protuberances com monly found on motors. Bearing housings, oil wells, etc., are encased and concealed inside the end-bell, so that the exterior presents a true streamline effect. Made in split-phase, polyphase and capacitor types. The capacitor is enclosed in the end-bell. Also en closed is terminal switch-board. Thermal cut-out, either automatic or manually operated, can be sup plied without affecting the streamline design. All these features can be included in the Resilient Base and Belt-tightening Ohio Motors described below. Resilient Base Type The resilient mounting, together with the smooth running qualities inherent in all Ohio Motors, doubly assures quiet operation. The cushion material on which the motor is mounted is not affected by oil. The housing, of streamline design, encloses the capaci tor and all accessories as in the rigid base type. A high-efficiency, long-hour-duty, split-phase, polyphase or capacitor start and induction run motor. Its characteristics are high starting torque, high efficiency and low current consumption. Furnished with or without thermal and overload protection. Can be used for floor, side-wall or ceiling mounting. Underdrive Belt-Tightening Type This resilient-mounted Ohio Motor keeps belts tight without springs or weights. It is suspended off-center so that the belt slack is taken up by the weight of the motor and after starting, the repelling force ofthe rotor in opposing the stator further adds to the belt-tighten ing effect. The result is that service calls to take up belt slack are reduced to a minimum. Streamline housing encloses all parts and accessories. Built-in thermal and overload cut-out are optional. Overdrive Belt-Tightening Type Similar in construction to the Underdrive Type except that the motor is suspended above and to the right of its center in the resilient mounting to take up slack in overdrive belts. Designed particularly for powering blowers and other appliances where overdrive belts are essential. The weight of the motor mounted off-center supplies initial tension and the force of the rotor opposing the stator increases the tension, taking up if necessary 1 in. stretch in the belt. Built-in ther mal and overload cut-out are optional. ' Ohio Motors are made in Shaded-Pole, Split-Phase, Capacitor, Torque, Polyphase and Direct-Current types, a-c and d-c Motor Generators, and High to Low Voltage d-c Dynamotors. Flange Mounted and many other special types of motors are made for particular application to oil burners and for other special applications. 1060 Pipe and Fittings (Copper) AMERICAN RADIATOR COMPANY division ofAmerican 'Radiator & Standard .Sanitary Corporation , 40 West 40th Street, New York, N. Y. ARCO WROUGHT COPPER PIPE AND FITTINGS THE ARCO PURE WROUGHT COPPER-TO-COPPER CONNECTION The Arco Copper-to-Copper solder connection offers plumbing, heating and air conditioning installations many distinct advantages. Rust proof, corrosion resistant, it is prac tically a permanent bond between identical metals. It successfully withstands pounding, strain, pressure and vibration--is guaranteed stronger than the pipe itself. Arco Pipe and fittings are made of pure copper, are non-porous, there fore have a smooth inside bore, free from butts that hinder full flow of steam, water, other liquids or gases. There's a full range of sizes from % in. to 4 in.--the line is complete. COMMINGLING OF PARTS Crow Practically any fitting required on a plumbing, heating or air condition ing installation may be made up from a few Arco basic fittings. This elim inates the need for stock ing many varieties of seldom used fittings. (See also American Radiator Co. pages 884-885, 940-943, and Subsidiaries) 1061 Pipe and Fillings, (Copper) The American Brass Company General Offices: Waterbury, Conn. Manufacturing Plants: Aksonu. Conn. Torhington, Conn. Watehbuht. Conn. Bottalo. N. Y. Detroit. Mich. Kenosha. Wts. Offices and Agencies In Principal Cities Anac^ndA from mine to consumer CANADIAN PLANT: Anaconda American Brass Limited, New Toronto. Ontario PRODUCTS--Anaconda Deoxidized'Copper Tubes and Fittings; Anaconda "85" Red-Brass Pipe; Everdur Metal for storage heaters, storage tanks, ducts and air conditioning equipment ANACONDA COPPER TUBES AND FITTINGS For Heating, Plumbing and Air Conditioning Anaconda Deoxidized Copper Water Tubes assembled with Anaconda Fittings offer an unusual combination of advan tages in hot water heating systems at a cost only slightly higher than black iron and approximately the same as wrought iron pipe. These advantages may briefly, be summarized as follows: Complete Immunity to Rust -- Copper heating lines can never rust through to leak, nor will they become clogged with rust deposits. This means long service at a minimum of upkeep expense. Low Friction Loss--Because the inside surfaces of copper tubes do not become roughened by the formation of rust, these tubes offer a minimum resistance to flow. In addition, the long radius turns of Anaconda Elbows and the smooth inside surface of Anaconda Wrought Copper Fittings further reduce friction losses. These factors naturally increase the efficiency of the system, particularly when it includes a forced pressure circulator. Low Heat Loss--The bright copper tubes radiate much less heat than black iron pipe of the same size. Ease of Installation--In many instal lations, a short section of soft copper tube can be installed between the lateral run and the radiator. As these soft tubes can readily be bent by hand, this frequently eliminates several fittings. In many other places, also, the flexibility of soft copper tubes simplifies connections that ordinarily would be awkward and expensive to make with rigid pipe and threaded fittings. Anaconda Solder Fittings are compact. They can be installed in constricted space where the use of a wrench would be impossible. Architects and builders naturally object to large holes and notches cut in' the framing members of a building for the passage of piping. Anaconda Copper Tubes can be installed with a minimum of cutting in the structure, although holes should be large enough to permit move ment of tubes due to expansion and contraction. ' Appearance -- Anaconda Deoxidized Copper Water Tubes assembled with Anaconda Solder Fittings present an at tractive appearance. It is customary practice to clean the tubes after they are installed and apply a coat of clear lacquer or similar substance. This treatment keeps the tubes bright and makes an installation of which both the plumber and owner can be proud. Temper and Gauges--Anaconda Cop per Tubes are made in both hard and soft temper and in three types as to wall thickness. Designated as types K, L and M, they meet the requirements for these types of tubes in U. S. Government Speci fication WW-T-799* and A.S.T.M. Speci fication B-88?33*. Type K, the heaviest, is recommended for heating lines and general piping. Type L tubes are suitable for interior plumbing. Type M tubes are not recommended for heating lines. Accuracy of Dimensions--Anaconda Deoxidized Copper Water Tubes are all finished to the close tolerances required'by the A.S.T.M. and Federal Specifications, which have been found essential for efficient assembly with solder fittings. Permanent Identification--For per manent identification, the name "Ana conda" and the letter designating the type of tube is stamped in the metal at intervals Specifications for Type M tubes include hard drawn tubes only. ' 1062 Pipe and Fittings, (Copper) The American Brass Company of approximately 18 in., throughout every coil or straight length of tube. Availability--Anaconda Copper Tubes, in all standard sizes, are carried in stock by distributors of Anaconda Pipe, located in the principal trading areas of the country. These tubes, in sizes up to and including 1}4 in. are furnished soft in 30, 45 and 60-ft coils; also hard and soft in 20-ft straight lengths. Sizes over 1 in. are fur nished, hard or soft, in straight lengths only. any usual type of connection can be made without resorting to the trouble and expense of using combinations of fittings. Literature -- Anaconda Deoxidized Copper Tubes, Fittings, Solder and Acces sories are discussed at length in Anaconda Publication 11 B-l, 11th Edition. Copies will be mailed to Heating, Piping, Venti lating and Air Conditioning Engineers on request. ANACONDA SOLDER FITTINGS Anaconda Solder Fittings are available in both wrought copper and cast bronze. They are made to the exacting dimensions so essential for sound, leak-proof joints. Smooth inside surfaces permit quick, thorough cleaning which is necessary for satisfactory soldered connections. Deep cups, with adequate shoulders for the tubes to butt against, provide a maximum area for the solder bond. All Anaconda Solder Fittings are tested to 90 lb air pressure under water, which is the equivalent of 400 to 450 lb water pressure. They are so designed as to offer a minimum of resistance to the flow of water. Anaconda Wrought Copper Solder Fittings--Anaconda Wrought Copper Solder Fittings provide copper to copper connections. They are uniformly true to size, of one piece, seamless construction, and are free from porosity--features which make these fittings ideal not only for heating lines.but also for air conditioning and refrigerating installations, where the penetrating power of the commonly used refrigerants demands absolute freedom from porosity. The American Brass Company offers Anaconda Wrought Copper Solder Fit tings, including elbows, tees, couplings, unions, and a complete range of reduction and adapter combinations from )4 in. to 4 in. inclusive. Anaconda Cast Bronze Solder Fit tings--Anaconda Cast Bronze Solder . Fittings are extensively used for interior plumbing. They are available in all standard sizes from )4 in- to 10 in. (sizes up to 4 in. are carried in stock), in a com plete line of elbows, tees, couplings and unions, including all standard reduction and adapter combinations. With such a broad range of Cast Bronze Solder Fittings, ANACONDA "85" RED-BRASS PIPE Anaconda "85" Red-Brass Pipe, in standard pipe sizes, is offered as the highest quality corrosion-resistant pipe commer cially obtainable at a moderate price and is recommended for steam return lines. Anaconda "85" Red-Brass Pipe con tains 85 per cent copper and conforms to government specifications for Grade "A"' water pipe. The words "Anaconda 85 Red-Brass" are stamped in the metal at intervals of one foot throughout each length. EVERDUR Everdur Tanks--Everdur Silicon Bronze is a special non-rust alloy which combines high strength and complete immunity to rust with ready weldability. It is an ideal material for durable, rustless water tanks of every description--from domestic range boilers to giant storage heaters for hotels, laundries, hospitals, textile plants, schools or breweries. Everdur is made in all commercial shapes, including tank plates which have physical properties as given in A.S.T.M. tentative specifications B96-36T. For ad ditional data, and names of fabricators, address our nearest office or agency. Everdur for Air Conditioning Equip ment--Everdur Metal has been used with marked success for fans and blowers, ducts, humidifiers (air washers) and for various cast and wrought parts of other equipment items subject to corrosive influences. Because of its strength and welding properties, Everdur may be substituted for steel, fabricated by substantially the same methods, and with the same equip ment. `Everdur" is a trademark of The American Brass Company registered in the U. S. Patent Office. 1063 Pipe and Fittings (Copper) Mueller Brass Co. Port Huron, Mich. Branch Offices and Representatives in Principal Cities Albany, N. Y. Atlanta, Ga. Birmingham, Ala. Boston, Mass. Buffalo, N. Y. Chicago, III. Cincinnati, Ohio Cleveland, Ohio St. Louis, Mo. Dallas, Texas Dayton, Ohio Denver, Colo. Detroit, Mich. Flandreau, S. D. Flint, Mich. Harrisburg, Pa. Indianapolis, Ind. Kansas City, Mo. Lansing, Mich. Los Angeles, Calif. Milwaukee. Wis. Minneapolis, Minn. Canadian Sales and Manufacturer Newark, N. J. Philadelphia. Pa. N. S. Pittsburgh, Pa. San Francisco, Calif. Sarasota, Fla. . Seattle, Wash. Washington, D. C. Canada Wire and Cable Co., Ltd., Toronto, Canada Mexico George F. Gilfrin, Edificio "La Nacional." Mexico. D. F. PRODUCTS--STREAMLINE Copper Pipe and Seamless Tubes; STREAMLINE Hard Copper Pipe and Solder Fittings; Valves, Flared and STREAMLINE Solder Fittings for Mechanical Refrigeration; Forgings of Brass, Bronze and Copper; Castings of Brass and Bronze; Rod; Screw Machine Products; Fabri cated Parts and Special Nickel and Chromium Plated Parts. Coupling Copper to Copper Copper to Outside I.P.S. 45 Deg Elbow Streamline Copper Pipe and Fittings for heating, plumbing, air conditioning and industrial use are made by the Streamline Pipe and Fittings Division, Mueller Brass Co., Port Huron, Mich. The Streamline Solder Fitting is the original solder type fitting, introduced and manufactured by the Mueller Brass Co. of Port Huron, Mich. It incorporates many advantageous features and has proved to be the revolutionary advance of the age in the development of piping systems Jor plumbing and heating and for many industrial uses. The Streamline Solder Fitting is not connected either by threading or flaring, but by soldering. The outside surface of the copper pipe and the^inner surface of the Stream line fitting are cleaned with sandcloth, and solder flux is' then applied to the cleaned surfaces to eliminate oxidation when the assembled joint is heated. The joint is then sufficiently heated with a blow or acetylene torch and the soldering operation is per formed by feeding wire or stick solder through the feed hole in the fitting. The Streamline Solder Fitting alone has the solder feed hole, groove and taper. The solder feed hole, through which the solder is introduced, enters directly into an internal feed channel. The feed channel is located equidistantly between the internal shoulder against which the pipe rests and the outer edge of the fitting. When solder is introduced it is distributed by capillarity from the feed channel and distributed evenly and thoroughly between the bonding surfaces, traveling inward to the shoulder and outward to the edge of the fitting where it appears as a continuous solder ring around the full circumference of the pipe. This ring, and feed hole completely filled with solder, constitute positive proof to the operator that the joint is permanently leak-proof. An actual pressure test is not necessary. The tapered ends, since they are the thinner sections of the fitting, hasten the cooling of the solder at these points and facilitate the completion of the joint. 1064 Pipe and Fittings (Copper) Streamline Pipe and Fittings Division MUELLER BRASS CO. Port Huron, Mich. Patents 1770852; 1776502 90 Deg Elbow Tee Copper to Inside /. P. S. Crosses The solder may be fed from any position, whether the feed hole is located at the top, side or bottom. Owing to the never failing phenomena of capillarity, the solder will flow up, down or laterally with equal facility. * Streamline Copper Pipe is a seamless cold drawn copper tubing conforming to A.S.T.M. B 88-33. For most piping purposes, hard drawn pipe is used though annealed material is supplied where bends are to be made. Three weights of Streamline Copper Pipe, Govt. Types K, L and M, are made in all sizes, and an additional lighter weight is made in sizes 3 in. and larger. The latter is used mainly by the paper industry for pressures not over 125 lb. This range of weights permits its use for water or air pressures up to 400 lb. Streamline Solder Fittings are furnished in sizes from in. to 12 in. inclusive with a full range of reducing sizes. Fittings above 6 in. are flanged and may be had with either A.S.A. or rivetted pipe standard flanges. Mating flanges are soldered to the pipe. The Streamline Solder Fitting permits the use of thin-walled copper pipe and places a non-rusting, non-clogging piping system within the reach of the ordinary investor. Vibration is not localized at the joints, but is harmlessly dissipated throughout the system. ^Copper Pipe has the property of transferring the heated element (steam or hot water) from the point of generation (boiler) to the radiators quickly and with slight temperature drop.) During the last five years architects and engineers have used Streamline Copper Pipe and Fittings successfully in every type of building construction and in thousands of installations throughout the United States and Canada. In addition to its rust, clog and vibration-proof qualities and long life, Streamline has many other advantages such as the reduction in size of pipe lines and radiator con nections from those nominally used, a neat, compact installation requiring a minimum of space and important advantages in industrial and drainage applications. There is a Streamline product for every, piping requirement. Write the Mueller Brass Co., Port Huron, Michigan, for Catalog illustrating and de scribing the complete line of Streamline Solder Fittings. . 1065 Pipe and Fittings Arthur Harris & Co. 210-218 N. Aberdeen (formerly Curtis) Street Chicago, 111. ENGINEERS -- FABRICATORS OF NONFERROUS METALS AND STAINLESS STEEL PRODUCTS--Apparatus for Brewers, Distillers, Dyers, Paper Mills, Pharma ceutical Manufacturers, Manufacturers of Acetic Acid, Grain and Wood Alcohol, Cider, Confectionery, Gelatine, Glucose, Glue, Glycerine, Lacquer, Malted Foods, Meat Extracts, Milk Products, Preserved Fruits, Sugar, Tan Liquor Extract, Turpentine, Varnish, Vinegar, etc. Bulletin on request. Metals Fabricated--Aluminum, Block Tin, Brass, Bronze, Copper, Everdur, Monel, Nickel and Stainless Steel. Metal Floats Ball Cylindrical Column Flat Head Flat Cylindrical ' Made of copper, plain steel, stainless steel, aluminum, brass, monel and pure nickel, for open tank and all pressures. Seamless copper ball floats carried in stock in diameters of 4 in., 5 in., 6 in., 7 in., 8 in., 10 in. 12 in. for open tank and pressures of 25, 50, 100 and 150 lb. Special sizes and pressures made to order. Stainless steel ball floats 23^2 in. to 12 in. for high pressure and corrosion carried in stock--special stainless steel floats made to order--stainless steel ball floats larger than 12 in. diameter can be made up specially. Float catalog sent on request. Copper Expansion Joints Coils For low pressure and vacuum. Made in two styles--convex and concave. Sizes 4 in. to 60 in. diameter. Cast iron or steel flanges. Flanges drilled to American standard unless otherwise ordered. 4\ . '. We have special equipment for making coils in all shapes and sizes from pipe or tubing--copper, brass, aluminum, stainless steel, monel,\ block tin and pure nickel. Standard or special fittings. Send sketch, blue-print or old coil. Bends We make bends in every shape from all sizes of pipe and tubing. Standard or special connections. Copper, brass, aluminum, stainless steel, monel, tin and nickel. U-bends for storage water heaters. Also special pipe work for industrial installations, plumbing, heating and brewing. Perforated pipe, double pipe coolers, etc. . 1066 Pipe and Fittings Revere Copper and Brass Incorporated Executive office: 230 Park Avenue, New York City MILLS--Baltimore, Md., Taunton. Mass., New Bedford, Mass. Rome, N. Y., Detroit, Mich., Chicago, III. SALES OFFICES--Boston, Mass., Providence, R. I,, Philadelphia, Pa., Atlanta. Ga., New Orleans, La., New York, N. Y., Pittsburgh, Pa., Cleveland, Ohio, Wise.,Cincinnati, Ohio, Grand Rapids, Mich., Milwaukee, St. Louis, Mo., Minneapolis, Minn., Dallas, Texas, Seattle, Wash., San Francisco, Calif., Los Angeles, Calif.. Hartford, Conn. REVERE COPPER WATER TUBE Revere Copper Water Tube is recom mended for heating lines, refrigerant lines, heat control lines and for other heating and ventilating piping. This tube is seamless, 99.9 per cent pure copper, completely deoxidized,'with a gun-barrel finish inside. It is furnished in three types known as "K," "L," and "M," which meet Govern ment and A.S.T.M. specifications. In general the Type "K" is used where cor rosive conditions are severe, and types "L" and "M" where these conditions are normal. For most heating work, Types "LM and "M" are satisfactory. Types "K." and "L" are furnished in both hard and soft tempers; Type "M " in hard temper only. The hard temper- is used for new and exposed work; the soft temper for hidden replacement work and where flexibility is essential. (A 40 page hand book on Revere Copper Water Tube will be sent on request.) Fittings--This tube is joined with Streamline soldered fittings or with any standard make of compression fittings. Thus, threading is eliminated and metal in.S.P.S. pipe used only for cutting threads is saved. The wall thickness of Revere Copper WatrfTube is uniform throughout and the joints are leak-proof, vibration-, proof and stronger than the tube itself. The Streamline-fitting is so made that friction is reduced to a minimum. Advantages of Revere Copper Water Tube--In brief these are as follows: 1. Revere Copper Water Tube has many installation advantages. With Streamline Fittings it can be installed in a minimum of space. The soft temper tube can be bent where needed, as for example, around spandrel beams. This saves installation time and eliminates fittings. Furring is greatly reduced. Joints may be easily disassembled. 2. Revere Copper Water Tube cannot rust, so that it is not necessary to install oversize pipe. It is recommended par ticularly for steam return lines where the greatest amount of corrosion takes place. 3. In forced circulation hot water heating systems, where small pipe sizes are used, Copper Water Tube can be installed at prices that are competitive with iron or steel. The range, of sizes is such that a balanced system can be designed using minimum pipe sizes. 4. In general pipe covering can be one size smaller with Copper Water Tube than for the same size S.P.S. pipe because of the smaller outside diameter of the tube. It can also be light in weight just heavy enough to prevent convection losses. 5. Because of its flexibility and the ingenuity with which Copper Water Tube can be joined with Streamline Soldered Fittings, this tube is recommended for all sorts of special hook-ups. To Heating and Air Conditioning Manufacturers--Revere Engineers are anxious to cooperate with manufacturers of heating and air conditioning equipment and to make recommendations with refer ence to the use of non-ferrous products. Revere Copper Water Tube STANDARD DIMENSIONS AND WEIGHTS TYPE K TYPE L TYPE M OX). Wall Wt Wail Wt Wall Wt In. Thick- Lb Thick- Lb Thick- Lb In. ness per Ft ness per Ft ness per Ft In. In. In. `A .375 Vs .500 i .625 Vs .750 % -.875 1 1.125 I1A 1.375 Wi 1.625 2 2.125 2'A 2.625 3 3.125 }'/2 3.625 4 4.125 5 5.125 6 6.125 8 8.125 .032 .133 .030 .126 .025 .106 .049 .269 .035 .198 .025 .144 .049 .344 .040 .285 .028 .203 .049 .418 .042 .362 .030 .263 .065 .641 .045 .455 .032 .328 .065 .839 .050 .655 .035 .065 1.040 .055 .884 .042 .072 1.360 .060 1.140 .049 .464 .681 .940 .083 2.060 .070 1.750 .058 1.460 .095 2.920 .080 2.480 .065 2.030 .109 4.000 .090 3.330 .072 2.680 .120 5.120 .100 4.290 .083 3.580 .134 6.510 .110 5.380 .095 4.660 .160 9.670 .125 7.610 .109 6.660 .192 13.870 .140 10.200 .122 8.910 .271 25.900 .200 19.290 .170 16.460 Recommended Operating Pressures Type K--Hard Temperup to 400 pounds Type K--Soft Temperup to 250 pounds Type L--Hard Temperup to 250 pounds Type L--Soft Temperup to 150 pounds Type M--Hard Temperup to 250 pounds Tempers and Lengths Type K--Hard and Soft Temper in straight 20 ft lengths Type L--Soft Temper in 30 ft, 45 ft, and 60 ft coils. Type M--Hard Temper in straight 20 ft lengths. 1067 Pipe and Tube (Flexible) Chicago Metal Hose Corporation (formerly Chicago Tubing & Braiding Co.) Exclusive Manufacturers of REXS VIBRA- SORBERS For Air Conditioning and Refrigerating Machinery Maywood (Chicago Suburb) Illinois Effectively Eliminates Vibration -- Dampens Compressor Noises These units consist of sections of REX-WELD Flexible Bronze Tubing to which are brazed couplings to fit standard copper water tubing. The unique patented welding process by which the tubing is formed produces walls of uniform thickness--and therefore of great strength and flexibility. A special bronze alloy of non-porous structure, and practically immune to crys tallization, is used--the ideal combination for absorber service. After exhaustive tests, REX VIBRA-SORBERS have been adopted by leading producers of air conditioning equipment. Submit specifications for prices. Recommended Lengths for Standard Installations Copper Water Tubing Sixe Actual O. D. >/.* vv wV." w W w w 2vr 2>/' w Unit Lengths Lgth. Tubing 6' 7" w 8' 9" 9* Vi'10* 11 13 15" 18" 20" Overall Lgth. 2Vf /." 93/,' 10'/,' 12'/,' 12'/,' 14'/,' 16" 173/,' 203/,' 24'/,' 27' . REX-WELD Flexible, All-Metal Charging Lines Leakproof--Non-Corrosive--Non-Crystallizing Absolutely sale--withstands pressures up to 2000 lb, far in excess of working requirements; Furnished with ^6-20 S.A.E. male or female couplings--or with 4)4 in. copper tube extension with swivel female couplings on both ends. For ammonia service, REX-WELD Steel Tubing with steel couplings is supplied, suitable for operating pressures up to 6000 lb per sq in. 1068 Pipe and Tube (Flexible) Titeflex Metal Hose Go. 504 Frelinghuysen Ave., Newark, N. J. Boston, Mass............. Buffalo, N. Y_____ Chicago, Ill._............ Cleveland, Ohio.... Des Moines, Iowa.. Los Angeles, Cal. Memphis. Tenn.___ Kansas City, Mo.. St. Louis, Mo........... Sales Offices ................. .49 Federal St. .506 Liberty Bank Bldg. .1112 Merchandise Mart ...310 Hippodrome Bldg. ...............414 Twelfth St. Detroit, Mich.._....... .5-211 General Motors Bldg. Dallas, Texas.....................................P. O. Box 2064 Philadelphia, Pa................................... Bourse Bldg. Pittsburgh, Pa........................ 1438 Park Blvd. (16) San Francisco, Cal....................950 Van Ness Ave. Represen tatlves ............. 1835 S. Hope St. .........1000-2 Lamar Ave. .............5741 Grand Ave. .................. 4549 Olive St. Denver, Colo........................................748 Broadway Seattle, Wash............................. 1530 Eleventh Ave. San Francisco, Cal............................... 1466 Pine St. Toronto, Ontario, Canada -.....525 Federal Bldg. Titeflex Metal Hose Co. now offers to the Refrigeration, Air-Conditioning, and Heating fields, an approved vibration joint adaptable to all phases of service. Titeflex, being all metal in construction will efficiently carry refrigerants under pressure. The use of Titeflex vibration joint in the solid tubing or pipe line assures safe, quiet, trouble free operation of oil burners, refrigerating apparatus and other units. It com pensates for the vibration and shocks due to motor operation, expansion strains, and stresses, and prevents the cracking and leakage which would otherwise result when crystallization occurs jn rigid tubing and pipe. SAFETY: Titeflex 0. Br assembly is listed as standard by Underwriters' Laboratories for Oil Burner service; approved by the United States Shipping Board as a flexible con nection for oil burner service; and approved by the Testing Laboratories of the Associated Factories Mutual Fire Insurance Companies. Cut showing typical oil burner assembly showing male and union pipe fittings. Available in any length and in pipe sizes offrom % in. to 8 in. ' Cut showing crCss-section .of typical vibration absorbing assembly for refrigeration service. Note streamline fittings which can be supplied for copper tubing sizes of from % in. to 8 in. I.D. W SB %* DB SB V db '/,' SB >/,' DB W*<s" SB DB Sizes of Titeflex Fiat Ribbon Bronze Braided Tubing O.D. 0.300 0.324 0.333 0.357 0.400 0.426 0.480 0.518 Weight per Ft 0.09. 0.11 0.13 0.15 0.15 0.17 0.21 0.24 I.D. 3/,'SB db Vl'A' SB DB /.' SB 3/,' DB 1" SB 1' DB Wl%" SB DB O.D. 0.562 0.590 0.770 0.810 1.071 1.110 1.390 1.442 1.707 1.767 Weight perFt 0.26 0.34 0.52 0.64 0.67 0.85 0.88 1.09 1.06 1.45 I.D. 1WVzi"* SB DB 2" SB 2' DB 2'/z" DB 3" DB O.D. 2.060 2.120 2.560 2.620 3.300 3.820 Weight per Ft 1.50 1.82 1.85 2.24 2.% 3.50 Send us your requirements today, and we will be very happy to quote. 1069 Pipe and Tube (Steel) Jones & Laughlin Steel Corporation AMERICAN IRON AND STEEL WORKS Jones & Laughlin Building, Pittsburgh, Pa. WELDED AND SEAMLESS STEEL TUBULAR PRODUCTS J & L Welded Pipe . Jones & Laughlin manufactures Standard Weight, Extra Strong, and Double Extra Strong Welded Pipe, Black and Galvanized, for steam. gas, air, water, refrigeration and sprinkler work. Sizes: in. to 16 in. O.D. inclusive. J & L Copper-bearing Steel. Pipe, when specified, can be supplied in standard weight, or extra strong, black or gal vanized. Use of this product is recom mended for long life, where piping is to be exposed to the atmosphere or other alternate wet and dry conditions.. Jones & Laughlin Steel Pipe is made of soft, weldable steel rolled from solid ingots made to a special analysis which, checked over a period of years, has proved to be very uniform in quality. The steel pipe produced from this special grade of J & L Steel is soft and ductile, free cutting, strong at the welds, and free from excess scale. J & L Pipe is commercially straight and free from blisters, cracks or other injurious defects and is well within the allowable tolerances as to dimensions and weights, and true to round in the outside diameter. Careful attention is given the threading of the pipe with good clean-cut threads fitted with sound couplings correctly tap ped to give a tight joint. Soft, ductile steel of free cutting quality enables the con tractor to cut clean, sound threads on the job. The Jones & Laughlin process of gal-' vanizing assures a thorough coating and insures against pipe being clogged with spelter. The surface of the pipe is care fully cleaned so that when the galvanized coating is applied it adheres strongly and does not tend to flake off. J & L Seamless Pipe J & L Seamless Pipe is made in three weights; standard, extra strong and double extra strong. Sizes: % in. nominal to 14 in. O.D. inclusive. J & L Seamless Steel Pipe is pierced from a solid billet--there are no welds. The result is dependable and uniform wail strength. The method of manufacture, and the use of only specially selected steel, assure exceptional ductility, a quali ty that is essential to successful coiling and bending, and flanging for Van Stone joints. J & L Seamless Pipe can be used with full satisfaction in either threaded joint or completely welded installations. Ductility, strength and safety--highly developed attributes of J & L Seamless--make this product es pecially adaptable for air, steam, gas and gasoline lines, boilers, refineries, dry kilns, refrigerating systems and other exacting applications. J & L Hot Rolled Seamless Steel Boiler Tubes J & L Seamless Boiler Tubes are manu factured in accordance with the A.S.M.E. Boiler Code and comply with the A .S. T. M. Specifications and the rules and regulations of the Bureau of Navigation and Steam boat Inspection of the U. S. Department of Commerce. They are supplied in a full range of standard sizes, from 1 in. O.D. to 6 in. O.D. inclusive. The process by which Jones & Laughlin manufactures seamless boiler tubes is largely responsible for the unusually high ductility of the product. It is a process in which a forging action is predominant. This forging action gives to the steel the greater density and higher ductility that may be expected of any forging operation. It makes it stronger yet more pliable and, therefore, more easily formed in its cold state. Forging also effectively eliminates any such imperfections as air holes or blow holes that nmy be present in the steel. Inspection of this product begins with the careful selection of the steel for the billets and continues without interruption through every stage of manufacture. It is your assurance of receiving only the very finest boiler tubes that can be manu factured. Other J & L Tubular Products J & L also manufactures Reamed and Drifted Pipe in sizes 1 in. to 6 in. inclusive, Dry Kiln Pipe, Pipe for Refrigeration Service, Water Well and Irrigation Casing, Line Pipe and a complete line of Oil Country Tubular Products in welded and seamless. 1070 Pipe and Sheets Republic Steel Corporation General Offices Cleveland, Ohio Albany, N.Y. Birmingham, Ala. Boston, Mass. Buffalo, N. Y. Chicago. III. Cincinnati, Ohio Cleveland, Ohio Denver, Colo. District Offices Detroit, Mich. Milwaukee, Wis. Grand Rapids, Mich. New York, N. Y. Houston, Texas Philadelphia, Pa. Indianapolis, Ind. Kansas City, Mo. Los Angeles, Calif. Pittsburgh, Pa. Salt Lake City, Utah San Francisco. Calif. Canadian Representative: Commerce & Transportation Bldg., Toronto, Ont. General Export Dept.: New York City Seattle, Wash. St. Louis, Mo. St. Paul, Minn. Toledo, Ohio Tulsa. Okla. Washington. D. C. Youngstown, Ohio THE CONTROL OR PREVENTION OF CORROSION Control or prevention of corrosion of metallic ma terials used in heating, ven tilating and air conditioning equipment involves a dual responsibility. The engineer or user of the material should: KMU.fir.CFF. <TQNCAN> *+++* COPPER MO-LYB-OEN-UM IRON Advantages of Toncan Iron (1) Resists to a high, degree the many and varied types of corrosion--a resis tance not confined to the surface of the metal, but uniform throughout. (1) Study and control .the p.H. of the water used to wash and cool the air and the p.H. of the steam and resulting condensate on the heating side of the system. (2) Combines high rust-resistance of an alloy iron with many desirable physical qualities of less resistant ferrous materials. (3) Is one of the most workable of ma (2) Control the oxygen content of the terials--sheets form easily, pipe may be water. handled like any iron. (3) Reduce to a minimum the presence of foreign materials which accelerate cor rosion electrolytically. (4) Assign reasonable temperature and . (4) Welds easily by any of the usually accepted modem methods. The use of Toncan Iron welding rod insures equal rust- and corrosion-resistance throughout. pressure conditions. Toncan Iron Sheets The materials manufacturer should: (1) Control rate of corrosion by in creasing nobility of the metal--by in creasing resistance of the metal to electro chemical solution. Addition of copper to iron makes iron more resistant to atmos pheric corrosion, contaminated water and steam condensate. (2) Control uniformity of corrosion by minimizing differences in surface, in chem istry and in physical structure. Toncan Copper Molybdenum Iron Republic's contribution to heating and ventilating engineers faced with the prob lem of corrosion is Toncan Copper Molyb denum Iron--a highly refined open-hearth iron alloyed with the correct proportion of copper and molybdenum. Toncan Iron in sheet form affords effective resistance to corrosion encountered in ducts, stacks and fittings used to convey conditioned air. For steam condensate return lines in heating and for water supply, circulating and effluent lines in air conditioning, Toncan Iron Pipe is recommended. Toncan Iron is available in various sheet forms--black in gauges 8 to 26, galvanized 8 to 28 gauge; widths from 24 to 50 in.; and lengths from 10 to 13 ft; depending upon gauge and width. . ' Toncan Iron Pipe Toncan Iron Pipe is available black or galvanized, in sizes from }4~inch to 16-inch O.D, All Toncan Iron Pipe, 2-inch and larger, is electric resistance welded, and combines the advantages of Toncan Iron with the advantages of Republic's exclu sive electric welding process. Source of Supply Toncan Iron Sheets and Pipe are stocked by jobbers in all large cities. Lead ing contractors everywhere use Toncan Iron and are glad to supply it where specified. If, for any reason, you cannot obtain Toncan Iron, write to us. ' Other Republic Products Enduro Stainless Steel in sheets and other usual forms, steel pipe, steel sheets, and steel or Toncan Iron boiler tubes. 1071 Publications American Artisan Published by KEENEY PUBLISHING COMPANY 6 North Michigan Avenue, Chicago, 111. merican AARTISAN, now in its 59th year of publication, covers the field of warm air heat ing, residential air con ditioning, and sheet metal contracting. A special section of each issue has been devoted to air conditioning since 1932, when it first became apparent that air conditioning for homes was to be along the lines of the central, forced warm air heat ing system. Its readers are warm air heating and sheet metal contractors, dealers, jobbers and manufacturers, and also architects, engi neers, and public utility companies who take it for its thorough coverage of air conditioning for the home field. To answer the industry's need for a dependable guide to equipment pur chases, it publishes in each January issue a complete and up-to-the-minute directory of warm air heating, air con ditioning and sheet metal products and equipment. This directory lists all products used in the field, their trade names, and the full names and addresses of all manufacturers. It is used by readers as a buying reference throughout the year. Almost from the day interest in resi dential air conditioning began to develop, the advantages of the warm air type of heating system, with its duct distribution of air, were plain to see. It was adapted to all air conditioning factors, either through a self-contained central unit or through a central furnace to which could be added step-by-step or as a whole, fan, washer, humidifier, filters, controls, cooling, and automatic firing. Today, as a result of this ready adapta bility as well as economy, tens of thousands of homes have winter air conditioning-- supplied through forced warm air heating with air cleaning and hu midification. Cooling apparatus can be at tached to these sys tems readily whenever complete, year-'round air conditioning is de sired. This trend in resi dential air conditioning has placed a premium on air handling know ledge, and has brought to the fore the one man experienced in "treat ing" air at a central place and getting it properly distributed-- the warm air heating and sheet metal con tractor. The warm air heating industry has, furthermore, undertaken and made notable progress toward the solution of the many new engineering problems involved. All this has helped to put warm air heating in the center of residential air conditioning. In aiding to develop this trend and assist in the solution of new problems, AMERICAN ARTISAN has provided a service to its field which has made it the recognized authority on residential air conditioning practice. To manufacturers whose products are used in residential air conditioning, AMERICAN ARTISAN offers full cover age of the leading buying factors. Such manufacturers will be interested in obtain ing a copy of "AMERICAN ARTISAN-- Warm Air Heating, Residential Air Con ditioning, Sheet Metal Contracting." This study will be sent upon request. AMERICAN ARTISAN is published monthly. It is a member of the A. B. C. and A. B. P. Subscription rates--$2.00 per year, $8.00 for two years in U. S., Canada, Mexico, Central and South America. Foreign $4.00 per year. Advertising rates furnished upon request. 1072 Publications Heating, Piping and Air Conditioning Published by KEENEY PUBLISHING COMPANY 6 North Michigan Avenue, Chicago, III. eating, Piping Hand Air Con ditioning is the pub lication which carries in each issue the official Journal of the American Society of Heating and Venti lating Engineers in addition to its own regular editorial sec tion. Its field is that of industry and large buildings. Editorially, it gives specialized at tention to the design, installation, operation, and maintenance of heating, piping, and air conditioning sys tems in such plants and buildings. In addition, there is published in each January issue a complete Directory of Commercial and Industrial Heating, Piping and Air Conditioning Equipment, which lists all products used in the field, their trade names, and the full names and addresses of all manufacturers. This directory has been established as the industry's buying and specifying guide, and is consulted by readers throughout the year, whenever equipment purchases are up for consideration. H. P. & A. C. is read by consulting engineers and architects . . . contractors . . . and engineers in charge of heating, piping, and air conditioning in industrial plants, large commercial and public buildings, federal, state, and city govern ments, school boards and public utilities. Among its subscribers are numbered all members of the A.S.H.V.E., who represent about 30 per cent of its total circulation. Such a coverage means, for the adver tiser, consideration at all points in the selling of a heating, piping, or air con ditioning product . . . consideration in the selection of a product during the pre paration of plans and specifications; con sideration in the actual purchase of a product for installation; consideration in the year 'round buying of a product for oper ating and maintenance requirements. It has been evident for some time that the air conditioning field is made up of two dis tinct markets: (1) In dustrial and Commer cial; (2) Residential. These two markets are different in equip ment used; different in engineering prob lems involved, dif ferent in engineering, distributing, and con suming personnel . . . require, therefore, dif ferent selling jobs. To sell the indus trial and large building field for air conditioning, the manufacturer must win acceptance from the engineers who design, specify, install, operate, and select the system to meet the particular requirements of the plant or building. The system may be central, unit, or "split," but it is these engineers who are the in fluencing or purchasing factors. It is to such groups that Heating, Piping and Air Conditioning editorially caters--exclusively in the industrial and large building field. Without waste, the manufacturer of air conditioning products and accessory equipment, such as motors, drives, controls, etc., can reach through its pages those from whom he is seeking the necessary engineering acceptance. These facts are clearly outlined in a folder which will be sent to interested manufacturers--"Heating, Piping and Air Conditioning--In Industry and Large Buildings." Heating, Pipingand Air Conditioning is a member of the A. B. C. and A. B. P. Subscription rates--$2.00 per year; $8.00 for two years in U. S., Canada, Mexico, Central and South America. Foreign, $4-00 per year. Advertising rates furnished upon request. 1073 Publications Domestic Engineering Publications 1900 Prairie Avenue Chicago, Illinois disers has been served by Domestic Engi neering. Its commanding position is based on all points by which business papers are judged. Because of its outstanding mer chandising helps and engineering data these . men have found Domestic Engineering an invaluable source of information to aid them throughout the year. . PLUMBING AND HEATING NEWS To further expand its service to its field, Domestic Engineering is supplemented by the Plumbing and Heating News, which ' reaches every man in the industry in mid- month. In tabloid form the News has filled a void in the industry by bringing up- to-minute news of current developments and new products. This news content has made it the newspaper of the industry! And because of its universal circulationin the industry, it has aided in welding into one vast selling force, the factors that sell this huge market. , DOMESTIC ENGINEERING To completely round out this selling service to the industry, a marketing service The major portion of the billion dollar is maintained. Also mailing lists to selected plumbing and heating market is sold each groups are available. An example of the year by a comparatively small percentage editorial content of these publications may of plumbing and heating contractors. For be seen in "Census of the Plumbing and over 49 years, this top group of merchanr Heating Industry,"--write for your copy. PLUMBING-HEATING CATALOG AND DIRECTORY The Plumbing-Heating Catalog and Directory is compiled exclusively for, and placed in the hands of, the top-notch buyers and specifiers of plumbing and heating ma terials. Its complete Catalog Section com bined with a Classified Directory Section, a Technical Reference Section, a Name and Address Section and a Trade Name Section have made it industry-accepted for years. Its entire contents are generously in dexed and every item listed is clearly described in such a manner to make it easy to order and specify from its fingertip information. The buyers' and specifiers' guide of the industry, it is also a valuable reference volume for actual work on the job as well as figuring specifications. It is this vital information contained in the- Catalog that enables it to do a year 'round selling job for the manufacturer. Your request will bring you full details. 1074 Publications Domestic Engineering Publications . 1900 Prairie Avenue Chicago, Illinois AUTOMATIC HEAT AND AIR CONDITIONING The development of the automatic heat and air conditioning industry to its present position in American business has been possible only through concentrated selling efforts and the creation of favorable public acceptance by the key men of the industry. Automatic Heat and Air Condition ing, the business paper of the industry, has played an important part in this rapid growth of its industry. Its many mer chandising helps and the wealth of techni cal information contained in it each month enables the specialty sales organizations to do a better selling job. This high grade editorial material and the fact that it reaches the entire industry makes Automatic Heat and Air Con ditioning an effective and economical means for the advertiser to place his sales story before all influencing factors of his sales. To further its value to the industry, this publication sponsors an extensive cam paign to create, through newspapers and periodicals, a wide acceptance of the ad vantages of automatic heat and air con ditioning equipment. The complete marketing facilities of the Marketing and Research Bureau are also available to aid sales and advertising executives in obtaining full information on markets and in building sales forces. Write for the latest copy of "Current Conditions." AIR CONDITIONING BLUE BOOK The rapid growth of the heating, cooling and air conditioning industry brought with it a definite need for a combined catalog and classified directory of authentic buy ing, specifying and technical information. The Air Conditioning Blue Book filled this long-felt need by combining in one^ volume a complete, centralized source of this information. That's why its manu facturers' Catalog Section is an effective and economical method of placing product and technical information before contrac tors, dealers, wholesalers, large industrial users, architects, engineers, electric utilities and other factors of influence. In conjunction with its Catalog Section is a comprehensive Classified Directory Section, a Trade Name Section, a Name and Address Section, and aTechnical Reference Data Section which covers every phase of air conditioning . . . heating . . . cooling ... circulating... cleansing ... humidifying... de-humidifying. This complete product and technical information enables the Blue Book to do a year 'round selling job for manufacturers because buyers and specifying engineers refer to it many times each day. 1075 Publications Heating Journals, Inc. 232 Madison Ave. Lex. 2-4566 New York, N. Y. Chicago 228 No. LaSalle St. Randolph 6086 San Francisco Don Harway & Co. 155 Montgomery St. Exbrook 6029 Los Angeles Don Harway & Co. 318 W. Ninth St. Tucker 9706 Baltimore Chandler Bldg. Plaza 7065 Surveys in 31 typical cities reveal that on J une 1, 1937, the Air-Condi tioning--Oil Burner Dealer group was selling 64.4 per cent of the winter air conditioning jobs and in some Eastern cities their share was 90 per cent. These dealers, formerly strictly oil bur ner dealers, are readers of "Air Conditioning . . . OIL HEAT" and have been educated in air conditioning by it. The number of dealer readers handling air con ditioning is steadily in creasing: winter air con ditioning from 48.8 per cent in 1936 to 57.1 per cent in 1937; complete conditioning, 33.1 per cent in 1936 to 39.2 per cent in 1937. Why do our dealer readers sell air-condi tioning? (1) They are progressive, else they would not have been in the oil burner business in the first place; (2) they are used to the educa tional type of selling re quired; (3) they under stand technical problems of installations and ser vice and are familiar with the mechanical equip ment used. Send for Your Free Copy of This Valuable Book During 1937, the number of advertisers using our pages increased to an all-time high of 184, and space used in creased 8.9 per cent to a new record of 563.8 pages. This is due to a growing appreciation of the value of our adver tising pages in building good will and sales. During 1937 this pub lication carried a total of 367 oil burner manufac turer advertisements. These manufacturers have men traveling through the field; they check on the dealer read ing habits; and they place their ads where they know the dealer wil 1 see and read them. In addition these manufac turers are also readers of the paper, and this selec tion of it as an advertis ing medium carries with it their endorsement as readers. Free lists of dealers "interested in air condi tioning", lists of manu facturers, a low-cost mailing plan, and selling helps are available to our advertisers. Advertising rates are low. Nov. 1937 CIRCULATION--Publisher's Figures Oil Burner and Other Air Conditioning Manufacturers............................................... Air Conditioning and Oil Burner Accessory Manufacturers.TM--..............................Oil Burner and Air Conditioning Manufacturing Executives.......... ........................... 312 623 113 Prospective Dealers (Heating Contractors, Electrical and Refrigerator Dealers, Oil and Coal Dealers, etc.)................................................................... (Rotational) 6,000 Miscellaneous (Government Bureaus, Schools, Branch Offices, etc.)....................... 67 Wholesalers of Air Conditioning and Heating Accessories and Supplies................. 834 Oil Burner and Air Conditioning Dealers........................................................-................ 13,119 94.7% handle oil burners 57.1% handle winter air cond. eqpt. 35.1% handle summer air cond. eqpt. ' (artificial cooling and dehumidifying) 21.1% handle single room coolers . 21.5% handle coal or oil 62.1% handle furnaces 66.7% handle boilers , 38% handle summer central units eqpt. that cools by circulation only. - 1076 Publications OILHEAjjflNG^r / AIR#ON]pITINING TUBIOil JOURNAL Published Monthly at 420 Madison Avenue New York MARKET: The oilheating market is a closely knit 4-way market--oilburners, heating, airconditioning, and fueloil. The modern and progressive oilheating dealer sells all four--a good oilburner, using good fueloil, firing a good heating or aircon ditioning system. From 1919 to 1930, the only oilheating product sold by burner dealers was the conversion burner. In 1930 the sale of conversion burners represented 77.3 per cent of the dealers' gross income. By the end of 1937, the average oil heating dealer got only 42.9 per cent of his income from conversion burners. But, beginning in 1932, he had added three other major oilheating lines--heating, fuel oil and winter airconditioning. 1937 gross dollar volume of the average dealer was divided: Conversion burner units........42.7 per cent Boiler burner units........ 7.5 per cent ^Heating.........25.6 per cent ' Fueloil...... 17.3 per cent Winter airconditioning........ 5.3 per cent Other......... 2.1 per cent In 1937, 26.4 per cent or 51,968 conver sion oilburners were sold with new cast iron or steel boilers. In addition, dealers sold 14,884 boilerburner units. Oilheating dealers did a total dollar volume in 1937 of 328,529,366 in winter airconditioning. This represents an increase of 57.6 per cent over 1936, the greatest gain in any single branch. SERVICES FOR ADVERTISERS The 1936 Key Market Study. Merchandising News. Specific Products Reports. Unit Sale Brand Preference Studies. Booklets, reprints of special articles. . OILHEATING & AIRCONDITION ING: Fueloil Journal covers this inte grated 4-way market. It is the oldest paper in the field-- established 1922. Editorially, it has con sistently fostered every progressive de velopment in the field and it has encouraged the trend to the complete oilheating dealer. Every issue is carefully balanced edi-, torially to cover the dealers' need for usable information on all four sides of his business. Heating equipment manufacturers have long known Fueloil Journal as a power ful sales aid. Its reader interest is unique among trade papers. . circulation: Like its editorial content, jfche circulation of Fueloil Journal is carefully controlled to give complete cover age of this great 4-way market. A detailed breakdown from the latest circulation statement (December 31, 1937) shows: Power oilburner dealers and dis tributors..................................................... 9,929 Key heating contractors, plumbing and heating contractors, and engineers.... 1.922 Fueloil distributors, selling fueloil and range oil, and their branches............... 2,558 Accessory and heating supply dis tributors 980 . _ Total dealers and distributors 15.389 Power oilburner manufacturers and their executives--................................... 496 Accessory manufacturers....................... 250 Total manufacturers--.............................. Total dealers and manufacturers. Percent of total circulation___________ Others miscellaneous and paid ...... 746 16.135 87.26 2,357 Grand total...._______ '............................. 18,492 Fueloil Journal circulation covers the automatic heating field at the lowest rate per thousand copies. It will pay you well to get full details. Write, wire or telephone. 1077 Publications HEATING 6-- VENTILATING yr AIR CONDITIONING THE INDUSTRIAL PRESS. . . Publisher 140-148 Lafayette St. New York, N. Y, Heating & VENTILATING reaches the " key men" of the in-. dustry:--the engi neers, contractors and manufacturers who have the final word in the specific ation, - installation, production and maintenance of the mechanical equip ment utilized in the heating, ventilating and air conditioning fields. An editorial pro gram of outstanding alertness and au thority is directed by qualified heating and ventilating engi neers. Special sections and timely feature articles are included from time to time in line with the forward-looking policy that has characterized the publication since its inception in 1904. News, trends, develop ments, personalities--every side of this important industry is faithfully and authoritatively reported in this out standing publication. There is a regular section devoted to new equipment, profusely illustrated and com prehensively reported. Degree-days and unit fuel consumption for various large cities in the country has been a regular monthly feature of the publication for over eight years. The weather in large cities in typical localities of the country is accurately charted. Two pages of refer ence data appear in every issue. Re ports of meetings, the activities of manufacturers, ab stracts of current papers, books and pamphlets, and edi torials on the plan ning, installation and operation of heating, ventilating and air condition ing systems in pub lic buildings, offices, factories, schools, hospitals and homes are other contents of continuous interest. ... Air conditioning, now coming into its own, has had a champion in HEATING & VENTILATING since 1904 when, in its very first issue, an article on this then infant industry appeared. Since that time, for more than thirty years, HEATING & VENTILATING has consistently pub lished the news and developments of air conditioning up to its present high state of perfection and its pages have carried an impressive total of editorial lineage on this subject. Subscriptions to HEATING & VENTI LATING are $2.00 a year. Advertising rate cards, sample copies and market data will be gladly submitted on receipt of application. 1078 Publications Plumbing and Heating Journal Published by THE ANGUS CO., INC. 515 Madison Ave., New York City P LUMBING and Heating Journal is edited to furnish a well-rounded, efficient service to the men engaged in the plumbing, heating, venti lating and air conditioning fields. To this end, it covers both the technical and business phases of their work, as well as many minor but exceed ingly important ones. It gives free technical service through a staff of practical engineers; expert merchandising assistance, and its technical and business articles are by men of recognized competence. Thousands of readers come to THE JOURNAL each year for solutions to their technical problems and while some of the questions and answers are published in the Readers' Technical Service section in each issue of the magazine, the vast majority of them--having- to do with practically every phase of heating, ventilating and air conditioning as well as plumbing--are answered by mail, because most of the requests for help are urgent and a delay in answering would, in some cases, entail actual monetary loss to the contractor. The Readers' Technical Service Depart ment of THE JOURNAL is staffed by editors who have spent their lives in the business; men who were successful plumb ing, heating, ventilating and air con ditioning engineers before they wrote a line for publication, and who now devote their entire time to keeping abreast of the field's technical developments and using their knowledge and experience for the benefit of JOURNAL subscribers. The technical service rendered its readers by THE JOURNAL is closely paralled by what it strives to do for them in a business way, for it also publishes many authoritative articles on and answers questions concerning the various ramifications of business management and prints as part of every issue, a special section devoted to selling. One associate editor spends his entire time in the field writing articles on the business man agement problems of JOURNAL readers, and the practical solution of those problems. Supplementing the busi, ness and technical articles is a large amount of exclusive, staffgathered news that high-lights the back ground of the trade's activities.. This news background is vital. It com pletes the industrial picture for the reader. It keeps him in intimate touch with what the various important associations and his fellow members of the craft are doing throughout the nation and it charts the trends that are likely to have a very definite influence on the future operation of his business. THE JOURNAL editorial department draws its news from over a hundred trained correspondents located at strategic points throughout the country--by far the largest group of exclusively editorial workers used by any paper in the industry. It is this combination of the technical, business and news aspects of the industry that enables THE JOURNAL to achieve a finely balanced magazine that gives the reader the type of information he wants and needs, in brief, compact, time-saving form. THE JOURNAL is a member of the A. B. C., and costs $2.00 per year by subscription. 1079 Publications American Society of Refrigerating Engineers 37 West 39th Street, New York, N. Y. REFRIGERATING DATA BOOK REFRIGERATING ENGINEERING T RHE '37-'38 Refrigerating Data Book, a one-volume encyclopedia contributed to by 73 refrigerating experts, achieves an efrigerating Engineering in its 35th volume continues to be the periodical source of authoritative information on all excellence matched by few engineering or phases of the arts and sciences of refrig scientific books in any field. Like its eration. In its most solid aspects it carries predecessors it contains all the funda the Journal of the A .S.R.E., a living record mental data available on the art of refriger of the technical advance of practice and ation, with many additions in the light of research in its field. The larger portion of recent researches. Unlike some earlier its pages is, however, devoted to material editions it is, however, arranged to permit of wider appeal, with original articles, none of use by the the less au novice or stu thoritative, dent in re but written frigeration, in a journal and as a istic style to general refer- ' enable the ance work. reader to get This book the back contains 520 ground of pages of text each subject plus a catalog and an un section with derstanding various direc of it that will tories and stick. Refrig lists. The erating Engi technical neering also contents are prints news, divided into features, four sections write-ups of separated by interesting section in personalities. dices on colored inserts for convenient Refrigerating Engineering has long been reference. The inside covers are likewise unique in its field not alone for the origi used for reference to the main topics and nality and authority of its contents, but the 33 chapters. for its coverage of all phases of refrigera All phases of refrigeration in theory and tion both as to machinery and application practice, from small to large machinery, problems. The applications of this art are covered in the Data Book, each part are, of course, very numerous. being written by a leading authority. The The rate has been reduced to $4 for applications include particularly several 1938. excellent chapters on all phases of air conditioning in design and layout, for large and small installations. In hard leather binding, $4.00, express charges collect. CODES AND STANDARDS MEMBERSHIP ACTIVITIES IT is the policy of the A.S.R.E. to treat in its meetings current subjects touching upon all phases of the art of refrigeration. Membership is in four grades with dues from $7.50 to $17.50. Sections hold meetings in the following cities: Boston, New York, Philadelphia, Detroit, Chicago, Milwaukee, St. Louis and Los Angeles. The Society holds its 34th Annual Meeting in 1938. THE /LS./LZs. has a number of technical codes in its series of Circulars. Recent additions include the code for testing and rating mechanical condensing units (No. 13, 15c) and the code for testing and rating air conditioning equipment (No. 14, 20c). Other current data: Plant test code, cor rosion prevention code, safety code, code for testing iced refrigerators. Write for free booklet Pointers to Authors, including style sheet and directions for locating in formation in refrigeration. - 1080 Publications Sheet Metal Worker Published by Edwin A. Scott Publishing Company ,45 West 45th Street New York THE Sixty-Fourth Anniversary Num ber of Sheet Metal Worker was published January 1938. Estab lished in 1874, it is the oldest publication in its field and is today efficiently serving the industries to which its editorial policy appeals, namely, sheet metal work--air conditioning --warm-air heating-- ventilation. Founded and published to 1909 by David Williams Co.; 1909 to 1920 by United Publishers Corp.; since 1920 by the present publishers, Edwin A. Scott. Sheet Metal Worker is today a monthly merchandising, business and technical journal basic to the use of sheet metal. It serves the various unified merchandising and installing branches of the industry, consuming sheet metal for the erection, maintenance and operating equipment of homes and buildings. Such equipment includes central air condition ing equipment, warm-air heating; ventila ting; dust and refuse removal an J systems for handling material by air; kitchen and restaurant work; a wide variety of interior and exterior work for commercial, industri al, institutional, and residential buildings. Today subscribers are mainly merchan dising contractors purchasing practically all products and equipment which they fabricate, erect, ' or install. Principal manufacturers of heating and air condi tioning equipment receive issues as do lead ing jobbers. ! The market has three main subdivisions. (1) Equipment for resale in connection with erection or installation work. (2) Materials for fabrication. (3) Shop equipment and supplies. CIRCULATION Sheet Metal Worker is a member of the Audit Bureau of Circulations. It has a uniform distribution, with the greater part of its circulation centered in states showing the greatest industrial activity. Sheet Metal Worker is read by warm-air heating, air conditioning and sheet metal contractors and dealers. Also by whole salers, branch offices and salesmen, utility companies, architects and engineers, manu facturers, libraries, etc. For detailed informa tion send for ABC statement. EDITORIAL Keenly alive to developments in the industries which it serves. Sheet Metal Worker has been outstandingly prac tical in its editorial service to the trade. Its editor has been identified with this publication since 1909; has served as In dustrial Advisor under NRA; Chairman of the Publication Committee of the National Association of Sheet Metal Contractors in charge of producing the book, Standard Practice in Sheet Metal Work. Sheet Metal Worker is noted for the practical usefulness of its articles and the timeliness of its editorials. Sheet Metal Worker is also a leading publisher of books on heating, ventilating, sheet metal work, air conditioning, etc.* ADVERTISING Sheet Metal Worker has an enviable record of long term advertising. Of 165 advertisers using space in 1936, 41 per cent began some 25 to 62 years ago. Recogni tion by advertisers of its position in the fabrication and installation markets is in dicated by its list of regular advertisers. Because of its long and intimate asso ciation with the field it covers, Sheet Metal Worker is unusually well qualified to cooperate with manufacturers regarding sales and advertising programs. . Annual subscription rates--$2.00 per year, U. S., Mexico, Canada; Foreign, $3.00. Advertising rates furnished on request. 1081 Pumps American-Marsh Pumps, Inc. Plant and General Offices: Battle Creek, Michigan Direct Factory Branch: 17 Battery Place. New York City Sales and Service Agencies Throughout the World PRODUCTS AND SERVICE--This Com pany, organized 1873, offers a complete line of centrifugal, turbine, steam and power driven pumps. Your inquiry for descriptive bulletins or specific recommenda tion is invited. . REDI-VAC HEAT ING PUMPS--An im proved outfit. Removes air and condensation from return lines, dis charging air to atmos-. phere and water to boiler, both functions automatically con trolled. Bronze fitted throughout. No close clearances to wear rapidly, or "freeze up" during idle season--an important advantage over other types, practically eliminating periodic service expense. RECIPROCATING VACUUM HEATING PUMP S--Time-tested design and construc tion. Standard equipment includes bronze fittings throughout. Motor driven, if desired. (We also build many types of simplex and duplex steam pumps for boiler feed, etc.) Rcdi-Vac Healing Pump REDI-RETURN CONDENSATION UNITS -- Designed to collect and pump back to the boiler returns from low and medium pressure heating sys tems. Furnished com plete as shown with full automatic control. Very compact. Large range of sizes. (Also built equipped with turbine pump for small capaci ties and high pressures). TURBINE PUMPS --Designed for utmost economy on high head services up to 175 lb; capacities up to 150 Gpm. No metal-tometal contacts--no rapidly wearing parts; no power overload with, decrease in Head; only one moving part--a properly balanced, cast bronze impeller. Redi-Return Condensation Unit Reciprocating l 'acuum Healing Pump BALL BEARING CENTRIFUGAL PUMP S--Single-stage, horizontally split . case type with deep groove ball bearings, stainless steel shaft and bronze seal rings. High efficiencies in sure low operating cost. (We also build multi-stage centri fugal pumps.) ' Turbine Pump--Only One Moving Part 1082 Ball Bearing Centrifugal Pump Pumps Buffalo Pumps, Inc. 450 Broadway, Buffalo, N. Y. Branch Offices Albany, N. Y., 611 Standard Bldg.. U. S. Johnson Atlanta, Ga., 724 Fust National Bank Bldg., C. R. Rink Baltimore, Md., 404 St. Paul St., G. G. Thompson Boston, Mass., P. 0. Box 71, Melrose, Station. E. D. Johnson Chicago, III., 20 N. Wacker Drive, L. D. Bmmert Cincinnati, Ohio. Building Industries Bldg., F. W. Tworably Cleveland, Ohio, 418 Rockefeller Bldg., T. A. Weager Davenport, Iowa, 305 Security Bldg.. D. C. Murphy Co. Inc. Denver, Colo., 1718 California St.. Stearns Roger Mfg. Co. Des Moines, Iowa, 214 Old Colony Bldg., D. C. Murphy Co., Inc. Detroit, Mich.. 2051 W. Lafayette Blvd., Coon-De Visser Co., T.- E. Coon Erie, Pa., P. 0. Box 144. F. W. Allen Greenville. S. C., 201 Franklin National Life Bldg., R. A. Stipp Houston, Texas, 900 St. Charles St., Southern Engine & Pump Co. Indianapolis. Ind., 1441 N. Delaware St., J. J. O'Shea Kansas City, Mo., 428 Dwight Bldg., T. EL Anspacherj j Knoxville, Tenn., 903 General Bldg., Buford Bros. * ~ Los Angeles, Cali?., 708 Pershing Sq. Bldg.. P. R. Adrianse Minneapolis. Minn., 619 Foshay Tower, E. F. Bell Nashville, Tenn.. 154 Second Ave., No., Buford Bros. New Orleans. La., Devlin Bros, 1003 Maritime Bldg. New York, N. Y., 39 Cortland St., W. S. Kiothan Philadelphia, Pa., 703 Cunard Bldg., Davidson <k Hunger Pittsburgh, Pa., 431 Fulton Bldg.. H. L. Moore San Francisco, Calif., 550 Fifth St., Moore Machinery Co., J. G. Scott Seattle, Wash., 500 First Ave., So., A. T. Forsyth St. Louis. Mo., 1598 Arcade Bldg., J. W. Cooper Toledo, Ohio, 1922 Linwood Ave., C. M. Eyster Washington, D. C., 820 Woodward Bldg., G. S. Frankel Complete line manufactured in Canada by Canada Pumps, Ltd., Kitchener, Ont. PRODUCTS--A complete line of Single and Multi-stage Centrifugal Pumps, Steam Pumps and Special Pumps for use in all types of heating and air conditioning installations. "Buffalo" Single Suction Closed-Coupled Pumps "Buffalo" Self-Priming Single and Double Suction Centrifugal Pumps. This pump is close-coupled to. electric motor, eliminating the necessity for bear ings. The impeller is overhung on the motor shaft, providing a compact, easily- serviced unit. Permanent alignment is assured and the pump mounted in this manner requires very little space. "Buffalo" Close-Coupled Pumps are suitable for handling hot water with low submergence on suction,, or for operating with suction lift as high as 25 ft. These pumps are also available in special alloys. "Buffalo" Double Suction Single Stage Centrifugal Pumps These pumps embody all of the accepted modern features of centrifugal pump design. Built for capacities from 10 to 50,000 U.S. ga! per minute. Recommended for almost any service where clear water is handled. High efficiency and absolute reliability are assured. "Buffalo" Single and Double Suction Pumps can now be had with positive self priming device built with the pump. This primer is built under license from the Nash Engineering Company, and fully covered by patents. Self-priming pumps have these advan tages: (1) Ail working parts are above the liquid to be pumped. (2) There is com plete access to all parts of installation. (3) Rotors are balanced--vibrationless. (4) "Buffalo" Self-Priming Pumps are very quiet--no long shafts to vibrate and fewer bearings. (5) Constant positive prime obtained without foot valves. "Buffalo" Automatic Sump Pumps "Buffalo" Sump Pumps are selfcontained and have unusually high efficiencies thus permitting the use of small motors. Ball Bearing thrust and enclosed shaft especially adapt these pumps for their service. 1083 Pumps Chicago Pump Company 2330 Wolfram Street BRUnswick 4110 Chicago PRODUCTS--Return Line Vacuum Heating and Boiler Feed Pumps, Con densation, House, Booster, Fire Pumps, Circulating, Brine, Sewage, Bilge, Sludge, Pneumatic and Tankless Water Supply Systems and Automatic Alternator. "CONDO-VAC" Return Line Vacuum Heating and Boiler Feed Pump "Sure-Return" Condensation Pump for Low and Medium Pressure, and Systems up to 35,000 Sq Ft Radiation Fig. S10S--Duplex "Condo-Vacs" with Duplex Double Automatic Control No vacuum on stuffing boxes, ample clear ance in rotating member. It costs less to operate a "Condo-Vac." "Condo-Vac" reduces corrosion in piping and- boiler to minimum--because pump does not take in air from atmosphere and entirely elimi nates all air coming back from system. "Condo-Vac" is quiet, has a low inlet, entirely automatic, fool-proof, easy to maintain. Ask for bulletin 137. Close-Coupled Pumps Boiler Feed, Circulating, Tank Filling, Water Supply Fig. ISO--Close-Coupled, side suction pump. Capa cities range from S to 600 Gpm against heads up to 189 ft. Motors from 1 /6 to 0 Hp. Discharge l to 8 in. Both closed and open type impellers. Fig. 1946 "Sure Return" Condensation Pumps and Receivers are built for systems up to 35,000 sq ft of direct radiation and for low and medium pressures. Built in either single or duplex units. Duplex units are alternated in their operation by the Auto matic Alternator. Complete data in Bulle tin 131. Vertical Condensation Pump for Low and Medium Pressure for Systems up to 100,000 Sq Ft Radiation Fig. 1940 Vertical Condensation Pump The vertical condensation pump is designed to re ceive returns from lowest radiation. The receiver is placed underground--an ordinary hole sufficing if necessary -- and requires very little floor space. Unit is shipped complete, easy to install, assembled so as to prevent steam leaks. Special bearings will stand up under hot water for several years. A special float mechanism is guaranteed not to leak or stick in stuffing box. Complete data and descrip tion in Bulletin 133. 1084 Pumps Decatur Pump Co. Decatur, 111. BURKS SUPER TURBINE PUMPS AND WATER SYSTEMS , nlf MIMING PUMPS Ot$ an* n#togj>or1 Burks Heavy Duty Self Priming Super Turbine Pumps Pressures to 100 lb per square inch. Capacities to 1,700 gal per hour. Only one moving part, the bronze impeller. A general utility pump, suitable for many applications, including domestic water systems, commercial building installations, booster and hot water service. Ideal for returning condensate to heating boilers. Ask for Bulletin No. 115. Series 1100-M Will handle air along with water, hence will not air or steam bind. Suction lift ability unsurpassed. A pump for service where powerful, economical and efficient performance are first considerations. Burks Self Priming Centrifugal Pumps High efficiency,semi-open-impeller type, positive self-priming Centrifugal Pumps having many outstanding features. Capa cities to 24,000 gal per hour. Ask for Bulletin No. 115. Burks Super Turbine Condensation Return Units ` Furnished with receiver tanks construc ted of copper bearing steel. Automatic float switch governs the operation of pump motor. Designed to operate against pressures up to 100 lb per square inch. Balanced Hydraulic Load. Will not steam bind. Traditional Burks quality insures trouble free performance and maximum efficiency. Ask for Bulletin No. 104-B covering complete line return units. ' 1085. Pumps The Nash Engineering Company South Norwalk, Conn., U. S. A. Sales and Service Offices in all Principal Cities Jennings Return Line Vacuum Heating Pumps Standard with the heating industry for over sixteen years. They remove air and con densation from the return lines of vacuum steam heating systems, discharging the air to atmosphere and returning the water to the boiler. Two independent units are combined in a single casing--an air unit and a water unit. Impellers of both are mounted on the same shaft. The pump is bronze fitted throughout. Supplied either direct connected to standard electric motors, for belt drive, or for steam turbine drive. For continuous or automatic operation against pressures up to 40 lb. Sup plied standard in capacities up to 300,000 sq ft E.D.R. Complete data in Bulletin No. 264 on request. Jennings Vapor Turbine Vacuum Heating Pumps The Jennings Vapor Turbine Heating Pump combines all of the advantages of the standard return line heating pumps with a new type of drive, a specially designed low pressure tur bine which operates directly on steam from the heating mains on any system, requiring a differential of only 5 in. of mercury, and returns that steam to the heating system with practically no heat loss. This pump affords the safety and economy which goes with a continuous condensation return and steady vacuum, and at no cost for electric current. Furnished standard in capacities up to 65,000 sq ft E.D.R. Over 65,000 sq ft and up to 150,000 sq ft, infor mation will be furnished upon request. Complete data.in Bulletin No. 246 on request. Condensation Pump and Receiver Removes condensation from radiators in return line steam heating systems and pumps condensation back to the boiler. - They are sturdy and compact in construc tion, and combine receiving tank, pump and driving motor in a single assembly. Bronze fitted throughout, with Tobin bronze shaft. Impeller is of special design adapted to hand ling hot water with highest efficiency. Jennings Condensation Pumps are fur nished in standard sizes with capacities ranging from to 225 gpnTof water. For serving from 1,000 up to 150,000 sq ft of equivalent direct radiation. Complete data in Bulletin No 241 on request. 1086 Pumps The Nash Engineering Company South Norwalk, Conn., U. S. A. Sales and Service Offices in all Principal Cities Centrifugal Pump Made in standard and suction (self-priming) types. For circulating hot and cold' water; boosting city water pressure; handling water in air washing and conditioning; handling ash sluicing water, etc. Compact--motor armature and pump im peller are mounted on the same shaft. Simp lified--no bearings in pump casing, one stuf fing box. Accessible--impeller removable without disturbing piping or shaft alignment. Self-priming types will handle air or gas con tinuously with liquid being pumped, and can-.! be operated intermittently without foot valve/ Supplied in 112, 3, 4, 6, and 8 in. sizes with capacity up to 2000 gpm. Heads up to 300 ft. Complete data in Bulletin No. 155 on request. Suction Sump and Sewage Pumps Jennings Suction Sump Pumps are self priming centrifugals for handling.. seepage* water and liquids reasonably free from solids. The Suction Sewage Pumps are equipped with a non-clog type impeller for liquids containing solids. Suction piping only is submerged. Centrifugal impeller and vacuum priming rotor are both mounted on same shaft that carries rotor of the driving motor, forming a single moving element and, rotating without metallic contact. 1 These pumps will handle air or gas with liquid being pumped, ari'd because of self priming feature are installed entirely outside of pit. This affords perfect; accessibility for inspection or cleaning. Capacities to-meet all requirements. Complete data in Bulletins 159, 161 and 188 on request. Air Compressor and Vacuum Pump The Nash Air Compressor operates on a unique and different principle. The one moving part rotates in casing without metallic contact. There are no valves, pistons, or sliding metal vanes. There is nothing to wear, and no internal lubrication. Nash Compressors deliver absolutely clean air. Unit illustrated is built integral with elec tric motor. Compact, may be installed any where. Ideal general service compressor. Suitable for priming pumps on water systems, handling CO, gas, agitation of liquids, as blood sucking pumps in hospitals, etc. Pressure 75 lb or vacuum 28 in. of mercury. Equipment furnished for any capacity. Complete data in Bulletin No. 258 on request. 1087 Registers and Grilles Anemostat Corporation of America 10 East 39th Street, New York City, N. Y. ANEMOSTAT HIGH VELOCITY AIR DIFFUSER Anemostat is an air diffusion device to provide draftless distribution of any volume of air at any velocity. It mixes room air with conditioned air and thus the predeter mined room temperature is established considerably above the breathing level. The Anemostat permits small ducts, great temperature differentials, resulting in smaller volumes to be conditioned and therefore less expensive plants and reduced operating expenses. The Anemostat has no moving parts. The Anemostat can be connected to air outlets of any existing or new system. Type A Registers and Grilles The Auer Register Co. 3608 Payne Avenue, Cleveland, Ohio Manufacturers of Registers and Grilles for Gravity and Air Conditioning Systems; Wrought Metal Grilles for Concealing and Protecting Radiation AIR CONDITIONING REGISTERS AND GRILLES Auer Registers and Grilles for Air Conditioning have been designed to meet all modern requirements--appearance, practicability, and simplicity in installation and operation. They are made in various designs to harmonize with modern interiors. Constructed and tested to operate with high efficiency in any system of forced air, they are a departure, not merely an adaptation, from gravity registers. They are designed for easy installation in either new construction or remodelling. Combination Device for supply and either extract or return. Tobies upon request. Anemostat Velocities--Feet per Minute (All types) Size No. Neck Dia. Inch 800 900 1000 *1100 1200 1400 1600 1800 2000 2200 2400 2600 Area of Neck Output Cubic Feet per Minute Sq In. 10 4 69 78 87 95 104 122 139 157 174 192 209 227 12 IS 6 157 176 196 215 235 274 314 353 393 432 471 510 28 20 8 279 314 349 383 419 489 558 629 698 767 837 906 50 25 10 436 490 546 599 655 76* 873 982 1092 1200 1320 1419 78 30 12 623 706 786 863 944 1100 1258 1415 1572 1730 1888 2042 113 35 14 855 962 1059 1175 1280 1495 1710 1920 2138 2350 2562 2780 153 40 16 1116 1256 1396 1535 1674 1954 2232 2510 2792 3070 3350 3630 201 Standard stock sizes range from 2 in. to 38 in. neck diameter. Write for catalog and tables. No. 2035 for Wail No. 2235C Sidewall The design shown is our standard This illustration shows register directing design, termed Classic. It is very adap air in three directions. table to most interiors; other designs, however, can be furnished. -V////IIWWV-This type is made with double band ' ! frame for extra rigid installation and for elimination of any possible warping of the face. The same model can be used with a valve, as a register. It can be made to direct air in one direction only or in two directions. The 'i directing air blades can be set at any angle specified. Installation can be made with band frame or sliding frame as shown in previous illustrations. Auditorium American Radiator Building New York. First Church of Christ Scientist Baltimore. Maryland. "No Air Conditioning System is better than its Air Distribution" 1088 No. 20X0 Sidewall This type is used in new construction exclusively. The sliding frame is anchored to studdings before plastering. After plastering, the register is easily attached to the frame and can be slid to the position desired between the studs. The same type furnished without a valve is used as a return. . No. 2005 Oblong Auer Registers and Grilles can be fur nished in many designs. Auer Registers and Grilles can be furnished in any standard finish. Illustrated catalogue showing complete line of registers for all purposes and chart of open areas and capacities will be forwarded on request. 1089 Registers and Grilles Hart & Cooley Manufacturing Co. . Established 1901 Air Conditioning Registers and Grilles - Warm Air Registers Damper Regulators - Furnace Regulators - Pulleys Chain Engineering Office and Factory--Holland, Mich. Chicago Office: 61 West Kinzie Street Philadelphia Office: 1600 Arch Street All of the designs described on the opposite page are available with or without valves, and are likewise available with any of the six types of frames described below. Grille Only, Register Only, Return Air Intake, Flat-- Without Installation Frame--Installed by screwing directly to wall, baseboard or wooden blocking. Margin has sufficient width to conceal opening and turned-down edge provides space for gasket. . Sidewall Register with Band Iron Frame--Frame is inserted inside of stackhead--fastened with straps or by bending stackhead over frame. May be nailed or screwed to blocking. Face is drawn up to frame with screws, assuring tight installation. REGISTER PACE Sidewall Register with Streakproof Frame--Frame and duct are embedded in plaster. Overlapping face with sponge rubber gasket, furnished as standard, insures a rigid and streakproof installation. Baseboard Register with Integral Frame and Face-- Easy to install at minimum cost. Flange is inserted inside the stackhead and register is simply- screwed to the walk, * Baseboard Register with. Streakproof Frame--Frame holds tackhead securely in place, eliminating streaking arid preventing interference between valve and stackhead. Return Air Intake with % in. Projection--For use where intake extends above baseboard. Similar to Baseboard Register with Integral Frame, except withqut valve. 1090 Hart & Cooley Manufacturing Co. Registers and Grilles Seven Complete Lines of Air Conditioning Registers and Grilles in Four Distinct Price Groups. . No. 71 DESIGN Perforated Plain Lattice No. 71 Design--A low priced, attractive grille-- easy to decorate. The % in. openings afford excel lent concealment of duct--improve appearance. Price Group A. No. 72 Design--Combines rigid bar type construc tion, neat appearance, maximum free area with low cost. Depth of bars is % in. Price Group A. No. 72 DESIGN Non-Adjuslable Vertical Bar Open Mesh Nos. 77 and 78 Designs -- Made up of fixed bars ^ in. in depth and spaced *Hs id. apart. These grilles and registers fulfill the No. 77 DESIGN demand for an in No. 78 DESIGN Non-Adjuslable Vertical Bar Close Mesh expensive, yet at Non-AdjuslableHorizontalBarCloseMesh tractive, register with straight air flow and effective duct concealment. The similarity in appearance to the Nos. 84 and 85 Designs also makes them adaptable for use as return air intakes with these designs. Price Group B. . Nos. 84 and 85 Designs -- An ad justable deflection grille with bars % in. in depth and spaced % in. apart --bars are connec No. 84 DESIGN ted in^2 in. sect^ions,. No. 85 DESIGN Adjustable Vertical Bar Close Mesh allowing sectional Adjustable Horizontal Bar Close Mesh adjustment. The unique construction assures positive directional control of air flow with quick adjust ability to any combination of deflections desired.. Depth of bars and close spacing com bine attractive appearance and concealment of the duct. Price group D. No. 90 Design--Made up of a number of thin strips, shaped into a series of grooves, which, when assem bled form an attractive grille with openings ^ in. wide and 1 in. in depth. The tubes may be straight . or curved to give any combination of directional flow desired. Construction provides dual control of airflow, both vertically and horizontally--air leaves No. 90 DESIGN Dual Control Directional Flow . in a horizontal plane regardless of approach. One inch depth and curved tubular openings conceal the duct and gradually change the path of the air stream with an absolute minimum of resistance and noise. Price Group E. . * Complete Separate Catalogs on Air Conditioning Registers and Grilles or Warm Air Registers Available on Request. 1091 Registers and Grilles Tuttle & Bailey, Inc. New Britain, Conn. Branch Offices: Boston, New York, Chicago, Philadelphia Air Conditioning Grilles, Registers and Intakes Air Control Devices Ornamental Grilles Cast or Wrought Metals Convection Heaters I !!iiiiiiimiiiiiiiiiiiimiiiiimiim!iti SIMPLIFIED SELECTION SYSTEM AND ENGINEERING DATA A new and authentic, yet simplified, system for selecting proper sizes of grilles is now ready for distribution. The information given is the result of actual laboratory tests, made under conditions closely resembling an actual job installation, and compiled only after many months of experimenting. The data are distributed to Engineers without charge as an assistance to them in determining proper sizes and con structions of grilles to meet specified conditions. THE AIRLINE GRILLE Neat and attractive. Provides fixed air deflection. Very moderately priced. Large effective area. Vertical or horizontal bars. THE FLEXAIR GRILLE Solid bar construction. Strong and sturdy. Provides adjustable air deflection. Easily painted to match trim. Vertical or horizontal bars. HIGH VELOCITY OUTLETS The Hivelair Grille pictured above is ' particularly adapted for use where it is necessary to use a high velocity outlet. Allows the use of abnormally high velocity without causing noise or whistle. A device which provides positive con trol of air volume throughout an entire duct system, and insures even distribution of air over each outlet face. An inexpen sive unit that accomplishes much. 1092 Registers and Grilles Tuttle & Bailey, Inc. New Britain, Conn. REMOTE CONTROL An outstanding development. Ideal for hotels, office buildings, large public build ings. Makes possible individual control of air volume by the mere turning of a knob in every room throughout the build ing. A real advance in air conditioning for commercial buildings, yet comparitively inexpensive to install. MOIVCUALLV OPERATED LOUVERS 7.7.T.TT COMBINATION VERTICAL AND HORIZONTAL DEFLECTION Combined vertical and horizontal de flection of air stream from the same face. A series of individually operated louvers are placed immediately behind the face of the grille and run in an opposite from the setting of the grille bars. McKNIGHT REGISTERS A scientifically designed register for commercial air conditioning work, that provides positive volume control of the air right at the outlet itself, accomplished by merely turning a special key that ris provided. For complete information on Tuttle & Bailey s entire line of air conditioning products, write for copy of latest Catalog No. 88. 1093 Registers and Grilles The Independent Register Co. Established 1898 3753 East 93rd Street, Cleveland, Ohio INDEPENDENT "Fabrikated" Reg. U. S. Pat. Office AIR CONDITIONING REGISTERS AND GRILLES No. 311-A--ADJUSTABLE DIRECTED AIR FLOW With "Independent" Adjustable Directed Air Flow Registers and Grilles the Engineer is in com plete control of the direction of air flow. . No. 3tt-A--Air Flow Downward Adjuttabls from itraighi to 45 deg. The directional adjustment can be made at the time of installation--or after the system is operating, to meet unforseen or changed con ditions. The method of adjustment is simple as shown, and many directions and combinations can be developed to suit the need. No. 321-A--ADJUSTABLE DIRECTED AIR FLOW Each interior grille bar is ad justed individ ually. Standard registers are furnished with single valves;--they are also supplied with "Multiple Valves"--and with "Multiple Valves" adjusted individually--the Engineer is given a dual control of the air flow--being able to secure right ana left together with up and down deflection at the same time. Grille Bars set for right and left deflection. The grille bars are set in a firm tension, yet easily ad justed, with the tool sent with each order. No. Stl-A--Showing a combination of Adjvstmentt REGISTERS WITH TANDEM VALVES . Knob Control Independent Catalogues Tell The Com plete Story--Yours For The Asking. 1094 Registers and Grilles ' . ;' i j r United States Register Company General Offices: Battle Creek, Mich., U.S.A. Branches: Minneapolis, Minn., Kansas City, Mo.. Albany, N. Y. Air Conditioning Registers, Vents and Grilles Style 145 Style 145--U. S. Adjustable Bar Air Conditioning Registers specially designed for Summer Cooling and Cool-weather Warming. Bars adjust from 60 deg UpFlow to 60 deg Down-Flow by a lever operating Pin that is removable after Adjustment. Does not mar or injure Register finish. Can be furnished with Box Band Frames or Studding Frames. Also furnished in Vertical Adjustable Bar, Styles for Right or Left Adjusted Setting of Diffusions. Style 122 Style 122--U. S. Close Space Air Con,, ditioning Register. Showing Diffusional- Fiow. Also made in Horizontal Bar, Straight, and Down Flow. Equipped with Band Steel Box Frames and Studding Frames. Close Spacing and bent type of Bars in Horizontal Design obstructs absolutely all Interior View. Consult Complete No. 27 Catalog for full Details. Grilles made in same styles as A-C Registers, . Style 120-0 Style 120-0--Showing one of several styles of open space A-C Registers which are made in Horizontal and Vertical Fixed-Bar Styles to any standard angle of Deflection. Style 120-0 illustrated here shows Down-Flow. Furnished with any standard styles of Box or Studding Frames. See Catalog 27 For complete styles of Registers and Grilles in this Style or Series. Style 152 Style 153--New "Louvre-Stamped" Style of Air Conditioning Register with Narrow Bar Spacing conducive to non vision through Grille. Bars are ]/i in. deep. Can be furnished in any Direction al Flow, Horizontal9or Vertical Styles. For complete Reference Refer to 1938 Edition General Catalog No. 27. ' Also furnished with all styles of setting frames. " All Styles of Registers on this page furnished with Rubber Sealing Gaskets as standard equipment. 1095 Registers and Grilles Waterloo Register Company Waterloo, Iowa Established 1902 Seattle, Wash. Representatives in Principal Cities AIR MASTER GRILLES Supply grilles are matched with return grilles for both styles 1-A and 2-A. All supply designs feature maximum adjustability and flexibility coupled with efficiency and rugged strength. Complete performance data for both types indicated are available in a range of standard sizes as part of a grille selection system published in catalog No. 17, copies of which may be obtained on request from main office or representatives. 1096 Registers and Grilles Buffalo Wickwire Spencer Steel Company 41 E. 42nd St., New York, N. Y. Worcester Los Angeles Chicago San Francisco CLINTON METAL GRILLES-- WICKWIRE SPENCER PERFORATED METALS Clinton Grilles are manufactured in a great variety of designs--45 different styles from standard dyes, and many special designs and curved shapes to conform with customer specifications. Grille perforations are designed so that uninterrupted vertical and horizontal members give adequate rigidity ana strength of grille structure with effective concealment and large free air opening. The new "Lacecane" design provides free air openings of 50 per cent of grille area--in other designs free air openings range upward to 70 per cent of lyirjivyiiyi grille area. In Wickwire Spencer r.irjirjirji plants, modern machinery produces grilles as heavy as r-irjir-iiyi in. in thickness, and in any size or shape up to 60 in. x 156 in., in one piece. Larger Cvwv rjirjir.-ir.-i sizes in two or more pieces suitable joined so that the AtliAA joint is virtually invisible on the front of the grille. Design 8S0 MATERIALS Design 850 "Wissco" Bronze, an alloy sheet metal of high tensile strength, is specially recom mended for Clinton Grilles. It compares favorably in cost with electroplated steel, but for durability equals commercial or naval bronzes. Finished in any manner to harmonize with surroundings. Clinton Grilles are also furnished in stainless and regular steels, brass, copper, bronze, nickel, monel, zinc or aluminum. Sheet Metals, because of their strength, permit use of thinner lighter materials-- Clinton grilles are perforated in sheet steels ranging from % in. thick to 16 U. S. gauge, and in bronzes and aluminum *^6 in* to 16 B. & S: gauge. FINISH In the Wickwire Spencer finishing plant any type of finish may be supplied -- electro plated, japanned, buffed, or painted; special finishes matched or supplied as desired. When a paint finish is desired it is Plain Lattice recommended that grilles be shipped from the manufactory with shop coat, only finishing coat to be applied where installed. Grille Design__ ti7 SPECIAL FEATURES Invisible doors, hinged grilles, angle frames; or other special features supplied as required. Other sheet metal designs and specialties produced as desired. The Clinton Grille Handbook giving detailed analysis of grillelayouts will be sent upon request. ' 1097 Sheets The American Rolling Mill Company Executive Offices, Middletown, Ohio Atlanta, Ga., Indianapolis, Ind_____________ ____________ .Circle Tower 1437 CitUens and Southern National Bank Bldg. Kansas Cm. Mo.............. ............. ...............7100 Roberta St. Boston, Mass._____________ __ ________201 Devonshire St. Buffalo, N. Y,,............. .......504 Seventeen Court St. Bldg. Middletown, Ohio-...... ................................... 703 Curtis St. New Orleans, La________________ 3901 S. Carrollton Ave. Chicago, III.-...................................... 310 S. Michigan Bldg. Cleveland, Ohio.--........-1516 B. F. Keith Bldg. Dallas, Texas._______ ____ _________ 1111 Santa Fe Bldg. New York, N. Y...........-_____ ______________ 50 Church St. Philadelphia, Pa......... .................. 1808 Lincoln liberty Bldg. Pittsburgh, Pa______ ,,1632 Oliver Bldg. Detroit, Mich_____ __________5-261 General Motors Bldg. San Francisco, Calif;-...465 Tenth St St. Louis, Mo_________________________1725 Ambassador Bldg. Choose the Correct Armco Grade These grades of Armco sheet metal are recommended for the air conditioning applications shown. For detailed information get in touch with the nearest district office or write direct to The American Rolling Mill Company, Middletown, Ohio. Armco Ingot Iron ' . (Galvanized) Ducts , Washer Chambers Plenum Chambers Steam Line Casings Furnace Casings Spray Towers Drip Pans Housings Machine Guards Unit Conditioners (Industrial) , Roof Ventilators Eliminator Blades .Armco Paintgrip . (Galvanized) Recommended for all applications listed above that need immediate painting, v Send for complete information. Plates (Armco Ingot Iron) Smoke Stacks Coal Hoppers Breeching . Unfired Pressure Vessels Low-fired Boilers Tanks Armco H. T. -50 A low alloy, high tensile steel possessing great strength. Used with proper design it results in weight reduction of frame work, tanks and similar items. Under atmospheric service conditions it has four to six times the resistance of regular steel. Hot Rolled (Sheets and Strip) Fan Blades Blower Casings Fuel Oil Tanks Unit Conditioners Stoker Hoppers Cold Rolled (Sheets and Strip) Furnace Casings Room Unit Casings ^Stainless Steel (Sheet, Strip and Plate) Furnace Construction Heat Flues and Tubes Casings for Room Controls - Furnace Casing Trim Grilles Heat Resistance . Corrosion Resistance Fan and Blower Blades ' Other Armco Products The grades for these applications are only a few that Armco makes. Others include copper bearing sheets and plates and open hearth steel, either galvanized or uncoated. 1098 Sheets (Copper Steel) Bethlehem Steel Company General Offices: Bethlehem, Pa. Bethlehem Steel Company, General Offices: Bethlehem, Pa. District Offices: Albany, Atlanta, Baltimore, Boston, Bridgeport, Buffalo, Chicago. Cincinnati, Cleveland, Columbus, Dallas, Detroit, Hartford, Honolulu, Houston, Indianapolis, Johnstown, Pa., Kansas City, Mo., Los Angeles, Milwaukee, Nashville, New York, Philadelphia, Pittsburgh, Portland, Ore., St. Louis, St. Paul, Salt Lake City, San Antonio, San Francisco, Savannah, Seattle, Syracuse, Toledo, Tulsa, Washington, Wilkes-Barre, York. Export Distributors: Bethlehem Steel Export Corporation, New York. ) SOME FACTS ON CORROSION-RESISTANCE OF STEEL and advantages of copper-bearing Beth-Cu-Loy Beginning some twenty years ago, the American Society for Testing Materials started a number of tests to determine the corrosion-resistance in atmosphere of vari ous irons and steels. The chart at the right summarizes the results to date; compares the life, in atmosphere, of the four most generally used materials. These tests are worth remembering when buying or speci fying iron or steel--they show one mate rial, copper-bearing steel, to be definitely superior. Beth-Cu-Loy, Bethlehem's copper-bear ing steel, is of the identical composition as that shown on the fourth column of the chart. It is available in the form of sheets, pipe, and plates. It costs only 3 to 5 per cent more than ordinary steel--the tests show that it has from three to four times the resistance to rust. It costs con siderably less than open-hearth or copper bearing iron. Results of tests conducted by American Society for Testing Materials on atmospheric corrosion of black 22-gage steel and.iron sheets--comparison of average life, index numbers based on life of ordinary steel as 1-00: Open-Hearth O^pen,-rHonearth C0u. -HBe. aIrroinng COu. -IBLeaSrtienegl Pittsburgh Test: Conducted for 75 months. (Proceedings of A.S.T.M.--Committee A-5, Volume 23.) BETHLEHEM MAKES: Sheet Steel--all types, hot-rolled (black), cold-iplled, and galvanized-- available in-Beth-Cu-Loy. . Steel Pipe--all sizes and weights, butt- welded and lap-welded--available in Beth- Cu-Loy. Ammonoduct--A new kind of pipe that has an outstanding advantage in its unusual ductility. It can be bent cold, without need for annealing, without danger of fracturing. Recommended for ammonia piping and for heater coils, water legs in furnaces and similar uses where pipe must be bent. Boiler Tubes--Charcoal iron and steel. Plates--all sizes; flanged and dished heads. Available in Beth-Cu-Loy. Literature and further information on any of these products can be secured from the nearest district office or from the general office in Bethlehem, Pa. Fort Sheridan Test: Conducted for 132 months. (Proceedings of A.S.T.M.--Committee A-5, Vol ume 28.) , flnterpolated, since while all other sheets failed, only 10 of the 61 copper-bearing steel sheets had failed by the end of the test. 9 1.00 1.00 Annapolis Test: Still under observation after 228 months. (Proceedings of A.S.T.M.--Committee A-5, Volume 36.) . Based on first failure, since many sheets have not yet failed. All ordinary steel sheets have already failed; all but 4 open-hearth iron sheets; 18 of the 37 copper-bearing iron sheets are finished--and there is still not. a single failure among the 77 copper-bearing steel sheets even after 19 years. 1099 ! Sheets (Copper-Steel) Camegie-Illinois Steel Corporation General Offices: Pittsburgh and Chicago District Offices Birmingham Boston Chicago Cincinnati Cleveland Denver Detroit Houston Indianapolis Milwaukee New York Philadelphia Pittsburgh St. Louis St. Paul Washington COLUMBIA STEEL COMPANY, San Francisco, Pacific Coast Distributors UNITED STATES STEEL PRODUCTS COMPANY, New York, Export Distributors U S S CORROSION-RESISTING, COPPER-STEEL SHEETS The practical, low cost way to fight rust in ducts and air conditioning equipment is to use copper steel. Numerous tests and installations prove that a small amount of copper added to steel more than doubles its resistance to atmospheric corrosion. The cost of this double protection is so small in comparison to the value of the increased life that U` S* S Copper-Steel should be definitely considered for all your jobs. Even when the base metal is galvanized or painted, copper-steel is worthwhile because surface coatings may become damaged. When copper-steel is used, the exposed metal still has excellent resistance to corrosion. v U S S Copper-Steel Black and Galvanized Sheets are saving thousands of dollars yearly in the ceaseless fight against rust. They give maximum protection per dollar of cost and are being used in ever-increasing volume by heating, ventilating and aircon ditioning engineers, architects and contractors. Gauges of Steel Sheets Used for Duct Construction HEATING AND VENTILATING Round Ducts . Rectangular Ducts | Other Exhaust Systems Di&xn.. Inches 6 to 19 20 to 29 30 to 39 40 to 49 50 and above Gauge Width. Inches 26 ' 4 to 18 24 19 to 30 22 31 to 60 20 61 to 118 18 118 and above Gauge 26 24 22 20 18 Diam.. Inches Up to 8 9 to 14 15 to 20 . 21 to 30 Gauge 24 22 20 18 In the above table rectangular ducts are to have cross breaks for the gauges shown, otherwise two gauges heavier should be used. One inch standing seams should be used on widths up to 48 in., in. seams on widths over 48 irk, and for widths over 60 in., the seams should in addition be provided with reinforcing bars or angles. (This material is reprinted by permission from "Fan Engineering," Buffalo Forge Co.). TJ-S S Black and Galvanized Sheets Two principal types of black sheets are used by air conditioning engineers. They are U*S*S Hot Rolled and U*S#S Hot Rolled Annealed. These steel sheets may be had in a number of different finishes, suitable for all sorts of forming operations and for painting. Remember that every kind of U S S Black Sheet is available in Copper-Steel Black Sheets for blowers, refrigerator cabinets, dust collectors, tube collectors, fans, ducts and a thousand other specialty products. Five types of galvanized sheets made by U*S S Subsidiaries are used extensively in heating and ventilating work. The best types for your particular products or installa tions may be ascertained by consulting U S S engineers. Write the nearest branch office. 1100 International Heating & Ventilating Exposition THE AIR CONDITIONING EXPOSITION Permanent Address--Grand Central Palace, New York, N. Y. EXPOSITIONS HELD The first in Philadelphia, 1930. The second in Cleveland, 1932. The third in New York, 1934. The fourth in Chicago, 1936. The fifth in New York, 1938. Subsequent Expositions will be held on alternate, even numbered years. These are held coincident with the Annual Meeting of the American Society of Heating and Ventilating Engineers and are directed by the International Exposition Company, under the auspices of the A.S.H.V.E. EXHIBITORS Comprise leading firms in each phase of the industry: number has varied from 160 to 327 exhibitors. EXHIBITS These range from and comprise all the types of articles discussed or advertised in this copy of The A.S.H.V.E. Guide. 1. The Combustion Group: Furnaces, burners (coal, oil and gas), grates, stokers, boilers, radiators (vari ous types), refractories and auxiliaries. 2. The Oil Burner Group. 3. The Hydraulic Group: Water feeders, water heaters, pumps, traps, valves, piping, fittings, expan sion joints, pipe hangers, etc. 4. The Steam Heating Group: Vapor heating and steam specialties. 5. The Hot Water Heating Group. . 6. The Air Group: Warm Air furnaces and stoves, regis ters and grilles, cooling towers, air filters, motors, fans, blowers, condi tioning equipment, ventilators (room and industrial types), unit heaters, etc. 7. The Air Conditioning Group: - Equipment which circulates and filters the air, in summer dehumidifies and cools; in winter heats and humidifies, and does all these in proper season for complete, all year round air condi tioning. ' 8. The Control Group: . Instruments of precision for indicating, controlling or recording temperature, pressure, volume, time, flow, draft or any other function to be measured. 9. The Refrigerating Group: Compressors, condensers, cooling ap paratus, contingent apparatus and refrigerants. - 10. The Central Heating Group: Apparatus and materials especially designed or adapted to the uses of central heating and central heating station supplies. 11. The Insulating Group: Structural insulators (refractory and cellulose materials), asbestos, mag nesia clays and combinations thereof, pipe and conduit covering, etc., weather-stripping, etc. 12. The Miscellaneous Group: Electric Heaters, boiler and pipe re pair alloys, liquids and compounds, and equipment not specifically includ ed in the above groups, but related thereto. 13. The Machinery and General Equipment Group. 14. Books and Publications. VISITOR ATTENDANCE Comprises a registered attendance in vited to the exposition and includes: (Figures are 1936 analysis) Industries Governmental________ 404 Distributional Channels Contractors, Dealers, Jobbers, Supply Houses,' 32 classifications.__ _ 7701 Home Owners_________ __________ Industrial Users, 49 classifications10,791 Professional and Service Organizations, 23 classifications. 2095 Public Utilities................... _______ ________ 474 1459 Real Estate Management and Operation, 10 classifications 1418 Educational Institutions........ Miscellaneous............. 1935 1460 Total27,743 Occupations ' Executive (44 titles)__________________ ____ 12,437 Construction (16 titles and trades)________ 2606 Operation (44 titles and trades)______ 4316 Technical (64 titles).... .......... 4477 Not Classified including Educators, Pub lishers, Home Owners, etc__ ____________ 3907 Total.27,743 The registered attendance at the 1938 Exposition in New York was over 30,000, but the analysis of industries and occupa tions has not been completed at the time this goes to press. Industrial Expositions in America lead the expositions of the world in style, business effectiveness, industrial influence and educational value. This Exposition stands among the leaders in Industrial Expositions in America. It is an edu cational institution which biennially brings together the research developments and improvements in equipment and materials for use in heating, ventilating and air conditioning all types of buildings. 1101 Specialties, Healing Armstrong Machine Works 851 Maple Street Three Rivers, Mich. Exclusive Manufacturers of Armstrong Inverted-Bucket Steam Traps ARMSTRONG fjgTg'v REPRESENTATIVES Atlanta, Ga., J. M. Tull Metal & Supply Co., Inc., 285 Marietta St.. N.W. Baltimore, Md., Milby & McKinney, 118 \ Light St. - Birmingham, Ala., Southeastern Products Co., 1401 Lomb Ave. - Boston, Mass., Files Steam -Specialty Co., 261 Franklin St. ` Buffalo, N. Y., Herr Steam Specialty Co., 360 Warwick Ave'. Charleston, W. Va., Baldwin Supply Co., 518 Capitol St. . Chicago, 111., Barrett-Christie Co., 108-112 N. Clinton St. Dallas, Texas, Geo. B. Allan & Co.. North Texas Bldg. Denver, Colo., Hendrie-Bolthoff Mfg. & Supply Co., 1637-17th St. Des Moines, Iowa, E. B. Carr, 910 Walnut St. Detroit, Mich., A. F. Squier, 2910 National ' Ave. Duluth, Minn., John E. Smith. 1720 W. Superior St., Erie, Pa., Coblentz Equipment Co., 1119 Peach St. Evansville, Ind., Evansville Supply Co., Esco Bldg. - Fond du Lac, Wis., A. N. Goff, 94 Eighth St. Honolulu, T. H., The von Hamm-Young Co., Ltd. Indianapolis, Ind.. Indianapolis Belting & Sup ply Co., 34 S. Capitol Ave. Kansas City, Mo., Hughes Machinery Co., 342 Mfrs. Exchange Bldg. Knoxville, Tenn., Leinart Engineering Co., 427 Walnut St. ', Los Angeles, Calif., Guy L, Warden, 114 West 17th St. Louisville, Ky., Graft-Pelle Co., 309 W. Main St. Memphis^ Tenn., The Power Equipment Co., 1352 Madison Ave. - Milwaukee, Wis., Hamacher & Williams. 2540 W. Wells St. sV I Minneapolis^ Minn., Albert C. Price Co., 257 Fourth' Ave. Montreal, Quebec, Preston, Phipps Inc., 955 St. James St. W. - New Orleans, .La.,'Louisiana Steam Equipment Co., 109 Tchoupitoulas St. v New York, N. Y., Advance Engineering". Co., 69 Dey St. Philadelphia; Pa., Brogan & Co., 810 Race St. Phoenix, Ariz., John W. Ladlow, Box 1784. x Pittsburgh, Pa., R. S. Eastman Co., 222 First Ave. . Portland, Ore., Heating and Ventilating Equip ment Co., 927 S. W. Oak St. Richmond, Va,, A. T. Shepherd, 411-12 Tenth St. Bldg. St. Louis, Mo., O'Brien Equipment Co., 2726 Locust Blvd- .^ Salt Lake City, Utah, Lee, Pace & Turpin, 144 S. Fifth West St. . San Francisco, Calif., Refrigerating & Power Specialities Co., 380 Brannon St. ' Seattle, Wash.,' Heating & Ventilating Equip ment, Inc., 500 First Ave., South. , South Bend, Ind., Smith-Monroe Co., 1912 S. Main St. Syracuse, N. Y., The Hopton Co., 321 Denison Bldg. Tampa, Fla., G. W. Neale, 504 E. LaFayette St. Toronto, Ont., Arthur S. Leitch Co., Ltd., 1123 Bay St. Vancouver, B. C., General Equipment, Ltd. 319 W. Pender St. Winnipeg, Man., Kipp-Kelly, Ltd., 68 Higgins Ave. Wooster, Ohio. Steam Economies Co., 1011 Beall Ave. . Armstrong traps are offered in two types for heating service, "standard" traps and "blast" traps. Standard traps are used for dripping headers and unit heaters where little air is to be handled. Where large volumes of air must be removed quickly, the blast trap is available. The "Blast" Type Trap--The stand ard'Armstrong trap can easily be furnished as a "blast" type trap by the use of a thermic bucket. The air handling capacity of this bucket is approximately 100 times as great as with the regular air vent. Simplicity-- The Armstrong Steam Trap has only two moving parts--the valve lever assembly and the inverted bucket. Friction is practically eliminated in this mechanism. All wearing parts are made from nickel chrome steel except the discharge valve and seat which are made from a special chrome steel heat treated after machining to obtain maximum hardness and toughness. Avoid Steam Trap Troubles--The intermittent action of this trap and the metal used in the valves stop scoring and wire-drawing, the common sources of leakage. Air-binding is impossible because the air passes out of the bucket through the vent at the top. When the trap is discharging, the flow of water under the bottom of the bucket prevents the accumu lation of dirt or sediment. Large Capacity--Discharge orifices used in Armstrong traps are very large in 1102 Armstrong Machine Worlds Specialties, Healing HOW THE ARMSTRONG STEAM TRAP WORKS The Standard Trap ' The "Blast" Trap proportion to the size of the pipe con nections. Armstrong trap capacity ratings are not theoretical but show actual test capacities when handling condensate at steam tem perature. The effect of flash steam and pipe friction to and from the trap is thus automatically taken into consideration. Service Organization.-- The satis- factory operation of all Armstrong traps is assured by 43 district representatives in the United States, Canada and Hawaii, Stocks of these traps are carried in nearly 200 201 211 212 213 214 215 Sizes, Capacities and List. Prices of Armstrong Traps 216 Trap Size No. 200 and 201 Vi** $7.00 $8.50 /Acacia /Acacette Telegraph Code (Blast Trap).......... \Acanettc Height....... ....................... ....... Weight........................... \. it41J4' 125 5 10 15 20 25 Continuous discharge caDftcitv .. 30 in lb of water per hour at g 40 pressure indicated. For more I 50 complete information, see the S 60 Capacity Chart in the Arm- " 70 strong Steam Trap Book. 3 80 90 100 125 *!f % in. connections are desired, order No. 2U2 tor straight way or No. 203 for angle. 150 200 250 450 560 640 690 460 500 550 600 635 660 690 640 650 660 No. 211 No. 212 No. 213 No. 214 No. 215 No. 216 *9V?i2"5 $10.75 '/z'orVs' Vi* or Va" |* $15.00 $20.75 $29.00 $17.00 $22.75 . $31.50 1'orlW rV/z' at $38.00 $55.00 $40.50 $60.00 Aspen Aspette w ivw& Birette 8' ` 5* IO>/2Lb 200 Walette \w w 19 Lb 250 Hemlette 32V 250 Larette 14' w 47 Lb 250 Tamrette \w 105*' 76 Lb 250 840 1560 1000 1900 1080 2060 890 1800 940 1940 970 2050 780 1700 840 1840 900 1950 940 2030 800 1650 840 1750 880 1840 960 2040 820 1530 900 1680 3000 3500 3900 3100 3390 3600 3450 3750 4050 3700 3920 3220 3400 3880 3500 3200 3500 4600 5600 6300 5900 6300 6600 5700 6200 6600 6100 6400 6(00 6300 6700 5900 5400 5700 7600 9100 10,000 8500 9200 9800 8400 6900 9300 9200 9700 (0,100 10,400 10,900 9500 9500 10,200 14,300 17,200 19,000 18,200 20,000 17,600 20,000 18,200 19,600 18,500 19,800 18,000 18,500 20,400 18,600 17,400 19,000 1103 Specialties, Healing The Beaton & Cadwell Mfg. Company Main Office and Factory : New Britain, Conn. New York Office: 234 Water Street CADWELL No. 45 UNIT FOR 1 HOT WATER HEATING SYSTEMS A complete unit nothing else to buy. A departure from the conventional type of equipment as used with tank in basement systems. To keep the,expansion pressure in the system within practical working limits even under sudden firing methods, ass in oil burners. Providing means for elastic pressure distribu tion within the system. Keeping the system filled to any desired pres sure, against increase of pressure aboye relief setting. All of this is achieved in a novel manner. The combined pressure governing and relief feature---which is new: 1. Has no springs. 2. Is governed entirely by physical laws. 3. Cannot increase setting at any time. 4. It tests itself automatically as long as there is any water in system. 5. It is responsive to the slightest dif ference of pressure within the system. Absolutely guaranteed to protect the boiler, against increase of pressure above relief setting. The filling arrangement is automatic and can be varied in pressure from 5 to 20 lb by adjusting screw. A large strainer prevents foreign matter from entering system. The strainer, valve disc and seat can be cleaned at any time without losing, water out of system. Valve and tank supplied in Maroon color. May be used in connection with any circulator system. Layout shows simplicity of installation. CADWELL PRESSURE AND TEMPERATURE RELIEF VALVE--Self Closing Cadwell No. 25 Pressure and Tempera ture Relief valve. Opening and closing governed entirely by in ternal pressure--not by heavy springs--no stick ing valve seats; only slight drop in pressure required to close valve, leak proof. Set to maximum temperature of 210 F, or on special order, supplied with temperature relief man ually adjustable to lower temperatures. Valve readily tested by pressing cap on top of valve--same opera tion also clears valve Cadwell No. 85 Relief Valve seat of sediment accumulation. Con struction of valve with split base allows valve seat to be inspected, cleaned or renewed without changing setting. Cadwell No. 35 Pressure and Vacu um Relief Valve is similar to valve No. 25 except it does not have the tempera ture relief feature. Standard No. 35 valve is set and sealed to 150 lb maximum water pressure--- other pressures if re quired. If desired, this valve can be supplied with pres sure relief manually adjustable to lower pressures. Valve tested for pressure Cadwell No. 85 Pressure and Vac uum Relief Valve and seat cleared of sediment by pressing cap on top of valve. Cadwell No. 35-F Pressure, Vacuum and Temperature Relief Valve is similar to No. 35 except it has a fusible-plug temperature relief--not self-closing; fus ible plug must be renewed after each temperature relief action. Complete request. 1104 new catalog sent upon The Beaton & Cadwell Mfg. Company Specialties, Heating CADWELL THERMOSTATIC AIR VALVES FOR ONE PIPE STEAM AND VACUUM SYSTEMS "PERFECTION" FLOOR AND CEILING PLATES No. 1 No. SA Bottom Outlet ^ and \i-in, and % x sizes Angle Type .Cadwell No. 10 positive action for radiators, non-vacuum, our best all metal syphon air valve now available in either the non-adjustable or adjustable type. Cadwell 10 S.S. same as No. 10 except straight shank for venting return lines, etc. No. 1--Sectional floor and ceiling plate. Cast iron or Brass--1 in. flange--sizes )4 in. to 12 in. No. 2--Same as No. 1 with set screw instead of springs. No. 3--Hinged floor and ceiling plate: Cast iron or Brass--1 in. flange--sizes % in. to 4 in. No. 3A--Same as No. 3, with set screw-- sizes % in. to 4 in.. No. 3 S.--Solid floor and ceiling plate, cast iron or brass. 1 in. Flange with or without set screw--sizes J/g in. to 8 in. No. 6--Sectional floor and ceiling plate cast iron or brass--1 in. flange--with set screw. 1 in. high--size )4in. to 4 in. No. 6A--Solid floor plate cast iron or brass--size M to 5 in.--with or without set screw. No. 7--Same as No. 1--But with 1)4 in. flange. Size )4 in. to 4 in. No. 9--Same as No. 1 but with 2 in. flange--size in. to 4 in. Cadwell No. 50 Bottom Outlet und H * H-in. sites . Angle Type No. W Hinged . No. 6A No. 50 Diaphragm operated vacuum air valve, closes efficiently against the escape of steam or vacuum. Large closing surface of diaphragm, through nickel silver pin forces check off seat with every close of main valve by steam or vacuum, positively preventing sticking of valve. Equalizes the system--port can be increased in size to take care of distant or sluggish radiators. Nickel silver pins are used in all Cadwell air valves to prevent corrosion. No. 10--The original No. 10--Perfec tion--1 in. flange--size in. to 6 in. Can be furnished in grained oak finish. No. 11--Same, as No. 10 but with set screw. Note:--No. 10 type Copper Service Tube Plates--% in. to 2 in. tube sizes. All plates can be furnished in plain, nickel or chromium plated finishes, as specified. Complete Catalog Upon Request 1105 y Specialties, Heating fiarnes clones INCeaPOAT(B^^ 129 Brookside Avenue, Jamaica Plain, Boston, Mass. New York Office: 101 Park Avenue Barnes and Jones Vapor and Vacuum Systems of S{eam Heating; Modulation Valves, Packless Quick Opening Supply Valves; Metering Orifice Supply Valves; Thermostatic Radiator Traps and Cage Units, that provide instant trap repair; ' Thermostatic Traps for medium and high pressures; Condensators (Boiler Return Traps); Float and Thermostatic Traps; Strainers, Damper Regulators; Gages; Proportionator Systems with Zone Control. ; Modulation Valves Type K Thermostatic Radiator Traps lever handle, wheel Size..................... '/llo. Cap. Sq Ft Rad... 30 <8 oz pressure). With non-tarnishable indicating dial, non-rising stem, re newable disc seat. Tail piece extra heavy to prevent breakage--extralong to facilitate connection to radi ator. Three models: ndle and lock shield. >/. In. 60 1 In. 100 !>/. I". 180 Packless Quick Opening Valve Type F The Cage Unit, complete operating unit in itself, carries its own seat of special alloy. Cali brated under actual working pressure at the factory and per manently locked in adjustment. Unit easily and quickly replaced without special tools; lift out old unit and insert a new one. Available in sizes to fit almost any make of trap. Symbol 120 12 124 134 13 14 % W w kVi' '/*' Capacity.Sq F*tC. I. Rad.. 200 200 too too l' 1' 1200 Capacities based on iMlb pressure differential. Non-rising stem and renewable disc seat. Large un obstructed passages to prevent trouble from dirt or scale. Furnished with wheel handle only. Condensators . For returning water of condensation to boiler from open return line systems in dependently of boiler pressure, without change in operating conditions, air binding, or admitting steam to.return side. Simple and rugged in construction; positive in operation. All working parts are of best bronze metal. No. St Condensaior Float and Thermostatic Traps For use on Unit Heaters, also drips from supply mains and risers and on returns from water heaters and indirect stacks. Float controlled Drip Type valve governs discharge of water; thermostatically controlled valve allows passage of all of air but prevents passage of steam. Made with % in., 1 in., ancf 13^ in., tappings. Capacities 200 lb to 1200 lb of water per hour at 2 lb pressure differential. Combination float and ther mostatic traps with air and water capacity large enough to take care of the load from the Heavy Duty Type largest vent stacks, dry kiln coils, hot water heaters and other units condensing large quantities of steam at low pressures. Made in 13^ in. and 2 in. sizes. Capacities to 5,000 lb of water per hour. 2 lb pressure differential. 1106 Specialties, Heating Cochrane Corporation 3130 North 17th Street, Philadelphia, Pa. Branch Offices in 40 Principal Cities COCHRANE STEAM TRAPS (Straight-Line Bucket Type) A new addition to the Cochrane line of steam specialties. Simple in design, well constructed, reasonably priced. Recom mended for condensate drainage of steam lines, coils, evaporators, jackets, rolls, mixers, stills, etc., at pressures up to 150 lb. Has only two moving parts; bucket and valve. No complicated parts to wear out or to be replaced. Installed straight across the steam line, trap can be disassembled quickly and easily for inspection or clean ing without disturbing pipe connections. Action is quick and positive, avoiding wire drawing or erosion. Positive water seal prevents blowing steam. Capacities are scientifically determined and traps are guaranteed to discharge at rates specified. Write for publication No. 2663. COCHRANE MULTIPORT RELIEF VALVES For back pressure, atmospheric relief, flow or check valve service on air, gas, steam or water lines to give positive pro tection against explosions aris ing from stuck, jammed or over weighted valves. Differ in the usual construc tion in that a number of small disks are used instead of one large disk. For full description write for publi cation No. 2710. Multiport Back Pressure Valve Bucket Trap ' MULTIPORT DRAINERS Of the multiport type, they afford un usual capacity for removing condensate or drips from purifiers, separators, jackets, radiators, pressure heating or drying coils, etc. Eliminating condensate delivers maxi mum heat from steam production at lower cost. Tremendous capacity assured by large port areas. Provides continuous dis charge. Instantly responsive. Compact and light in weight. For pres sures up to 150 lb. Multiport Drainer ALL-SERVICE SEPARATORS Steam is rarely or never generated dry or clean and, in that state, corrodes turbine blades, engine and pump cylinders, valves, pistons, etc. Exhaust steam contains oil and entrained solids which should be re moved to eliminate friction and wear. Cochrane Separators purify steam by separating out oil, slugs of water and con densate. Complete removal of entrain.`ment is accomplished by vertical baffle I-ribs which guide it into a direct unrestric ted fall, and a baffle area which extends far ' beyond the flow from the inlet pipe. Ports at the sides of the baffle prevent the puri fied steam from passing over the drip area and coming into contact with the entrain ment. The steam flow is uninterrupted and pressure loss is minimized. All Service Separator . F/>r information on other Steam Special ties write for individual publications. 1107 =? Specialties, Heeding C. A. Dunham Company Administrative and General Offices 450 E. Ohio Street, Chicago, 111. Factories: Marshalltown, Iowa; Michigan City, Ind.; Toronto, Canada; London, England C. A. Dunham Co., Ltd., 1523 Davenport Road, Toronto, Ont., Canada OLHlHfldl, C. A. Dunham Co., Ltd., (Of the United Kingdom) Morden Road, London, S.W. 19, England HEHTinS Local Dunham Heating Service in classified telephone directory in all principal cities. For over one-third of a century, the C. A. Dunham Company, through a national organization of research and specialized engineering, has been engaged solely in the science of heating. The accumulated experience of the entire Dunham Organization is put at the disposal of the Heating, Ventilating and Air Conditioning Engineer. This cooperation is available for Modernization Work, as well as for new construction in in dustrial, commercial and other projects. A modern combination of heating, coolingand air conditioning in one unit is now available. See opposite page. The Dunham Differential Vacuum Heating System is a two-pipe sub-atmos pheric Steam Heating System which continuously distributes steam at a variable rate equal to the heat loss from the building. It provides control of building temperature without resorting to "on" and "off" circulation of steam. It controls the heat output by variation of both the steam temperature and steam volume within the radiator. The heat output from supply piping, as well as radiation, is governed through variation in steam temperature. When the rate of heat output from a Differential System has been reduced to its practical minimum by a reduction in steam temperature, the system automatically reduces the volume entering the radiators establishing a condition of partial filling as mild weather calls for a further reduction in heat supply. See Fig. 1813 A. The radiator surface temperature, therefore, is kept in step with the building heat loss at the existing weather conditions. The system is suited for all types of buildings and for either manual or automatic control. It may be economically applied to existing two-pipe steam heating installations and to one-pipe steam systems. The cost of "change-over" varies with the type of heating system already in service. We will gladly cooperate with architects, air conditioning and consulting engineers in supplying data as the basis for the surveys upon which modern izing recommendations can be made to clients. 1108 C. A. Dunham Company Specialties, Heating Dunham Line of Pumps for Differential Vacuum Heating Systems and for Vacuum Return Line Heating Service The operation of these pumps is charac terized by a quietness which is outstanding. Their use contributes to this essential of satisfactory heating--quietness. They pro vide a vacuum-producing means of great effectiveness which is proved in its ability to perform consistently over long periods with minimum of attention and maintenance. The unit combines added refinements of construction including ball bearing centri fugal pump of improved design and discharge valves operated by a positive mechanism. The pumps are built in eleven sizes ranging from capacity of 2,500 to 150,000 sq ft of radiation inclusive. These pumps amply fulfill the adopted standard for the American Society of Heat ing and Ventilating Engineers and like wise the requirements of the Vacuum Return "DV" Series Pump for Dunham Differential Vacuum Heoiing System. "VR" Series Pumpjor Dunham Vacuum Return Line Heating Service. Line Heating Pump Manufacturer's Section of the Hydraulic Institute. Pumps to meet sp( rial requirements will be supplied. "Oriflex" Dunham Self Contained Adjustable Orifice Valve for Sub-atmospheric Steam Heating Combining the conveniences of both lever and wheel handled valves, Oriflex has a unique "handle movement' which eliminates graduated opening or closing. It need only be turned "on" or "off." The adjustable orifice within the valve, not the position of the handle, controls the steam flow. The Oriflex Valve has no packing, springs or stuffing box. It is permanently leak-proof. Neither steam, water nor sediment can contact the operating mechanism, hence it never binds or sticks, always freely moves to "of" or "on" Calibrated for adjustments in increments of 1 sq ft. A turn of the key provides minute or extensive adjust"Oriflex". Adjustable Radiator ment of the steam orifice to meet the individual require- Vaivc ments of the radiator. This valve eliminates need for regulating, or for orifice plates and makes for an accurately balanced system in a very simple manner. This tailor-made permanent adjustment eliminates need for the occupant to make graduated setting of the handle. Oriflex is either "on" in balance or completely "of" "Temperator"--the New Dunham Cabinet-Type Heating, Circulating and Air Conditioning Unit Temperator is styled for tomorrow--available today--incorporating many innovations--developed from the eminently successful Type "M" heater introduced seven years ago. Cabinet completely conceals all piping, wiring and operating parts, yet all are easily accessible. A refined recirculating type unit heater. Available in types to ventilate- and perform air conditioning functions--heating, cooling, circulating, cleaning, de-humidifying, and humidi fying the air which it handles noiselessly. Recent research in air-movement equipment provides this . Temperator unit heater, rounding out a complete line of heating units in this field. Its application to the Differential System in lieu of radiators makes for a year 'round service. 1109 Specialties, Heating GUNNELL COMPANY Heating, Industrial and Power Plant Piping, Fittings, Hangers, Valves, Pipe Bending, Welding, Piping Supplies, Etc. Executive Offices: Providence, R. I. National Distributors of Thermoflex Traps and Heating Specialties For data on other Grinnell Products, see pages 1000-1002 Thermoflex Specialties Thermoflex High Pressure Traps The heart of all Thermoflex Traps is the Hydron Bellows. The Hydron Bellows is formed under hydraulic pressure. This powerful internal pressure locates any weakness of any nature in the tubing. Such hydraulic pres sure is many times more severe than any pressure the Trap will ever be called upon to control. Every Thermoflex Trap, there fore, is practically indestructible. . Thermoflex Traps have an exceptionally large orifice. This large orifice combined with high lift, insures fast action and freedom from clogging. ' We supply Thermoflex Traps "guaran teed for steam pressures of 25 lb, to 50 lb and to 125 lb. Complete information and details of typical installations will be gladly sent on your request. Ask for Catalogue on Thermoflex Heating Specialties. Valves, Traps, Gauges, Etc. The Thermoflex line includes: Radiator Traps, Offset Traps, Blast Traps, Drip Traps, High Pressure Traps, Vent Traps, High-grade Packless Inlet Valves, and the Thermoflex Alternator, Thermoflex Com- Emnd Gauge, Thermoflex Damper Regutor. . No. 12 Thermoflex Radiator Trap The No. 100A Thermoflex Trap is guar anteed for steam pressures from 50-125 lb. Must not be used where the steam temperature exceeds 400 F. For use with all types of process work, Laundry Machinery, Kitchen Equipment, Hospital Sterilizers, Vulcanizers, Dry Kilns, Unit Heaters, Street Steam Service, etc., in fact any place that a trap is desired for service at the above, pressures. Small, compact and inexpensive. Extra heavy body. Renewable nickel steel seat and disc. Bellows made from special bronze tubing and encased in brass sleeve to prevent distortion due to pressure. Regularly furnished without unions, plain nickel finish. Can be furnished with unions, polished nickel or chromium plated at extra cost. No. 4 Thermoflex Drip Traps The full eight-fold Thermoflex-Hydron Bellows is guaranteed because of the Hydron-forming process. Body is heavy bronze construction throughout, with renewable seat. Fully nickel-plated with highly polished trimmings. The No. 12 is made in angle and in corner patterns, with l/i in. inlet and x/i in. outlet tappings. The inlet neck is double thick to allow for expansion strains. Guaranteed for steam pressures up to 25 lb. Used for dripping mains, risers, coils and unit heaters. Semi-steel body, bronze cap and inserted renewable bronze seat, angle pattern only, without unions. Can be used for any general purpose where a finished, nickel-plated trap is not neces sary, and at a lower cost. Guaranteed for steam pressures up to 25 lb. (See also Pages 1000-1002) 1110 Specialties, Heating William S. Haines & Company 12th and Buttonwood Sts., Philadelphia, Pa. Manufacturers of Equipment for Vapor and Vacuum Heating Systems PRODUCTS--Haines Vento Radiator Traps, Medium Pressure arid Blast Type Traps, Com bined Float and Thermostatic Blast Traps, Air Eliminators, Heavy Duty Float Traps, High Pressure Traps, Boiler Return Traps and Packless Inlet Valves and Modulating Supply Valves. All Haines Traps, whether designed for pressures below atmosphere or pressures in excess of 100 lb per square inch, employ as their operating member a specially constructed Bourdon Tube--the principle that actuates the steam gage. Haines Thermostatic Trap The tube is of tempered steel. It is charged with a volatile fluid and hermetically sealed. It is the- expansion and contraction of the fluid, under varying temperatures, that furnishes the operating power. The tube is mounted vertically on a horizontal valve motion. The end opposite the valve is anchored so that the travel of the tube either opens or closes the valve piece. The thermostatic member is outboard the valve seat and closes the valve against the flow of steam. This arrangement prevents fouling of the trap due to scale or other foreign matter and permits a thorough draining of the unit to which it is attached. THERMOSTATIC TRAPS Haines-Thermostatic Traps are constructed. to endure, as well as to operate efficiently, in sizes ranging from Y to 1Y in. They are thoroughly inspected and proved in our test laboratory under operating conditions to insure their serviceability. Haines Modulating Valve MODULATING VALVES Haines Modulating Valves are permanently packed, furnished with a genuine Jenkins Bros, valve disc. Its modulating features permit varying the amount of steam admitted to the radiator. They seat tightly and open full area on less than a complete turn. Furnished in Lever, Round. Handles or Lock Shield type. The body is made of heavy brass, nickel plated with polished trimmings. Made in sizes from Y to 2 in. in angle, straightway or corner patterns. ` mi Specialties, Heating Hoffman Specialty Co., Inc. Executive Office 500 Fifth Avenue, New York, N. Y. Main Office and Factory: Waterbury, Conn. Sales Representatives in Principal Cities Manufacturers of Adjustable Port Radiator Venting Valves, Quick Vents and Air Eliminators for One and Two Pipe Steam and Vacuum Systems; Hoffman Supply Valves, Traps and Basement Specialties for Controlled Heat Systems, Air Conditioner and Hoffman-Economy Vacuum and Condensation Pumps. Hoffman offers a complete line of Radiator Air and Vacuum Valves and Quick Vents for every venting purpose on One or Two Pipe Steam Systems. The entire line of radiator venting valves is equipped with the Six-Speed Adjustable Orifice Venting Port (illustrated at left), making it possible to balance the steam distribution in One-Pipe Steam Systems accurately, by increasing or decreasing the rate of venting of each radiator, which controls the flow of steam into that radiator. SIPHON AIR VALVES The Nos. 1, 70 and 71 are used for venting radiators on One or Two Pipe Steam Systems, and the Nos. 4, 5 and 75 are used in conjunction with these valves for venting steam mains, risers and other quick venting services. OPERATION OF THE No. 1 VALVE One of the vent ports is always open, regardless of the port adjustment. The larger ports allow a more rapid rate of venting than standard and the smaller ones a slower rate of venting and thereby control rate of steam flow into the radiators. When steam reaches the float, vaporization of the heat sensitive fluid within the float expands, with "snap" action, the flexible diaphragm forming the float base and raises the valve pin to its seat, thus preventing the passing of steam. Whenever air reaches the valve, its lower temperature reduces the fluid pressure within the float. The diaphragm contracts and the port is opened for the escape of the air. Should water surge into the valve, the'float raises by its buoy ancy thereby forcing the pin to its seat and preventing the escape of water through the vent port. As soon as water drops below the valve connection, air must entersthe float chamber before the water can run out. Air enters through the valve connection and passes up through the air channels in the double shell construction to the top of the valve. As the air enters it displaces an equal volume of water through the siphon connection and allows the float to drop and open the vent port, allowing the air to escape. VACUUM VALVES The Nos. 2, 77 and 78 Vacuum Air Valves operate on a similar principle as described above, but in addition feature the Hoffman Double Air Lock con sisting of the vacuum check and vacuum diaphragm. These valves are used on One Pipe Vacuum Systems; and for venting the ends of steam mains or heating risers, where it is also desired to prevent the return of air into the system, the Nos. 6, 16 or 76 Float Vacuum vents are used. 1112 Hoffman Specialty Co., Inc. Specialties, Heating HOFFMAN CONTROLLED HEAT A Hoffman Controlled Heat System consists of the No. 7 Adjustable Orifice Modulating Valve on the supply end of the radiator, the No. 8-A Thermostatic Trap on the return end and either a Hoffman Differential Loop (for coal-fired installations operating at pressures up to 8 oz), or a Boiler Return Trap where higher pressures are encountered, for returning the condensate to the boiler. No. 7 Modulating Volvo :- , SUPPLY VALVES Besides the No. 7 Adjustable Orifice Modulating Valve the Nos. 37 and 47 series represent a complete line of Packiess Supply Valves that meet the exacting requirements of architects and engineers. THERMOSTATIC TRAPS , , The line of Bellows Type Thermostatic Traps, with hydraulically formed and tested bellows, consists of the Nos. 17-A, 18-A, 8-A and 9-A, and are principally used for low pressure steam or vapor systems. These traps have nominal capacities from 200 sq ft up to 700 sq ft of radiation. The Nos. 8-A and 9-A have renewable elements, which combine the thermostat, valve pin and renewable seat into a single unit. The No. 10-A Hoffman Trap, which is equipped with waterhammer proof bellows, 1 in. connection, has a nominal capacity of 2800 sq ft. . No. 8A--M ** The Nos.'8 and 9 Traps have a thermostatic element-consisting of three chambers each having a top and bottom diaphragm. These chambers are all joined together and the complete thermostatic member is housed in a cage and is not attached to the valve body or cap. This allows the thermostatic element and valve pin to be easily removed and replaced without adjustment. These traps range in sizes from % in. to 1 in., are medium pressure traps, and are recommended where pressures up to 50 lb are encountered. The Nos. 20-A and 21-A High Pressure Traps are equipped with waterhammer proof bellows and integral strainer, for use on pressures up to 100 lb. Available in % in. to 1 in. connection. . DRIP AND HEAVY DUTY TRAPS Where large amounts of condensation are encountered, it is recommended to use one of the float and thermostatic traps, which are available with or without the thermostatic element. These traps are available in large capacities and are mainly used for venting and dripping risers, steam mains, unit heaters, blast coils, etc. VACUUM AND CONDENSATION PUMPS The Hoffman-Economy line of Vacuum and Condensation Pumps offers a dependable method of economically returning the condensation from larger heating systems to the boiler. These pumps are made in single and duplex units, for varying capacities and pressures. . HOFFMAN SALES AND SERVICE Hoffman Products are sold and stocked by leading wholesalers of heating and plumbing supplies everywhere. Hoffman representatives are available to assist in selection of suitable equipment for various services. - 1113 Specialties. Heating ILLINOIS ENGINEERING COMPANY General Offices and Factory: Chicago Branches and Representatives in Principal Cities Illinois Selective Pressure Control Systems HT^niroUer An entirely new and unique method of Steam Circulation Control . . . Heating Systems that set new standards in comfort, economy, simplicity and convenience of operation. Each system is individually engineered to meet the exact requirements. Recorded fuel savings, without sacrifice of comfort, warrant your investigation. Ask for Bulletin 16. Illinois Thermo Radiator Traps Illinois Thermo Ra diator Traps for vacuum, vapor and low pressure heating sys tems. Has Senes C cone type valve. Flushes thoroughly and seats perfectly at all times. Valve and seat are of Nitralloy. The duplex diaphragm is of special phos phor bronze. Scientific design and rugged construction assure flexibility and long life. These diaphragms have withstood over three million strokes on a breakdown test. Made in three sizes ^ in., % in. and 1 in. and in a variety of patterns. Special thermostatic traps can be fur nished for working pressures up to 125 lb. Illinois Modulating Supply Valve Quick-opening, packless. Steam tight on 50 lb pressure. Large diameter of thread spool and machine cut threads make valve operation easy. Furnished in a complete line of sizes and patterns. Illinois Combination F & T Traps Unsurpassed for draining ventilating units, unit heaters, and for dripping mains .and risers-- wherever it is desira ble quickly to vent air. from the main as well as handle the water of condensation in quantity, whether Illinois Combination Trap This is the heavy duty type similar in operation to the 6G, 7G, and 8Gi traps. Series 36 traps are available in a complete range of sizes. They are equipped with sep arate thermostatic by pass and are furnished where specifications re quire this type, or where capacities are beyond the range of the 6G, 7G or 8G. Illinois Return Trap Automatic ally returns the condensa tion to the boiler, regard less of pressure on the boiler up to 8 lb, at the same time discharging the air. Insures positive and complete circulation, and prevents cracked boiler sections. Trap is self-contained, with no external working parts to be misadjusted, tampered with or injured. No stuffing boxes or packed joints, which insures continuous tightness against air or water leakage. Write for Bulletins 1114 Specialties, Heating ILLINOIS ENGINEERING COMPANY General Offices and Factory: Chicago Branches and Represen ta tives In Principal Cities Illinois Thermal-Zone Control Prevents over heating and fuel waste in large buildings or groups of buildings heated from one central power plant. Buildings may be zoned as to occupancy, time, location, exposure and so on. In many installations this valve has paid for itself in one heating season. Illinois Reducing Valve In general use on vacuum or low pres sure heating systems. Will reduce to 4 oz pressure from an in itial pressure of 150 lb. The large diaphragm insures sensitive opera tion. Made in both straightway and ex ' panded outlet bodies in sizes from %jn. to 12 in. Master Type Pressure Regulator For exacting re quirements, such as tire and rubber vul canizing, chemical process pressure control, and wher ever high pressure steam must be ac curately reduced in varying amount to any steady lower pressure not less than 10 lb. It will reduce initial pressure up to 300 lb down to any lower pressure not less than 10 lb, and does not build up pressure on a closed or dead end line. Made of bronze with Monel metal valves and seats. Illinois Steam Trap Valve and stem are separate from the bucket and operatedonly by the bucket at the ex treme top and bottom of travel-- result--valve is always either full JC7IM Jl/ open or c,losed, . tNijgp.oht wire drawing or cutting of valve and seat which are of Monel metal. Eclipse Spring Controlled Regulating Valve . Fig. 121 Furnished in either single seated or double seated type as the service conditions re quire, for the control of steam, air or gas. Con trolling spring is completely enclosed, protecting it from dirt and rust. Valves are furnished with the proper size diaphragm and the proper length spring to give satisfactory service under all operating conditions. Steam and Oil Separators Eclipse steam sepa rators are made in both horizontal and vertical type, and also the special receiver sepa rators for standard or extra heavy pressures. Eclipse oil separators are furnished in the horizontal type and have a removable baffle Vertical Standard plate to facilitate clean Separators ing of baffle and keep ing the separator's effi ciency at the highest point. Write for Bulletins . 1115 1 Specialties, Heating Kieley & Mueller, Inc. Established 1879 Engineering Specialties for Pressure and Flow Control 40 West 13th Street, New York, N. Y. Factory: NEWARK, N. J. ' Agents in All Principal Cities PRODUCTS--Valves: Altitude, Stop and Check, Pressure Regulating, Float, Pilot Reducing, Back Pressure, Tank Control. Liquid Level Controllers, Water Feeders, Pump Governors, Steam Traps, Y-Type Strainers. Also Damper Regulators, Hot Water Temperature Controllers, Oil Separators, Steam Separators, Return Traps, Water Columns, etc. Catalogs sent upon request . Pressure Regulating Valve Spring and lever weighted valves for all services and for initial pressures up to 250 lb and reduced pressures from 0 to threequarters of the initial pressure. Single or double seated in sizes % to 16 in. Suitable for steam, water, air, oil and gas. Con trolled by a small feeler pipe connected from diaphragm to low pressure side. Back Pressure and Atmospheric Relief Valve For use where plant is operated either con densing or non-condensing. Outside air dash pot insures noiseless operation. Maintains exhaust line back pressure from 0 lb to 25 lb. Made horizontal or vertical lever and weight or spring operated. Steam Traps Large capacity, small sized inverted bucket traps; quick acting, self-cleaning and non-air bind ing. Sizes % to 2 in. Pressures up to 250 lb. Body and cover, semi - steel. Valve and seat, stainless steel. Re movable cap allows inside inspection or , replacement of valve parts without disturbing pipe connections. (All parts are interchangeable). . For the accurate control of liquids in tanks or other vessels; suitable for use in in dustrial plants, gasoline plants, refineries, etc. Direct connected or remote control; bali bearing spindle and easy-to-pack stuffing box; rotary or sliding valve. Write for special bulletin C-3. 1116 Specialties, Heating J. E. Lonergan Co. . 207 Florist Street, Philadelphia, Pa. Pop Safety Valves; Relief Valves; Steam Gauges; Hydraulic Gauges; Air Gauges; Water Gauges; Pressure and Temperature Gauges; Test Gauges; Gauge Boards; Oil Gauges; Clocks; Counters; Gauge Cocks; Steam Gauge Syphons; Lubricating Specialties. Send for Latest Catalogue Model "GV" Vacuum Gauge. Gauges graduated to 30 in. vacuum. Ten sizes, 254 to 10 in. dial. Model "CLP" Model "U" Low pressure, Iron Body, Bronze Mounted. Set to blow off at 10. 15, 20, 25 or 30 lb. . Five sizes-254 to 454 in. Relief Valve. Snifter, Water or Cylinder -- Bronze. Recommended for steam engines, pumps, pipe lines, etc. Ten sizes, 54 to 4 in. Gauge for indica ting height of water in feet. Graduation 70 ft. Three sizes, 354. 454 and 5 in. dial. Special valve for vacuum, breaking. Six sizes, 54 to 2 in. Positive in its action. Oil Relief Valve. Sizes 54 to 2 in. For use on. oil burning systems. Has large relieving capacity. Water Relief Valve for tank ser vice. Sizes 54 and % in. Model "WRV*' Model Pop Safety Valve A.S.M.E. "Heat ing Boiler" Type. Standard pres sures, 5; 10 and 15 lb. Specialties, Heating Milwaukee Valve Company Milwaukee Wisconsin Manufacturers of a complete line of Heating Specialties for vapor, vacuum and gravity heating systems. Each item is scientifically designed, accurately machined and thoroughly tested before final approval. MILVACO engineers, located in principal cities from coast-to-coast, render an intelligent, courteous service to architects, engineers and heating contractors in the design and installation of modern heating systems. Fig. No. 215 Radiator Packless Angle Valve. Highly polished nickel plated bonnet, tail-piece and nut. Body nickel plated, rough finish. Available in chrome finish, also lock and shield pattern. Sizes--M in. to 2 in. inclusive. Fig. No. 209 Radiator Packless Angle Valve. Lever Handle, Graduated. Finish same as No. 215. MILVACO Radiator Valves cannot bind or stick in operation. Sizes--Yi in. to 2 in. inclusive. Fig. No. 350-6 Thermo static Trap. A single, full- . floating Thermal Element closes in the steam. Distinctive design insures positive seating accuracy . and dependable, sensitive oper ation. Nickel finish rough body with polished cover, tail-piece and nut. Available also in chrome finish. Made in sizes 34 in. and % in. and capacities 200 to 400 sq ft E.D.R. Fig. No. 100-6 STv Thermostatic Trap. For use in connection with concealed and convector radiation. ' Fig. No. 3^0-6 Assem bly. Trap cover may be removed and diaphragm assembly lifted out and replaced without disturb ing trap adjustment. Double Diaphragm Trap Fig. No. 750-6 Double Diaphragm Traps are recommended where thermostatic traps of large capacity are required. They embody the same advantageous features of design and construction which characterize the single diaphragm type traps ana he same efficiency of operation. Made in % in. and 1 in. sizes and capacities 700 to 1000 sq-ft E.D.R. No. 760 Double Diaphragm For complete detailed information, roughing-in dimensions, weights, etc. consult current condensed catalog of MILVACO Heating Specialities. 1118 Specialties, Heating Baltimore, Md. Boston, Mass. Chicago. 111. Cincinnati. O. Cleveland, O. Columbus, O. Dallas. Texas Denver, Colo. Milwaukee Milwaukee Detroit, Mich. Evansville, Ind. Glen Rock, N. J. Grand Rapids, Mich. Indianapolis, Ind. Kansas City, Mo. Los Angeles, Cal. Louisville, Ky. Valve Company ict Offices Wisconsin Moline, III. N.New York City, Y. Omaha, Nebr. Philadelphia, Pa. Pittsburgh, Pa. Portland, Ore. Richmond, Va. N.Rochester, Y. St. Louis, Mo. Salt Lake City, Utah Scranton, Pa. Seattle, Wash. Toledo, O. Washington, D. C. Toronto, Ont. Winnipeg, Man. Fig. No. 32 Quick Vent. For quick venting of mains, blast coils or any high point where a large volume of air must be vented and water is not a factor. Made in ^ in. and % in. sizes. Fig. No. 47 Sediment Strainer. Prevents pass age of dirt, scale or solids. Easily clean ed. Sizes 34 In. to 3 in. inclusive. 2 in., 234 in. and 3 in. sizes have flanged strainer cap. Fig. No. 12 Air Eliminator. For rapid elimination of air from mains, coils or any low pressure system. Air is rapidly vented past a check valve and through large . ports. Float rises to prevent passage of water and thermal element closes against passage of steam. Sensitive, posi tive in operation. Pipe connections--34 in., - 24 in., 34 in. and 24 in. Fig. No. 85 Boiler Return Trap. When the heating system is operating under a very low pressure or under atmospheric pressure only this return trap acts as a re ceiver and air vent. When the boiler pressure increases, the condensate, rising in the trap causes the float to rise. The float rising automatically opens the steam valve admitting boiler pressure to the top of the trap, and at the same time closes the vent valve. The pressure in the boiler and trap is thus equalized and the water of conden sation flows by gravity back to the boiler without collecting in the return mains or risers regardless of boiler pressure. When condensation is discharged the float drops to the bottom of the trap opening the vent valve and closing the steam valve. This action is repeated as long as there is a differential in pressure between boiler ana return line piping. Operates on any pressure not exceeding 15 lb. Capacities 1500 sq ft to 4000 sq ft of radiation. Pipe connections 134 in. and 2 in. Fig. 13 Series Float and Thermostatic Trap. Entire mechanism is attached to cover assembly. The float valve is self-aligning and closes horizontally against a self cleaning, reversible monel seat. Diaphragm thermal element insures sensitive, positive operation. A baffle plate in the body prevents conden sate from flowing directly onto the bail float insuring smooth, full capacity flow at all times. Made in 14 sizes and capacities ranging from 600 lb to 8000 lb of water an hour at a 2 lb pressure differential. Recommended for use in connection with industrial heaters, unit heaters, vents, blast and dry kiln coils, evaporators, etc. and other units condensing large quantities of steam at pressures-not to exceed 15 lb. Sizes 34 in- to 2^4 in. inclusive. 1119 S Specialties, Heating Mueller Steam Specialty Co., Inc. 349-351 West 26th Street, New York City Steam, Water, Air, Oil and Gas Specialties for Heating and Power Plants Pressure Reducing Valves--Straight Pattern and With Increased Outlet No. 11--For Vacuum, Vapor and Low Pressure Heating Systems. Initial Pressures, up to 200 lb; Reduced Pressures, 0 to 10 lb. No. 17 and 21--For automatic control of reduced pressures on dead-end service, requiring a tight closing valve, such as tank heaters, kitchen utensils, sterilizing ap paratus, laundry equipment, kettles, cookers, driers, etc. Initial Pressures up to 200 lb. Reduced Pressures 0 to 150 lb. Constructed with full globe bodies. Center guide eliminates the wings on discs, and increases efficiency, assures minimum noise and prolongs the life of the seats and discs. Lever and weight operates on a steel roller bolt, assuring a most sensitive valve. Spring type furnished with special long springs for sensitive operation and wide ranges of reduced pressures. Automatic Water Feeders With a powerful leverage to control the water line in steam boilers, etc. They supply make-up water to compensate for evaporation, leaks, steam utilized in process work and condensation wasted. Where condensation held up in the system eventually returns in large quantities, our Duplex type protects the boiler against flooding. All working parts of non-corrosive metal, are accessible without breaking pipe connections. Provided with an integral strainer. For steam pressures up to 100 lb, water pressures up to 120 lb. . Equipped with low water and pressure Mercoid Tube Switches for all services. , Steam Traps Simple, Sturdy and Compact Ball Float and Inverted Bucket Steam Traps 'for draining water of condensation from steam apparatus and steam mains. Powerful leverage enables them to take care of large quantities of condensation. Ball Float Steam Traps equipped with integral strain er, water gages, air cocks, blow-off and integral by-pass valve, when desired. All working parts are ac cessible without disturbing any pipes. Inverted Bucket Ball Float No. No. att9t---Uupp to to tSsOo lab.. Site* MtoSin. Valves are sealed with sev eral inches .of water, making theescapeofsteam impossible. No. tit--For Preuvrca Up to 250 0). Sizet to tin. Catalogue and Bulletins covering our Complete Line gladly furnished on application. 1120 Specialties, Heating Sterling Engineering Company 3726 No. Holton Street Milwaukee.................... Wisconsin Manufacturers of Steam and Water Heating Equipment See Telephone Directory for Local Addresses Albany, N. Y..................................... Murcan Sales Corp. Alexandria, La........ .......... ......... .............. Roy Cookston Appleton, Wis...... ................ Htg. Prod. & Engrg. Co. Atlanta, Ga........................................................R. L. Hicks Boston. Mass.................. .............................. W. B. Parsons Buffalo, N. Y........... .................................... J. A. Sullivan Chicago, III........... ......................................_.W. P. Nevins Cleveland, Ohio.....................M. M. Berger & Assoc. Dallas, Texas....... .. .....................Paul R. Winston Co. Detroit, Mich............. ,,................... ..................J. M. Main Dodge City, Kansas....................................C. H. Parkes El Paso, Texas.................... ..W. F. Lucas Engrg. Co. Grand Rapids, Mich.............. ...C. H. Alexander Co. Indianapolis, Ind........... ......................l. W. Cotton Co. Jacksonville, Fla.._........................Specialty Sup. Co. Kansas City, Mo.............. ...................Disney-Leffel Co. Knoxville, Tenn....................................... .......J. A. Ahler Los Angeles, Calif..'.............................. James G. Bain Louisville, Ky............ ....................................Greene Hogg Minneapolis, Minn.........................Elliott Equipt. Co. Newark, N. J............... ............................. George C. Alam New Orleans, La..................................... W. J. Houlihan New York, N. Y...........................Crawford Engrg. Co. Phila., Pa.............................................. Parent & Kirkbride Portland. Ore............................................. Otto A. Cook St. Louis, Mo............................. ...............Russell J. Smith San Antonio, Texas.......... ............................. E. H. Starr Scranton, Pa...................................... John P. Gilboy Co. Seattle, Wash .................................... J. W. Mitchell Syracuse, N. Y............................O'Brien Specialty Co. Washington, D. C...................Clyde H. Miller Assoc. Waukegan, III....................................... Ralph A. Nelson PRODUCTS A complete line of vacuum, vapor and hot water heating specialties, pumps for heating purposes and temperature controls, combined with competent engineering service to architects and contractors. A telephone call will bring our nearest representative to you. For convenience our products are grouped in our catalog as follows: Group Is Vacuum Vapor Heating Specialities. Products in this group are described in Bulletin No. 234-A of the Sterling Engineering Company's loose leaf catalog. They consist of: Diaphragm type thermostatic radiator traps; bellows type thermostatic radiator traps, float and thermostatic traps, blast traps, boiler return traps, bellows packless quick-opening radiator valves, spring packed quick-opening radiator valves, vents and air eliminators, strainers, dam per regulators, orifices, air line valves and pressure-vacuum gauges. Group 2: Vacuum Pumps. Pro ducts in this group are described in Bulletin No. 372 of the Sterling Engineering Com pany's loose leaf catalog. They consist of: Return line vacuum heating pumps, condensation pump and receiver units and air line vacuum pumps. Group 3: Temperature Controls. Products in this group are described in Bulletin No. 361 of the Sterling Engineer ing Company's loose leaf catalog. They consist of: Type E self-contained thermostatic radiator control valves, Types G 101 to 106 remote control valves, Type F Remote control valves, Type J unit heater control valves No. Ill liquid and tank control valves and motor operated valves. Group 4: Hot Water Specialties. Products in this group are described in Bulletins No. 434 and No. 371 of the Sterling Engineering Company's loose leaf catalog. They consist of: Sterling Circulators for circulating water in closed circuits, Sterling Instant Water Heaters which heat water instantaneously, using the water from the heating boiler as a heat transfer medium and Sterling No. 21 Flow Valves which control the flow of hot water to the heating system. The com bination of these products, with the necessary electrical controls and thermo stats, constitutes the Sterling Instant System of Water Heating. The Sterling Engineering Company maintains direct company representatives in the cities listed above. The representatives are engineers schooled in the technique of steam, and water heating and are prepared to give technical advice and cooperation to archi tects, engineers and contractors on the application and use of Sterling equipment. Write the Company at Milwaukee or communicate with our representative in your territory for a copy of our complete loose leaf catalog describing the above mentioned products in detail and giving complete information regarding their use, application and installation. 1121 Z'' Specialties, Heating Sarco Company, Inc. 183 Madison Ave., New York, N. Y. Branches in Principal Cities SARCO CANADA LIMITED, Federal Bldg., Toronto, Ont. PRODUCTS--A complete line of Specialities for Vapor, Vacuum and Gravity Steam Heating Systems and Control combined with a competent Engineering Service to architects and heating engineers to assist them in providing modern heating. SARCO RADIATOR TRAPS Sarco Heating Systems are "prestige Systems." The traps and valves are the system as far as maintenance and cost is concerned. . Sarco Type H Traps--Are available in angle, straightway, and corner patterns. The Sarco Thermo static Bellows--made by special machinery, has not been duplicated or even imitated with success. It works efficiently, repeatedly and persistently. It has worked that way for a quarter of a century. Sizes ^ in. to 1 in. Bellows-Packless Valve SARCO RADIATOR VALVES Sarco Packless Valves--Used for one and two pipe heating systems and are truly packless. Steam leaks are impossible. Furnished with round or lever handles or lock shield in angle straightway, or corner patterns. Sizes H in. to 1H in. SARCO N-100 TRAP For high pressure radiators and heating coils in sta tionary and marine service, and for hospital and kitchen equipment. Has full length protecting shield and stainless steel valve head and seat. Sizes % in. to 1 in. SARCO FLOAT-THERMOSTATIC TRAPS For dripping ends of,mains and risers, and for stack or blast heaters, large'* unit heaters and hot water generators. Automatic thermostatic air vents built in. Available in six sizes with connections % to 2 in. Float-Thermoslatic Trap Inverted Bucket Trap SARCO INVERTED BUCKET TRAPS Are recommended for high pressure unit heaters and sometimes preferred for kitchen and laundry equipment. Strainers are built right into these sturdy traps. Seats and valves are stainless steel* and renewable. Ther mostatic air vents can be furnished on the larger sizes. Available in sizes ^ in. to 2 in. for pressures up to 250 lb. Catalog HV-165. . See Sarco Catalog HV-45 for all heating specialities 1122 Sarco Company, Inc. Specialties, Heating SARCO ALTERNATING RECEIVER A complete line of boiler return traps for vapor systems. Returns water of condensation to boiler auto matically, thereby assuring positive return of water under all pressure conditions. Made in six sizes for. from 1500 to 25,000 sq ft of radiation. SARCO AIR ELIMINATORS For venting air from vapor systems at one central point in the basement. Available in two sizes: No. 6 for systems up to 2500 sq ft and No.. 12 for 15,000 sq ft. Both are equipped with float valves to stop water escaping through the vent and with check valves to prevent ingress of air when system is under vacuum. Alternating Receiver IV SARCO SELF-CONTAINED TEMPERATURE REGULATORS Sarco Temperature Regulators are simple, selfoperated valves--the only self-contained units that use the irresistible force of liquid expansion. No stuffing boxes to leak, no auxiliary "power" required; all moving parts are inside the equipment. Here again-- a type and size for every purpose--for steam, gas, oil, water, brine or Freon for temperatures ranging from 0 to, 300 F. Type TR-S1 Standard for hot water storage tanks, fan units, Type KR-U Designed for room control and air conditioning. SARCO ELECTRIC CONTROLS Comprise-room thermostats, aquastats, and limit controls for all heating and air conditioning needs; also motor valves for steam, water, brine, or Freon. The Sarco Graduator System provides simple mechanical control of building heating, direct by the weather. Catalogs HV-150 and HV-128. Motor Valve . Room , Thermostat SARCO WATER BLENDER Mixes very hot and cold water and delivers blended water at any temperature for which it has been adjusted. Valves are fully balanced so that control is not dis turbed by differing or fluctuating water pressures. Available in sizes % in. to 4 in., for pressures up to 150 lb. Catalog HV-140. . See Sarco Catalog HV-45 for all heating specialities ' 1123 Water Blender s' Specialties, Heating WARREN WEBSTER & COMPANY Pioneers of the Vacuum System of Steam Heating i-since!888 Main Office and Factory: Camden, New Jersey Systems of Steam Heating Representatives in over 60 cities-- Consult Your Local Phone Directory UNIT HEATERS PRODUCTS AND SERVICES Improved Webster Systems of Steam Heating including Vacuum and Type "R" (vapor). . Webster Central Control Systems Including HYLO and MODERATOR. Modernization of Obsolete and Faulty Heating Systems. Webster System Equipment in cluding Light-Weight Concealed Ra diation (Gravity Convection Heaters'), Webster-Nesbitt Unit Heaters, Radi ator Supply Valves, Metering Orifices, Thermostatic Traps, Drip Traps, Heavy Duty Traps, Dirt Strainers, Dirt Pockets, Boiler Return Traps, Vent Traps, Damper Regulators, Boiler Protectors, Lift Fittings, Ex pansion Joints, Separating Tanks, Steam and Oil Separators, Steam Vacuum Pump Governors, Air Sepa rating and Receiving Tanks, Gages, Water. Accumulators. - Webster Series "78" and Series "79" Traps for use at process pressures (10 to 125 lb per sq in.) IMPROVED WEBSTER SYSTEMS The Improved Webster Systems are low pressure, two-pipe systems of steam circu lation with the addition of accurately-sized metering orifices at radiator supply con nections and, when required, intermediate metering orifices at points in branch mains. Metering orifices effect even dis tribution of steam to all parts of the heating system and permit the successful application of a centralized control. Web ster Valves are used at supply of radiators Webster Thermostatic Traps prevent flow of steam into return mains when radiators are filled. Webster Drip Traps and Dirt Strainers are used where needed on steam mains. Improved Webster Systems are available for vacuum, open return or "vapor" operation. The Type "R" Sys tem corresponds to the so-called Vapor type. Fig. 1 illustrates a typical arrange ment of Boiler Return Trap, Vent Trap, etc., when low pressure boiler is the source of steam. CENTRAL CONTROL SYSTEMS These are patented systems for varying the amount of steam to all radiators ac cording to outside temperature. They provide continuous heat delivery with effec tive fractional filling of radiators. The Hylo Systems may be provided for manual control, or if desired, may be semi-automatic by incorporation of inside thermostat or thermostat and schedule clock. The Moderator Systems employ an automatic Outdoor Thermostat sup plemented by a manual Variator. The latter is used for quick heating-up, night load, and unusual weather or oc cupancy conditions. Use of Webster Centra! Control Systems results in (1) increased comfort because over-heating and underheating are minimized and (2) lower fuel or steam costs. - Fig. J. Conventional arrangement of piping around Webster Basement Equipment for the Webster Type "R" System 1124 Fig 8. Webster System Radiation ir Warren Webster & Company Specialties, Heating WEBSTER SYSTEM RADIATION Concealed, non-ferrous type for use exclusively with Improved Webster Sys tems. Is unique in that it combines in a single unit, a light-weight heating element of high efficiency with an orificed radiator supply valve, a radiator trap and supply and return piping connections. Metal enclosures for installation within the wall and exposed metal cabinets are available. Webster System Radiation and enclosures are so designed that the entire heating element can be quickly removed without damage to plaster or paint. Space require ments reduced to a minimum and instal lation greatly simplified. RADIATOR SUPPLY VALVES "Three-Point" The finest Webster Valve. Has sleeve orifice in seat open ing. Can be used as open-shut opera tor or "three-point" providing shut-nor mal-excess. Excess permits 140% of Fig. 8. Webster Three-Point Valve normal heat with Webster Central Controls. Especi ally suitable for hospitals, hotels, homes where extra flexibility is desired. Quick opening, non-rising stem type. Uses mol Sylphon Packless--A high quality valve incorporating a Sylphon Bellows completely enclosing a non-rising stem and fully meeting "bellows packless" spe cification. Made in angle model in sizes of A, At 1, 1 At 1A and 2 in. Right-corner, left-corner and straightway single-union models in sizes of At At and 1 in. Choice of lever, wheel, lockshield, chain wheel or extended stem handles. Type "B"--A good quality valve. Quick opening. Non-rising stem. Molded ring packing meets usual "packless" specifi cation. Made in angle model in sizes of A, At 1, VA, 1A and 2 in. Right-corner, left-cor ner and straightway Fig. 6. Webster single-union and Type " B" Valve double-union models in sizes of A, A and 1 in. Choice of wheel,, lever, lockshield, chain wheel and extended stem handles. ded ring packing which meets usual "pack less" specifications. Available in angle, right corner, left corner and single union straightway models with bake- lite wheel handle, or lever, lockshield or extended stem fix tures. Sizes % and 1 in. only. Type "W" -- Same high quality Fig. 4- Webster Type " W" Valve as "Three-Point" Valve except "Three-Point" fea tures are omitted and modulating device included. Successful "modulation" re quires that proper pressure be main tained on system. Made in angle mod el in sizes of A, At 1 and 1A in. Right- corner, left-corner, straightway single union and double union models in se lected sizes. Choice Fig. 7. Metering Orifice Inserted in Union Connection of a Webster Supply Valve Metering Orifices--Accurately sized and made of heavy gage Monel Metal to resist erosion and corrosion, amply thick to be free from vibration and shaped for quiet operation. Available in a number of types to fit both new and installed radiator supply valves of Webster or other make. RETURN TRAPS Sylphon-Orig inal and highly perfected type of low pressure, ther mostatic bellows trap. Rugged in construction. Re Fig. 6. Webster Packless Valve of wheel, lever, lockshield, chain wheel orextended handles. newable seat. Fac tory adjusted. Made in angle, Fig. 8. Webster 608 Sylphon Trap 1125 Warren Webster & Company Specialties, Healing right-comer, left-corner and straightway bodies. Sizes: Y, % and 1 in. Normal oper ating pressures up to 15 lb per sq in. Max imum occasional pressure 25 lb per sq in. Series "7"-- Perfected dia phragm-type thermostatic trap. Unusually strong in con struction. Re newable seat. Factory ad Fig. 9. Webster Size 70S Trap justed, phos phor-bronze dia- phragm. Made in a__n_g_l0e_,__r_ig__h_t-_c_o__m_e_r,, [eft-comer and straightway bodies. Sizes: Y, % and 1 in. Normal operating pres sures up to 15 lb per sq in.; maximum occasional pressure 25 lb per sq in. Series "7-M"--Similar in design to Series 7 but built for normal-operating pressures up to 25 lb per sq in. Maximum occasional pressure is 50 lb per sq in. Uses Monel Metal diaphragm, Stainless Steel valve piece and seat insert. piece and seat insert. Angle model only. Sizes: Y, % and 1 in. Extensively used with laundry, cooking, sterilizing and other process-steam uses. Series "79"--For use where large volumes of very hot condensate form more quickly than can be discharged by thermo static traps alone. Float and thermostatic traps designed for normal working pres sures between 15 and 125 lb per sq in. Water of condensation is passed through a float-controlled seat opening while air is discharged into the return piping by a thermostatically controlled vent. Com pact and light in weight. Can be readily mounted in a pipe line without other support. Available with either % in. or 1 in. inlet and outlet. Cast iron body, copper asbestos gasket and cover bolted together with steel cap screws. Monel Metal valve piece and stem. Stainless steel seat. Air vent unit is Monel Metal diaphragm with Stainless Steel valve piece and brass seat with Stainless Steel insert. DIRT STRAINERS AND POCKETS Placed in return lines of steam heating systems to prevent dirt, rust and scale from impairing tightness of traps. Fig. 10. The Webster Size 000S6-T Drip Trap is Rated 00 lb Water per Hour at S lb Pressure Difference Series "26"--A heavy duty trap for drips of mains, blast radiation, unit heaters, hot water generators and similar applications. A rugged float-type trap available with and without thermostatic air vent. Made in five sizes: 200, 700, 1200, 2400 and 5000 lb water per hour at 2 lb pressure difference. Maximum work ing pressure is 15 lb per sq in. Series "78" -- thermostatic trap built for process steam pressures (10 to 125 lb per sq in.). Monel Metal dia phragm. Stainless Steel valve _____ p. tl Webster Series "78" Trap -\ Fig. IS. Size S4C-1 Webster Boiler Protector with how Water Electrical Cut-out Switch. Size 84 bos no Cut-out Switch BOILER PROTECTOR Prevents breakage in low pressure heating boilers when water level becomes inadequate. Automatically supplies raw . water to boiler when water level drops to 1 in. above bottom of gage glass. For maximum boiler pressure of. 15 lb per sq in. Maximum cold water main pressure should not exceed 150 lb per sq in.; minimum must not be less than 25 lb per sq in. Made with % in. connections, with or without electrical cut-out switch. 1126 Warren Webster & Company Specialties, Healing UNIT HEATERS Propeller-fan Type Webster-Nesbitt Unit Heaters are man- factured by John J. Nesbitt, Inc., Holmesburg, Philadelphia, Pa., and are distributed solely through Warren Webster & Com pany, Camden, New Jersey. Webster-Nesbitt Unit Heaters are de signed to circulate large volumes of air at assembly is held in the casing by means of snugly fitted angle guides which permit of linear expansion or contraction within the casing. Center Steam and Return Connec tions--permitting especially the three smaller size units to be suspended direct from steam piping, without additional hangers, and to be adjusted for direction after installing. - Quiet Fans--of four-blade type. Series 12, 16, and 20 units have exceptionally wide overlapping blades of gradual pitch . for especially quiet service. Rubber-Mounted Motors--to pre vent transmission of motor hum or vibra tion. . Discharge Louvres--individually ad justable, may be fastened in position after setting. For complete information send for catalog W-N 100 Fig. 18. Webster-Nesbitt Unit Heater, Propeller-fan Type comparatively low temperatures. The heated air is mixed thoroughly with the room air to reduce overheating in upper areas and temperature stratification, and to assure quick heating, low fuel costs, and complete comfort for room occupants. Six Unit Sizes--Webster-Nesbitt Unit Heaters are made in six distinct casing sizes, and with air capacities at maximum fan speed increasing progressively from 860 cfm to 4950 cfm. Three types of Heating Elements-- For each of the six sizes there are available three heating elements that afford a wide range in final temperature for given air volume. This feature permits of flexibility in the selection of units for varying steam pressures or entering-air temperatures and fan speeds. Modern Casing Design--Heavy furni ture steel, die-formed and welded, all corners rounded. Black featherweave finish, Stainless Steel trim. All-Copper Heating Element--of dieformed copper fins forced over % in seamless, hard-drawn copper tubes. Tubes and headers joined by compression unions. Assembly tested, rated, and guaranteed for working steam pressures up to 150 lb per square inch. Steam and Return Headers-of heavy, seamless steel tubing, with steel couplings and tube bosses welded to header body. Freedom for Expansion--The heating GIANT HEATERS Centrifugal-Fan Type For the economical heating of large areas. Available in floor-mounted, wallmounted, and ceiling-suspended types in a.wide range of sizes and capacities, from 1895 cfm, 124,000 Btu, to 22,200 cfm, 1,350,000 Btu, with 2 lb steam, 60 deg entering air. Furnished with or without the Thermadjust Temperature Control Damper which prevents overheating and stratification, and effects substantial fuel savings. Quality products throughout, from the sturdy, efficient copper tubeand-fin radiators to the fans, motors, and durable, attractively designed casings. Giants of efficiency and endurance. For complete information send for catalog W-N 102 All ratings of Webster-Nesbitt Unit Heaters are based on tests made in accor dance with the standard test * code of Industrial Unit Heater A ssociation and American Society of Heating and Ventilating Engineers. 1127 Specialties, Heating Wright-Austin Co. 317 West Woodbridge St., Detroit, Mich. PRODUCTS--Steam Traps, Strainers, Air Traps, Steam and Oil Separators, Compressed Air Purifiers, Exhaust Heads, Boiler Feeders, Alarm Water Columns, Water Gauges, Trycocks. "Airxpel" Bucket Type Steam Traps Are "double duty" traps, because they automatically discharge both air ana condensate. A t 1 e f t is illustrated the "Baby" Airxpel, a new streamline body design, which adds at tractiveness to the installation. Has the handiest type of pipe connection for radiation, etc. The Cub sizes are made in % in., % in., 1 in. Especially suitable for in dividual unit drainage on heating and process equip ment. Also three "Master" sizes in. to 2 in., for general service. "Combination" Steam Trap "Emergency" Float Type Steam Trap Three valve trap with large capacity at high pressures. An ex ceptionally reliable trap for use in inac cessible places. Air Relief Trap For relieving air from forced circulation hot water heating systems, water supply lines, closed tanks, receivers, pumps, etc. "Tuway" Strainer May be used two ways-- ^ as a straight-way or angle strainer, in either hori-; zontal or vertical pipe line, because it has the < choice of two inlets at right angles to one another. For cleaning, flush through blow-off connection, or remove screen by unscrewing bottom plug. Separators--Steam and Oil Type "A" Vertical Steam Type "S" Horizontal Oil Float Type with internal thermo static air bypass and strainer. A modernly design ed and very suc cessful trap for vacuum and pres sure heating. "Victor" Low I Steam Trap For heavy vol umes of conden sation at low pressures. We make separators of every type and all sizes. Exhaust Head Designed to eliminate noise and spray. Three types to select from--the "Cyclone" Heavy Duty, and Standard Galvanized Steel--also, the cast iron type, to remedy all condi tions. Sizes 1 in. to 48 in. Send for descriptive Bulletins on any of the items listed on this page. 1128 Specialties, Heating Yamall-Waring Company Manufacturers of Steam Specialties 7600 Queen Street, Philadelphia, Pa. YARWAY IMPULSE STEAM TRAPS Construction--The Yarway Impulse Steam Trap is unique in that there is only one moving part, the simple valve F. This trap is made of bar stock throughout, no castings used. Body and bonnet of cold rolled steel, cadmium plated; cap of tobin bronze, valve and seat of heat treated stainless steel. For pressures 400 to 600 lb, bonnet and cap are stain less steel. Operation--When handling conden sate, pressure required to lift valve F is greater than reduced pressure in control chamber K; therefore, valve F opens, allowing free discharge of condensate. As remaining condensate approaches steam temperature, flashing takes place, flow through center orifice is choked and pressure builds up in control chamber K, closing valve F. A--Cap Nut E--Lock Pin B--Lock Nut F--Valve C--Bonnet K--Control Chamber D--Control Cylinder L--Control Disc G--Valve Seat H--Test PXuq J--Body Advantages Light Weight--Yarway traps need no support--in. trap weighs.only lb. 2 in. trap weighs 8% lb. Small Size--They practically eliminate radiation losses--can be installed in cramped quarters--^ in. trap measures 2\i in. long--2 in. trap, 4% in. long. Will not air bind. Require no priming. Insure quick heating. Operate on exclusive Impulse principle (U. S. Patents No. 2,051,782. Other Pat. Petid.). Low Price--Often cheaper than re pairing old traps. Factory set to operate at all pressures up to 400 lb (or 600 lb) without change of valve seat. Prices, Weights and Dimensions Conn. Size Trap No. Trap Wt Length Complete Lb Inches 4001b 6001b Vz" %" i" 1W` Wl" 2" 60 61 63 64 66 67 70 71 $15.00 22.00 VA i4 % 73 31.00 2V? y/> 74 48.00 i`A VA 76 68.00 6 4% 77 90 00 S'/i 4y. For further information send for descriptive bulletin T-1733. YARWAY GUN-PAKT EXPANSION JOINTS All-steel welded construction; light but strong. Chromium covered sliding sleeves. Cylinder guide and stuffing box integral, assuring perfect alignment. Internal limit stops. Gun-pakt and Gland-pakt types; Gun-pakt (illustrated) fitted with screw guns which permit insertion of plastic packing while joint is under pressure. Sizes 2 in. to 24 in., single - end or double end, flanged or welding ends; 150, 300 and 400 ib pressures. For additional details send for bulletin EJ-1906. . 1129 Stokers The Brownell Company Established 1855 Dayton, Ohio Manufacturers of BROWNELL BOILERS AND STOKERS Representatives in All Principal Cities Welded Boilers built in Standard and Master types. "Standard" type, Direct Draft or Smokeless, Coal Hand Fired-- 500 to 34,000 sq ft. Stoker Fired-- 930 to 43,130 sq ft. "Master" type, Coal Hand Fired--500 to 35,520 sq ft. Stoker Fired-- 1070 to 45,110 sq ft. Brownell Standard Welded Smokeless Boiler . Riveted Double Pass Firebox Boilers built for. both high and low pressure. Coal Hand Fired-- 4000 to 35,000 sq ft. Stoker Fired--4860 to 42,500 sq ft. Brownell Riveted Double Pass Firebox Boiler, Stoker Fired The Browndl Type "C" Stoker is built in both stationary dead plate and side dump types, in sizes suitable for medium and large industrial and heating plants. Brownell Type "C" Side Dump Stoker The Brownell Type " R" Heavy Duty Ram Feed Stoker is designed for use in the larger industrial and heating plants. Ruggedness, flexibility, economy and low maintenance costs are features of this stoker. - Brownell Matched Units, Boiler and Stoker combinations, are available in sizes-from 500 sq ft to 45,000 sq ft. . Brownell Type "R" Heavy Duty Stoker ` In addition to the above, a complete line of Domestic Stokers is built. These Stokers are built in either ratchet or continuous feed. . Send for-Descriptive Bulletins 1130 Butler Manufacturing Company 1282 Eastern Ave. Kansas City, Missouri "AUTOMATIC BUTLER STOKER 14 Sizes. Feeding* Capacities 12 to 2,000 Lb Per Hour. Hopper Capacities Up to 1,400 Lb. Boiler Capacities up to 400 Hp. Steam Radiation up to 58,178 Sq Ft. Hot Water Radiation Up to 93,084 Sq Ft. Con t ro 18-- Minneapolis - Honeywell. Thermostats; magnetic switch and relay transformer or M-H Relay; limit controls either pressuretrol, aquastat or vaporstat. Motor--Standard high grade ball bear ing for any standard voltage, frequency, phase or direct current. Zoned Air Control--Steel wind box under retort with air damper. Permits controllable volume of air to retort zone and to entire zone of live side grates. Result is uniformly active fire-bed over entire grate area and not just in retort zone. Hopper--Vertical and equipped with up and down and sidewise agitator to in sure positive coal feeding into feed screw inlet. Self-Coaling--Bin-ToBurner Models. Designed with side fuel flow on separate worm screw which carries fuel from bin to stoker screw. Operated by independent mo tor and gear drive. Auto matic trip control regulates Fan--Cast aluminum mounted indepen dently on own ball bearings--not on motor. Pumps -- On Hydraulic Ram Feed Stokers variable speed type. Drive--Three center, double V-belt sys tem, drives transmission and fan. Constant Mesh Gears--Steel. Con stant mesh, anti-friction bearings, running in oil. Speed changes made without disen gaging gears or stopping motor or gears. Coal Duct--Cast iron, equipped with removable serrated jaw breaker plate to trap foreign matter accidently entering coal d uct. / ' Feed Screw--Straight flight cast of special alloy steel torsion tested to with stand tremendous stresses. Retort--Chrome nickel alloy, narrow tuyere blocks and side grates--easily re placed by removing locking rods. Retort suspended to allow for expansion and contraction without setting up stresses, which otherwise distort retort or crack its setting. flow of coal into stoker base only as required by firing conditions. Also sup plied with dust-tight steel bins shipped in sections to be bolted together. Complete Manual--Gives detailed capacities on coals of various Btu content, combustion space requirements, instal lation dimensions and drawings, heating cost tables and performance records. Write Stoker Division. Authorized dis tributors widely located. 1131 Stokers Combustion Engineering Company, Inc. All Types Fire and Water-Tube Boilers Pulverized Fuel Systems Complete Steam Generating Units Mechanical Stokers 200 Madison Avenue, New York, N. Y. Canadian Associate: Combustion Engineering Core., Ltd., Montreal CE-SKELLY STOKER UNIT The CE-Skelly stoker is designedfor installation under boilers ranging from small heating units to power boilers developing up to JfiO hp. Summary of Features A Self-Contained Unit--Hopper, fuel feeding and distributing mechanism, grate, windbox, driving mechanism and forceddraft fan are combined in a compact unit. Hopper--Made of rust- and corrosionresisting metal. Non-clogging and easily removable. Does not interfere with access to furnace doors. Located at convenient height for filling with shovel. Coal Feed--Screw conveyor, located entirely outside of retort and protected from heat, advances the coal from hopper to entrance of retort. Reciprocating ram in retort continues the feeding and provides agitation of the fuel bed in the retort zone. Grate Surface--Alternate fixed and moving grate bars. Designed for correct air distribution and made of a special heatresisting metal assuring tow maintenance. Air Supply--Integral forced draft fan, with inlet'damper control, supplies air to windbox under the stoker. Volume of air may be regulated by control to suit the rate of coal burning. Control--Automatic control furnished as standard equipment. . Application--For new boilers or for existing boilers having obsolete or in efficient firing equipment. Small clearances permit installation with only slight alter ations in most cases. Operation--Simple, easy, dependable. Variable-speed transmission permits 16 rates of coal feed. Control levers con veniently located. .Write for Sew 24-page Catalog So SV-5 OTHER CE STOKERS Nearly 14,000 CE stokers installed to date. The CE line of larger stokers in cludes the following, of which Type E, Coxe and Green are among the leaders in their respective fields. Type K Stoker--A single retort under feed stoker for burning bituminous coals under boilers in the upper size range of the CE-Skelly Stoker Unit. Type E Stoker--A single retort under feed stoker for burning bituminous coal under boilers up to about 600 rated hp. CE Multiple Retort Stoker--For burning semi-bituminous and bituminous coals under boilers up to the largest sizes. Coxe Stoker--A traveling grate stoker for burning small sizes of anthracite, coke breeze and lignite. Green Stokers--A chain grate stoker available in both natural and forced draft types for burning non-caking or freeburning bituminous coals. CE BOILERS All fire tube and water tube types in sizes ranging from 25 hp up to the largest. In cluded are all designs formerly known by the trade names "Heine, " "Walsh & Weidner." "Casey-Hedges" and "Ladd." Classified broadly, the various types of CE Boilers are as follows: BENT TUBE --multi-drum, four-drum, three-drum, two-drum (complete steam generators). STRAIGHT TUBE--sectional header, box header (cross drum and long drum). STEAM GENERATORS --complete standardized units available in two types. FIRE TUBE--hrt, vertical, internallyfired, locomotive type. MARINE-- sectional header, bent tube. WASTE HEAT--straight tube, bent tube. CE PULVERIZED FUEL SYSTEMS Formerly known by the trade name Lopulco,"' available in both direct fired and storage types for boilers ranging from 200 hp up. The CE-Raymond Bowl Mill, a pulverizer of advanced design, may be used in either direct fired or storage installations. A-316 1132 Stokers Detroit Stoker Company Sales and Engineering Offices General Motors Bldg., Detroit, Mich. District Offices in Principal Cities Main Offices and Works at Monroe, Mich. Built in Canada at London, Ont. Since 1898 PRODUCTS AND SERVICE Detroit Stokers: Built in various types and sizes to serve heating and power boilers from approximately 30 hp upwards. Bituminous coals obtainable in all sections are successfully burned. Many featuresembodied in the various designs represent 40 years of experience in stoker design, manu facture and proper application exclusively. May we study your individual require ments? District Offices, located in princi pal cities, will furnish catalogues; or write Detroit Stoker Company, Detroit, Mich. Detroit LoStoker Built in various widths and lengths to fit furnaces of all types of boilers. Compact, easily installed, responsive and automatic. Savings, due to increased efficiency, combined with the ability to successfully burn less expensive grades of coal, make Detroit Stokers pay a handsome return on the in vestment. Write for Bulletin 369. Detroit LoStokers are Plunger Feed, mechani cally driven through ma chine cut worms and gears, fully enclosed. Side cleaning, built in many sizes to Jit the furnace. One of Six Types of . Detroit Stokers Detroit LoStoker Advantages: Large Active Fuel Bed. with Provision for Admitting Air under the Dumping Grates at each side to burn out the Combustible Prior to Dumping Ashes. Agitator in coal hopper for positive coal feed. Cannot stick or jam with wet coal. Adjustable Plunger Feed for the con trol of the quantity of coal. Heavy Mechanical Drive of simple de sign. Little power is required for operation. Side Cleaning with dumping grates. Ash doors are provided. No hand cleaning. Automatically Controlled. Motor or turbine driven, controlled from steam pres sure, water temperature or thermostat. 1133 Stokers Iron Fireman Manufacturing Company Automatic Coal Burners ' Portland, Oregon Factories: Portland, Ore.; Cleveland, Ohio; Toronto, Canada Retail Branches or Subsidiaries Chicago, III^; Milwaukee, Wis.; St. Louis, Mo.; New York, N. Y.; Brooklyn, N. Y.; Montreal, Can. Dealers in Principal Cities and Towns in the United States and Canada Representation in numerous foreign countries IRON FIREMAN Automatic Coal Burners "Forced Underfiring" Principle --Iron Firemen "Forced Underfiring" is based on the scientific principle of feeding fuel to the fire from below, under forced draft. From the con veyor screw coal enters the firebox under the fire and is gradually forced up ward into the flame. As the coal ap proaches the fire, it is gradually heated. The volatile gases are distilled off in the presence of an excess of oxygen and are thoroughly ignited while passing through the incandescent fuel bed. This insures complete combustion. The ash is fused into clinkers which are easily removed. Advantages--Iron Fireman saves money and in creases heating n - ____ . plant efficiency in four major ways: (1) Cuts fuel P"X costs; (2) Reduces fl iB labor costs; (3) .. Lf Provides steady, Typical installation Dawn even h e a tor Draft Firebox Boiler power; (4) Elimi nates the smoke nuisance. Installation and Sizes--Iron Fireman is made in a range of hopper and bin-feed sizes for commercial heating and power boilers and also for homes. It can be installed quickly in practically any solid fuel boiler or furnace, old or new. Machines are shipped complete from the factory. All parts are standard and interchangeable. Features of Design and Construe-? tion--Construction and operation of the Iron Fireman are characterized by sim- plicity. throughout. Outstanding fea tures of design and construction are: (1) Pressed steel construction. (2) Special patented transmission--three speeds and neutral. Gears run in bath of oil. (3) Electric motor--standard make. (4) V-belt drive. (5) Safety shear pin protects mechanism from damage. (6) Quiet ball bearing fan supplying forced draft to fire. (7) Automatic fire banking damper--conserves fuel and holds fire in proper condition when stokejr is idle. . (8) Positive pneumatic fume eliminator--an auxiliary air supply that insures positive movement of all gases through the fire. (9) Volumeter that supplies exactly the amount of air needed for perfect com bustion regardless of fuel bed con ditions or type of coal used. (10) Sectional retort especially design ed to allow for heat expansion. (11) Dead plates of heavy iron and ribbed. (12) Sec tional, self-clean ing tuyere blocks. Typical Installation Four Drum Water Tube Boiler (13) Conveyor screw cast of special Iron Fireman alloy steel from one-piece pattern. (14) Automatic electric controls designed for and used exclusively on Iron Fireman. Automatic Controls--Iron Fireman starts and stops at the command of sensi tive, accurate automatic controls. Direct ing controls govern stoker operation according to demands of time, tempera- Iron Fireman Manufacturing Company Stokers Domestic Installation--Coal Flow model that carries coal direct from bin to fire Commercial Model--For Heat or Power ture, or pressure. An example of the efficiency of Iron Fireman directing con trols is the "Syncro-Stat" which provides automatic control of day and night tem perature. Other directing controls include pressure regulators, hot water and furnace regulators, and the "Timetactor," a device which runs the Iron Fireman during pre determined intervals in order to keep the fire alive during mild weather. The most important unit of the oper ating control system is the motor-driven relay switch. This device starts and stops the stoker motor at the com mand of the Syncro-Stat or other directing controls. In the case of the larger stokers a magnetic Typical InslaUalim Operating switch Cast Iron Boiler . works in conjunc tion with the relay switch. Iron Fireman, for Homes--The Iron Fireman residential model employs "Forced Underfiring" principle the same as larger machines, with simplified operation. Can be recommended for any steam, hot water, vacuum, or warm air furnace. Quickly installed. Hopper and bin- feed- models for both bituminous and anthracite coal. Anthracite models have been tested and ap proved by The Anthracite Insti tute. Typical Installation Domestic Boiler ENGINEERING SERVICE The Iron Fireman organization is nationwide. Trained men--backed by one of the largest manufacturing organiza tions in the field--are at your service to help you with the experience and practical heating information gained through servic ing thousands of boiler rooms and heating plants in all parts of the country. Any Iron Fireman engineer will gladly call and submit any additional. informa tion requested. CATALOG AND INFORMATION . Catalogs give full information about the Iron Fireman. Descriptive folders give special data about installation in particular types of industries and in homes. Secure them by addressing the factory or any Iron Fireman representative. Iron Fireman in Operation in Horizontal Return Tubular Boiler, Loro Bridge Wall _ Multiple Installation of Bunker--Feed Stokers 1134 For High Pressure Boilers Industrial "Poweram" Model--For Heal or Power 1135 Stokers Schwitzer-Cummins Company AUTOMATIC COAL STOKERS Indianapolis, Indiana, U. S. A. Dealers in principal cities and towns in the United States and Canada and certain foreign countries. STOKOL MODELS There are 38 STOKOL Models for burn ing bituminous and anthracite coal-- capacities range from 20 lb per hour on domestic sizes to 500 lb per hour on com mercial Models. Both bituminous and anthracite Models are made in hopper type and bin feed construction. All STOKOLS employ the "underfeed" principle of feeding coal. SUPERIOR FEATURES OF DESIGN AND CONSTRUCTION Schwitzer-Cummins Company pioneered in many basic improvements that have been important to the success of small Stokers --the Hydraulic Transmission, the Auto matic Air Control, the Universal Bin Feed are outstanding. Superior features to be found in STOKOL are STOKOSTAT, hydraulically operated "Holdfire" control --STOKOL AUTOMATIC AIR CON TROL for metering the supply of air delivered by the blower--STOKOLARM, an automatic device for signaling notice of any obstruction in feed screw and pro tecting against resultant overload--AIR TIGHT HOPPER with' low door for con venient filling--HY-DUTY multi-blade blower fan--AUTOMATIC ASH RE MOVER for anthracite models. An unusual engineering feature is the STOKOL Hydraulic Transmission--An oil pump located on the inner end of the shaft which carries the fan and drive pulley, draws the oil from the reservoir in the bottom of the case and forces it into the hydraulic cylinder. The pressure of the oil moves the piston forward and with it a lever which is in contact with the piston. This lever turns a ratchet wheel attached to a main shaft which drives the coal feed screw. Change in rate of coal feed is easily accomplished by turning a simple valve which varies the rate of oil. flow from the cylinder. An unlimited number of coal feeds are thus obtainable. The oil which is used to operate the piston is then diverted to flood every moving part of the mechanism with a bath of cool, clean oil assuring perfect lubrication and long-lived operation. (See also Page 880) 1136 Stokers VULLCjcttri Vulcan Anthracite Stoker Co STTOOKf ER Offices and Factory: 642 So. Main St. Wilkesbarre, Pa. Manufacturers and Distributers, Vulcan Anthracite Stokers Nine Different Sizes can be built on one chassis--fire pots from 14 in. to 30 in.--coal feed 15 to 80 lb per hour--rigid three-point suspension, one fixed point, two leveling screws--heat-resisting nickel cast iron adjustable self locking ash ring permits changes in size of fire pots. Four Types of Coal-Bin-Con veyors; Hopper Stoker on Same Chassis--Bin-feed type with feed screw 12 ft standard length to 35 ft without loss of efficiency; straight feed--pull feed-- overfeed and under feed at any angle--hopper type with hopper capacity of 350 lb or more--either type applied to same chassis. Back-Gas Trap built in the coal box prevents leakage of gases into coal bin--gases taken through by-pass and to main air chamber and burned, increasing efficiency of anthracite combustion. Repulsion-Induction Motor, single phase, brush-lifting type with built-in safety overload switch--especially built for start-and-stop operation. Burners-of heat-resisting nickel cast-iron specially designed for anthracite--air admitted to fuel bed uniformly around circumference of concentric burner rings, con structed to prevent coal siftings dropping into air chamber. Burner casing sealed to prevent air leakage from burner base. Coal Feed to Burner--straight line feed with gas trap to prevent gas leakage to bin-- feed rate increased or decreased by changing gears or pulleys. Anthracite-Burning Fan-- quiet operation; delivers right amount of air to give efficient combustion at standard feed rates. Ash System having patented ash agitator with slowly rotating wiper remoying clinkers from fire pot into ash pit, permitting use of larger pot and increase in efficiency of anthracite combustion. . Three Types of Ash Con veyors--one can--two can--mul tiple cans on either side of stoker-- equipped with an overload device to prevent stoppage of conveyor. 1137 Temperature Control Barber-Colman Company Rockford, Illinois AUTOMATIC fledrSC CONTROLS Barber-Colman Controls are all electric. Precision built to insure long, continuous, and dependable service. Easy to install in either new or existing installations. Ready for instant service at all times, even after long shut down periods. Thermostats. All types--room, duct, immersion and air-stream. Single, duplex, two-temperature and heater. Range and sensitivity to meet requirements. Hygrostats. Room, and duct types. Motor-Operated Valves. Packless, packed, single seat, pilot piston, vee-ported, three-way, four-way, and butterfly. , Solenoid Valves. For air, oil, water, gas, and refrig erants. Damper Control Motors. Unidirectional, or rever sible, fixed or adjustable speed. Program Switches. Automatic contact-making mech anisms for multi-compressor control or similar appli cations. Micro Controls give accurate proportioning control of modulating valves or dampers by operating them rapidly to a. definite position for each different temper ature at the thermostat. Literature is available describing complete automatic control of heating, ventilating, and air conditioning systems. Consult a Barber-Colman representative, or write the factory. Listed as standard by Underwriters' Laboratories. 5 \ 1 1138 Barber-Colman Company Temperature Control ENGINEERED AIR DISTRIBUTION OUTLETS Aspiration--Diffusion--Distribution--Directional Flow GRILLES REGISTERS Cores, of UNI-FLO fin and bar type construction, may be selected to give desired directional flow and throw, and permit placing outlets in most convenient locations. Smaller ducts and openings are possible because higher velocities and lower temperatures may be used without increasing the noise level or causing drafts. Frames are available for either baseboard, side wall, panel or cabinet mounting. . Finish: Plain metal; gray prime coat; gun-metal; clear lacquer; brushed-bronze; zinc cadmium; satin nickel; satin copper; buffed cadmium; brushed cad mium; polished nickel. Registers are same construction as grilles, with the addition of spring loaded,-positive closing, chain or key- operated dampers. Sizes. Grilles and registers are available in a number of standard sizes or may be made to any desired dimen sions. Special shapes are available to harmonize with any style of architecture. Accessories: Roughing-in frames, Elbow Turns and Volume Control Deflectors, together with technical data on UNI-FLO grilles and'registers, are described in the general UNI-FLO Catalog. UNI-FLO should be specified for all conditioning installations involving both heating and cooling. UNI-FIN should be specified for residential warm air installations. Write for descriptive literature on both UNI-FLO and UNI-FIN. Air-Lite (right)--Combina tion supply (or exhaust) outlet and lighting fixture. Ceiling Grille (left)--. Round, square or rectangular. Supply only, or combination supply and return. 1139 Temperature Control Detroit Lubricator Company Detroit, Michigan, U. S. A. New York, N. Y...40 West 40th Street Chicago, III., 816 S. Michigan Avenue Los Angeles,' Calif., 320 Crocker Street Canadian Representative: Railway and Engineering Specialties Limited, Montreal, Toronto, Winnipeg Division o/ American Radiator Ef Standard Sanitary Corporation Detroit Thermostatic Expansion Valve No. 673 Detroit valves are scientifically designed to keep evaporators completely refriger ated under all conditions. Orifice sizes available from 3^t2 in. to in. with capacities up to 3J tons on Dichloro- difluoromethane or 6 tons on Methyl or Sulphur. Two-Eleven Room Thermostat A thermostat neat in ap pearance and of new design for heating, cooling or in combination for both heating and cooling. Supplied with or without adjustable com pensator providing uniform control. Difierentlal Thermostat No. 691 Detroit Ther mostatic Ex pansion Valves Nos. 781-783 and 785 An inexpensive room thermostat for room cooling which modifies indoor temperature in accordance with outdoor temperature to maintain comfort conditions. . Provides economy of operation and prevents shock due to over-cooling. Large capacity valves for air conditioning in stallations. Capacities up to 20 tons on Dichlorodifluoromethane and 35 tons on Methyl. Line Strainer illustrated avail able for large valves. Pressure Control (Model RB-3) Controls low side pressure. Available with high pressure cut-out. to protect against high head pressures. .. Also available to control temperatures. Duct Damper Motor No. 431 An inexpensive means of provid ing individual temperature control for zones or groups of rooms. Is quiet and can be mounted directly on the duct. Furnished with auxiliary switch to control heating equip ment. Neat in appearance and easily installed. . ' Other Controls This Company can also supply you with Refrigeration Solenoid Valves, a full line of Boiler and Furnace Limit Controls-- Room Thermostats both. high and low voltage for both heating and cooling--Fan controls--Humidity and Stoker Controls and Solenoid Valves for the control of water, fuel and gas. 1140 Detroit Lubricator Company Temperature Control NEW IDEAL FAST-VENTING SYSTEM For All One Pipe Steam Jobs -- New and Old There are three fundamental requirements for the venting of one pipe steam jobs-- particularly when automatically fired. . 1. Venting must proceed rapidly and be accomplished as early in the ON period of the burner as possible. 2. All radiators must start venting simultaneously. 3. Steam flow to each radiator must be regulated in accordance with its location and capacity. It follows that most of the venting must be done before boiler pressure increases beyond a few ounces--also that large port large capacity valves are thus necessary. Large port low pressure venting has been made possible by the AUTOMATIC MODULATOR (patented). This permits full port action up to approximately 2 oz pressure. Beyond that the AUTOMATIC MODULATOR reduces port area so as not to jeopardize subsequent venting at normal pressures. . The No. 300 Arco-Detroit Multiport for radiators, is ideal for automatic heat as its construction permits much faster venting than the average air valve. Multiport The No. 861 Arco-Detroit Hurivent for mains, which has a in. port area, vents with amazing rapidity and cannot be compared with the ordinary vent valve in performance. The No. 300 Multiport is adjustable over a. wide range and its adjustment is proportional to the movement of the adjusting arm. Thus any system can be quickly and accurately balanced, and when desired, the adjustment can be locked to prevent unauthorized tampering. Adjustment in no way interferes with the action of the AUTOMATIC MODULATOR. The No. 300 Multiport is new, modern, and very attractive--has a lustrous black molded jacket accentuated by brilliant chromium striping. Of great importance to the installer when necessary to "balance" the system, is the scientifically designed slide valve method of adjust ment. The movement of this adjusting lever, which is located at the --' top of the valve, effects a corresponding adjustment of port area, and this adjustment is in direct proportion to the distance through which the lever moves. Moving the lever over Hurivent half its arc increases or decreases port area just 50%--moving the lever through a quarter of the arc changes port area 25%. The diagram to the left below shows port area wide open. The center diagram shows port area reduced one half. In the diagram to the right, the lever has been moved to its extreme slow position. Sectional View of Multiport 1141 Temperature Control The Fulton Sylphon Company Manufacturers of Sylphon Automatic Temperature Controlling Instruments and Packless Expansion Joints Knoxville, Tenn. Sales Representatives In Principal Cities PRODUCTS Automatic Radiator Valves, Air Conditioning Controls, Temperature Regulators for Storage Water Heaters; Ther mostatic Water Mixers; Re frigeration Temperature Re gulators; Packless Expansion Joints; Pressure Reducing Valves. GENERAL INFORMATION Fulton Sylphon Products depend upon the famous Sylphon Metal Bellows for their trouble-free service and long life. Over thirty-five years ago, The Fulton Sylphon Company originated this bellows ... a precision-built, seamless, jointless "miracle in metal." By continuous engineering study and intimate contact with heating and re frigeration problems, this company has used this efficient, practically indestructi ble bellows in the development of a line of temperature control and heating special ties known everywhere for outstanding service and quality. . SPACE HEATING AND AIR CONDITIONING CONTROL No. 885 Automatic Radiator Valve For exposed radiation. Small, neat, finely finished, adjustable to room tem perature desired. Simply replace ordinary radiator valves with these Sylphon Automatic Regu lators---no wiring, piping or auxiliary equipment are __ required.- These valves answer the demand for an - Valve inexpensive means of pro- viding accurate, depend able space temperature control in rooms, sections or throughout large buildings, new or old. Similar type valves for con cealed radiation--get Bulletin HVG-80. Sylphon Thermostats Heat accelerated and onoff types, with or without night set-back feature and with or without anticipating feature. 1 ML tC3P Sylphon Thermostats U type*) No. 890 Electric Radiator Control Valve For either exposed or con cealed radiation. Similar in appearance and action to Sylphon Automatic Valves, but operated by an electric wall thermostat. The closing of the thermostat circuit energizes a low voltage electric heatercoil surround ing a bulb containing a volatile liquid. This liquid expansion causes pressure Sylphon No. 890 Electric Control on a bellows in the valve Valve head operating the valve. This provides radiator valve control from a remote location, permits regulation of several radiators from a single thermostat, enables a time switch to be installed, if desired, offers effective zone control of large areas at a fraction of the cost of con ventional motor-operated valve systems. Bulletin HVG-70. . No. 7 Temperature Control A self-contained, self-powered regulator for controlling unit heaters, wall or ceiling type radiators, heating coils in duct-type heating systems, etc. A sturdy, control, quickly installed, holds temperatures within close limits. Valve is placed in steam line to Sylphon No. 7 Temperature Control (Self-operating) one or a battery of heaters, thermostat is mounted on wall or col umn. Designed for use on regular heating pressures up to 15 lb. Similar regulators, Nos. 7-2 and 7-3 for 50 and 75 lb pressure and temperatures up to 170 F. Bulletin HVG-50. . No. 928-C Temperature Regulator A compact regulator, especially suited to con trol of duct temperatures. Bulb is a series of copper coils, sensitive to slightest N 9&8-C ln a*r temperature, l Convenient adjustment. Regukttm Three types for 15, 50 and 75 Id steam pressures and temperatures not exceeding 170 F. 1142 Temperature Control The Fulton Sylphon Company No. 889-E Unit Ventilator Control An electrically and mechanically opera- * ted dual valve devel oped for use in unit ventilators. The elec tric side of the valve utilizes the same "heat motor" as used ,ElectriRadiator Valves and (BlectricaUy operated type) is operated by a wall thermostat in the room. Valve operates to bring room temperature to desired level during heating up period, and maintains desired temperature during period of "ther mal balance." Mechanical side of valve is operated by a thermostat bulb placed in dis charge air stream and is known as "mini mum air stream thermostat." This modulates the valve, when the electric thermostat is "off," to prevent dis charged air from falling below a predeter mined minimum temperature, eliminating objectionable cold drafts. Suitable for steam pressures up to 15 lb and for any two-pipe steam, vapor or vacuum system. No. 371 Damper Motor Sylphon Damper Motors *'i&elf'operatinQand electric type*) A positive type motor for on-and-off control of dampers. Operation may be controlled by thermostat, hand switch, motor starting , switch, or other means. Motor, safety type, closes on current ^ failure. Write for literature. 0 Refrigeration Controls 53 No. 916-Z Regulator _ Showing detail of "freeze proof' valve Adaptable wherever brine is used as the refrigerant. Latest development is a "freeze-proof" valve (illustrated at left on the popular Sylphon No. 945-Z Reg ulator). Bulletin HVG-20. PRESSURE REGULATORS No. 955--Sylphon Inter locking Valve is a safety appli ance protecting oil-fired fur naces by shutting off oil flow should atomizing pressure fail or fall below the required mini mum. Approved by Associ ated Factory Mutual Fire Insurance Companies. Bul letin HVG-100. No. 955 Interlocking Valve HOT WATER SUPPLY No. 923 Temperature Regulator For controlling tempera ture of water in heaters, open or closed tanks and various types of equipment. Operation is unaffected by temperature fluctuations at the valve, either above or below bulb temperature. Neat. Compact. AH parts, except steel adjustment spring, made of non-ferrous any position. metals. May be installed in Ranges from 40 -- 80 F to 290 - 330 F. Bulletin HVG-20. Bdow No. 90t Sylphon Thermostatic Water Mixer--n to JS1 9pm depending on water pressure. Above No. 905 Ther mostatic shower mixer with temp erature selector iandle permiting setting for my desired, ther mostatically maintained, imperativefrom old to a safe wmmum temprpture fof hot PACKLESS EXPANSION JOINTS The Sylphon Packless Ex pansion Joint eliminates use less building height, expen sive construction and non revenue producing space. No costly leaks and repairs, no repacking,always tight, allows heating system to operate at full efficiency. Write for Bul letin HVG-140. No. 110 Sylphon Expansion Joint Sylphon Thermostatic Water Mixers Utilize hot water from any storage tank or instantaneous heater, and effectively regulate the amount of cold water required to temper it to the desired degree, actually mixing the hot and cold water together before delivery. Temperature remains constant in spite of fluctuations in supply water temperatures or pressures. Four sizes with capacities ranging from 5 to 131 gpm. Bulletin HVG-40. 1143 Temperature Control Julien P. Friez & Sons, Inc., (A Subsidiary of the Bendix Aviation Corporation) Baltimore Established Maryland in 1876 Manufacturers of a Complete Line of Automatic Electric Controls for Industrial and Comfort Applications. Also a Complete Range of Recording and Accurate Measuring Instruments for Indoor and Outdoor Applications Humidistat--accurate over long periods and complete range; double length human hair ele ment. Bulletin A. Thermostat--sensitive, accurate for highest grade work. Bulletin T. Comfortrol--effective tem perature Thermostat resetting itself as prevailing humidity varies, using human hair compensating element. Exclusive. Bulletin E. Hand Aspirated Psy ch rome ter--replacing `slings', no whirling; re liable, immediate reading; thermometers perfectly ventilated by typical air, in duced by venturi action with hand operated bellows. Ex clusive. Bulletin S. perature varies. Windowstat -- placed at window in doors, positively pre venting condensation from excess humidity. Controls humidity sup ply just below critical point as outdoor temExclusive. Bulletin W. Portable-Recorder-- for surveys or tests of humidity and tempera ture. Inked records on charts the size of filing cards (3* x 5"). Exclusive. Bulletin G. Microstat--Small sized ther mostat, featuring powerful Alnico magnets. Though priced with the lowest, unsurpassed for accuracy and fine appearance. Bulletin TM. Magnetic Gas Valve--New principle, free floating disc, no diaphragm; quiet, durable; range of sizes; low priced, low voltage, especially suited for control by Microstat pictured above. Exclusive. Bulletin VG. Remote Reading Temperature and Humidity Recorder--Electrically opera ted ; humidity uniquely recorded from distant location directly in percent rela tive. Exclusive. Bulletin R. Write for Bulletins Relay-Transformer-- combined by new discovery in one unit, at price of relay alone. Advances use of low voltage controls; eliminates high voltage disadvantages at low cost. Exclusive. Bulletin AT/R. modern advanced controls for modern needs 1144 Temperature Control generalmttcontrols 267 Fifth Ave. New York City 1505 Broadway Cleveland, Ohio 450 East Ohio St. Chicago, Illinois t3?0 Harrison. St. San Francisco, Calif. DISTRIBUTORS IN ALL PRINCIPAL CITIES AUTOMATIC TEMPERATURE - riVI/OOURL-rLUW tiUiM KULb The Metrotherm ROOM THERMOSTATS LOW AND LINE VOLTAGE Low thermal inertia with heat acceleration adjustable to the type of installation and its load characteristics. Finished in soft, satin-silver and chrome, the Metrotherm blends with the prevailing shades of the modern rooms or the warm darker tones of SOLENOID VALVES LEVER-ACTION TYPE K-10 The automatic leveraction K-10 Valve is particularly designed for the control of viscous fluids. Positive opening and tight closing on oils as heavy as No. 6 at room temperatures. Also controls steam, water, air and gas. Two-wire. Packless construction Entirely hum-free. the English type. AUTOMATIC THERMOCOUPLE MAGNETIC GAS VALVE TYPE K-3B The GENERAL K-3B is a two-wire, straight-magnetic, current-failure valve of packless construction. Closing with the flow, the pressure is on top of the seat, insuring a tight shut off, indefinitely. Solen oid is absolutely hum less--a feature origi nated by GENERAL CONTROLS. Manual PILOT TYPE A-100--THE THERMOPILOT Flame applied to tip doses contact, allowing main gas valve to open. If gas pilot light fails, the Thermopilot opens circuit to the main gas valve. Automatically resets itself when pilot is relit. Flex- ible thermocouple tube for easy installation. Type ThermopHot by-pass allows for , opening in case of REFRIGERANT CONTROL KSB prolonged current fail ure. Terminal boxes may be turned in any direction to facilitate wiring. TYPE K-15 The GENERAL K-15 is a full-ported, current-fail ure, pilot-operated solenoid valve of packless construc SLOW OPENING GAS VALVE ELECTRICALLY OPERATED TYPE B-55 Simultaneous control of gas flow and damper opening on industrial furnaces and domestic heating plants. Adjust able opening time from 5 to 60 seconds. Fast closing time factory set. tion. Closes with the pres-, sure on top of the seat,, giving an absolutely tight shut-off. All materials are adapted to refrigerants and are non-corrosive. Port sizes from % in. to 2 in. Other GENERAL Refrigerant Valve sizes as small as %4 in. port for fractional tonnage installations. K-16 Type B-55 Incorporates the quiet GENERAL current-, CATALOGS AND BULLETINS failure solenoid as the pilot valve. Packless construction. Never requires oiling or servicing. For individual bulletins or Catalog of complete General Controls line, phone or write our nearest office. 1145 Temperature Control Johnson Service Company AUTOMATIC TEMPERATURE AND HUMIDITY CONTROL General Offices and Factory Milwaukee, Wis. Branch Offices in all Large Cities Johnson Temperature Regulating Co. of Canada. Lid., 113 Simcoe St., Toronto, Ont. Montreal. Que. Winnipeg, Man. Calgary, Alta. Vancouver, B. C. Products and Services Manufacturers, engineers, and contractors for Automatic Temperature and Humidity Control Systems applied to all types of heating, cooling, ventilating, and air conditioning installations. Also, for every range required in manufacturing and industrial processes. A single nation-wide organization devoted to Design, Manufacture and Installation for more than 50 years. . `# . Room temperature control applied to radiators, unit ventilators, and- heat delivery ducts. Johnson "Duo-Stats** to maintain the proper relationship between outdoor and radiator temperatures for groups of radiators or "heating zones." A complete line of devices for automatic control of air conditioning systems, heating, cooling, humidifying, dehumidifying. Automatic seasonal shifting of control cycles. Periodic Flush Systems for intermittent flushing in various sections of a building, reducing load on piping system and insuring economy in use of water. Special bulletins and catalogues on request. Sales Engineers at direct branch offices in all principal cities. Johnson All-Metal Thermostats Johnson thermostats, room, insertion, and immersion types, are all metal throughout, no soft or hard rubber parts to deteriorate and become inoperative. Every thermostat precise in construction and thoroughly tested for accuracy, efficiency, and durability. The Johnson intermediate action thermostat gives a true graduated action to mixing dampers and valves. It holds them in an intermediate position to maintain the temperature of the room accurately within one degree above or below the setting of the thermostat, if desired. Room Thermostat Johnson "Dual" or Two-Temperature Thermostats The Dual, two-temperature, room thermostat especially adapted for use where various rooms or groups of rooms are occupied when the remainder of the building is not in use. Separate steam mains avoided. The shifting from "day" or occupancy temperature to an economy temperature for "non-occupancy" conditions, accomplished by a switch or Johnson program clock at a central point. Push buttons on the thermostat are provided when "occupant control" is desired. Dual thermostats are all-metal and operate valves and dampers gradually to maintain temperature accurately within one degree. Dual Thermostat Johnson Valves "Sylphon" Radiator Valve Johnson diaphragm valves are simple and rugged. Seamless metal bellows and heavy spring operate the valve stem. No complicated moving parts. Made in all- standard sizes and patterns. Direct acting (normally open) or reverse acting (normally closed). Three-way mixing and three-way bypass valves. - For steam, water, brine, and special service. Johnson valves are available, if desired, with diaphragms of special moulded rubber, super-aged and heat-resistant. Room Uumuiosiai 1146 Johnson Seroice Company Temperature Control Humidostats and Humidifiers The Johnson Humidostat automatically controls the supply of moisture delivered to the air by a humidifier or air washer and maintains a constant percentage of relative humidity. Available in both room and insertion patterns, and with various types of elements as determined by requirements, controlling within 1 pier cent at relative humidity of 95 per cent and 100 F if desired. Johnson humidifiers are furnished in steam "grid" type or pan type with copper evaporating pan, brass heating coil, and float control. Air Conditioning Control Summer-Winter room thermostats for operation of valves and dampers in reverse sequence for cooling and heating. Four-Point Insertion Thermostat Insertion and immersion thermostats in one, two, three, and four-point patterns for opierating valves and dampers suc cessively at different temperatures. Remote readjustable thermostats, reset from a distant point by pilot or differential thermostat or by pressure switch. Differential , thermostats to maintain desired temperature differences between two points, such as outdoors and treated space. Solenoid air switches, manual switches, static pressure regulators,.velocity regulators, and all types of dampers to regulate flow of air in ducts. The Johnson sensitivity adjustment is an important development in the field of automatic tempierature and humidity control for air conditioning. A unique and convenient means of adjusting the sensitivity of Johnson thermostats and humidostats on the job, with respect to the capacity of the conditioning appiaratus. Zone Control Johnson "Duo-Stats" to regulate the flow of heat in a group of radiators constituting a "heating zone" by maintaining the propier relationship between outdoor and radiator tempieratures. Summer- Winter Thermostat Remote Readjustable Thermostat Process Control Calibrated insertion thermostats for control ling temperature of liquids, air and gases. Mercury extended tube thermostat for remote location of sensitive element. Wet-bulb thermostats for close regulation of humidity. " Record - O - Stats," combination instruments to record and control tempiera tures. . Modulating Attach- ' ment for Expansion Valves Rubber Diaphragm Coil Valve Louvered Damper 1147 Johnson *'Duo-Stat" Temperature Control Minneapolis-Honeywell Regulator Company Automatic Control Systems for Heating, Ventilating, Air Conditioning BROWN INSTRUMENTS for Indicating, Recording, Controlling NATIONAL PNEUMATIC CONTROLS for Heating and Air Conditioning Factories: MINNEAPOLIS, MINN., PHILADELPHIA, PA., WABASH, IND., CHICAGO, ILL. Branch Offices!`Stock carried Akron Allentown Atlanta* Austin, Minn. Baltimore Birmingham Bismarck. N. D. Boston* Buffalo* Butts Charlotte. N. C. Chicago* Cincinnati Cleveland" Columbus Dallas Datton Denver* Des Moines Detroit* Duluth East Orangb Eau Claire. Wis. Evansville Fargo, N. D. Fort Watnb Grand Rapids Hartford* Haverhill, Mass. Houston Indianapolis* Jackson, Mich. Kalamaxoo Kansas Citt* Little Rock Los Angeles* Louisville, Kt. Memphis Milwaukee* Minneapolis-- St. Paul* Mitchell, S. D. New Orleans New York* Oklahoma Citt Omaha* Peoria Philadelphia* Pittsburgh* Portland* Providence* Reading Rock Island, III. St. Louts* Saw Lake Citt* San Antonio* San Francisco*- Scranton Seattle Sioux Falls, S. D. Springfield, Mass. Syracuse* Toledo ` Tuisa Washington, D. C.* Wichita* Worcester, Mass. York. Pa. ' Youngstown In Canada: Montreal. Toronto.* Calgabt, Winnipeg In Europe: Amsterdam. Holland,* London, England* THE MODUTROL SYSTEM OF AUTOMATIC CONTROL The Modutrol System designation is applied to any combination of MinneapolisHoneywell Automatic Electric or Pneumatic Controls or Self-contained Automatic Valves used to govern the operation of air conditioning or heating systems other than the small domestic installations. A wide variety of both modulating and two position motors, controllers and valves are available thus making the Modutrol System extremely flexible as to the selection of control equipment to produce the desired results. ENGINEERING SERVICE Each Minneapolis-Honeywell office maintains a factory trained engineering personel. Your Minneapolis-Honey well engineer will be glad to furnish you with recommended control layouts and cost estimates. He is trained to recommend control results before in stallation of equipment and to produce control ^results after the installation has been completed. Chronotharm COMPLETE INSTALLATION SERVICE Minneapolis-Honeywell Branch Offices are equipped to make the complete installation of the Modutrol System for control of Air Conditioning or Heating installations. Thoroughly trained men are also available to supervise, adjust, or service' the control equipment. A stock of standard control equipment is carried at more than twenty points throughout the country for quick delivery. Modutrol Motor ELECTRIC CONTROL SYSTEMS Complete electric control systems are available for those installations where precise, flexible and dependable results are required. Electric controls of the Modutrol System provide a dependable means of effecting modu lation through the use of the "Series 90" control circuit. Ail electric motor power units used in this system are completely oil immersed in order to insure quiet operation and years of trouble-free service. 1148 Minneapolis-Honeywell Regulator Company Temperature Control PNEUMATIC CONTROL SYSTEMS Minneapolis-Honeywell offers a complete line of Pneu matic Controls. Such features as "Helmet Seal" thermo stats and Metaphram construction for valves and damper motors, are found only in Modutrol pneumatic equipment. For large commercial air conditioning and space heating installations, where low first cost is of special importance, use M-H Pneumatic Control Systems. National Pneumatic Thermostat COMBINATION ELECTRIC AND PNEUMATIC SYSTEMS The Modutrol System makes it possible to combine the outstanding advantages of both electric and pneumatic control equipment in a single installation. For maximum flexibility and low installation cost, use a combination Electric-Pneumatic control sequence. Compressor Brown Portable Recorder BROWN INSTRUMENTS The extent to which air conditioning equipment is being used in office buildings, theatres, stores, industrial buildings, etc., has opened up a wide demand for indicating and recording resistance thermometers because the temp eratures throughout these air conditioning systems should be checked periodically in order to obtain the best results at minimum operating cost. To obtain uniform conditions from modem equipment, it is necessary that the engineer in charge of operation have a visual picture of actual conditions. Brown Resistance thermometers are available for in dicating, recording, and controlling service and are applicable to all types of air conditioning and space heating installations. In addition to Resistance Thermometers, The M-H Brown Instrument Division manufactures: . Thermometers Hygrometers Pressure Gauges Vaccum Gauges Potentiometer Pyrometers Flow Meters CO2 Meters . Tachometers Liquid Level Gauges Protectoglo System Brown Recording Resistance Thermometer RESPONSIBILITY FOR ENTIRE CONTROL SYSTEM The Modutrol System and its supplementary equipment is so complete that the MinneapolisHoneywell Regulator Co. is equipped.to assume the entire responsibility for any control installation, thereby eliminating the difficulties and misunder standings which division of responsibility may create. 1149 y Temperature Control The Mercoid Corporation SOLE MANUFACTURERS OF THE MERCOID SWITCH Chicago. I lx. 4201 Belmont Ave. New York, N. Y. 90 West Street Boston. Mass. 25 Ivy Street Philadelphia. Pa. 3137 N. Broad Street COMPLETE LINE OF AUTOMATIC CONTROLS AND MAGNETIC VALVES FOR HEATING AND AIR CONDITIONING Mercoid Controls are equipped throughout with sealed mercury contact switches. These switches cannot be affected by dust, dirt or corrosive gases. They are not subject to open arcing, pitting or sticking of contacts. Mercoid switches will operate indefinitely without deterioration. Write for catalog No. 100AS. SENSATHERM Extremely sensitive ther mostat which requires no artificial stimulation to main tain an even room tempera ture. Operates on tempera ture variation of x/l deg above or below point set (total dif ferential 1 F). Small in size, neat in appearance and un failing in performance. TRANSFORMER-RELAY A low voltage transformerrelay but also operates as a mercury contact repulsion re lay. Does not hum or chatter. No residual magnetism. De signed to meet severe service conditions encountered with automatic operating equip ment. Write for Bulletin 110G. PRESSURE AND TEMPERATURE LIMIT CONTROLS These instruments have f proven their reliability over a long period of years. The outside double adjustment provided with a calibrated dial, is a special feature that saves considerable time when making the necessary operating adjust ments. Available for steam, hot water arid warm air furnaces. These controls are also used for various industrial applica tions. COMBINED PRESSURE AND LOW WATER CONTROL Every automatically fired steam boiler should have pro tection against the hazard of building up excess steam pressure or firing into a dry boiler. Mercoid Controls are accurate and dependable under various operating conditions. They are sturdy in construction, easy to install and adjust. Various ranges available. SAFETY CONTROLS "K" line controls have a number of desirable features . which make them pre eminent in the field. KM I illustrated herewith, is for burners employing intermit tent ignition. Other types available. N These controls offer positive protection against flame or ignition failure. . STOKER CONTROLS This stoker control oper ates stoker for only the very shortest periods necessary to maintain a fire while ther mostat is off. Prevents over heating and saves fuel. Auto matically stops stoker in case fire goes out. A Mercoid Stok-A-Timer is also available where a reliable stoker timer is required. 1150 Temperature Control Penn Electric Switch Co. Goshen, Indiana Offices--New York, Boston. Philadelphia. Detroit. Dayton. Chicago, Moline, (III.) Export--100 Varick St., New York City Representatives--Garland-Affolter Engrc. Corp., San Francisco, Los Angeles, Seattle Portland- Monarch Sales. Denver; Forslund Pump and Machinery Co., Kansas City; Jules Beneke, St. Louis'- The Uhl Co., Minneapolis. * Distributors and Jobbers in All Principal Cities Automatic Controls for Heat ing, Air Conditioning, Refriger ation, Pumps, Air Compressors. Tem-Clock Heating, air conditioning and refrigera tion control installations that once seemed complex are made simple to plan . . . easy to install--with Penn Controls. Penn has pioneered many outstanding improve ments in temperature and pressure control during the last 20 years . . . many note worthy contributions to control functions and dependability. Yet, during this time, Penn also has simplified control constructions, eliminat ing unnecessary parts . . . selecting new materials and new alloys . . . constantly building to more than satisfy practical engineers and installation men, not just to suit a laboratory technician's whims. Type 660 Stoker Control Illustrated are only a few Penn units for oil, stoker and gas heating, industrial temperature regulation, refrigeration, air conditioning and pressure control prob lems. Type 850 Water Valve--1}4" Size Type 480 Immersion Limit Switch Write for catalog on Penn controls to cover your particular applications, or 'phone the nearest Penn office or repre sentative. Penn engineers always are available for consultation on control problems, without obligation, of course. Type 400 Steam Pressure Limit Switch Type 807 Refrigeration Control Model LRT Temperature Control Type 678 Saftrol Type 518 Fan and Limit Switch Penn control engineers have simplified design and production problems for others! Let them assist you. . 1151 y Temperature Control The Powers Regulator Co* 45 Years of Temperature and Humidity Control Offices in 45 Cities--See Your Phone Directory General Offices and Factory: 2719 Greenview Ave., CHICAGO; General Eastern Office: 231 East 46th Street, NEW YORK; 1808 W. Eighth Street, LOS ANGELES; The Canadian Powers Regulator Co., 195 Spadina Ave., TORONTO, ONT. PRODUCTS--A very complete line of compressed air operated and selfoperating temperature, humidity and air flow controls for automatically regulating heating, cooling, ventila ting and air conditioning systems and industrial processes. A complete line of self-operating and compressed air operated valves and regulators made for: Controlling steam heated hot water heaters, and submerged type heaters; and for auto matically mixing hot and cold water or steam and cold water delivering a mixture at a predetermined tempera ture. Dial Indicating and Recording Thermometers. Thermometer-Regu lators. High pressure steam traps and pressure reducing valves. Powers Compressed Air Operated Apparatus The Powers Regulator Co. f l I Temperature Control 1152 POWERS ENGINEERING SERVICE As the accurate performance of a heat ing, cooling, ventilating or an air condi tioning system, or an industrial process is so dependent upon its automatic control equipment, and as the cost of such control is but a fraction of the entire system, the use of the proper type of regulation is always sound economy. . To secure the maximum return on the in vestment in automatic control equipment, it is exceedingly important that proper selection of control apparatus' be made when each installation is being planned. Forty-five years of experience in fur nishing and installing temperature aind humidity control for every conceivable purpose in all types of buildings has given us a wealth of experience from which you can draw in selecting the proper type of control for any purpose. CATALOGS AND BULLETINS de scribing any or all of our products fur nished upon request. Phone or write our nearest office. See your phone directory. 1153 Temperature Control Spence Engineering Company, Inc. 28 Grant Street, Walden, N. Y. Manufacturers of Pressure Regulators, Pump Governors, Weather Compensators, Self-Cleaning Strainers, Seco Metal. Advantages of Spence Regulators Accurate Regulation--Regardless of fluctuations in either load or initial pres sure. Spence Pilots fit any size main valve, are connected to main valve with unions, and are guaranteed to hold a dead-end. All main valves and most pilots are packless. A balanced single seat is used even in large sizes, of SECO Metal, guaranteed to resist wiredrawing action of steam. The metal diaphragms, under normal con ditions, never require replacement. Spence Weather Compensator--Type EWM3T This simple, dependable Control, when installed on a properly de signed orificed heating system, will show a substantial degree-day steam saving, at a low maintenance cost: The delivery pressure of the Regulator is automatically adjusted in direct proportion to the building heat losses. In other words, as the losses become greater, steam pres sure on the system is automatically increased. Any number of zones can be con trolled by one automatic Signatrol, automatic Wind Loss Compensator (Anemometer). Time Switch and Master Control Panel equipped with Manual and Automatic Dials for each zone. In this way each zone can be" set individually and at the same time be under the Master Control. When a Manual Dial is used, the automatic controls are cut off from that zone without affecting other zones. Pressure Regulator-- Type ED Designed to regulate a steady or varying initial pressure so as to maintain a constant, adjustable, de livery pressure. Applica ble to heating systems, power plant operations, or manufacturing processes. Combined Temperature and Pressure Regulator --Type ETD Self-contained, pilot oper ated, dead-end. Designed to control flow of fluid to a heating or cooling element, so as to maintain a constant, adjustable temperature, and protect the element against excessive pressure. 1154 Electrically Operated Valve--Type EM Can be opened or closed independently by an elec trical switch. TypeET--Same as ETD except pressure control is omitted. Order a SPENCE Regula tor for 40 days* free trial. Valoes Alco Valve Company, Inc. ENGINEERED REFRIGERANT CONTROL VALVES 2626 Big Bend Blvd. St. Louis, Mo.' THERMO EXPAN SION VALVES--To secure the greatest effi ciency from an evaporator, as much of its surface as possible must be used to absorb latent heat by vaporizing the liquid re frigerant. Alco Thermo Valves assure positive indepen dent and automatic con trol of the liquid feed in an evaporator in accord with the refrigerating load. They are responsive to any change in the suction gas superheat--this means less evaporator surface is required for securing control and a higher average suction pressure is maintained, with a corresponding increase in compressor capacity and shortened running time. There is a size and type of Alco control for all the usual refrigerants, with capacities from fractional tonnage to 60 tons Ammonia, 100 tons Methyl Chloride or 50 tons Freon-12. MAGNETIC LIQUID STOP VALVES --are positive acting, and tight closing. They are indispensable wherever instan taneous closing of the liquid supply line is in dicated. They are used extensively with expan sion valves where the tem perature difference be tween the refrigerant and the refrigerated substance or area is very small. They are also used ex tensively with Alco Float Switches to maintain a constant liquid level in flooded evaporators. All types are available in all the ordinary pipe sizes UfTto in., and for tonnage capacities ranging from fractional tonnage to 350 tons Ammonia, 115 Methyl Chlor ide, or 55 tons Freon-12. LIQUID FLOAT VALVES-- are provided with a vent tube which prevents gas binding, and permits the valve to be installed at the highest point on a full flooded system even though many feet above the liquid receiv er. They may also be installed at a low point in the system and will perform equally as well. Available in a variety of capacities up to 25 tons Ammonia, 10 tons Methyl Chloride, or 5 tons Freon-12. MAGNETIC SUCTION STOP VALVES--are designed for use as suction line shut-off or as low side by-pass valves. They are built without packing so as to operate successfully on heavily frosted lines. Makes pos sible individual control of two or more evaporating units in a multiple system even though there is a wide difference in tem perature requirement or load conditions. They provide individual tem perature control in any number of refrigerated units in a series system either flooded or fed by a constant pressure expansion valve. Built in ^in., % in.; 1 in., \ ]/i in., 1 J^in., or 2 in., sizes. ELECTRIC FLOAT SWITCHES--will stand high pressures and may be used on either a-c or d-c current. They will main tain a liquid level within 1 in. when used to operate a Magnetic Stop Valve in the liquid line on individual flooded evaporators or cool ers. They may be used as a high or low level alarm or to start small motors. Write for the complete story of ENGINEERED REFRIGERANT CONTROL .-; 1155 Valoes. Air Anderson Products, Incorporated Cambridge, Massachusetts Vent-Rite Radiator Air Valves. The Vent-Rite Balancer. Originators of "Balanced Radiation by Controlled Venting." Vent-Rite No. 1 Non-Vacuum VENT-RITE AIR VALVES The correct venting rate for each radiator in a system that will insure Positive Controlled Distribution of steam cannot be predeter mined. It requires regulation after the air valves are installed to properly "Balance" the particular system on which the installation is made. Vent-Rite Valves, therefore, are provided with a venting orifice which insures an ex ceptionally wide range of venting rates. Vent-Rite No-5t Non-Vacuum Thus, with Vent-Rites it is possible to obtain the correct venting rate of each radi ator in a system regardless of its size, location or pressure carried. .. Vent-Rite No. 2 IVS Vacuum Vent-Rite No. 3 Non-Vacuum Other Unusual Vent-Rite Features Tamper proof adjustment--out of sight, cannot be disturbed by accident or meddle some fingers--once set by the heating con tractor it remains Set. Take-Apart-Construction--valves can be Vent-Rite taken apart for thorough cleaning should they No. 621 VS Vacuum become clogged with dirt or cither matter. Vent-Rite Valves are made in both vacuum and non-vacuum types--are Noiseless in Operation--Positive in Action--Seal by Float Action against Water--Will not Leak or Sputter--Close Thermostatically under Tem perature. , . Vent-Rite Valves are made of the finest non-rusting--non-corroding materials to in sure years of trouble-free service. Bases are Brass Drop Forgings, Valve Pins are Nickel Silver, Finish is Chromium Plate. . Vent-Rite No. 4 IVS Vacuum 1156 Valoes, Air Anderson Products, Incorporated Cambridge, Massachusetts A Complete Line of Vent-Rite Valves Moderately Priced--is available to meet every venting requirement. Their Wide Venting Range and Tamper Proof Adjustment Improve the Operation of Any One-Pipe Steam System. Vent-Rite No. 5 Non-Vacuum The Vent-Rite Balancer Vent-Rite No. 6 IVS Vacuum Used in Conjunction with any Type Vacuum Valves on any Automatically Fired One-Pipe Steam System Creates the Vent-Vac System The Vent-Rite Balancer is a Solenoid operated Valve which--used in conjunction with Vacuum Type Valves on any Automatically Fired One-Pipe Steam System-- Improves the Performance of that System to a Remarkable Degree. The Vent-Rite Balancer, synchronized with the thermostat and firing unit, automatically returns a system under vacuum to atmospheric pres sure at the beginning of every firing cycle. The question sometimes arises, "Why break the vacuum when vacuum is the very condition to be established with vacuum valves?" The answer is that--Controlled Distribution of Steam can only be established in a system in which there is air to vent. The distribution of steam-vapor in a vacuum cannot be controlled by venting, hence, the admission of air into the system by means of the Balancer. Operation of The VENT-VAC SYSTEM , As steam is generated, its distribution is so controlled by correct venting of the Air Valves that all radiators are heated uniformly, thus, "Balanced "Radiation" is attained. When indicated room temperature is reached the thermostat shuts off the burner. After the firing unit tjas stopped, a further controlled distribution of heat units is provided by vapor, under vacuum to all radiators in proportion to their respective heat losses. When the vapor cools to the point where room temperature is no longer satisfied-- the thermostat calls for heat--the firing unit is automatically started--at the same instant the Balancer solenoid is energized, opening the orifice of the Balancer to intake air and the air valves return to their correct venting positions. . The above cycle is automatically repeated and controlled distribution assured on every heating cycle. The Vent-Rite Balancer is easily installed on the boiler or on one of the mains. It is electrically connected with the automatic heating unit and operates automatically in conjunction with the heat control or thermostat. The Vent-Rite Sales Policy Vent-Rite Air Valves and Accessories are carried in stock and sold only through Selected, Recognized Wholesalers of Plumbing and Heating Supplies, and to protect your profits and interests, we shall, to the limit of our ability and resources, continue to keep the sale of Vent-Rites in these recognized trade channels. Voices, Air The Dole Valve Company Main Office and Factory: 1901-1941Carroll Avenue, Chicago, 111. Branch Offices and Representatives in All Principal Cities The Dole Valve Company is a progressive manufacturer of air and vacuum valves for one or two pipe steam and hot water heating systems. There is a Dole Air and Vacuum Valve for every purpose. The line is complete and it is kept up to date by aggressive designing, engineering and manufacturing policies. Our latest contributions are the new DOLE NO. 3A in. connection), NO. 3B ( in. connection) and NO. 3C in. male, ^ in. female connections) AIR VALVES. Here is a picture of the No. 3C A:~ -- These Dole Nos. 3A, 3B and 3C Air Valves are designed to meet the in creasing demand for popu larly priced straight shank valves that give satis factory venting perform ance on systems where ex treme water conditions are encountered. They posi tively do not "stick" or spit water and they insure free venting at any pres sure up to 15 lb. Look at the illustrated installation suggestions. Notice that a nipple con nection is not required when Dole No. 3 Air Valves are installed on either cast iron or copper convectors, provided the heater has sufficient space to accommodate the siphon tube. Do not cut or bend this tube. Another important ad dition which rounds out the Dole line is the DOLE- NO. 7 SIGNAL AIR VALVE for venting con cealed hot water convec tors or radiators. This valve actually signals the operator when all the air is expelled. It is very easy to operate (no holding a cup to catch the water overflow) and it is easy to install. Dole Air and Vacuum Valves for other venting purposes on one or two pipe steam and hot water heating systems are the No. 2B Vacuum Valve, No. 6B Vacuum Valve, No. 100 Vacuum Valve, No. 103 Vacuum Valve, No. 2 Vacuum Valve, No. 6 Vacuum Valve, No. 1 Air Valve, No. 4 Quick Vent Valve, No. 5 Quick Vent Float Valve, No. 8 Quick Vent Valve, No. 9 Quick Vent Vacuum Valve, No. 1933 Air Valve, No. 10 Hot Water Key Valve and the Dole Compound Gauge. . Dole Air and Vacuum Valves that are equipped with the new Vari-Vent feature for "balancing" one pipe steam heating systems are the No. 2B Vari-Vent Vacuum Valve, No. 100 Vari-Vent Vacuum Valve, No. 101 Vari-Vent Vacuum Valve, No. 1 Vari-Vent Air Valve and No. 3A Vari-Vent Air Valve. We have prepared folders and illustrated price sheets on the whole Dole Air and Vacuum Valve line. These are not only informative but make splendid sales material. They are yours for the asking. 1158 Voices BRONZE - IRON - STEEL VALVES - SINCE 1864 Mechanical Rubber Goods Principal Stores and Offices 80 White St., New York, N. Y.; 524 Atlantic St., Boston, Mass.; 376 Spring St., Atlanta. Ga. 133 N. Seventh St., Philadelphia. Pa.; 822 Washington Blvd., Chicago. III. Bridgeport, Conn. (Office and Factory). Jenkins Bros., Ltd.: London, W.C. 2; Montreal, Que., (Works and Main Office). OVER 500 DIFFERENT JENKINS VALVES COVER EVERY HEATING AND AIR CONDITIONING NEED To adequately describe the complete Jenkins line of valves requires a Catalog of more than 300 pages. There are over 500 different types and patterns of valves that bear the trusted "Diamond" trade mark. Practically speaking, Jenkins can furnish any valve that you may require for plumb ing, heating, air' conditioning, general industrial or engineering service. General Classifications of Jenkins Valves Include--Bronze Valves fitted with Jenkins renewable composition disc. Bronze Regrind-Renew Valves' with bevel and plug type seats. Bronze Gate Valves. Iron Body Valves fitted with Jenkins renewable composition disc. Iron Body Regrinding Valves. Iron Body Gate Valves with solid wedge and double disc parallel seats. All-Iron Valves. Cast Steel Gate Valves and Swing Check Valves. Electrically and Hydraulically Operated Valves. Radiator Valves. Fire Line Valves. Quick-opening and Self closing Valves, Needle Valves, Y Valves, Solder-End Valves. Other Jenkins Products Are -- Colored Valve Wheels with or without service markings molded in relief letters. Composition Valve Discs exactly suited to service conditions. Sheet Packing. Gas kets. Moncrieff Scotch Gage Glasses. CONSULT THIS HELPFUL BOOK This 307 page Jenkins Catalog not only gives complete details on over . 500 Jenkins Valves, but also it has a large section of engineering data and practical information about valves and lay . outs. Make sure you have a. copy, including the new Supplement "B." JENKINS VALVES ARE SOLD BY MOST GOOD SUPPLY HOUSES 1159 r Voices New York Chicago Boston Air Valve Corporation Since 1898 Detroit St. Louis Cleveland Pittsburgh orifice Control Air. Valves 611-621 Broadway, New York vacuum orifice Control Air Valves NYAVCO ORIFICE "CONTROL BY VENTING" VALVES Air which fills each unheated radiator must be driven out by entering steam before heat is obtained. Using this air as an "air brake" and thus limiting or increasing its evacuation time on each radiator, accordingly slows or increases speed of entering steam and its consequent heating time. The NYAVCO Orifice Control Air Valve incorporates in one valve six gradually ascending vent speeds, which make possible the simultaneous heating of the largest and smallest radiator--or the equalization in steam delivery of the farthest unit from or nearest unit to the boiler. Thus balancing the job. The NYAVCO method of metered venting can so "time" each room radiator large or small--near or far--as to heat simultaneously, on coal fired constant heat jobs, or with room containing the automatic control (if an automatic gas, oil or stoker fired job). NYAVCO venting is fast because of unusually large vent port. It can only be set by the heating man--is consequently tamper-proof--because it is "locked in" the "armored cap" by him. Has a definite metered disc--Does not depend on thread or needle valve, but actual room or distance equalizing on each setting. wgwt com<on Air Valve--For one or two pipe gravity steam jobs. --Note open cut showing indestructi ble construc tion and con trol disc. Made also in in., X in.. in.. Straight and H in. Quick Vent. ..itcmm ^OBiriCt tOUTKOil CONTROL! Vacu-Seal Vacuum--A Gold - Seal- Lock-Vac ball check type vacuum uum--The Bellows oper valve--for use on inter ated atmospheric pres mittent heat- sure locked -- Vacuum i n g jobs Valve, will where price maintain is a consider vacuum on ation. Made also in H in., X in.. X in.. Straight Shank and X in. Quick Vent. one pipe gravity steam jobs over very long periods. Made in angle and quick vent types only. Fig. No. 1 Fig. No. e OPERATION OF VALVE INDESTRUCTIBILITY NYAVCO because of its open float and bi-metallic mechanism, depending upon actual steam contact functions immedi ately and will operate efficiently under all service requirements of one pipe systems. NYAVCO factory adjustment cannot be injured and valve is guaranteed fatigueproof -- rust-proof -- shock-proof. Write for details. GIANT Three Speed Air ELIMINATOR For Rapid Air Elimi nation from Large Mains -- Coils -- Air Conditioning Units --Unit Heaters, etc. 3 Speed control--X in.. X in.. X *n.--Secured by removing screw from speed size desired. X in. Size for load up to 1500 ft. X in. Size for load of 1500 ft to 3000 ft. X in. Size for load of 3000 ft Up. Made in regular Venting and Vacuum Valve 6X Actual Height. 1160 Fig. No. SO Water Treatment Aquatic Chemical Laboratories, Inc. 118 East 28th Street, New York, N. Y. . .. _ _ --Eliminates Rust, Scale, and Foaming in Marine and Stationary' Boilers, Diesel Plants, Heating, Piping and Air Conditioning Systems with Automatic Feeding and Sampling Devices The Aquatic Chemical Laboratories, by water and air changes. This eliminates Inc., successfully treats and services ma all handling of chemicals and the control rine and stationary boiler plants, low pres thereof by the engineer. Treatments are sure heating plants, air conditioning, street non-injurious and non-poisonous in physi steam heating, and domestic water systems. cal contact with them or air treated by them. Our Treatment Services are complete Treatments also provided for cleaning control services. We install feeding equip filters harmlessly, thereby doubly insuring ment and chemicals, make periodic check odor prevention. ups and boiler examinations, take samples Advantages: Increases metal life of of waters for laboratory analysis in order equipment. . Economizes by decreasing to make proper recommendations. shut-downs and repairs. Saves time, labor, High Pressure Boiler Treatments and water by decreasing frequency of water correct the varied scale and corrosion prob changes. lems of marine and stationary plants. Domestic Water and Heating Sys Treatments are individualized to comform to tems: Apartment and office buildings plant conditions---no one universal treatment serviced for corrosion prevention on annual is used. Periodic analyses, inspections and contract basis--a combined Treatment reports are rendered to the operating engi Service at reduced rate. Domestic water neers. The plant engineer also makes his system service: Initial injection of chemi own tests with a simple "Kit" furnished cals to loosen scale in piping; installation him. . of chemical feeder; necessary treatment Advantages: Minimizes boiler repairs, materials throughout contract year; con fuel consumption, costly interruption of tinuous servicing and check-up; semi boiler operation. Removes causes of monthly analyses. Heating system service'. foaming and priming. Prevents new and Complete boiler cleanings by our service dissolves old mineral scale formation. department; treatment materials through Helps to eliminate oil. Eliminates expen out contract year; chemical and engi sive external equipment, saving space. neering service; check-up; semi-monthly Treatments are simple of application. analyses. (See our 1 H.P. Folder). Low Pressure Boiler Treatments are Air Conditioning Systems protected three separate preparations--Gas-Fired, against corrosion by automatically-fed Steel, and Cast-Iron boiler treatments treatments properly varied to the demands giving the entire system a chemical scrub of the air conditioning system, as caused bing, without harmful effects. . Quick, easy method of blowing down boilers, used TREATMENTS FOR HEATING BOILERS with correct treatment, thoroughly cleanses all types of heating boilers. (See illustration. Ask for Folder 1 L. P.). Street Steam Heating System Services: Proportioning mech anism, and chemicals to protect en tire system against corrosion, reach ing every point in accurate propor tions. . Advantages: Increases life of piping and metals up to 95 per cent. Stops steam losses due to unclean traps, saves electricity through shortened vacuum pump operation. Capacity of attached heaters increased Prolongs life of equipment and gives 3 to 4 times, with fuel savings up to 25%. smoother, trouble-free operation by More and faster heat at lower pressures. removing causes of pipe failures and No Priming -- No Rusting -- No Clogging. costly repair and paint work. RECOMMENDED AND USED BY LEADING HEATING AND VENTILATING ENGINEERS 1161 Water Treatment Oakite Products, Ine. 22 Thames Street, New York, N. Y. Branch Offices and Representatives in All Principal Cities of the U. S. OAKITE AIREHNER Established 1909 A new material that prevents corrosion, controls bacteria growth, prevents slime and algae ac cumulations. Materials also available for rust and scale removal, cleaning and deodorizing. Bacteria, Slime and Algae Control Does your air conditioning equipment use a recirculating water supply? Increase the efficiency from it by preventing the growth of bacteria, slime and algae in the circulating water. This is accomplished easily, inexpensively with a new develop ment of the Oakite Research Laboratories, known as Oakite Airefiner. It is a dry, non-volatile white powder, completely soluble in water to provide safe, odorless, non-toxic solutions. Used in extremely low concentrations, one pound to 300 to 500 gal of water, this powerful bacteri cidal agent controls the growth of bacteria, ` slime and algae. Equipment is kept free of these accumulations, and from the un pleasant odors which they create. Preventing Corrosion Oakite Airefiner has been specially com pounded to also incorporate sufficient alkalinity to counteract the development of acidity in the water due to extraction of sulphur dioxide, and carbon dioxide gases from the air. If not prevented, this acid condition causes rapid corrosion of elim inators, air wash chambers and other metallic surfaces with which the untreated water comes in contact. Cleaning and Deodorizing Users of Oakite Airefiner enjoy a number of other definite advantages. Increased wetting power of water con taining Oakite Airefiner has resulted in actual removal of more dirt from the washed air. Eliminators, spray heads and water feed lines are kept free of scale and similar corrosion as well as of bacterial accumulations, slime and algae. The washed air is freed of practically all the matter which is responsible for objection able odors in re-used air. Cleaning Filter Screens Where filters are of the re-usable and washable type, Oakite cleaning methods provide a quick, safe, complete removal of the accumulated dust and dirt. No injury is done to the glass, metallic or similar material which comprises the filtering surface. Rust and Scale Removal Removal of rust and scale from feed water pipes, water cooling chambers or on other metallic surfaces can be accomp lished safely and economically with Oakite Compound No. 32. This is an acidic material especially prepared to provide absolutely uniform scale and rust dis solving action without having any harmful effect on the sound underlying metal. Specific recommendations on work of this type will be sent upon request. Nation-Wide Service Oakite materials are supplied through a nation-wide group of service representa tives who are thoroughly experienced in their application. Users are thus assured of employing the materials in the way to get the full bene fits they provide. Write for FREE, interesting fact-filled booklet on the use of Oakite Airefiner and the other Oakite materials designed specifically for help ing you get the max imum life and perfor mance from your air conditioning equip ment. No obliga tion, of course. 1162 INDEX TO MODERN EQUIPMENT In the Index to Modern Equipment are com plete detailed listings of heating, ventilating and air conditioning equipment and materials. Arranged alphabetically according, to. names of products are more than 300 items listing not only those products shown in the Catalog Data Section but also many other products made by the manufacturers represented in The Guide. On pages 1165-1188, under each index head ing--Air Cleaning Equipment, Fans, Humidi fiers, Ventilators, etc.--will be found, fully cross-indexed, a complete list of manufacturers of any desired products and page numbers' in the Catalog Data Section where the products are described. By reference to these index headings, the manufacturers names and the page numbers, any item of equipment or ma terials may be located quickly. On pages 843-848 will be found an alphabetical list of manufacturers whose products are shoton in the Catalog Data Section of The Guide. INDEX TO MODERN EQUIPMENT Heating, Ventilating, Air Conditioning Guide, 1938 AIR CLEANING EQUIPMENT Delco-Frigidaire Conditioning Div., General Electric Co., 902-903,1058 Air-Maze Corporation, 924-925 Airtemp Incorporated, 882-883 General Motors Sales Corp., 890 1059 892 General Refrigeration Corp., 864 American Air Filter Co.. Inc.. Electrol Incorporated, 898-899, 967 Grinnell Co., Inc.. 1000-1002, 1110 926-927 Fairbanks Morse & Co., 860 Henry Furnace & Foundry Co.. American Blower Corp., 850-851 Fedders Manufacturing Co., 991 912-913 American Radiator Company, 884 Fitzgibbons Boiler Co., 956-957 Ilg Electric Ventilating Co., 984 885, 940-943, 1061 Fox Furnace Co., The, 893-897 Ingersoll-Rand Company, 862-863 Autovent Fan & Blower Co., 977 General Electric Co., 902-903,1058 Kelvinator Division of Nash- Binks Manufacturing Co., 972-973 1059 Kelvinator Corp., 907-911 Buffalo Forge Company, 981 General Refrigeration Corp., 864 McQuay, Incorporated, 865 Burnham Boiler, Corp., 944-945 Gilbert & Barker Mfg. Co., 904-906 Modine Manufacturing Co., 993 Carrier Corporation, 853 Grinnell Co., Inc., 1000-1002, 1110 Herman Nelson Corp., 1004-1005 Clarage Fan Company, 858 Henry Furnace & Foundry Co., Niagara Blower Company, 868 Coppus Engineering Corp., 928 912-913 Parks-Cramer Company. 869 Delco-Frigidaire Conditioning Div., General Motors Sales Corp., 890 Ilg Electric Ventilating Co., 984 S. T. Johnson Co., 968-969 Research Corporation, 870 Servel, Inc., 871 . 892 Kelvinator Division of Nash- B. F. Sturtevant Co., 985 C. A. Dunham Co., 1108-1109 Kelvinator Corp., 907-911 Trane Company, The, 872-873 Fitzgibbons Boiler Co., 956-957 Kewanee Boiler Corp., 960-961 Unit Heater & Cooler Co., 994 Fox Furnace Co., The, 893-897 Lau Blower Co., 879 Utica Radiator Corp., 920-921 Gar Wood Industries, Inc., 900-901 Lennox Furnace Co., Inc., 914-915 Vilter Manufacturing Co., 875 General Electric Co., 902-903,1058 Lochinvar Corp., 916 Westinghouse Electric & Manu 1059 McQuay, Incorporated, 865 facturing Co., 876 Gilbert & Barker Mfg. Co., 904-906' Meyer Furnace Company, 917 Williams Oil-O-Matic Heating Cor Independent Air Filter Co., 929 Modine Manufacturing Co., 993 poration. 922-923 ' Kelvinator Division of Nash- L. J. Mueller Furnace Co., 918-919 L. J. Wing Mfg. Co., 988-989 Kelvinator Corp., 907-911 " .Herman Nelson Corp., 1004-1005 York Ice Machinery Corp., 877 Martocello, Jos. A. & Co., 866 Niagara Blower Company, 868 Young Radiator Company, 995 . L. J. Mueller Furnace Co., 918-919 Parks-Cramer Co., 869 Owens-Illinois Glass Company, 930 Servel, Inc., 871 AIR DIFFUSERS Parks-Cramer Company. 869 Research Corporation, 870 H. J. Somers, Inc.; 931 Staynew Filter Corp., 932-933 B. F. Sturtevant Co., 985 Unit Heater and Cooler Co., 994 Universal Air Filter Corp., 934 Utica Radiator Corp., 920-921 Westinghouse Elec. & Mfg. Co., 876 AIR COMPRESSORS (See Com H. J. Somers, Inc., 931 . Spencer Heater Division, 948-949 Schwitzer-Cummins Co., 880, 1136 Trane Company, The, 872-873 Unit Heater and Cooler Co., 994 Weil-McLain Company, 952 Westinghouse Electric & Manu facturing Co., 876 Williams Oil-O-Matic Heating Cor poration, 922-923 York Ice Machinery Corp., 877 American Blower Corp., 850-851 Anemostat Corp. of America, 1088 Auer Register Co., The. 1089 Barber-Colman Co., 1138-1139 Hart & Cooley Mfg. Co., 1090-1091 Independent Register Co., 1094 Tuttle & Bailey, Inc.. 1092-1093 Waterloo Register Co., 1096 AIR ELIMINATORS pressors, Air) Young Radiator Company, 995 American Radiator Company, 884 885, 940-943, 1061 AIR CONDITIONING CON TROLS, (See Controllers and Control Equipment, Humidity AIR COOLING AND DEHUMIDIFYING APPARATUS Armstrong Machine Works, 1102 1103 Beaton & Cadweil Mfg. Co., The , Controls) AIR CONDITIONING GRILLES (See Grilles, Registers) AIR CONDITIONING REG . ISTERS (See Grilles, Registers) Aerofin Corporation, 996-998 ' 1104-1105 - Air Devices Corporation, Units Div., 849 Thermal ` Burnham Boiler Corp., 944-945 C. A. Dunham Co., 1168-1109 Airtemp Incorporated, 882-883 American Blower Corp., 850-851 Hoffman Specialty Co., Inc., 1112 1113 American Gas Products Corp., 886, Illinois Engineering Co., 1114-1115 953 Milwaukee Valve Co., 1118-1119 AIR CONDITIONING UNITS Air Devices Corporation, Thermal Units Div., 849 Airtemp Incorporated,-882-883 American Blower Corp., 850-851 American Gas Products Corp., 886, 963 American Radiator Company, 884 885, 940-943. 1061 Autovent Fan & Blower Co., 977 Baker Ice Machine Co., 854-855 American Moistening Co., 852 Autovent Fan & Blower Co., 977 Baker Ice Machine Co., 854-855 Bayley Blower Company, 980 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 Carbondale Div., Worthington Pump & Machinery Co., 856-857 Carrier Corporation, 853 Chicago Pump Co., 1084 Clarage Fan Company, 858 Crane Co., 946-947 Mueller Steam Specialty Co.. Inc.. 1120 New York Air Valve Corp., 1160 Sarco Company, Inc., 1122-1123 Sterling Engineering Co., 1121 Trane Company, The, 872-873 Warren Webster & Co., 1124-1125 Wright-Austin Co., 1128 AIR FILTERS (See Air Cleaning Equipment) . Bryant Heater Co., 888-889 Buffalo Forge Company, 981 Burnham Boiler Corp., 944-945 Carbondale Div., Worthington Pump & Machinery Co., 856-857 Carrier Corporation, 853 Clarage Fan Company, 858 Curtis Refrigerating Machine Co., Div. Curtis Manufacturing Co.. 859 Curtis Refrigerating Machine Co., AIR MEASURING AND RE Div. of Curtis Mfg. Co., 859 CORDING INSTRUMENTS Delco-Frigidaire Conditioning Div., American Moistening Co., 852 - . General Motors Sales Corp., 890 892 C. A. Dunham Co., 1108-1109 Babcock & Wilcox Co., 954 Binks Manufacturing Co., 972-973 ; Bristol Company, The, 1012 Electrol Incorporated, 898-899, 967 Fairbanks Morse & Co., 860 Consolidated Ashcroft Co., Inc., 1013 Hancock Fedders Manufacturing Co., 991 Julien P. Friez & Sons, Inc., 1144' Frick Company (Incorporated), 861 Grinnell Co., Inc., 1000-1002, 1110 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 1165 Heating Ventilating Air Conditioning Guide 1938 Illinois Testing Laboratories, Inc., Mueller Steam Specialty Co., 1120 American Coolair Corp., 978-979 ' 1014 Preferred Utilities Corp., 970 Autovent Fan & Blower Co., 977 Johnson Service Co., 1146-1147 Wright-Austin Company, 1128 Bayley Blower Company, 980 Minneapolis-Honeywell Regulator Yarnall-Waring Company, 1129 Buffalo Forge Co., 981 Company, 1148-1149 Palmer Co., 1017 . Parks-Cramer Company, 869 ALGAE PREVENTION (See Slime Prevention) also Champion Blower & Forge Co., 982 .Clarage Fan Company, 858 Coppus Engineering Corp., 928 Powers Regulator Co., 1152-1153 Aquatic Chemical Laboratories, DeBothezat Division American Taylor Instrument Companies, Inc., 1161 , Machine & Metals, Inc., 983 1018-1019 Oakite Products, Inc., 1162 C. A. Dunham Co., 1108-1109 AIR MOISTENING APPAR ATUS (See Humdifiers) '. AMMONIA COILS Ammonia) .. (See Coils, Henry Furnace & Foundry Co.. 912-913 Ilg Electric Ventilating Co., 984 AIR PURIFYING APPARATUS American Air Filter Company, Inc., 926-927 Binks Manufacturing Co., 972-973 Buffalo Forge Co., 981 Burnham Boiler Corp., 944-945 Carrier Corporation, 853 Coppus Engineering Corp., 928 Delco-Frigidaire Conditioning Div., General Motors .Sales Corp., 890-892 C. A. Dunham Co., 1108-1109 Ilg Electric Ventilating Co., 984 Independent Air Filter Co., 929 Niagara Blower Company, 868 Owens-Illinois Glass Company, 930 Staynew Filter Corp., 932-933 Universal Air Filter Corp., 934 ANEMOMETERS Julien P. Friez & Sons; Inc., 1144 Illinois Testing Laboratories, Inc., 1014 , Taylor Instrument Companies, 1018-1019 . ASBESTOS PRODUCTS (See also Insulation) Carey, Philip, Co., 1028 Ehret Magnesia Manufacturing Co.. 1034-1035 Johns-Manville, 1042-1043 Ric-wiL Company, The, 1054 Ruberoid Co.. The, 1044-1045 AUTOMATIC SHUTTERS (See Shutters, Automatic) . Lau Blower Co., 879 Lennox Furnace Co., Inc., 914-915 McQuay, Incorporated, 865 Meyer Furnace Company, The, 917 L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Schwitzer-Cummins Co., 880, 1136 B. F. Sturtevant Co., 985 Trane Company, The, 872-873 Williams Oil-O-Matic Heating Cor poration. 922-923 L. J. Wing Mfg. Co.. 988-989 BLOWER MOTORS (See Motors, Electric) BLOWERS, Pressure . American Blower Corp., 850-851 American Coolair Corp., 978-979 Westinghouse Elec. & Mfg. Co., 876 AUTOMOBILE HEATER FANS . Autovent Fan & Blower Co., 977 L. J. Wing Mfg. Co.. 988-989 AIR RECEIVERS (See Receivers, Air) ' AIR TUBING, Flexible Metal (See Tubing, Flexible Metallic) . AIR VELOCITY METERS (See Meiers, Air Velocity) . AIR VELOCITY REGULATORS Johnson Service Co., 1146-1147 Powers Regulator Co., 1152-1153 Young Regulator Company, 935 Torrington Mfg. Co., The, 986-987 BENDS, Pipe Baker Ice' Machine Co., 854-855 Crane Co., 946-947 Frick Company (Incorporated), 861 Grinnel! Co.. Inc., 1000-1002. 1110 Arthus Harris & Co., 1066 Vilter Manufacturing Co., The, 875 York Ice Machinery Corp., 877 BENDS, Return (See Pipe, Return ' Bends) Bayley Blower Company, 980 ' Buffalo Forge Company, 981 Champion Blower & Forge Co., 982 Clarage Fan Company, 858 Henry Furnace & Foundry Co., 912-913 Ilg Electric Ventilating Co.. 984 Ingersoll-Rand Co., 862-863 Lau Blower Co., 879 Martocello, Jos. A. & Co., 866 Schwitzer-Cummins Co.. 880, 1136 B. F. Sturtevant Co., 985 L. J. Wing Mfg. Co.. 988-989 air washers BLOCKS; Asbestos BLOWERS, Turbine Air-Maze Corp., 924-925 American Blower Corp., 850-851 American Coolair Corp., 978-979 American Radiator Company, 884 885. 940-943, 1061 Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co., 1034rl035 . -Johns-Manville, 1042-1043 . Ruberoid Co., The, 1044-1045 Coppus Engineering Corp., 928 General Electric Co., 902-903,1058 1059 B. F. Sturtevant Co., 985 L. J. Wing Mfg., Co., 988-989 Autovent Fan & Blower Co., 977 Baker Ice Machine Co., 854-855 Bayley Blower Company, 980 , Binks Manufacturing Co., 972-973 BLOWERS, Fan (See Fan, Supply and Exhaust) BLOWERS, Forced Draft . BLOWERS, Warm Air Furnace Air Controls, Inc., 857 American Blower Corp.,-850-851 Buffalo Forge Company, 981 'Clarage Fan Company, 858 'American Blower Corp., 850-851 American Coolair Corp., 978-979 American Coolair Corp., 978-979 Autovent Fan & Blower Co., 977 Cooling Tower Co., Inc., 971 . Autovent Fan & Blower Co.. 977 Buffalo Forge Company, 981 Delco-Frigidaire Conditioning ` Di Bayley Blower, Company, 980. Champion Blower & Forge Co., 982 vision, General - Motors Sales Buffalo Forge Company, 981 Clarage Fan Company, 858 . Corporation, 890-892 - Champion Blower & Forge Co.,n982 DeBothezat Division American ' C. A. Dunham Co., 1108-1109 Clarage Fan Company, 858 ' Gilbert & Barker Mfg. Co., 904-906 Coppus Engineering Corp., 928 Machine & Metals, Inc:, 983 Fox Furnace Co., The, 893-897 Henry Furnace & Foundry Co., Curtis Refrigerating Machine Co., General Electric Co., 902-903. 912-913 Div. of Curtis Manufacturing 1058-1059 . Meyer Furnace Company, 917 Co., 859 . Gilbert & Barker Mfg. Co., 904-906 L. J. Mueller Furnace Co., 918-919 DeBothezat Division American Henry Furnace & Foundry Com Niagara Blower Company, 868 Machine & Metals, Inc., 983 pany, 912-913 Parks-Cramer Company, 869 ' Fox Furnace Co., 893-897 . Lau Blower Co., 879 B. F. Sturtevant Co., 985 Trane Company, The. 872-873 Unit Heater and Cooler Co., 994 Utica Radiator Corp., 920-921 Vilter Manufacturing Co., 875 Henry Furnace & Foundry Co., 912-913 . Lau Blower Co., 879 . Schwitzer-Cummins Co., 880, 1136 Servel, Inc., 871 Lennox Furnace Co., Inc., 914-915 Meyer Furnace Company, 917L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Schwitzer-Cummins Co., 880, 1136 York Ice Machinery Corp., 877 ALARMS, Water Level Illinois Engineering Co., 1114-1115 McDonnell & Miller, 938-939 Mercoid Corporation,- 1150Minneapolis-Honeywell Regulator B. F. Sturtevant Co., 985 . Utica Radiator Corp.,-920-921 L. J. Wing Mfg. Co.. 988-989 BLOWERS, Heating and Venti lating Air Controls, Inc., 878 Trane Company, The, 872-873 L. J. Wing Mfg. Co., 988-989 BOILER-BURNER Airtemp Incorporated, 882-883 Burnham Boiler Corp. 944-945 Carrier Corporation, 853 Co., 1148-1149 American Blower Corp., 850-851 Crane Co., 946-947 Please mentic n THE GUIDE 1938 when writing to Advertisers 1166 Index to Modern Equipment \ )' j Delco-Frigidaire Conditioning Di General Electric Company, 902- BOILERS, Steel .. vision, General Motors Sales Corp., 890-892 . Electrol, Inc., 898-899, 967 Gar Wood Industries. Inc., 900-901 General Electric Co., 902-903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co., 968-969 Kelvinator Division of Nash- Kelvinator Corp., 907-911 Herman Nelson Corp., 1004-1005 Williams Oil-O-Matic Heating Cor poration, 922-923 BOILER COMPOUNDS (See Compounds, Boiler) 903, 1058-1059 E. Keeler Company, 958-959 ' Kelvinator Division of Nash- Kelvinator Com., 907-911 * Kewanee Boiler Corp., 960-961 L. J. Mueller Furnace Co.. 918-919 Spencer Heater Division, 948-949 Union Iron Works, 962 United States Radiator Corpora tion, 950-951 Waterfilm Boilers, Inc., 963 BOILERS, Heating . American Gas Products Corp., 886, 953 American Radiator Company, 884 855, 940-943, 1061 Brownell Company, 1130 Babcock & Wilcox Co., 954 . s* Brownell Company, The, 1130- Burnham Boiler Corp-, 944-945' ' Combustion Engineering Co., 1132 Electrol Incorporated. 898-899, 967 Farrar & Trefts, Incorporated, 955 Fitzgibbons Boiler Co., 956-957 Frick Company (Incorporated), 861 Gar Wood Industries, 900-901 S. T. Johnson Co., 968-969 ' E. Keeler Company, 958-959 Kewanee Boiler Corp., 960-961 Spencer Heater Division, 948-949 Union Iron Works, 962 United States Radiator Corpora tion, 950-951 Waterfilm Boilers, Inc., 963 , . ' BOILER COVERING (See Cover ing, Pipes and Surfaces) ' . BOILER FEED PUMPS (See Pumps, Boiler Feed) BOILER FEEDERS (See Feeders, Boiler) BOILER TUBES (See Tubes, Boiler) BOILER WATER TREATMENT Bryant Heater Co., 888-889 Burnham Boiler Corp., 944-945 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899, 967 Farrar & Trefts, Incorporated, 955 Fitzgibbons Boiler Co., 956-957 Gar Wood Industries, 900-901 General Electric Company, 902 903, 1058-1059 Henry Furnace & Foundry Co., BOILERS, Water Tube American Radiator Company, 884 885, 940-943, 1061 '* Babcock & Wilcox Co., 954 Brownell Co., 1130 Burnham Boiler Corp., 944-945 Combustion Engineering Co., 1132 Fitzgibbons Boiler Co., 956-957 Frick Company (Incorporated), 861 E. Keeler Company, 958-959 Spencer Heater Division, 948-949 .Union Iron Works,'962 Aquatic Chemical Laboratories, . Inc., 1161 Cochrane Corp., 1107 - ___ Vinco Company, Inc., 936-937 " . BOILERS, Cast-Iron American Gas Products Corp., 886,953 . American Radiator Company, 884 885, 940-943, 1061 Burnham Boiler Corp., 944-945 912-913 E. Keeler Company, 958-959 Kewanee Boiler Corp., 960-961 L. J. Mueller Furnace Co., 918-919 Spencer Heater Division, 948-949 Union Iron Works, 962 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Waterfilm Boilers, Inc., 963 Weil-McLain Company, 952 BREECHINGS AND CHIMNEYS Farrar & Trefts, Incorporated, 955 E. Keeler Company. 958-959 Union Iron Works, 962 Young Regulator Company, 935 BURNERS, Automatic (See also Coal Burners, Stokers) Airtemp Inc., 882-883 Automatic Burner Corp.,- 964 Crane Co.. 946-947 BOILERS, Magazine Feed Crane Co.. 946-947 * Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Gilbert & Barker Mfg. Co., 904-906 . L. J. Mueller Furnace Co., 918-919 American Radiator Company, 884 885, 940-943, 1061 . Spencer Heater Division, 948-949 Weil-McLain Company, 952 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Detroit Stoker Company. 1133 Electrol Incorporated, 898-899, 967 Spencer Heater Division, 948-949 BOILERS, OU Burning General Electric Company, 902- ' United States Radiator Corpora tion, 950-951 Utica Radiator'Corp., 920-921' ' Weil-McLain Company, 952 BOILERS, Down Draft American Radiator Company, 884 .885, 940-943, 1061 Brownell Company, 1130 Crane Co., 946-947 - Airtemp Inc., 882-883 American Radiator Company, 884 885, 940-943, 1061 Babcock & Wilcox Co., 954 Branford Div., Malleable Iron Fittings Co., 966 ` Brownell Company, The, 1130 Burnham Boiler Corp., 944-945 Crane Co., 946-947 Delco-Frigidaire Conditioning Di . 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Iron Fireman Mfg. Co., 1134-1135 S. T. Johnson Co., 968-969 - Kelvinator Division of Nash- Kelvinator Corp., 907-911 Kleen-Heet, Inc., 965 Herman Nelson Corp., 1004-1005 Schwitzer-Cummins Co., 880, 1136 Williams Oil-O-Matic Heating Cor- . Farrar & Trefts, Incorporated, 955 Fitzgibbons Boiler Co., 956-957 Henry Furnace & Foundry Co., 912-913 E. Keeler Company, 958-959 Kewanee Boiler Corp., 960-961 United States Radiator Corpora tion, 950-951 ' vision, General Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899, 967 Farrar & Trefts, Incorporated, 955 Fitzgibbons Boiler Co., 956-957 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903. 1058-1059 poration, 922-923 BURNERS, Coal (See Coal Burners) ` BURNERS, Gas (See Gas-Burners) BURNERS, OU (Se OiljBurriers) . BOILERS, Gas Burning Gilbert & Barker Mfg. Co., 904-906 S. T. Johnson Co., 968-969 CALKING, BuUding . Airtemp Inc.,'882-883 American Gas Products Corp., 886, E. Keeler Company, 958-959 Kelvinator Division of Nash- Chamberlin Metal Weather Strip Co., 1032-1033 953 Kelvinator Corp., 907-911 American Radiator Company; 884 Kewanee Boiler Corp., 960-961 CEMENT, Asbestos ' 885, 940-943, 1061 L. J. Mueller Furnace Co., 918-919 Carey, Philip, Co., 1028 . Brownell Company, 1130 Herman Nelson Corp., 1004-1005 Eagle-Picher Lead Co., 1036 Burnham Boiler Corp., 944-945 .Spencer Heater Division, 948-949 Ehret Magnesia Manufacturing Crane Co.. 946-947 - Union Iron Works, 962 Co.. 1034-1035 Delco-Frigidaire Conditioning Di United States Radiator Corpora Johns-Manville, 1042-1043 vision, General Motors . Sales tion, 950-951 Ruberoid Co., The, 1044-1045 ' - Corporation, 890-892 - Utica Radiator Corp., 920-921 Farrar & Trefts, Inc., 955.' .. Waterfilm Boilers, Inc., 963 CEMENT, Refractory (See Re- Fitzgibbons Boiler Co., 956-957 Weil-McLain Company, 952 fractories) - ` Numerals following-Manufacturers* Names refer to pages In the Catalog Data Section 1167 Heating Ventilating Air Conditioning Guide 1938 CEMENT, Rock Wool COILS, Ammonia Frick Company (Incorporated), 861 Carey, Philip, Co., 1028 Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co.. 1034-1035 General Insulating & Mfg. Co., 1037 . Johns-Manville, 1042-1043 Air Devices Corporation, Thermal Units Div., 849 Baker Ice Machine Co., 854-855 Carbondale Division Worthington Pump and Machinery Corp., 856-857 Carrier Corporation, 853 Arthur Harris & Co.,' 1066 Kewanee Boiler Corp., 960-961 McQuay, Incorporated, 865 Taco Heaters Inc., 1008-1009 Unit Heater & Cooler Co., 994 Vilter Manufacturing Co., 875 York Ice Machinery Corp., 877 Ruberoid Co., The, 1044-1045 Clarage Fan Company, 858 Standard Lime & Stone Co., 1047 Crane Co., 946-947 COLUMNS, Water Fedders Manufacturing Co., 991 Brownell Company, 1130 CHAIN PULLEYS . (See Pulleys, Frick Company (Incorporated), 861 Crane Company, 946-947 Chain) ' G & O Manufacturing Co., 999 Detroit Lubricator Co., 1140-1141 CIRCULATORS, Hot Water Heating Bell and Gossett Co., 1006-1007 General Electric Co., 902-903, 1058-1059 Minneapolis-Honeywell Regulator Co., 1148-1149 Sterling Engineering Co., 1121 Taco Heaters Inc., 1008-1009 H. A. Thrush & Co., 1010-1011 Westinghouse Electric & Manu facturing Co., 876 CLEANERS, Air (See A ir Cleaning Equipment) General Refrigeration Corp., 864 McQuay, Incorporated, 865 Trane Company, The, 872-873 Unit Heater and Cooler Co., 994 Vilter Manufacturing Co., 875 Yarnall-Waring Co., 1129 York Ice Machinery Corp., 877 Young Radiator Company, 995 COILS, Brass E. B. Badger & Sons Co., 976 Carrier Corporation, 853 Crane Co., 946-947 Grinnell Co., Inc., 1000-1002, 1110 Arthur Harris & Co., 1066 Kieley & Mueller, Inc., 1116 . Mueller Steam Specialty Co., 1120 Wright-Austin Company, 1128 Yarnall-Waring Company, 1129 COMPOUNDS, Asphalt, for Conduits Ric-wiL Company, The, 1054 Ruberoid Co., 1044-1045 . COMPOUNDS, Boiler Aquatic Chemical Laboratories, Inc., 1161 Gilbert & Barker Mfg., Co., 904-906' Vinco Company, Inc, The, 936-937 COAL BURNERS, Automatic, B. F. Sturtevant Co.', 985 COMPOUNDS, Boiler and Radi Anthracite COILS, Pipe, Copper ator Sealing Babcock & Wilcox Company, 954 Buffalo Forge Company, 981 Crane Company, 946-947 Combustion Engineering Co., 1132 Delco-Frigidaire Conditioning Div. General Motors Sales Corp., 890-892 Fairbanks, Morse & Co., 860 Fox Furnace Company, 893-897 Henry Furaace & Foundry Co., 912-913 Iron Fireman Mfg. Co., 1134-1135 Meyer Furnace Company, 917 Schwitzer-Cummins Co., 880, 1136 Spencer Heater Division, 948-949 Vulcan Anthracite Stoker Corp., 1137 COAL BURNERS, Automatic, Bituminous Babcock & Wilcox Co., 954 Brownell Company, 1130 Crane Company, 946-947 Combustion Engineering Co., Inc., 1132 Delco-Frigidaire Conditioning Div. General Motor Sales Corn., 890-892 Detroit Stoker Company, 1133 Fairbanks, Morse & Co., 860 Henry Furnace & Foundry Co., 912-913 Aerofin Corporation, 996-998 American Brass Co., 1062-1063 American Radiator Company, 884 885, 940-943, 1061 E. B. Badger & Sons Co., 976 Baker Ice Machine Co., Inc., 854 855 Bell and Gossett Co., 1006-1007 Carrier Corporation, 853 Crane Co., 946-947 Curtis Refrigerating Machine Com pany, Div. of Curtis Manufact uring Co., 859 ' Fairbanks Morse & Co., 860 Fedders Manufacturing Co., 991 Frick Company (Incorporated),861 Grinnell Co., Inc.. 1000-1002, 1110 Arthur Harris & Co., 1066 Kelvinator Division of NashKelvinator Corp., 907-911 Kewanee Boiler Corp., 960-961 McQuay, Incorporated, 865 Mueller Brass Co., 1064-1065 Niagara Blower Company, 868 Revere Copper and Brass Incor porated, 1067 Servel, Inc., 871 Streamline Pipe and Fittings Co., 1064-1065 York Ice Machinery Corp., 877 Young Radiator Company, 995 ^ Dole Valve Company, The, 1158 Vinco Company, Inc., The, 936-937 COMPOUNDS, Cleaning Aquatic Chemical Laboratories, Inc., 1161 Dole Valve Company, The, 1158 Oakite Products, Inc., 1162 Preferred Utilities Corp., 970 Vinco Co., Inc., 936-937 ~ COMPRESSORS, Air : American Marsh Pumps Inc., 1082 Baker Ice Machine Co., 854-855 Binks Manufacturing Co., 972-973 Curtis Refrigerating Machine Co. Div. of Curtis ' Manufacturing Company, 859 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Ingersoll-Rand Company, 862-863 . Nash Engineering Co., 1086-1087 Worthington Pump and Machinery Co., 856-857 COMPRESSOR MOTORS (See Motors, Electric) COMPRESSORS, Refrigeration Air Devices Corporation, Thermal Units Div., 849 Iron Fireman Mfg. Co., 1134-1135 COILS, Pipe, Iron Airtemp Incorporated, 882-883 Kelvinator Div. of Nash-Kelvina- E. B. Badger & Sons Co., 976 ' tor Corp., 907-911 . Meyer Furnace Company, 917 Bayley Blower Company, 980 Clarage Fan Company, 858 ` Herman Nelson Corp.,. 1004-1005 Crane Co., 946-947 * Baker Ice Machine Co., 854-855 Carbondale Div. Worthington Pump & Machinery Co., 856-857 Carrier Corporation, 853. Schwitzer-Cummins Co., 880, 1136 Fairbanks Morse & Co., 860 Curtis Refrigerating Machine Co., COILS, Aluminum Aerofin Corporation, 996-998 Baker Ice Machine Co., Inc., 854 855 Frick Company (Incorporated), 861 Grinnell Co.. Inc., 1000-1002, 1110 Vilter Manufacturing Co., 875 York Ice Machinery Corp., 877 Div. Curtis Manufacturing .Co., 859 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Delco-Frigidaire Conditioning Di COILS, Tank Fairbanks Morse & Co., 860 vision, General Motors - Sales American District Steam Co., 975, Frick Company (Incorporated), 861 Corp., 890-892 1052 - Fox Furnace Co., 893-897 Arthur Harris & Co., 1066 American Radiator Company, 884 General Refrigeration Corp., 864 McQuay, .Incorporated, 865 885, 940-943, 1061 . General Electric Company, 902 Niagara Blower Company, 868 E. B. Badger & Sons Co., 976 903, 1058-1059 B. F. Sturtevant Co.-, 985 Baker Ice Machine Co., 854-855 Ingersoll-Rand Company, 862-863 Trane Company, The, 872-873 Bell and Gossett Co., 1006-1007.. Kelvinator Division of Nash-' Unit Heater and Cooler Co., 994 Clarage Fan Company, 858 Kelvinator Corp., 907-911 Young Radiator Company, 995 .- Crane Co., 946-947 Merchant & Evans Co., 867 Please mention THE GUIDE 1938 when writing to Advertisers 1168 Index to Modern Equipment .Herman Nelson Corp., 1004-1005 Republic Steel Corporation, 1071- CONVECTION HEATERS. Servel, Inc., 871 Universal Cooler Corp., 874 Vilter Manufacturing Co., 875 Westinghouse Electric & Manu facturing Co., 876 Williams Oil-O-Matic Heating Cor poration, 922-923 York Ice Machinery Corp., 877 COMPRESSOR TUBING, Flex .. ible (See Tubing, Flexible Metallic) CONDENSERS Aerofin Corporation, 996-998 Air Devices Corporation, Thermal Unit Div., 849 . Airtemp Inc., 882-883 Baker Ice Machine Co., 854-855 Ric-wiL Company, The, 1054 Underground Steam Construction Co.. 1055 Wyckoff & Sons Co., 1056 Zonolite Company. The, 1050-1051 CONTROL, Air Volume Damper Auer Register Co., The, 1089 Barber-Colman Co., 1138-1139 Fulton Sylphon Co., 1142-1143 Hart & Cooley Mfg. Co., 1090-1091 Illinois Engineering Co., 1114-1115 Independent Register Co., 1094 Minneapolis-Honeywell Regulator Co.. 1148-1149 Tuttle & Bailey, Inc.,- 1092-1093 Waterloo Register Co., 1096 Young Regulator Company, 935 - American Radiator Company, 884 885, 940-943, 1061 Crane Co., 946-947 l. C. A. Dunham Co., 1108-1109 Grinnell Co., Inc., 1000-1002, 1110 McQuay, Incorporated, 865 Modine Manufacturing Co., 993 John J. Nesbitt, Inc.; 1003 Revere Copper and Brass Incor porated, 1067 Trane Company, The, 872-873 Tuttle & Bailey, Inc., 1092-1093 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Warren Webster & Co., 1124-1127 Weii-McLain Company, 952 Young Radiator Co., 995 ' Carbondale Div. Worthington Pump & Machinery Co., 856-857 Carrier Corporation, 853 CONTROL EQUIPMENT, Combustion . COOLING EQUIPMENT, Air Aerofin Corporation, 996-998 Curtis Refrigerating Machine Co., Div. Curtis Manufacturing Co., 859 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Fairbanks Morse & Co., 860 . Fedders Manufacturing Co., 991 Frick Company (Incorporated), 861 _G & O Manufacturing Co., 999 General Electric Company, 902 903, 1058-1059 _ General Refrigeration Corp.. 864 Ingersoll-Rand Company, 862-863 Kelvinator Div. of Nash-Kelvina- tor Corp., 907-911 McQuay. Incorporated, 865 Modine Manufacturing Co., 993 Servel, Inc., 871 ' Barber Gas Burner Co., 887 Bristol Company, The, 1012 Bryant Heater Co., 888-889 Detroit Lubricator Co., 1140-1141 Fulton Sylphon Co., 1142-1143 General Controls, 1145 Gilbert & Barker Mfg. Co., 904-906 Leeds & Northrup Co., 1015 Mercoid Corporation, 1150 Minneapolis-Honeywell Regulator Co., 1148-1149 Penn Electric Switch Co., 1151 Preferred Utilities Corp., 970 Spence Engineering Co., 1154 . Vulcan Anthracite Stoker Corp., 1137 Westinghouse Electric & Manu facturing Co., 876 B. F. Sturtevant Co., 985 Trane Company, 872-873 Unit Heater and Cooler Co., 994 Universal Cooler Corp., 874 Vilter Manufacturing Co., 875 CONTROLLERS AND CON TROL EQUIPMENT (See also Humidity and Temperature Con trol) Air Controls, Inc., 878 Air Devices Corporation, Thermal Units Div., 849 Airtemp Incorporated, 882-883 American Blower Corp., 850-851 Autovent Fan & Blower Co., 977 Baker Ice Machine Co., Inc., 854 855 - Binks Manufacturing Co., 972-973 Buffalo Forge Company. 981 Carbondale Div. Worthington Pump & Machinery Co., 856-857 Carrier Corporation, 853 Champion Blower & Forge Co., 982 Clarage Fan Company, 858 Coppus Engineering Corp., 928 Curtis Refrigerating Machine Com pany, Div. of Curtis Manu facturing Co., 859 Delco-Frigidaire Conditioning - Di vision, General Motors Sales Corporation. 890-892 Electrol, Incorporated, 898-899,967 Fairbanks Morse & Co., 860 . . Westinghouse Electric & Manu American Radiator Company, 884 Fedders Manufacturing Co., 991 facturing Co., 876 885, 940-943, 1061 York Ice Machinery Corp., 877 Barber-Colman Co., 1138-1139 'Young Radiator Company, 995 Barber Gas Burner Co., 887 Bristol Company, The, 1012 CONDUIT, Flexible Metallic Bryant Heater Co., 888-889 Chicago Metal Hose Corp., 1068 Republic Steel Corporation, 1071 . Titeflex Metal Hose Co., 1069 Trane Company, 872-873 Carrier Corporation, 853 Consolidated Ashcroft Hancock Co., Inc., 1013 Detroit Lubricator Co., 1140-1141 Fox Furnace Co., The, 893-897 CONDUITS, Underground Fittings Julien P. Friez & Sons, Inc., 1144 Fulton Sylphon Co., 1142-1143 General Controls, 1145 American Brass Co., 1062-1063 American District Steam Company, 975, 1052 E. B. Badger & Sons Co., 976 General Electric Company, 902 903, 1058-1059 , Ric-wiL Company, The, 1054 ' Underground Steam Construction Co., 1055 Zonolite Co.. 1050-1051 Gilbert & Barker Mfg. Co., 904-906 Hoffman Specialty Co., Inc., 1112 1113 Illinois Engineering Co., 1114-1115 Illinois Testing Laboratories, Inc., 1014 Johnson Service Co., 1146-1147 Kieley & Mueller, Inc., 1116 Leeds & Northrup Co., 1015 ' Minneapolis-Honeywell Regulator Co., 1148-1149 CONDUITS, Underground Pipe Penn Electric Switch Co., 1151 Powers Regulator Co., 1152-1153 American Brass Co., 1062-1063 Preferred Utilities Corp., 970 American District Steam Company, . Sarco Company, Inc., 1122-1123 975, 1052 . Spence Engineering Co., 1154 Fox Furnace Co., The, 893-897 Frick Company (Incorporated), 861 General Electric Company, 902 903, 1058-1059 General Refrigeration Corp., 864 Henry Furnace & Foundry Co., 912-913 Ilg Electric Ventilating Co., 984 . Kelvinator Division of Nash-., Kelvinator Corp., 907-911 Lau Blower Co., 879 . McQuay, Incorporated, 865 Meyer Furnace Co., 917 Modine Manufacturing Co., 993 Herman Nelson Corp., 1004-1005 Niagara Blower Company, 868 Research Corporation, 870 Servel, Inc., 871 B. F. Sturtevant Co., 985 Trane Company, The, 872-873 Unit Heater and Cooler Co., 994 Vilter Manufacturing Co., 875 - Westinghouse Electric & Manu facturing Co.. 876 Williams Oil-O-Matic Heating Cor poration, 922-923 L. J. Wing Mfg. Co.. 988-989 York Ice Machinery Corp., 877 Young Radiator Company, 995 E. B. Badger & Sons Co., 976 Ehret Magnesia Manufacturing Sterling Engineering Co., 1121 Taylor Instrument Companies; COOLING EQUIPMENT, Oil ' Co.. 1034-1035 1018-1019 Aerofin Corporation, 996-998 . Frick Company (Incorporated), 861 H. A. Thrush & Co., 1010-1011 Carbondale Div. Worthington Johns-Manville, 1042-1043 Warren Webster & Co., 1124-1127 Pump & Machinery Co., 856-857 Jones & Laughlin Steel Corp., 1070 Westinghouse Electric & Manu Frick Company (Incorporated), 861 H. W. Porter & Co., 1053 facturing Co., 876 G & O Manufacturing Co., 999 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section - 1169 Heating Ventilating Air Conditioning Guide 1938 Niagara Blower Company, 868 COVERING, Surfaces Sarco Company, Inc., 1122-1123 Serve], Inc., 871 Unit Heater and Cooler Co., 994 Universal Cooler Corp., 874 Williams Oil-O-Matic Heating Cor poration, 922-923 York Ice Machinery Corp., 877 Young Radiator Company, 995 COOLING EQUIPMENT, Water (See also Water Cooling) Aerofin Corporation, 996-998 .Air Devices Corporation, Thermal Units Div., 849 American Blower Corp., 850-851 Baker Ice Machine Co., 854-855 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 Carbondale Div. Worthington . Pump & Machinery Co., 856-857 Carrier Corporation, 853 Cooling Tower Co., Inc., 971 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Fairbanks Morse & Co., 860 Alfol Insulation 1023 Armstrong Cork Co., Inc.,-'1022- - Products Com Spence Engineering Co., 1154 Tuttle & Bailey, Inc., 1092-1093 Young Regulator Co., 935 ' pany, 1024-1025 Baker Ice Machine Co., 854-855 Carey, Philip, Co., 1028 DAMPERS, Air Volume Control Air Controls, Inc., 878 Cork Insulation Co., Inc., 1026 Eagle-Picher Lead Company, 1036 Ehret Magnesia Manufacturing Co., 1034-1035 General Insulating & Mfg. Co., 1037 Insul-Wool Insulation Corp., 1040 International Fibre Board Ltd., 1041 . Auer Register Co., The. 1089 Barber-Colman Co., 1138-1139 Champion Blower & Forge Co., 982 Hart & Cooley Manufacturing Co., 1090-1091 . Independent Register Co., 1094 Tuttle & Bailey, Inc., 1092-1093 Waterloo Register Co., 1096 Young Regulator Company, 935 Johns-Manville, 1042-1043 Mundet Cork Corp., 1027 Owens-Illinois Glass Company, 930 Pacific Lumber Co., The. 1046 Ruberoid Co., The, 1044-1045 Standard Lime & Stone Co., 1047 Western Felt Works, 1049 DAMPERS, Flue Henry Furnace & Foundry Co., 912-913 ' Preferred Utilities Corp,, 970 - Tuttle & Bailey, Inc., 1092-1093 Young Regulator Company. 935 York Ice Machinery Corp., 877 Zonolite Company, The, 1050-1051 DAMPERS, Mechanical Air Controls, Inc., 878 Feddere Manufacturing Co., 991 Frick Company (Incorporated), 861 Ingersoll-Rand Company, 862-863 DAMPER REGULATORS, Boiler (See also Regulators) Buffalo Forge Company, 981 Carrier Corporation, 853 Fulton Sylphon Co., 1142-1143 .Marley Co., The, 974 McQuay, Incorporated, 865 > Modine Manufacturing Co., 993 Niagara Blower Company, 868 American Radiator Company, 884 Hart & Cooley Manufacturing Co., 885, 940-943, 1061 1090-1091 Barber-Colman Co., 1138-1139 Henry Furnace & Foundry Co:, Barnes & Jones, Inc., 1106 912-913 . - Research Corporation. 870 Trane Company, The, 872-873 Consolidated Ashcroft Hancock Johnson Service Co., 1146-1147 Co., Inc., 1013 . Powers Regulator Co., 1152-1153 Unit Heater and Cooler Co., 994 Detroit Lubricator Co., 1140-1141 Preferred Utilities Corp., 970 Vilter Manufacturing Co., 875 C. A. Dunham Co., 1108-1109 Young Regulator Company, 935 ` Westinghouse Elec. & Mfg. Co., 876 Fulton Sylphon Co., 1142-1143 Yamal]-Waring Co., 1129 ' General Controls, 1145 DEHUMIDIFIERS , York Ice Machinery Corp., 877. Gilbert & Barker Mfg. Co., 904-906 .Airtemp Inc., 882-883 . Young Radiator Company, 995 Hart & Cooley Manufacturing Co., American Blower Corp.. 850-851' . 1090-1091 Carrier Corporation, 853 COOLING TOWERS, Mechan Henry Furnace & Foundry .Co., Grinnell Co., Inc., 1000-1002, 1110 ical Draft, Forced Draft, Induced Draft (See also Cooling 912-913 . Hoffman Specialty Co., Inc., 1112 Parks-Cramer Co., 869 . Research Corporation, 870 Equipment, Water) 1113 . York Ice Machinery Corp., 877 Baker Ice Machine Co., 854-855 Binks Manufacturing Co., 972-Q73 Buffalo Forge Company, 981 Cooling Tower Company, 971 Illinois Engineering Co., 1114-1115 Johnson Service Co., 1146-1147 Kieley & Mueller, Inc., 1116 Leeds & Northrup Co., 1015 DIFFUSERS, Air (See Air Dif fusers, and Ventilators, Floor and Wall) Marley Company, 974 Research Company, 870 Unit Heater & Cooler Co., 994 York Ice Machinery Corp., 877 Minneapolis-Honeyweli Regulator Co.. 1148-1149 . Powers Regulator Co., 1152-1153 Preferred Utilities Corp., 970 Sarco Company, Inc., 1122-1123 DISTRICT HEATING (See also Corrosion Treaiment,-qf--Expan sion Joints--Insulation, Under ground--Meiers, Pipe) . CORROSION, Treatment of Spence Engineering Co., 1154 American District Steam Co., ' `Aquatic Chemical Laboratories, Inc., 1161 Oakite Products, Inc., 1162 Vinco Company, Inc., 936-937 COVERING, Pipe Taylor Instrument Companies, 975, 1052 1018-1019 H. A. Thrush & Co., 1010-1011 DOOR BOTTOM SEALS , Trane Company, The, 872-873 Warren Webster & Co., 1124-1127 Westinghouse Electric & Manu-. Chamberlin Metal Co., 1032-1033 Weather Strip . Alfol Insulation 1023 Co., Inc., 1022 facturing Co., 876Young Regulator Co., 935 V DRAFT APPARATUS (See Blow- ers. Forced Draft) Armstrong Cork Products Com pany. 1024-1025 DAMPER REGULATORS, Baker Ice Machine Co., 854-855 Furnace DRYING EQUIPMENT Air Devices Corporation, Thermal Cork Insulation Co., Inc., 1026 Barber-Colman Co., 1138-1139 \ Units.Div., 849 . Eagle-Picher Lead Co., 1036 Consolidated Ashcroft Hancock American Blower Corp., 850-851 Ehret Magnesia Manufacturing Co.. Inc., 1013 , American Coolair Corp., 978-979 Co., 1034-1035 * Detroit Lubricator Co., 1140-1141 American Radiator Company, 884 Frick Company (Incorporated), 861 Fulton Sylphon Co.',' 1142-1143 885, 940-943, 1061 Grinnell Co., Inc., 1000-1002, 1110 General Controls, 1145 Autovent Fan & Blower Co., 977 * General Insulating & Mfg. Co., Gilbert & Barker Mfg. Co., 904-906 Buffalo Forge Company, 981 1037 Hart & Cooley Manufacturing Co., Carrier Corporation, 853 Johns-Manville, 1042-1043 1090-1091 Champion Blower & Forge Co., 982 Mundet Cork Corp., 1027 Henry Furnace & Foundry Co.-, Clarage Fan Company, 858 Owens-Illinois Glass Company, 930 912-913 Delco-Frigidaire Conditioning Di H. W. Porter & Co., 1051 Kieley & Mueller, Inc., 1116 vision, General Motors Sales Ric-wiL Company, The. 1054 Leeds & Northrup Co., 1015` Corporation, 890-892 Ruberoid Co., The, 1044-1045 Minneapolis-Honeyweli Regulator G & O Manufacturing Co., The, 999 Standard Lime & Stone Co., 1047 Co., 1148-1149 . McQuay, Incorporated, 865 . .. Wyckoff & Sons Co., 1056 Powers Regulator Co., 1152-1153 B. F. Sturtevant Co., 985 ' Zonolite Company, The. 1050-1051 Preferred Utilities Corp., 970 ` Trane Company, The, 872-873 Please mention THE GUIDE 1938 when writing to Advertisers Index to Modern Equipment Unit Heater and Cooler Co., 994 L. J. Wing Mfg. Co., 988-989 York Ice Machinery Corp., 877 DUST COLLECTING EQUIP MENT Underground Steam Construction Co., 1055 Warren Webster & Co., 1124-1127 Yarnall-Waring Co., 1129 EXPOSITIONS Torrington Mfg. Co., 986-987 Trane Company, The, 872-873 L. J. Wing Mfg. Co., 988-989 FAN MOTORS (See Motors, Ele- tric) - American Air Filter Co., 926-927 American Blower Corp., 850-851 International Exposition Co., 1101 FANS, Portable Binks Manufacturing Co., 972-973 FAN BLADES Air Devices Corporation, Thermal Buffalo Forge Company, 981 American Blower Corp., 850-851 Units Div., 849 . Clarage Fan Company, 858 American Coolair Corp., 978-979 American Blower Corp., 850-851 Owens-Illinois Glass Company, 930 Research Corporation, 870 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 .. American Coolair Corp., 978-979 Autovent Fan & Blower Co., 977 Staynew Filter Corp., 932-933 B. F. Sturtevant Co., 985 Champion Blower & Forge Co., 982 Clarage Fan Company, 858 Barber-Colman Co.. 1138-1139 Bayley Blower Company, 980 Unit Heater & Cooler Co., 994 Servel. Inc., 871 Binks Manufacturing Co., 972-973 . Universal Air Filter Corp., 934 Schwitzer-Cummins Co., 880, 1136 Buffalo Forge Company, 981 Westinghouse Elec. & Mfg. Co., 876 Torrington Mfg., Co., 986-987 Champion Blower & Forge Co., 982 DUST COLLECTORS, Cloth . Westinghouse Electric & facturing Co., 876 Manu Coppus Engineering Corp., 928 General Electric Company, 902 Type Alfol Insulation Co., 1022-1023 American Air Filter Co., 926-927 American Btower Corn., 850-851 Coppus Engineering Corp., 928 Staynew Filter Corp., 932-933 . Independent Air Filter Co., 929 Universal Air Filter Corp., 934 L. J. Wing Mfg. Co., 988-989 FANS, Centrifugal . Air Controls, Inc., 878 American Blower Corp., 850-851 American Coolair Corp., 978-979 Autovent Fan & Blower Co., 977 Bayley Blower Company, 980 903. 1058-1059 Henry Furnace & Foundry Co.,. 912-913 Ilg Electric Ventilating Co., 984 Torrington Mfg. Co., 986-987 Westinghouse Electric & Manu facturing Co., 876 L. J. Wing Mfg. Co., 988-989 EVAPORATORS Buffalo Forge Company, 981 Carrier Corporation, 853 FANS, Propeller ' Aerofin Corporation, 996-998 Champion Blower & Forge Co., 982 Air Controls, Inc., 878 Air Devices Corporation, Thermal Clarage Fan Company, 858 Air Devices Corporation, Therma - Units Div., 849 ' Coppus Engineering Corp.. 928 Units Div., 849 Baker Ice Machine Co., Inc., 854 Fox Furnace Co., The, 893-897 American Blower Corp., 850-851 . 855 - General Electric Company, 902 American Coolair Corp., 978-979 Buffalo Forge Co., 981 903. 1058-1059 Autovent Fan & Blower Co., 977 ' Carbondale Div. Worthington Henry Furnace & Foundry Co., Binks Manufacturing Co., 972-973 Pump & Machinery Corp., 012-913 - Buffalo Forge Company, 981 856-857 Ilg Electric Ventilating Go., 984' Champion Blower & Forge Co., 982 Carrier Corporation, 853 Lau Blower Co., 879 . Clarage Fan Company, 858 . Curtis Refrigerating Machine Co.,- Lennox Furnace Co., Inc., 914-915 Coppus Engineering Corp., 928 Div. Curtis Manufacturing Co., Meyer Furnace Company, The, 917 De Bothezat Division American .859 Niagara Blower Company, 868 Machine & Metals, Inc., 983 Delco-Frigidaire Conditioning Di Schwitzer-Cummins Co., 880, 1136 General Electric Company, 902-' vision, General Motors Sales B. F. Sturtevant Co., 985 903, 1058-1059 . Corporation, 890-892 Torrington Mfg. Co., 986-987 Henry Furnace & Foundry Co., Fairbanks Morse & Co.', 860 . Trane Company, The, 872-873 912-913 Fedders Manufacturing Co., 991 r L. J. Wing Mfg. Co., 988-989 Ilg Electric Ventilating Co., 984 ' Frick Company (Incorporated), 861 General Electric Company, 902 FANS, Electric Marley Co., The, 972 Schwitzer-Cummins Co., 880, 1136 903, 1058-1059 American Coolair Corp., 978-979 Servel, Inc., 871 Kelvinator Division of Nash- Autovent Fan & Btower Co., 977 B. F. Sturtevant Co., 980 ' Kelvinator Corp., 907-911 Barber-Colman Co., 1138-1139 Torrington Mfg. Co., 986-987 ' McQuay, Incorporated, 865 . Binks Manufacturing Co., 972-973 Trane Company, The, 872-873 Servel, Inc., 871 Buffalo Forge Company, 981 Westinghouse Electric & Manu Trane Company, The, 872-873 Champion Blower & Forge Co., 982 facturing Co., 876 Unit Heater & Cooler-Go., 994 Coppus Engineering Corp., 928 L. J. Wing Mfg. Co., 988-989 Vilter Manufacturing Co., 875 Westinghouse Electric &, Manu- General Electric Company, 903, 1058-1059 902 , FANS, Supply and Exhaust - . facturing Co., 876 ' Henry Furnace & Foundry Co., Air Controls, Inc., 878 . York Ice Machinery Corp., 877 ' 912-913 Air Devices Corporation, Thermal Young Radiator Company, 995 Ilg Electric Ventilating Co., 984 Units Div., 849 . Torrington Mfg. Co., 986-987 American Blower Corp., 850-851 EXHAUST HEADS (See Beads. Westinghouse Electric & Manu American Coolair Corp., 978-979 ' Exhaust) facturing Co., 876 Autovent Fan & Blower Co., 977 L. J. Wing Mfg. Co., 988-989 EXHAUST TUBING, Flexible (See Tubing, Flexible Metallic) FANS, Furnace Bayley Blower Company, 980 . Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 . - EXPANSION JOINTS Air Controls, Inc., 878 Champion Blower & Forge Co.. 982 American Blower Corp., 850-851 Clarage Fan Company, 858 ' American District Steam Co., 975, Autovent Fan & Blower Co., 977 Coppus Engineering Corp., 928 1052 Buffalo Forge Company, 981 De Bothezat Division American E. B. Badger & Sons Co., 976 Champion Blower & Forge Co., 982 Machine & Metals, Inc.', 983 Baker Ice Machine Co., 854-855 Clarage Fan Company, 858 Delco-Frigidaire Conditioning Di Carrier Corporation, 853 Coppus Engineering Corp., 928 vision, General Motors Sales Chicago Metal Hose Corp., 1068 . Fox Furnace Co., The, 893-897 . Corporation, 890-892 Crane Co., 946-947 - Henry Furnace & Foundry Co., General Electric Company, 902 Fulton Sylphon Co., 1142-1143 912-913 903, 1058-1059 - Grinnell Co., Inc., 1000-1002, 1110 Ilg Electric Ventilating Co., 984 Henry Furnace & Foundry Co., Arthur Harris & Co., 1066 Lau Blower Co., 879 912-913 ' . Illinois Engineering Co., 1114-1115 Lennox Furnace Co., Inc., 914-915 Ilg Electric Ventilating Co., 984 Mueller Brass Co., 1064-1065 Meyer Furnace Company, The, 917 Lau Blower Co., 879 -,`Ric-wiL Company, 1054 ' L. J. Mueller Furnace Co., 918-919 Meyer Furnace Company, 917 Titeflex Metal Hose Co., 1069 Schwitzer-Cummins Co., 880, 1136 L. J. Mueller Furnace Co., 918-919 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 1171 Heating Ventilating Air Conditioning Guide 1938 John J. Nesbitt, Inc., 1003 FITTINGS, Pipe, Solder FURNACES, Electric Niagara Blower Company, 868 Schwitzer-Cummins Co.. 880, 1136 B. F. Sturtevant Co., 985 Torrington Mfg. Co., 986-987 Trane Company, The, 872-873 American Brass Co., 1062-1063 Crane Co., 946-947 Mueller Brass Co., 1064-1065 ' Revere Copper & Brass Inc., 1067 General Electric Company, 902 903, 1058-1059 Westinghouse Electric & Manu facturing Co., 876 Westinghouse Electric 8c Manu facturing Co., 876 L. J. Wing Mfg. Co., 988-989 FEED WATER HEATERS (See Heaters, Feed Water) FEED WATER REGULATORS (See Regulators, Feed Water) FEEDERS, Boiler ' Crane Co., 946-947 General Controls, 1145 Gilbert & Barker Mfg. Co., 904-906 Kieley 8c Mueller, Inc., 1116 McDonnell & Miller, 938-939 Milwaukee Valve Co., 1118-1119 Mueller Steam Specialty Co., 1120 Spence Engineering Co., 1154 H. A. Thrush & Co., 1010-1011 Warren Webster & Co., 1124-1127 Westinghouse Electric 8c Manu facturing Co., 876 Wright-Austin Co., 1128 FITTINGS, Pipe, Sweat American Brass Co., 1062-1063 American Radiator Co., 884-885, 940-943, 1061 Crane Co., 946-947 Detroit Lubricator Co., 1140-1141 Mueller Brass Co., 1064-1065 Revere Copper & Brass Inc., 1067 Streamline Pipe and Fittings Co., 1064-1065 Taco Heaters, Inc., 1008-1009 FITTINGS, Welding American Rolling Mill Co., 1098 Crane Co., 946-947 GrinneU Co., Inc., 1000-1002, 1110 York Ice Machinery Corp., 877. . FLOATS, Metal (See ,Trap and Valve) Arthur Harris & Co., 1066 Spence Engineering Co., 1154 Wright-Austin Co., 1128 . FURNACES, Warm Air Acme Heating & Ventilating Co., 881 ' Airtemp Inc., 882-883 Airtherm Manufacturing Co., 990 Americaq Gas Products Corp.,- 886 953 Bryant Heater Co., 888-889 . Carrier Corporation, 853 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 . Electrol Incorporated, 898-899, 967 Fox Furnace Co., The, 893-897 Gar Wood Industries, 900-901 General Electric Co., 902-903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co., 968-969 . Lennox Furnace Co., Inc., 914-915 Meyer Furnace Co., The, 917 L. J. Mueller Furnace Co., 918-919 FEEDERS, Water Decatur Pump Co., 1085 General Controls, 1145 Kieley 8c Mueller, Inc, 1116 McDonnell 8c Miller, 938-939 Milwaukee Valve Co., 1118-1119 Mueller Steam Specialty Co., 1120 FLOOR AND CEILING PLATES American Radiator Co., 884-885, 940-943, 1061 Beaton & Cadweil Mfg. Company, 1104-1105 Crane Co., 946-947 Herman Nelson Corp., 1004-1005 Spencer Heater Division, 948-949 Trane Company, The, 872-873 United States Radiator Corpora tion, 950-951 Westinghouse Elec. & Mfg. Co., 876 H. A. Thrush 8c Co., 1010-101*1 . GrinneU Co., Inc., 1000-1002, 1110 GAGE BOARDS Wright-Austin Co., 1128 FLUE GAS ANALYSIS Baker Ice Machine Co., 854-855 Bristol Company, The, 1012 ' FELT, Sound Deadening Gilbert & Barker Mfg. Co., 904-906 Consolidated Ashcroft Hancock Carey, Philip Co., 1028 Ehret Magnesia Mfg. Co., 1034 1035 Johns-Manville, 1042-1043 Ruberoid Company, 1044-1045 Western Felt Works, 1049 Leeds & Northrup Company, 1015 Co., Inc., 1013 Minneapolis-Honeywell Regulator Frick Company (Incorporated), 861 Company, 1148-1149 ' J. E. Lonergan Co., 1117 - Minneapolis-Honeywell Regulator FORCED DRAFT COOLING Company, 1148-1149 TOWERS (See also Cooling Tow- ;; Spence Engineering Co., 1154 ers. Induced Draft, Mechanica Taylor Instrument Companies, FELT, Insulating (See Insulation, Draft) . 1018-1019 Felt) Baker Ice Machine Co., 854-855 ' United States Gauge Co., 1020 FILTERS, Air (See Air Cleaning Equipment) FITTINGS, Pipe, Flanged American Rolling Mill Co., 1098 Baker Ice Machine Co., 854-855. Branford Div. Malleable Iron Fittings Co., 966 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 Cooling Tower Company, 971 ' Marley Company, 974 .. Research Company, 870 . Unit Heater & Cooler Co., 994 York Ice Machinery Corp., 877 FURNACE-BURNER GAGE GLASSES American Radiator Company, 884 885, 940-943, 1061 Beaton & Cadweil Mfg. Co., The 1104-1105 Crane Co., 946-947 Jenkins Bros., 1159 Yarnall-Waring Co., 1129 Carnegie-Illinois Steel Corp., 1100 Crane Co., 946-947 Frick Company (Incorporated), 861 GrinneU Co.. Inc, 1000-1002,1110 Arthur Harris 8c Co.,. 1066 Mueller Brass Co., 1064-1065 United States Register Co., 1095 Vilter Manufacturing Co., 875 York Ice Machinery Corp., 877 Automatic Burner Corp., 964 Delco-Frigidaire Conditioning Di vision, General. Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899. 967 Fox Furnace Co., The, 893-897 Gar Wood Industries, Inc., 900-901 General Electric Co., 902-903, 1058-1059 GAGES. Altitude American Radiator'Company, 884-. 885, 940-943, 1061 Bell and Gossett Company, 1006 1007 Bristol Company, The, 1012 Consolidated Ashcroft Hancock Co., Inc., 1013 . Crane Co., 946-947 . FITTINGS, Pipe, Screwed American Radiator Co., 884-885, 940-943,1061 . Baker Ice Machine Co., 854-855 Branford Div. Malleable Iron Fittings Co., 966 ' Carnegie-Illinois Steel Corp.,. 1100 Crane Co., 946-947 Frick Company (Incorporated), 861 GrinneU Co., Inc., 1000-1002. 1110 Gilbert & Barker Mfg. Co.', 904-906' Henry Furnace & Foundry Co., 9127913 Kleen-Heet. Inc., 965 Lennox Furnace Co., Inc, 914-915 - Meyer Furnace Company, 917 L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Vulcan Anthracite Stoker Corp., 1137 Williams Oil-O-Matic Heating Cor Julien P. Friez & Sons, Inc., 1144 Gilbert & Barker Mfg. Co., 904-906 J. E. Lonergan Co., 1117 Mercoid Corporation, 1150 New York Air Valve Corp., 1160 Taylor Instrument Companies, 1018-1019 H. A. Thrush & Co., 1010-1011 United States Gauge Co., 1020 .GAGES, Ammonia - Taco Heaters. Inc., 1008-1009 poration. 922-923 Baker Ice Machine Co., 854-855 United States Register Co., 1095 Bristol Company, The, 1012 Vilter Manufacturing Co., 875 FURNACE REGULATORS (See Consolidated Ashcroft Hancock. York Ice Machinery Corp., 877 Regulators, Furnace) Co., Inc., 1013 Please mention THE GUIDE 1938 when writing to Advertisers ; 1172 Index to Modern Equipment Crane Company, 946-947 J. E. Lonergan Co., 1117 Mercoid Corporation, 1150 . J. E. Lonergan Co., 1117 . Mercoid Corporation, 1150 Minneapolis-Honeywell Regulator Martocello, Jos. A. & Co., 866 Minneapolis-Honeywell Regulator Company, 1148-1149 . Mercoid Corporation, 1150 Company, 1148-1149 New York Air Valve Corp., 1160 United States Gauge Co., 1020 New York Air Valve Corp., 1160 Wright-Austin Co., 1128 Vilter Manufacturing Co., 875 Spence Engineering Co., 1154 Yarnall-Waring Co., 1129 York Ice Machinery Corp., 877 GAGES, Compound Taylor Instrument 1018-1019 Companies, GAS BURNERS United States Gauge Co., 1020 Airtemp Inc., 882-883 American Radiator Company, 884 Warren Webster & Co., 1124-1125 American Gas Products Corp., 886, 885, 940-943, 1061 Consolidated Ashcroft Hancock Co.. Inc., 1013. Dole Valve Company, 1158 Hoffman Specialty Co., Inc., 1112 1113 Illinois Engineering Co., 1114-1115 Sarco.Company, Inc., 1122-1123 Spence Engineering Co., 1154 " United States Gauge Co., 1020 Warren Webster fit. Co., 1124-1125 GAGES. Tank Bristol Company, 1012 Detroit Lubricator Co., 1140-1141 Frick Company, 861 Julien P. Friez & Sons,.1144 Liquidometer Corp., 1016 Minneapolis-Honeywell Regulator Co., 1148-1149 - Taylor Instrument Companies, 1018-1019 Wright-Austin Co., 1128 Babcock & Wilcox Co., 954 Barber Gas Burner Co., 887 Bryant Heater Co., 888-889 Combustion Engineering Co., 1132 Coppus Engineering Corp., 928 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Fox Furnace Co., 893-897 Henry Furnace & Foundry Co., GAGES, Hot Water GAGES, Vacuum . American Radiator Company, 884 885, 940-943. 1061 Bell and Gossett Co., 1006-1007 Bristol Company, 1012 Consolidated Ashcroft Hancock Co., Inc., 1013 Frick Company (Incorporated), 861 Julien P. Friez 8c Sons, Inc., 1144 Mercoid Corporation, 1150 Minneapolis-Honeywell Regulator Company, 1148-1149 . New York Air Valve Corp.r 1160 Taylor Instrument Companies, 1018-1019 H. A. Thrush &. Co.. 1010-1011 United States Gauge Co., 1020 American Radiator Company', 884 885, 940-943, 1061 * Anderson Products, Inc., 1156-1157 Bristol Company, 1012 Burnham Boiler Corp., 944-945 Consolidated Ashcroft Hancock Co., Inc., 1013 . Crane Co., 946-947- C. A. Dunham Co., 1108-1109 . Julien P. Friez & Sons, Inc., 1144 Gilbert & Barker Mfg. Co., 904-906 Hoffman Specialty Co., Inc., 1112 1113 .Illinois Engineering Co., 1114-1115 J. E. Lonergan Co., 1117 Mercoid Corporation, 1150 912-913 Spencer Heater Division, 948-949 GASKETS, Asbestos Crane Co., 946-947 Ehret Magnesia Manufacturing Co., 1034-1035 Frick Company (Incorporated), 861 Jenkins Bros., 1159 . .Johns-Manville, 1042-1043 ' ' Ruberoid Co., The, 1044-1045 GASKETS, Cork Armstrong Cork Products Com pany, 1024-1025 Crane Co., 946-947 ' ' Johns-Manville, 1042-1043 Mundet Cork Corp., 1027 GAGES, Liquid Level Liquidometer Corp., 1016 Taylor Instrument Companies, 1018-1019 Minneapolis-Honeywell Regulator Company, 1148-1149 New York Air Valve Corp., 1160 Spence Engineering Co., 1154 Sterling Engineering Co.. 1121 GASKETS, Felt Western Felt Works, 1049 GASKETS, Rubber - GAGES, Pressure American Radiator Company, 884 885, 940-943, 1061 Anderson Products, Inc., 1156-1157 -Baker Ice Machine Co., Inc., 854 855 Taylor Instrument Companies, 1018-1019 Trane Company, 872-873 United States Gauge Co., 1020 Warren Webster & Co., 1124-1125 GAGES, Vapor Crane Co., 946-947 Ehret Magnesia Manufacturing Co., 1034-1035 Frick Company (Incorporated), 861 Jenkins Bros., 1159 Johns-Manville, 1042-1043 , Bell & Gossett Co., 1006-1007 American Radiator Company, 884 GOVERNORS, Pump . Binks Manufacturing Co., 972-973 Bristol Company, 1012 Consolidated Ashcroft Hancock Co., Inc., 1013 Crane Co., 946-947 , . Gilbert & Barker Mfg. Co., 904-906 J. E. Lonergan Co.,-1117 Mercoid Corporation, 1150 Minneapolis-Honeywell Regulator Company, 1148-1149 New York Air Valve Corp., 1160 Spence Engineering Co., 1154 Sterling Engineering Co., 1121 Taylor Instrument Companies, 1018-1019 H. A. Thrush & Co., 1010-1011 Trane Company, The,-872-873 United States Gauge Co., 1020 885. 940-943, 1061 ' Crane Co., 946-947 Bristol Company, The, 1012 C. A. Dunham Co., 1108-1109 Burnham Boiler Corp., 944-945 Kieley & Mueller, Inc., 1116 Consolidated Ashcroft Hancock Mueller Steam Specialty Co., Inc., Co., Inc., 1013 1120 . C. A. Dunham Co., 1108-1109 . Schwitzer-Cummins Co., 880, 1136 Hoffman Specialty Co., Inc., 1112 Spence Engineering Co., 1154 1113 Warren Webster & Co., 1124-1125 Illinois Engineering Co., 1114-1115 Wright-Austin Co., 1128 Mercoid Corporation, 1150 Minneapolis-Honeywell Regulator Company, 1148-1149' GRATES FOR BOILERS AND FURNACES New York Air Valve Corp., 1160 American Coolair Corp., 978-979 Spence Engineering Co., 1154 American Radiator Company, 884 United States Gauge. Co., 1020 885, 940-943. 1061 Warren Webster fit Co.. 1124-1125 Combustion Engineering Co., 1132 GAGES, Water Fox Furnace Co., 893-897 -. ' E. Keeler Company, 958-959. GAGES, Steam ' American Radiator Company, 884 Kewanee Boiler Corp., 960-961. 885, 940-943, 1061 L. J. Mueller Furnace Co., 918-919 American Radiator Company, 884 Baker Ice Machine Co., 854-855 Unit Heater and Cooler Co., 994 885, 940-943, 1061 Anderson Products Inc., 1156-1157 Bristol Company, 1012 . Consolidated Ashcroft Hancock Binks Manufacturing Co., 972-973 Bristol Company, 1012 ' Consolidated Ashcroft Hancock Co.. Inc., 1013 GRILLES, REGISTERS AND ORNAMENTAL METAL WORK (See also Registers) Co., Inc., 1013 Crane Co., 946-947 American Blower Corp., 850-851 Crane Co.. 946-947 Detroit Lubricator Co., 1140-1141 American Coolair Corp., 978-979 C. A. Dunham Co., 1108-1109 . Frick Company (Incorporated), 861 American Radiator Company, 884 Hoffman Specialty Co., Inc.,. 1112 Julien P. Friez & Sons. Inc., 1144 885, 940-943, 1061 1113 Gilbert & Barker Mfg. Co., 904-90C Anemostat Corp. of America, 1088 Illinois Engineering. Co., 1114-1115 J. E. Lonergan & Co., 1117 .Auer Register Co., The, 1089 Numerals following Manufacturers' Names referto pages in the Catalog Data Section . Heating Ventilating Air Conditioning Guide 1938 Barber-Colman Co., 1138-1139 Clarage Fan Company, 858 Trane Company, The, 872 Carrier Corporation, 853 Combustion Engineering Co., 1132 Unit Heater & Cooler Co.. 994 Fox Furnace Co., 893-897 Delco-Frigidaire Conditioning Di L. J. Wing Mfg. Co.. 988-989 Hart & Cooley Manufacturing Co., vision, General Motors Sales Young Radiator Company, 995 1090-1091 Independent Register Co., 1094 Corporation, 890-892 Electro!, Incorporated, 898-899,967 HEATERS, Cabinet L. J. Mueller Furnace Co.; 918-919 Fairbanks Morse & Co., 860 Air Devices Corporation, Thermal Trane Company, The. 872-873 Fedders Manufacturing Co., 991 Units Div., 849 Tuttle & Bailey, Inc., 1092-1093 Fox Furnace Co., 893-897 American Radiator Company, 884 United States Register Co., 1095 Gar Wood Industries. Inc., 900-901 885, 940-943, 1061 j* Waterloo Register Co.. 1096 General Electric Company, 902 Burnham Boiler Corp., 944-945 Wickwire Spencer Steel Co., 1097 903, 1058-1059 Delco-Frigidaire Conditioning Di HANGERS, Pipe Henry Furnace & Foundry Co., vision, General Motors Sales 912-913 Corporation, 890-892 American Brass Co., 1062-1063 Ilg Electric Ventilating Co., 984 C. A. Dunham Co.. 1108-1109 American Radiator Company, 884 Lennox Furnace Co., Inc., 914-915 Electrol, Incorporated, 898-899,967 885, 940-943, 1061 McQuay, Incorporated, 865 ' Fairbanks Morse & Co., 860 Baker Ice Machine Co., 854-855 Meyer Furnace Company, The, 917 Fox Furnace Co., The, 893-897 Beaton and Cadwell Mfg. Com-' Modine Manufacturing Co., 993 General Electric Company,' 902 pany. The. 1104-1105 Herman Nelson Corp., 1004-1005 903, 1058-1059 Crane Co.. 946-947 John J. Nesbitt, Inc., 1003 Henry Furnace & Foundry Co., Frick Company (Incorporated), 861 Niagara Blower Co., 868 - - 912-913 Grinnell Co., Inc., 1000-1002, 1110 B. F. Sturtevant Co., 985 S. T. Johnson Co., 968-969 Mueller Brass Co.. 1064-1065 Trane Company, The, 872-873 McQuay, Incorporated, 865 . Ric-wiL Company, The, 1054 Unit Heater and Cooler Co., 994 Modine. Manufacturing Co.,`993 Vilter Manufacturing Co., 875 Westinghouse Electric & Manu John J. Nesbitt, Inc., 1003 HANGERS, Radiator facturing Co., 876 L. J. Wing Mfg. Co., 988-989 Trane Company, The, 872-873 Unit Heater & Cooler Co., 994 American Radiator Company, 884 York Ice Machinery Corp., 877 Weil-McLain Company, 952 - 885, 940-943, 1061 Young Radiator Company, 995 Young Radiator Company, 995 Burnham Boiler Corp., 944-945 Crane Co., 946-947 Grinnell Co.. Inc., 1000-1002, 1110 HEATERS, Automatic - Hot Water, Domestic HEATERS. Electric Air Devices Corporation, Thermal HEADS, Exhaust American Gas Products Corp., 886, Units Div., 849 . 953 Autovent Fan & Blower Co., 977 Crane Co.. 946-947 . American Radiator Company, 884 Burnham Boiler Corp., 944-945 . Kieley & Mueller, Inc., 1116 885, 940-943. 1061 General Electric Company, 902 Wright-Austin Co., 1128 Automatic Burner Corp., 964 903, 1058-1059 HEADS, Sprinkler Crane Co., 946-947 Grinnell Co.. Inc., 1000-1002, 1110 Delco-Frigidaire Conditioning Di Ilg Electric Ventilating Co., 984 Grinnell Co., Inc., 1000-1002; 1110 vision, General Motors Sales B. F. Sturtevant Co., 985 - Mueller Brass Co., 1064-1065 Corporation, 890-892 Trane Company, 872-873 Streamline Pipe & Fittings Co., Electrol. Incorporated, 898-899,967 Weil-McLain Company, 952 1064-1065 Fitzgibbons Boiler Company, Inc., Westinghouse Electric & Manu ' HEAT SURFACE, Fan System 956-957 . Gar Wood Industries, Inc., 900-901 facturing Company, 876 Young Radiator Company, 995 Aerofin Corporation, 996-998 Henry Furnace & Foundry Co., Air Devices Corporation, Thermal. 912-913 HEATERS. Feed Water Units Div., 849 . ' -S. T. Johnson Co., 968-969 Brownell Company, 1130 . American Blower Corp., 850-851 Kleen-Heet, Inc., 965 Cochrane Corp., 1107 . Buffalo Forge Company, 981 Kewanee Boiler Corp., 960-961 Carbondale Div.- Worthington Fairbanks Morse & Co., 860 Lochinvar Corp., 916 . Pump & Machinery Co., 856-857 Fedders Manufacturing Co., 991- - Sterling Engineering Co., 1121 General Electric Company, 902 G & O Manufacturing Co., 999 . Taco Heaters, Inc., 1008-1009 903. 1058-1059 General Electric Company, 902 Spencer Heater Division, 948-949 Westinghouse Electric & Manu . 903, 1058-1059 Trane Company, 872-873 facturing Co., 876 McQuay, Incorporated, 865 . . Vulcan Anthracite Stoker Corp., - Modine Manufacturing Co., 993 1137 HEATERS, Fuel Oil John J. Nesbitt, Inc., 1003 .Williams Oil-O-Matic Heating Cor American District Steam Co. * Niagara Blower Company, "868 poration, 922-923 975, 1052 . B. F. Sturtevant Co., 985 Westinghouse Electric & Manu- Automatic Burner Corp., 964 . Trane Company, The, 872-873 . facturing Co., 876 Bell and Gossett Co., 1006-1007 Unit Heater & Cooler Co., 994 . `Young Radiator Company, 995^ Delco-Frigidaire Conditioning Di- Westinghouse Electric facturing Co., 876 & Manu ' HEATERS, Blast vision, General Motors Sales Corporation, 890-892 .. L. J. Wing Mfg. Co:, 988-989 - Aerofin Corporation, 996-998 Fox Furnace Co., 893-897 York Ice Machinery Corp., 877 Air Devices Corporation, Thermal General Electric Company, 902- Young Radiator Company,' 995 Units Div., 849 903, 1058-1059 HEATERS. Air American Blower Corp., 850-851' Kewanee Boiler Corp., 960-961 American Radiator Company, 884- Kleen-Heet, Inc., 965 . Aerofin Corporation, 996-998 885, 940-943, 1061 . Lochinvar Corp., 916 Air Devices Corporation, Thermal Autovent Fan & Blower Co., 977 Meyer Furnace Co., 917 ' Units Div., 849 Bayley Blower Company; 980 Williams Oil-O-Matic Heating Cor Airtherm Manufacturing Co.. 990 Buffalo Forge Company, 981 poration. 922-923 '. American Blower Corp., 850-851 Carrier Corporation, 853 American Gas Products Corp.', Clarage Fan Company, 858 HEATERS, Gas 886, 953 - -Fairbanks Morse & Co.. 860 American Gas Products Corp., American Radiator Company, 884 Fedders Manufacturing Co., 991 886, 953 885, 940-943. 1061 llg Electric Ventilating Co;, 984 Crane Co., 946-947 Autovent Fan & Blower Co., 977 McQuay, Incorporated; 865 Burnham Boiler Corp., 944-945 Baker Ice- Machine Co., 854-855 Modine Manufacturing Co.. 993 - C. A. Dunham Co., 1108-1109 Buffalo Forge Company, 981. John J. Nesbitt, Inc., 1003 Fox Furnace Co., 893-897 _ Burnham Boiler. Corp., 944-945 - Niagara Blower Company, S6S General Electric Company. 902 Carrier Corporation, -853 B. F. Sturtevant Co., 985 903, 1058-1059 .. Please mention THE GUIDE 1938 when writing to Advertisers Index to Modern Equipment Kewanee Boiler Corp., 960-961 American Radiator Company, 884 Electrol Incorporated. 898-899, 967 Meyer Furnace Company, 917 885, 940-943, 1061 Fedders Manufacturing Co., 991 United States Radiator Corpora Bell & Gossett Co., 1006-1007 Fox Furnace Co., The, 893-897 tion, 950-951 Burnham Boiler Corp., 944-945 Gar Wood Industries, Inc., 900-901 Westinghouse Elec. & Mfg. Co., 876 Fitzgibbons Boiler Company, Inc., General Electric Company, 902^ HEATERS, Hot Water Service 956-957 903. 1058-1059 ' Grinnell Co., Inc.. 1000-1002, 1110 Henry Furnace & Foundry Co., Air Devices Corporation, Thermal Kewanee Boiler Corp., 960-961 912-913 Units Div., 849 L. J. Mueller Furnace Co., 918-919 Ilg Electric Ventilating Co.. 984 American District SLeam Co., 975, Spencer Heater Division, 948-949 S. T. Johnson Co., 968-969 1052 Sterling Engineering Co., 1121 Kelvinator Division of Nash- American Gas Products Corp., Taco Heaters, Inc., 1008-1009 Kelvinator Corp., 907-911 886, 953 United States Radiator .Corpora Lennox Furnace Co., Inc., 914-915 American Radiator Company, 884 tion, 950-951 Lochinvar Corp., 916 . 885, 940-943, 1061 Weil-McLain Company, 952 Meyer Furnace Company, The, 917 Automatic Burner Corp., 964 Westinghouse Electric & Manu Modine Manufacturing Co., 993 Bell & Gosset Co.. 1006-1007 facturing Co., 876 L. J. Mueller Furnace Co., 918-919 Brownell Company, 1130 Herman Nelson Corp., 1004-1005 Burnham Boiler Corp.,.944-945 . HEATERS, Unit John J. Nesbitt, Inc., 1002 Crane Company, 946-947 ` Electrol, Incorporated, 898-899,967 Fitzgibbons Boiler Company, Inc., 956-957 ' . Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co., 968-969 Kleen-Heet, Inc., 965 Kewanee Boiler Corp., 960-961 L. J. Mueller Furnace Co., 918-919 ` Preferred Utilities Corp., 970 Spencer Heater Division, 948-949 Sterling Engineering Co., 1121 Taco Heaters, Inc., 1008-1009 United States Radiator Corpora tion, 950-951 Waterfilm Boilers, Inc., 963 Williams Oil-O-Matic Heating Cor-' poration, 922-923 Westinghouse Electric & Manu facturing Co., 876 HEATERS, Indirect _ Aerofin Corporation, 996-998 Air Devices Corp., Thermal Units Div., 849 . American District Steam Company, 975, 1052 American Radiator Company, 884 885. 940-943, 1061 Bell & Gossett, 1006-1007 Electrol, Incorporated, 898-899,967 - Fitzgibbons Boiler Company, Inc., 956-957 . Kewanee Boiler Corp., 960-961 McQuay, Incorporated, 865 Sterling Engineering Co., 1121 Air Devices Corporation, Thermal Units Div., 849 Airtherm Manufacturing Co., 990 American Blower Corp., 850-851 Autovent Fan & Blower Co., 977 Bayley Blower Company, 980 Buffalo Forge Company, 981 ' Burnham Boiler Corp., 944-945 Carrier Corporation, 853 Champion Blower & Forge Co., 982 Clarage Fan Company, 858 Crane Co.. 946-947 Delco-Frigidaire Conditioning Di Niagara Blower Company, 868 Spencer Heater Division, 948-949 ' B. F. Sturtevant Co., 985 Trane Company, The, 872-873 Unit Heater and Cooler Co., 994 ' United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Westinghouse Electric & Manu facturing Co., 876 L. J. Wing Mfg. Co.. 988-989 Young Radiator Company, 995 York Ice Machinery Corp., 877 vision, Genera] Motors Sales'* Corporation, 890-892 HEATING SYSTEMS, Auto C. A. Dunham Co., 1108-1109 matic Electrol, Inc., 898-899, 967 Fairbanks Morse & Co., 860 Fedders Manufacturing Co., 991 Fox Furnace Co., 893-897 Grinnell Co., Inc., 1000-1002, 1110 Ilg Electric Ventilating Co., 984 McQuay. Incorporated, 865 Modine Manufacturing Co., 993 Herman Nelson Corp., 1004-1005 John J. Nesbitt, Inc., 1003 Niagara Blower Company, 868 B. F. Sturtevant Co., 985 Trane Company. The, 872-873 Unit Heater and Cooler Co., 994 United States Radiator Corpora tion, 950-951 '' Warren Webster & Co., 1124-1125 Westinghouse Elec. & Mfg. Co'., 876 L. J. Wing Mfg. Co., 988-989 Young Radiator Company, 995 ' Airtemp, Incorporated, 882-883 American Gas Products, Corp., 886. 953 American Radiator Company, 884 885, 940-943, 1061 Anderson Products, Inc.,-1156-1157 Automatic Burner Corp., 964 Burnham Boiler Corp., 944-945 Carrier Corporation, 853 . Crane Co., 946-947 .. Delco-Frigidaire Conditioning" Di vision, General Motors ' Sales Corporation, 890-892 Electrol, Incorporated, 898-899,967 Fox Furnace Co., The, 893-897 Gar Wood Industries, Inc., 900-901 General Electric Company, 902- ` 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Henry Furnace & Foundry Co., Taco Heaters, Inc., 1008-1009 Unit Heater and Cooler Co., 994 , L. J. Wing Mfg.'Co., 988-989 . HEATERS, Refuse Burning American Radiator Company, 884 885. 940-943, 1061 . Kewanee Boiler Corp., ;960-961 . L. J. Mueller Furnace Co., 918-919 HEATERS, Unit, Gas Fired American Gas Products Corp., 886, 953 Buffalo Forge Company, 981 Crane Company, 946-947 Fox Furnace Co., 893-897 L. J. Mueller Furnace Co., 918-919 Trane Company, The, 872-873 912-913 Hoffman Specialty Co.. Inc., 1112 1113 S. T. Johnson Co., 968-969 . Kelvinator Division of Nash- Kelvinator Corp., 907-911 . Kleen-Heet, Inc.. 965 ' Lennox Furnace Co.. 914-915 _ Lochinvar Corp., 916 ' HEATERS, Storage HEATING SYSTEMS, Air Meyer Furnace Company, 917 ' L. J. Mueller Furnace Co., 918-919 American District Steam Company, Air Devices Corporation, Thermal Herman Nelson Corp., 1004-1005 975. 1052 American Gas Products Corp., . -886, 953 Bell & Gossett Co., 1006-1007. Brownell Company, 1130 Burnham Boiler Corp., 944-945 Units Div., 849 Airtemp, Incorporated, 882-883 Airtherm Manufacturing Co., 990 American Blower Corp., 850-851 American Gas Products Corp., 886, 953 Research Corporation, 870 - Sarco Co., Inc., 1122-1123 . Schwitzer-Cummins Co., 880, 1136 Spence Engineering Co., 1154 Spencer Heater-Division,-948-949 . Crane Co., 946-947 American Radiator Company, 884 Sterling Engineering Co., 1121 . General Electric Company, 902 903, 1058-1059 Taco Heaters, Inc., 1008-1009 HEATERS, Tank . American District Steam Co., 975. 1052 . 885.940-943,1061 . Autovent Fan & Blower Co., 977 Buffalo Forge Company, 981 ' Burnham Boiler Corp., 944-945 Carrier Corporation, 853 Clarage Fan Company, 858 Delco-Frigidaire Conditioning Di H. A. Thrush & Co.. 1010-1011 . Trane Company, The, 872-873 Vulcan Anthracite Stoker' Corp., 1137 . Williams Oil-O-Matic Heating Cor .- IK)ration, 922-923 ; American Gas Products Corp., vision, General Motors Sales Warren Webster & Co., 1124^-1127 886, 953 .. Corporation, 890-892 L. J. Wing Mfg. Co., 988-989. 'J Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 1175 Heating Ventilating Air Conditioning Guide 1938 HEATING SYSTEMS, Furnace Electrol Incorporated, 898-899, 967 S. T. Johnson Co., 968-969 Acme Heating & Ventilating Co., 881 Airtherm Manufacturing Co., 990 American Gas Products Corp., 886, 953 Carrier Corporation, 853 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electrol, Incorporated, 898-899, 967 Fox Furnace Co., The, 893-897 GarWood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co., 968r969 Kelvinator Division of NashKelvinator Corp., 907-911 Lennox Furnace Co., Inc., 914-915 Lochinvar Corp., 916 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg., Company, 904-906 Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co.,- 968-969 Kleen-Heet, Inc., 965 L. J. Mueller Furnace Co., 918-919 Parks-Cramer Company, 869 Spencer Heater Division, 948-949 Sterling Engineering Co., 1121 Taco Heaters, Inc., 1008-1009 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Williams Oil-O-Matic Heating Cor poration, 922-923 L. J. Wing Mfg. Co., 988-989 Meyer Furnace Company, 917 . L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Schwitzer-Cummins Co.,'880, 1136 Spencer Heater Division, 948-949 United States Radiator Corpora tion, 950-951 Williams Oil-O-Matic Heating Cor poration, 922-923 HEATING SYSTEMS, Oil Fired Acme Heating & Ventilating Co., 881 . Airtemp Incorporated, 882-883 American Blower Corp., 850-851 American Radiator Company, 884 885, 940-943, 1061 Automatic Burner Corp., 964 -Barnes & Jones, Inc., 1106 HEATING SYSTEMS, Gas Fired * Acme Heating & Ventilating Co., S81 Airtemp, Incorporated, 882-883 American Blower Corp., 850-851 American Gas Products Corp., 886, 953 American Radiator Company, 884 885, 940-943, 1061 Barnes & Jones, Inc., 1106 Burnham Boiler Corp., 944-945 Carrier Corporation, 853 . . Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 C. A. Dunham Co., 1108-1109 Fox Furnace Co., The, 893-897 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Henry Furnace & Foundry Co., 912-913 S. T. Johnson Co., 968-969 Lennox Furnace Co., Inc., 914-915 Meyer Furnace Company, The, 917 Carrier Corporation, 853 Crane Co., 946-947 . Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899, 967 Fox Furnace Co., The, 898-897 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 . Gilbert & Barker Mfg. Co., 904-906 S. T. Johnson Co., 968-969 . Kelvinator Division of Nash- Kelvinator Corp., 907-911 ' Kleen-Heet, Inc., 965 Lennox Furnace Co., Inc., 914-915 Meyer Furnace Company, The, 917 L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 ' United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Williams Oil-O-Matic Heating Cor poration, 922-923 . L. J. Mueller Furnace Co., 918-919 HEATING SYSTEMS, Steam Spencer Heater Division, 948-949 H. A. Thrush & Co.. 1010-1011 Trane Company, The, 872-873 . United States Radiator Corpora tion, 950-951 * Westinghouse Elec. & Mfg. Co., 876 . Airtherm Manufacturing Co., 990 American Gas Products Corp,, 886, 953 x American Radiator Company, 884 885, 940-943, 1061 Anderson Products, Inc., 1156-1157 Kelvinator Div. of Nash-Kelvina- tor Corp., 907-911 Kewanee Boiler Corp., 960-961 Milwaukee Valve Co., 1118-1119 L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Ric-wiL Company, The, 1054 Sarco Company, Inc., 1122-1123 Spence Engineering Co., 1154-1155 Spencer Heater Division, 948-949 Sterling Engineering Co., 1121 Trane Company, The, 872-873 Unit Heater & Cooler Co., 994, ' United States Radiator Corpora tion, 950-951 * Utica Radiator Corp.,-920-921 Vulcan Anthracite Stoker Corp., 1137 Warren Webster & Co., 1124-1127 Westinghouse Elec. & Mfg. Co., 876 Williams Oil-O-Matic Heating Cor poration, 922-923 L. J. Wing Mfg. Co., 988-989 HEATING SYSTEMS, Vacuum American Gas Products Corp., 886, 953 - American Radiator Company, 884- 885, 940-943. 1061 * Barnes & Jones, Incorporated, 1106 Beaton and Cadwell Mfg. Co., The 1104-1105 Burnham Boiler Corp., 944-945 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 C. A. Dunham Co., 1108-1109 Electrol Incorporated, 898-899, 967 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 William S. Haines & Co., 1111 Hoffman Specialty Co., Inc., 1112 1113 Illinois Engineering Co., 1114-1115 Milwaukee Valve Co., 1118-1119 L. J. Mueller Furnace Co., 918-919 New York Air Valve Corp., 1160 Sarco Company, Inc., 1122-1123 Spencer Heater Division, 948-949' Sterling Engineering Co., 1121 Trane Company, The, 872-873 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Vulcan Anthracite Stoker Corp., 1137 Warren Webster & Co., 1124-1127 Williams Oil-O-Matic Heating Cor poration, 922-923 , HEATING SYSTEMS, Vapor American District Steam Com HEATING SYSTEMS, Hot Water Barnes & Jones, Inc., 1106 pany, 975, 1052 Bell & Gossett Company, 1006-1007 American Gas Products Corp., Burnham Boiler Corp., 944-945 886, 953 . American Blower Corp., 850-851 Carrier Corporation, 853 American Radiator Company, 884 American Gas Products Corp., Crane Co., 946-947 885, 940-943, 1061 886, 953 / Delco-Frigidaire Conditioning Di- Barnes & Jones, Incorporated, 1106 American Radiator Company, 884 . vision. General Motors Sales Crane Co., 946-947 885, 940-943, 1061 Corporation, 890-892 . Delco-Frigidaire Conditioning Di-' Automatic Burner Corp., 964 C. A. Dunham Co., 1108-1109 vision. General Motors Sales Beaton and Cadwell Mfg. Com Electrol Incorporated, 898-899, 967 Corporation, 890-892 pany, The, 1104-1105 - Gar Wood Industries, Inc., 900-901 C. A. Dunham Co., 1108-1109 Bell & Gossett Company, 1006-1007 General Electric Company, 902 Electrol Incorporated, 898-899,- 967 Burnham Boiler Corp., 944-945 903, 1058-1059 Gar Wood Industries, Inc, 900-901 Crane Co., 946-947 Gilbert & Barker Mfg. Co., 904-906 General Electric Company, 902 Delco-Frigidaire Conditioning Di Hoffman Specialty Co., Inc., 1112 903, 1058-1059 vision, General Motors Sales 1113 Gilbert & Barker Mfg. Co., 904-906 Corporation, 890-892 Illinois Engineering Co., 1114-1115 William S. Haines & Co., 1111 Please mention THE GUIDE 1938 when writing to Advertisers "'I W Index to Modern Equipment Hoffman Specialty Co., Inc, 1112 HUMIDIFIERS, Central Plant General Controls, 1145 1113 Illinois Engineering Co., 1114-1115 S. T. Johnson Co., 968-969 Kelvinator Division of Nash- Kelvinator Corp., 907-911 Milwaukee Valve Co., 1118-1119 L. J. Mueller Furnace Co., 918-919 Herman Nelson Corp., 1004-1005 Sarco Company, Inc., 1122-1123 Spencer Heater Division, 948-949 Sterling Engineering Co., 1121 Trane Company, The, 872-873 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 Vulcan Anthracite Stoker Corp., 1137 Warren Webster & Co., 1124-1127 Williams Oil-O-Matic Heating Cor poration, 922-923 HOSE, Flexible Metallic (See also Conduit, flexible; Tubing, flexible) American Brass Co., 1062-1063 Chicago Metal Hose Corp., 1068 TiteSex Metal Hose Co., 1069 HOSE, Refrigerant Charging, . {See Hose, Flexible Metallic) - Acme Heating & Ventilating Co., 881 Airtemp Incorporated, 882-883 American Blower Corp., 850-851 American Radiator Company, 884 885, 940-943. 1061 Baker Ice Machine Co., 854-855 Bayley Blower Company, 980 Buffalo Forge Company, 981 Carrier Corporation, 853 Clarage Fan Company, 858 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electro! Incorporated, 898-899, 967 Fairbanks Morse & Co., 860 Fox Furnace Co., The, 893-897 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Ilg Electric Ventilating Co., 984 Johnson Service Co., 1146-1147 Meyer Furnace Co., The, 917 Niagara Blower Company, 868 Parks-Cramer Company, 869 . Powers Regulator Co., 1152-1153 Research Corporation, 870 H. J. Somers, Inc., 931 B. F. Sturtevant Co., 985 General Electric Company,' 902 903, 1058-1059 Grinnell Co., Inc., 1000-1002, 1110 Henry Furnace & Foundry Co., 912-913 Johnson Service Co., 1146-1147 Mercoid Corporation, The, 1150 Minneapolis-Honeywell Regulator Co., 1148-1149 Niagara Blower Company, 868 Parks-Cramer Company, 869 Penn Electric Switch Co., 1151 Powers Regulator Co., 1152-1153 Taylor Instrument Companies, 1018-1019 - HUMIDITY RECORDERS and Indicators Bristol Company, The 1012 Consolidated Ashcroft Hancock Co., Inc., 1013 Julien P. Friez & Sons, Inc., 1144 Leeds & Northrup Company, 1015 Minneapolis-Honeywell Regulator Co., 114&-1149 Palmer Co., 1017 Powers Regulator Co., 1152-1153 Taylor Instrument Companies, 1018-1019 HOT WATER HEATING SYS. TEMS (See Heating Systems, Hot Water) HUMIDIFIERS - Air Devices Corporation, Thermal Units Div., 849. Air-Maze Corp., 924-925 Airtemp Incorporated, 882-883 American Blower Corp., 850-851 American Moistening Co., 852 American Radiator Company, 884 885, 940-943, 1061 Armstrong Machine Works, 1102 1103 . Baker Ice Machine Co., 854-855 Binks Manufacturing Co., 972-973 Buffalo Forge'Company, 981 Burnham Boiler Corp., 944-945 Carrier Corporation, 853 Clarage Fan Company, 858 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision. General Motors Sales Corporation, 890-892 , . Electrol, Incorporated, 898-899, 967 Fairbanks Morse & Co.', 860 Fox Furnace Co:, The, 893-897 General 'Electric Company, 902 . 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Grinnell Co.. Inc.. 1000-1002, 1110 Henry Furnace & Foundry Co., 912-913 . Ilg Electric Ventilating Co., 984 Utica Radiator Corp., 920-921 Westinghouse Elec. & Mfg. Co., 876 York Ice Machinery Corp., 877 HYGROMETERS (See also Hu midity Recorders and Indicators) American Moistening Co., 852 HUMIDIFIERS, Unit Air Devices Corporation, Thermal Units Div., 849 Airtemp Incorporated, 882-883 American Blower Corp., 850-851 American Moistening Co., 852 Armstrong Machine Works, 1102 . Detroit Lubricator Co., 1140-1141 Julien P. Friez & Sons, 1144 Grinnell Co., Inc., 1000-1002,. 1110 Johnson Service Co.. 1146-1147 Palmer Company, 1017 Taylor Instrument Companies, 1018-1019 1103 . INDUCED DRAFT COOLING Buffalo Forge Company, 981 TOWERS (See also Cooling Tow Burnham Boiler Corp., 944-945 ers. Forced Draft, Mechancial Carrier Corporation. 853 Draft) Clarage Fan Company, 858 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899, 967 Fairbanks Morse & Co., 860 . General Electric Company, 902 903, 1058-1059 Baker' Ice Machine Co., 854-855 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 Cooling Tower Company, 971 Marley Company, 974 Research Company, 870 Unit Heater & Cooler Co., 994 York Ice Machinery Corp., 877` Grinnell Co.. Inc., 1000-1002, 1110 INSTRUMENTS, Indicating Ilg Electric Ventilating Co., 984 and Recording Marley Company, The, 974 . McQuay, Incorporated, 865 Niagara Blower Company, 868 Parks-Cramer Company, 869 B. F. Sturtevant Co., 985 Trane Company, The, 872-873 Unit Heater and Cooler Co., 994 Westinghouse Electric & Manu facturing Co., 876 Bristol Company, The, 1012 ' Cochrane Corp., 1107 ' Consolidated Ashcroft Hancock Co., Inc., 1013 Julien P. Friez & Sons, Inc., 1144 Illinois Testing Laboratories, Inc., 1014 Johnson Service Co., 1146-1147 Leeds & Northrup Company, 1015 Johnson Service Co., 1146-1147 Lennox Furnace Co., Inc., 914-915 HUMIDITY CONTROL Minneapolis-Honeywell Regulator Co., 1148-1149 McQuay Incorporated, 865 Meyer Furnace Co., The, 917 American Moistening Co., 852 /. Palmer Co., 1017 American Radiator Company, 884 Powers Regulator Co., 1152-1153 L. J. Mueller Furnace Co., 918-919 885, 940-943, 1061 Niagara Blower Company, 868 Barber-Colman Co., 1138-1139 Taylor Instrument Companies, 1018-4019 / Parks-Cramer Company, 869 Bristol Company, The, 1012 Westinghouse Electric & Manu Schwitzer-Cummins Co., 880, 1136 Carrier Corporation, 853 facturing Co., 876 ' H. J. Somers. Inc., 931 ' B. F. Sturtevant Co., 985 Cochrane Corp., 1107 Consolidated Ashcroft v Hancock' INSULATION, Building Trane Company, The, 872-873 Co., Inc., 1013 . Alfol Insulation Co., Inc., 1022-1023 Unit Heater & Cooler Co.; 994 Delco-Frigidaire Conditioning Di Aluminum Aircell Insulation Co., United States Radiator Corpora vision, General Motors Sales 1021 tion, 950-951 Corporation, 890-892 Armstrong Cork Products Com Utica Radiator Corp., 920-921 Detroit Lubricator Co., 1140-1141 pany, 1024-1025 Weil-McLain Company, 952 Fox Furnace Co., The, 893-897 - Carey, Philip, Co., 1028 WestiHghouse Electric & Manu Julien P. Friez & Sons, Inc., 1144 Celotex Corporation, The, 1029 facturing Company, 876 . Fulton Sylphon Co., 1142-1143 1031 Numerals following Manufacturers' Names refer to pages In the Catalog Data Section , . 1177 Heating Ventilating Air Conditioning Guide 1938 Chamberlin Metal Weather Strip Owens-Illinois Glass Company, 930 MECHANICAL DRAFT APPAR Co., 1032-1033 H. W. Porter & Co., 1053 ATUS (See Blowers, Farced Cork Insulation Co.. Inc., 1026 Ric-wiL Company, The, 1054 ' Draft) Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co., 1034-1035 Ruberoid Co., The, 1044-1045 Underground Steam Construction Co., 1055 MECHANICAL DRAFT COOL ING TOWERS (See also Cooling General Insulating & Mfg. Co., Wyckoff & Sons Co., 1056 1037 Zonolite Company, 1050-1051 Towers, Forced Draft, Induced , Draft) Insulite Company, The, 1038-1039 Baker Ice Machine Co., 854-855 Insul-Wool Insulation Con>., 1040 INSULATION, Ventilating Binks Manufacturing Co., 972-973 International Fibre Board Limited, Ducts . Buffalo Forge Company, 981 1041 John9-Manville, 1042-1043 Mundet Cork Corp., 1027 Owens-Illinois Glass Company, 930 Pacific Lumber Co., The, 1046 Ruberoid Co., The. 1044-1045 Standard Lime & Stone Co., 1047 United States Gypsum Co., 1048 Western Felt Works, 1049 . Zonolite Company, 1050*1051 . Alfol Insulation Co., Inc., 1022-1023 Armstrong Cork Products Com pany, 1024-1025 ' Carey, Philip, Co., 1028 ' Celotex Corporation, 1029-1031 Cooling Tower Company, 971 Marley Company, 974 Research Company, 870 Unit Heater & Cooler Co., 994 York Ice Machinery Corp., 877 Cork Insulation Co., Inc., 1026 METALS, Perforated (See Perfo Eagle-Picher Lead Co., 1036 rated Metals) Ehret Magnesia Mfg. Co., 1034-1035 General Insulating & Mfg. Co.,- METERS, Air 1037 Bristol Company, The, 1012 ' INSULATION, Felt Insulite Company, The, 1038-1039 Julien P. Friez & Sons, Inc., 1144 . ' Eagle-Picher Lead Co., 1036 Ehret Magnesia Mfg. Co., 1034 1035 ' General Insulating & Mfg. Co., 1037 Johns-ManviUe, 1042-1043 Ruberoid Co., 1044-1045 Western Felt Works, 1049 International Fibre Board Limited, 1041 Minneapolis-Honeywell Co., 1148-1149 Regulator Johns-Manville, 1042-1043 Mundet Cork Corp., 1027 Taylor Instrument Companies, 1018-1019 Owens-Illinois Glass Company, 930 Pacific Lumber Co., The, 1046 ' METERS, Air Velocity Ruberoid Co., The, 1044-1045 Anderson Products, Inc., 1156-1157 Standard Lime and Stone Co., 1047 Julien P. Friez & Son?, Inc., 1144 Western Felt Works. 1049 * ' Illinois Testing Laboratories, 1014 INSULATION, Pipes and Sur Zonolite Company, 1050-1051 Minneapolis-Honeywell Regulator faces (See Coverings, Pipes and Co., 1148-1149 . . Surfaces) LIQUID LEVEL CONTROLS Powers Regulator Co., 1152-1153 INSULATION, Magnesia Carey, Philip Mfg. Co., 1028 Ehret Magnesia & Mfg. 1034-1035 Johns-Manville, 1042-1043 Co.', Bristol Company, The, 1012 Cochrane Corp., 1107 Detroit Lubricator Co., 1140-1141 Frick Company (Incorporated), 861 General Controls Co., 1145 Johnson Service Co., 1146-1147 Taylor Instrument Companies, 1018-1019 METERS, Condensation American District Steam Company 975, 1052 . INSULATION, Sound Deadening (See also Fell, Sound - Deadining) Alfol Insulation Co., Inc.. 1022-1023 Aluminum Aircell Insulation Co., 1021 Armstrong CoTk Products Com pany, 1024-1025 Carey, Philip, Co., 1028 ' Celotex Corporation, 1029-1031 Cork Insulation Co., Inc., 1026 Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co.. 1034-1035 ' General Insulating & Mfg. Co., - 1037 Insulite Company, The, 1038-1039 Kieley & Mueller, Inc., 1116 Liquidometer Corp., 1016 Carbondale Div. Worthington Pump & Machinery Co., 856-857 McDonnell & Miller, 938-939 Minneapolis-Honeywell Regulator METERS. Feed Water Co.. 1148-1149 Minneapolis-Honeywell Regulator Mueller Steam Specialty Co., Inc., Co., 1148-1149 1120 Preferred Utilities Corp., 970 . METERS, Flow . Spence Engineering Co., 1154 American District Steam Company, Taylor Instrument Companies, 975, 1052 . 1018-1019 Bristol Company, The, 1012 . Cochrane Corp., 1107 . LIQUID LEVEL GAGES (See . Leeds & Northrup Company, 1015- Gages, Liquid Level) . Minneapolis-Honeywell Regulator LOUVERS Co.,, 1148-1149 Taylor Instrument Companies, American CooJair Corp., .978-979 1018-1019 . Insul-Wool Insulation Corp., 1040 International Fibre Board Limited. 1041 Johns-Manville, 1042-1043 Mundet Cork Corp., 1027 Owens-Illinois Glass Company, 930 Pacific Lumber Co., The, 1046 Anemostat Corp., of America, 1088 Auer Register Co., 1089 Autovent Fan & Blower Co., 977 Binks Manufacturing Co., 972-973 Buffalo Forge Company, 981 \ Champion Blower & Forge Co., 982 Clarage Fan Company, 858 - METERS, Steam . . . American District Steam Company, 975, 1052 Cochrane Corp., 1107 . . Minneapolis-Honeywell Regulator Co., 1018-1019 Ruberoid Co., The, 1044-1045 Standard Lime & Stone Co.,' 1047 Western Felt Works, 1049 . Zonolite Company, 1050-1051 General Controls, 1145 Henry Furnace & Foundry Co., 912-913 Independent Register Co., 1094 ' Trane Company, The, 872-873 MOTORS, Electric Barber-Colman Co., 1138-1139 Century Electric Company. 1057 General Electric Company, 902 INSULATION, Underground Tuttle & Bailey, Inc., 1092-1093 , 903, 1058-1059 ' Steam Pipe ' Unit Heater & Cooler Co., The, 994 Ohio Electric Mfg. Co., 1060 Alfol Insulation Co., Inc., 1022-1023 American District Steam Company, 975, 1052 E. B. Badger & Sons Co., 976 Carey, Philip, Co., 1028 Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing . Co.. 1034-1035 .. General Insulating & Mfg. Co., United States Register Co., 1095 Waterloo Register Co., 1096 Young Regulator Company, 935 MANHOLE COVERS, For Underground Systems American Coolair Corp., 978-979 American District Steam Company. 975, 1052 B. F. Sturtevant Co., 985 Westinghouse Elec. & Mfg. Co.; 879 Williams Oil-O-Matic Heating Cor poration, 922-923 NOISE ELIMINATORS (See also Hose, flexible; - Tubing, flexible; Sound Deadeners; Vibration Ab sorbers) . 1037 Johns-ManviUe. 1042-1043 ' - H. W. Porter & Co., 1053 * Ric-wiL Company, The, 1054 NOZZLES^ Spray (See Spray Nozzles) Please mention THE GUIDE 1938 when writing to Advertisers Index to Modern Equipment OIL BURNER EQUIPMENT Spence Engineering Co., 1154 . PIPE, Steel Airtemp Inc., 882-883 . American Radiator Company, 884 885. 940-943. 1061 Automatic Burner Corp., 964 Branford Div. Malleable Iron Fittings Co., 966 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Sterling Engineering Co., 1121 H. A. Thrush & Co., 1010-1011 American Rolling MiU Co., 1098 Trane Company, The, 872-873 .Carnegie-Illinois Steel Corp., 1100 Warren Webster & Co., 1124-1127 Crane Co., 946-947 PACKING. Asbestos Grinnell Co., Inc., 1000-1002, 1110 Arthur Harris & Co., 1066 Ehret Magnesia Manufacturing Jones & Laughlin Steel Corp., 1070 Co., 1034-1035 Republic Steel Corporation, 1071 Johns-ManviUe, 1042-1043 Vilter Manufacturing Co., 875 Corporation, 890-892 Detroit Lubricator Co., 1140-1141 Electrol Incorporated, 898-899, 967 Fox Furnace Co.. The, 893-897 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 S. T. Johnson Co., 968-969 Herman Nelson Corp., 1004-1005 Kelvinator Division of Nash- Kelvinator Corp., 907-911 Kleen-Heet, Inc., 965 Preferred Utilities Corp., 970 Westinghouse Elec. & Mfg. Co., 876 Williams Oil-O-Matic Heating Cor poration, 922-923 - OIL BURNERS PANELS, Insulated Alfol Insulation Co., Inc., 1022-1023 Aluminum Aircell Insulation Co., 1021 Carey, Philip, Co., 1028 . . Celotex Corporation, 1029-1031 General Insulating & Mfg. Co., 1037 Insulite Company, The, 1038-1039 International Fibre Board Limited, 1041 United States Gypsum Co., 1048 Zonolite Company, 1050-1051 PERFORATED METALS U. S. Register Co., 1095 Wickwire Spencer Steel Co., 1097 PIPE, Wrought Iron Crane Co., 946-947 . Grinnell Co., Inc., 1000-1002, 1110 Vilter Manufacturing" Co., 875 PIPE ANCHORS American District Steam Co., 975, 1052 E. B, Badger & Sons Co., 976 Crane Co.. 946-947 Grinnell Co., Inc., 1000-1002, 1110 H. W. Porter & Co.. 1053 Ric-wiL Company, 1054 Underground Steam Construction Co., 1055 . PIPE BENDING Airtemp Incorporated, 882-883 Automatic Burner Corp., 964 Babcock & Wilcox Co., 954 Branford Div. Malleable Iron Fittings Co., 966 Combustion Engineering Co., 1132 Crane Co., 946-947 _ - PIPE, Asbestos . Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co., 1034-1035 . Johns-Manville, 1042-1043 Standard Lime & Stone Co., 1047 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Electrol Incorporated, 898-899, 967 Fox Furnace Co., 893 Gar Wood Industries, Inc., 900-901 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 PIPE, Brass American Brass Co.; 1062-1063 Crane Co., 946-947 Mueller Brass Co., 1064-1065 Revere Copper and Brass Incor porated, 1067 - Streamline Pipe and Fittings Co., 1064-1065 Baker Ice Machine Co., Inc., 854-855 _ Crane Co., 946-947 '' Frick Company, 861 Grinnell Co., Inc., 1000-1002, 1110 Arthur Harris & Co., 1066 Parks-Cramer Co., 869 Vilter Manufacturing Co., 875 PIPE CONDUITS (See Conduits, Ifnderground Pipe) ' . PIPE COVERING (See Covering, Pipe) PIPE FITTINGS (See Fittings, Pipe) S. T. Johnson Co., 968-969 Kelvinator Division of Nash- Kelvinator Corp., 907-911 Kleen-Heet, Inc., 965 - Lennox Furnace Co., Inc., 914-915 ' Lochinvar Corp., 916 Meyer Furnace Co., 917 Herman Nelson Corp., 1004-1005 Preferred Utilities Corp., 970 Williams Oil-O-Matic Heating Cor poration, 922-923 * PIPE, Cement Eagle-Picher Lead Co., 1036 Johns-Manville, 1042-1043 Ruberoid Co., The, 1044-1045 Standard Lime & Stone Co., 1047 Zonolite Company, 1050*1051 PIPE, Copper American Brass Co., 1062-1063 American Radiator Company, 884 885. 940-943. 1061 PIPE GUIDES E. B. Badger & Sons Co., 976 . Crane Co., 946-947 H. W. Porter & Co., 1053 Ric-wiL Company, The, 1054 . Underground Steam Construction Co.. 1055 PIPE HANGERS (See Hangers, Pipe) , . OIL BURNER MOTORS. (See ` Motors, Electric) OIL BURNER" TUBING, Flex ible (See Tubing, Flexible Met allic) Crane Co., 946-947 Mueller Brass Co., 1064-1065 Revere Copper and Brass, Incor-. PIPE SUPPORTS, ground Conduit For Under ' porated, 1067 American District Steam Company. Streamline Pipe and Fittings Co., 975, 1052 1064-1065 E. B. Badger'& Sons Co., 976.. .OIL TANK Gages, Oil) GAGES (See Tank PIPE, Copper Bearing Steel ORIFICES. Flow Meter Bethlehem Steel Co., 1099 Crane Co., 946-947 . . Grinnell Co., Inc., 1000-1002, 1110 H. W. Porter & Co., 1053 Ric-wiL Company, The, 1054 Underground Steam Construction Bristol Company, The, 1012 Jones & Laughlin Steel Corp., 1070 Co., 1055 Cochrane Corp., 1107. Taylor Instrument Companies. 1018-1019 Republic Steel Corporation, 1071 PIPE, Copper Molybdenum Iron PITOT TUBES (See Air Measur ing and Recording Instruments) ORIFICES. Radiator Republic Steel Corporation, 1071 PLASTER BASE, Fire Retarding American Radiator Company, 884 PIPE, Return Bends . 885, 940-943. 1061 American Brass Co., 1062-1063 Barnes & Jones, Incorporated, 1106 - American Radiator Company, 884 Bell and Gossett Co.. 1006-1007 885, 940-943. 1061 Detroit Lubricator Co., 1140-1141 Crane Co., 946-947 Armstrong Cork Products Com pany. 1024-1025 . Celotex Corporation, 1029-1031 Johns-Manville, 1042-1043 United States Gypsum Co.. 1048 C. A. Dunham Co., 1108-1109 Frick Company, 861 Zonolite Company, 1050-1051 Hoffman Specialty 1112-1113 Co., Inc., . Grinnell Co.. Inc., 1000-1002, 1110 Arthur Harris &' Co., 1066 PLASTER BASE, Insulating Illinois Engineering Co., 1114-1115 Mueller Brass Co., 1064-1065 Armstrong Cork Products Com Milwaukee Valve Co., 1118-1119 Streamline Pipe and Fittings Co., pany, 1024-1025 New York Air Valve Corp., 1160 1064-1005 * Celotex Corporation, 1029-1031 . Sarco Co., Inc., 1122-1123 ' . Vilter Manufacturing Co., 875 Insulite Company, The, 1038-1039 Numerals following Mariijfacturers' Names refer to pages in the Catalog Data Section Heating Ventilating Air Conditioning Guide 1938 International Fibre Board Limited, PUMPS, Ammonia PUMPS, Oil 1041 Johns-Manville. 1042-1043 United States Gypsum Co., 1048 Zonolite Company, 1050-1051 American Marsh Pumps, Inc., 1082 Worthington Pump and Machinery Corp., 856-857 York Ice Machinery Corp., 877 American Marsh Pumps, Inc., 1082 Ingersoll-Rand Company, 862-863 PUMPS, Steam PLASTER BASE, Sound Deadening PUMPS, Boiler Feed American Marsh Pumps, Inc., 1082 Buffalo Pumps, Inc., 1083 American Marsh Pumps, Inc., 1082 Fairbanks, Morse & Co., 860 Armstrong Cork Products Com Buffalo Pumps, Inc., 1083 Ingersoll-Rand Company, 862-863 pany, 1024-1025 Chicago Pump Co., 1084 Trane Company, The, 872-873 Celotex Corporation, 1029-1031 Insulite Company, The, 1038-1039 Decatur Pump Company, 1085 Ingersoll-Rand Company. 862-863 PUMPS, Sump International Fibre Board Limited, Nash Engineering Co., 1086-1087 American Marsh Pumps, Inc., 1082 1041 Sterling Engineering Co., 1121 Buffalo Pumps, Inc., 1083 Johns-Manville, 1042-1043 Trane Company, The, 872-873 Chicago Pump Co., 1084 United States Gypsum Co., 1048 Westinghouse Electric & Manu Fairbanks, Morse & Co., 860 Zonolite Company, 1050-1051 facturing Co., 876 Ingersoll-Rand Company, 862-863 PLATES, Iron . American Coolair Corp., 978-979 ' American Rolling Mill Co., 1098 ' Worthington Pump and Machinery Nash Engineering Co., 1086-1087 Corp., 856-857 ' PUMPS, Turbine PUMPS, Brine American Marsh Pumps, Inc., 1082 Carnegie-Illinois Steel Corp., 1100 American Marsh Pumps, Inc., 1082 Decatur Pump Company, 1085 Republic Steel Corporation, 1071 Baker Ice Machine Co., Inc., Hoffman Specialty Co., Inc., PLATES, Stainless Steel 854-855 Buffalo Pumps, Inc., 1083 1112-1-113 Ingersoll-Rand Company, 862-863 American Rolling Mill Co., 1098 Carbondale Div., Worthington Nash Engineering Co., 1086-1087 Republic Steel Corporation, 1071 PLATES, Steel Pump & Machinery Co., 856-857 Chicago Pump Co., 1084 Decatur Pump Company, 1085 PUMPS, Vacuum American Marsh Pumps, Inc., 1082 American Coolair Corp., 978-979 Fairbanks, Morse & Co., 860 . Chicago Pump Co., 1084 ' American Rolling Mill Co., 1098 Frick Company, 861 Curtis Refrigerating Machine Com Carnegie-Illinois Steel Corp., 1100 Ingersoll-Rand Company, 862-863 pany,' Division of Curtis Manu Jones & Laughlin Steel Corp., 1070 Nash Engineering Co., 1086-1087 facturing Company, 859 Republic Steel Corporation, 1071 Trane Company, The, 872-873 C. A. Dunham Co., 1108-1109 Worthington Pump and Machinery Hoffman Specialty Co., ' Inc., PRESSURE REDUCING Corp., 856-857 1112-1113 VALVES sure) (See Regulators, Pres PUMPS, Centrifugal Ingersoll-Rand Company, 862-863 Nash Engineering Co., -1086-1087 American Marsh Pumps, Inc., 1082 Sterling Engineering Co., 1121 - PROPELLER FANS (See Fans, Bell and Gossett Co., 1006-1007 Propeller) Buffalo Pumps, Inc., 1083 Chicago Pump Co., 1084 PYROMETERS, Portable and Stationary PSYCHROMETERS (See also Air -Decatur Pump Company, 1085 Bristol Company, The, 1012 * Measuring, Indicating and Re C. A. Dunham Co., 1108-1109 Illinois Testing Laboratories, Inc., cording Instruments) ' Frick Company, 861 1014 American Moistening Co., 852 Fairbanks, Morse & Co., 860 Bristol Company, The, 1012 Consolidated Ashcroft Hancock Co., Inc., 1013 Julien P. Friez & Sons, Inc., 1144 Johnson Service Co., 1146-1147 Ingersoll-Rand Company. 862-863 .Nash Engineering Co., 1086-1087 Schwitzer-Cummins Co., 880, 1136 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 . Leeds & Northrup Company, 1015 Palmer Company, The, 1017 Parks-Cramer Company, 869 Taylor Instrument Companies, . 1018-1019 . . * PUMPS, Circulating American Marsh Pumps. Jnc., 1082 Bell and Gossett Co., 1006-1007 Binks Manufacturing Co., 972-973 Buffalo Pumps, Inc., 1083 Leeds & Northrup Company, 1015 Minneapolis-Honeywell Regulator Co., 1148-1149 Taylor Instrument Companies, 1018-1019 RADIATION, Aluminum Aerofin Corporation, 996-998 Air Devices Corp., Thermal Units Div., 849 McQuay, Incorporated, 865 , Trane Company, The, 872-873 ' PUBLICATIONS Air Conditioning--Oil Heat, 1076 American Artisan, 1072 American Society of Refrigerating Engineers, 1080 ,, Domestic Engineering, 1074-1075 Fueloil Journal, 1077 . Chicago Pump Co., 1084 Decatur Pump Company, 1085 Ingersoll-Rand Company, 862-863 Nash Engineering Co., 1086-1087 Sterling Engineering Co., 1121 H. A. Thrush & Co., 1010-1011 \ Trane Company, The, 872-873 Heating & Ventilating, 1078 - PUMPS, Condensation Heating Journals, Inc., 1076 Heating, Piping and Air Condi tioning, 1073 Plumbing and Heating Trade Journal, 1079 Sheet Metal Worker, 1081 American Radiator Company, 884 885, 940-943, 1061 . American Marsh Pumps. Inc., 1082 Buffalo Pumps, Inc., 1083 Chicago Pump Company, 1084 Decatur Pump Company, 1085 PULLEYS, Chain C. A. Dunham Co., 1108-1109 Hoffman Specialty Co., Inc., Hart & Cooley Mfg. Co.. 1090-1091 1112-1113 , United States Register Co., 1095 Ingersoll-Rand Company, 862-863 PUMPS, Air and Gas Nash Engineering Co., 1086-1087 Sterling Engineering Co.; 1121 Unit Heater and Cooler Co., 994 Warren Webster & Co., 1124-1127 RADIATION, Brass Fedders Manufacturing Co., 991 . . G & O Manufacturing Co., 999 McQuay, Incorporated, 865 . Revere Copper and Brass, Incor- porated, 1067 RADIATION, Cast-Iron American Radiator Company, 884 885, 940-943, 1061 Burnham Boiler Corp., 944-945 Crane Co.. 946-947 Unit Heater and Cooler Co., 994 United States Radiator Corpora tion, 950-951 Utica Radiator Corp., 920-921 , Weil-McLain Company, 952 ' American Marsh Pumps, Inc., 1082 . Curtis Refrigerating Machine Com pany, Division of Curtis Manu Trane Company, The, 872-873 Worthington Pump & Machinery Co., 856-857 ` . RADIATION, Copper Aerofin Corporation, 996-998 . facturing Company, 859 . American Radiator Company, 884 Ingersoll-Rand Company. 862-863 PUMP MOTORS, (See Motors, 885,940-943,1061 Nash Engineering Co., 1086-1087 Electric) C. A. Dunham Co., 1108-1109 Please mentipn THE GUIDE 1938 when writing to Advertisers 1180 Index to Modern Equipment Fairbanks, Morse & Co., 860 . Unit Heater and Cooler Co., 994 Consolidated Ashcroft Hancock Fedders Manufacturing Co., 991 United States Radiator Corpora Co., Inc., 1013 G & O Manufacturing Co., 999 tion, 950-951 Detroit Lubricator Co., 1140:1141 McQuay, Incorporated, 865 Warren Webster & Co., 1124-1127 Julien P. Friez & Sons. Inc., 1144 Modine Manufacturing Co;, 993 Weil-McLain Company, 952 Fulton Sylphon Co., 1142-1143 John J. Nesbitt, Inc., 1003 Young Radiator Company, 995 General Controls, 1145 Revere Copper and Brass, Incor porated, 1067 RECEIVERS, Ate Illinois Engineering Co., 1114-1115 IUinois Testing Laboratories, Inc., B. F. Sturtevant Co., 985 Anemostat Corp. ot America, 1088 1014 Trane Company, The, 872-873 Baker Ice Machine Co., 854-855 Johnson Service Co., 1146-1147 Tuttle & Bailey, Inc., 1092-1093 Binks Manufacturing Co., 972-973 Leeds & Northrup Co., 1015 Warren Webster & Co., 1124-1125 Brownell Company, The, 1130 Minneapolis-Honeywell Regulator. Young Radiator Company, 935 Butler Mfg. Co., 1131 Co., 1148-1149 RADIATION, Plain tended Surface and Ex . Crane Co., 946-947 Curtis Refrigerating Machine Com pany, Division Curtis Manu Penn Electric Switch Co., 1151 Powers Regulator Co., 1152-1153 Taylor Instrument Companies, Aerofin Corporation, 996-998 . facturing Company, 859 1018-1019 American Radiator Company, 884 Farrar & Trefts. Incorporated, 955 Westinghouse Electric & Manu 885, 940-943, 1061 IUinois Engineering Co., 1114-1115 facturing Co., 876 Buffalo Forge Company. 981 Crane Co., 946-947 Fairbanks, Morse & Co., 860 Ingersoll-Rand Company, 862-863 .Kewanee Boiler Corp., 960-961 REFRIGERATING EQUIP- . Parks-Cramer Company, 869 MENT, Centrifugal Fedders Manufacturing Co., 991 Trane Company, The, 872-873 Airtemp Inc., 882-883 G & O Manufacturing Co,, 990 Warren Webster & Co., 1124-1127 Carrier Corporation, 853 General Electric Company, 902 903, 1058-1059 RECEIVERS, Ammonia GrinneU Co., Inc., 1000-1002, 1110 Baker Ice Machine Co., 854-855 Ingersoll-Rand Company, 862-863 REFRIGERATING EQUIP Modine Manufacturing Co., 993 Carbondale Div., Worthington MENT, Steam Jet John J. Nesbitt, Inc., 1003 Pump & Machinery Co., 856-857 American Blower Corp., 850-851 B. F. Sturtevant Co., 985 Frick Company (Incorporated), 861 Carbondale Div., Worthington Trane Company, The, 872-873 York Ice Machinery Corp., 877 Pump & Machinery Co., 856-857 Utica Radiator Corp., 920-921 Weil-McLain Company, 952 RECEIVERS, Condensation Carrier Corporation, 853 Ingersoll-Rand Company, 862-863 Young Radiator Company, 995 American Marsh Pumps, Inc., 1082 Universal Cooler Corp., 874 Baker Ice Machine Co., Inc., Westinghouse Electric & Manu RADIATOR ENCLOSURES ^ . 854-855 . facturing Co., 876 AND SHIELDS Chicago Pump Co., 1084 Williams Oil-O-Matic Heating Cor American Radiator Company, 884 Crane Co., 946-947 poration, 922-923 885, 940-943, 1061 Auer Register Co., The, 1089 Crane Co.. 946-947 Illinois Engineering Co., 1114-1115 Nash Engineering Co., 1086-1087 Sarco Company, Inc., 1122-1123 ' REFRIGERATING MACHINERY . Modine Manufacturing Co., 993 Trane Company, The, 872-873 Air Devices Corporation, Thermal Revere Copper and Brass Incor Warren Webster & Co., 1124-1127 Units Div., 849 ' porated, 1067 H. J. Somers; Inc., 931 RECEIVERS. Water Vapor Airtemp Incorporated, 882-883 Baker Ice Machine Co., 854-855 Wickwire Spencer Steel Co., 1097 American Blower Corp., 850-851 Carbondale Div., Worthington RADIATORS, Cabinet # IUinois Engineering Co., 1114-1115 Pump & Machinery Co., 856-857 Trane Company, The, 872-873 Carrier Corporation, 853 Air Devices Corporation, Thermal Warren Webster & Co., 1124-1127 Curtis Refrigerating Machine Com Units Div., 849 American Radiator Company,' 884 885, 940-943. 1061 RECORDERS, Humidity, Tem perature pany, Division of Curtis Manu- . facturing Company! 859 Delco-Frigidaire Conditioning Di Burnham Boiler Corp., 944-945 Bristol Company, The, 1012 vision, General Motors Sales Crane Co., 946-947 Consolidated Ashcroft Hancock Corporation, 890-892 C. A. Dunham Co., 1108-1109 Co., Inc., 1013 Fairbanks. Morse & Co., 860 Fairbanks, Morse &. Co.,-860 . Julien P. Friez & Sons, Inc;, 1144 Frick Company (Incorporated), 861 Grinnell Co., Inc., 1000^1002. 1110 Johnson Service Co., 1146-1147 General Electric Company, 902 McQuay, Incorporated, 865 Leeds & Northrup Co., 1015 903, 1058-1059 - . Modine Mfg. Co., 993 . Minneapolis-Honeywell Regulator General Refrigeration Corp., 864 John J. Nesbitt, Inc., 1003 ' ' 1148-1149 . Ingersoll-Rand Company, 862-863 Trane Company, The, 872-873 , Powers Regulator Co., 1152-1153 Kelvinator Division of Nash- Unit Heater and Cooler Co., 994 Taylor Instrument Companies, Kelvinator Corp., 907-911 . United States Radiator. Corpora 1018-1019 Merchant & Evans Co., 867 ' tion, 950-951 Warren Webster & Co., 1124-1127 Weil-McLain Company, 952 REFRACTORIES, Materials Cements, Serve!, Inc., 871 - Universal Cooler Corp., 874 . Vilter Manufacturing Co., 875 . Wickwire Spencer Steel Co., 1097 Babcock & Wilcox Co., 954 Westinghouse Electric & Manu Young Radiator Company, 995 Carey, Philip, Co., 1028 ' facturing Co., 876 RADIATORS, Concealed Combustion Engineering Co., 1132 Williams Oil-O-Matic Heating Cor Eagle-Picher Lead Co., 1036 poration, 922-923 Air Devices Corporation, Thermal Ehret Magnesia Mfg. Co., 1034 York Ice Machinery Corp., 877 ' Units Div., 849 1035 American Radiator Company, 884 Johns-Manville, 1042-1043 885, 940-943, 1061 Preferred UtiUties Corp., 970 REFRIGERATION EQUIP MENT, Water Vapor Burnham Boiler Corp., 944-945 Ric-wiL Company, 1054 Ingersoll-Rand Company, 862-863 Crane Co., 946-947 C. A. Dunham Co., 1108-1109 GrinneU Co., Inc., 1000-1002, 1110 McQuay, Incorporated, 865 Zonolite Company, 1050-1051 REFRIGERATION CONTROLS (See also Controls) . REGISTERS (See also Grilles, Reg isters, etc.) American Blower Corp., 850-851 ' Modine Manufacturing Co., 993 Alco Valve Company, 1155 American Coolair Corp., 978-979 John J. Nesbitt, Inc., 1003. - American Blower Corp., 850-851 American Radiator Company, 884 . Revere Copper and Brass Incor Barber-Colman Co., 1138-1139 885, 940-943, 1061 porated, 1067 Bristol Company, 1012 . Anemostat Corp. of American, 1088 -Trane Company, The, 872-873 Carrier Corporation, 853 Auer Register Co., The, 1089 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 1181 - Heating Ventilating Air Conditioning Guide 1938 Barber-Colman Co., 1138-1139 Carrier Corporation, 853 Fox Furnace Co., 893-897 Hart & Cooley Manufacturing Co., 1090-1091 Independent Register Co., 1094 L. J. Mueller Furnace Co., 918-919 Trane Company, The, 872-873 Tuttle & Bailey, Inc., 1092-1093 United States Register Co., 1095 Waterloo Register Co., 1096Wickwire Spencer Steel Co., 1097 Henry Furnace & Foundry Co- 912-913 .. Minneapolis-Honeywell Regulator Co- 1148-1149 Penn Electric Switch Co., 1151 Preferred Utilities Corp- 970 Spence Engineering Co., 1154 REGULATORS, Gas American Gas Products Corp886, 953 Barber Gas Burner Co- 887 SEPARATORS, Oil ' Air-Maze Corp., 924-925 / Cochrane Corp., 1107 Crane Co., 946-947 Frick Company (Incorporated), 861 Kieley & Mueller, Inc., 1116 Staynew Filter Corp., 932-933 Warren Webster & Co., 1124-1127 Wright-Austin Co., 1128 SEPARATORS, Steam . Cochrane Corp., 1107 REGULATORS, Air Volume Bryant Heater Co., 888-889 Crane Co., 946-947 Crane Co., 946-947 ' Kieley & Mueller, Inc., 1116 Barber-Colman Co., 1138-1139 Jenkins Bros., 1159 Warren Webster & Co., 1124-1127 Hart & Cooley Manufacturing Co.. Mercoid Corp- 1150 Wright-Austin Co., 1128 ' 1090-1091 . Young Regulator Co., 935 Penn Electric Switch Co- 1151 . SHEETS, Aluminum Foil REGULATORS, Humidity (See Alfol Insulation Co., 1022-1023 REGULATORS, Damper Humidity Control) Aluminum Aircell Insulation Co., American Radiator Co., 884-885. 940-943, 1061 Barber-Colman Co., 1138-1139 Barnes & Jones, Incorporated, 1106 Carrier Corporation, 853 . Consolidated Ashcroft Hancock Co.. Inc.. 1013 . Detroit Lubricator Co., 1140-1141 C. A. Dunham Co., 1108-1109 Julien P. Friez & Sons, Inc., 1144 Fulton Sylphon Co., 1142-1143 General Controls, 1145 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co., 904-906 Williams S. Haines & Co., 1111 - Hart & Cooley Manufacturing Co., 1090-1091 Henry Furnace & Foundry Co.. 912-913 : REGULATORS, Pressure American Radiator Company, 884 ' 885, 940-943, 1061 Beaton & Cadwell Mfg. Company, 1104-1105 Bell & Gossett Co- 1006-1007 Binks Manufacturing Co., 972-973 Bristol Company, The, 1012 Consolidated Ashcroft Hancock Co., Inc- 1013 Crane Company, 946-947 Detroit Lubricator Co., 1140-1141 C. A. Dunham Co.. 1108-1109 Fedders Manufacturing Co- 991 Fulton Sylphon Co., 1142-1143 General Controls, 1145 General Electric Company, 902 903. 1058-1059 Henry Furnace & Foundry Co- 1021 SHEETS. Asbestos, Flat and Corrugated Eagle-Picher Lead Co., 1036 . Ehret Magnesia Manufacturing Co., 1034-1035 Johns-Manville, 1042-1043 Ruberoid Co., The, 1044-1045 SHEETS, Black, Galvanized American Rolling Mill Co., 1098 Carnegie-Illinois Steel Corp., 1100 Jones & Laughlin Steel Corp., 1070 Republic Steel Corp., 1071 SHEETS, Copper American Brass Co., 1062-1063 Revere Copper and Brasfe Incor porated, 1067 Hoffman Specialty Co., Inc.. 912-913 ' SHEETS, Copper Alloy 1112-1113 Johnson-Service Co., 1146-1147 Kieley St Mueller, Inc., 1116 Leeds & Northrup Company, 1015 Minneapolis-Honeywell Regulator Illinois Engineering Co., 1114-1115 Jenkins Bros- 1159 Kieley & Mueller, Inc- 1116 Minneapolis-Honeywell Regulator Co- 1148-1149 American Brass Co., 1062-1063 Carnegie-Illinois Steel Corp., 1100 Revere Copper and Brass Incor porated, 1067 ' Co- 1148-1149 Powers Regulator Co., 1152-1153 Sarco Company, Inc- 1122-1123 Spence Engineering Co., 1154 Taylor Instrument Companies. 1018-1019 - Mueller Steam Specialty Co- Inc., 1120 . '' Penn Electric Switch Co., 1151 Powers Regulator Co- 1152-1153 Spence Engineering Co., 1154 Taco Heaters Inc., 1008-1009 SHEETS, Copper Bearing Steel American Rolling Mill Co., 1098 Carnegie-Illinois Steel Corp., 4100 Jones & Laughlin Steel Corp., 1070 Republic Steel Corporation, 1071' H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 Tuttle & Bailey, Inc- 1092-1093 Warren Webster & Co- 1124-1127 Young Regulator Co., 935 ' REGULATORS, Feed Water Taylor Instrument Companies, SHEETS, Copper Molybdenum 1018-1019 H. A. Thrush & Co., 1010-1011 Warren Webster & Co., 1124-1127 Iron r. Republic Steel Corporation, 1071 SHEETS, Felt REGULATORS, Temperature (See Temperature Control) Western Felt Works, 1049 SHEETS, Lead Coated Copper Be?,tS? .&,^adweU M,g- Company. 1104-1105 General Controls, 1145 Kieley & Mueller, Inc., 1116 McDonnell & Miller, 938-939 Mueller Steam Specialty Co., Inc- 1120 RELIEF VALVES (See Valves. Relief) SAFETY VALVES (See-Valves, Safety) SEALS, Inside Door Bottoms American Brass Co- 1062-1063 Revere Copper and Brass Incor porated, 1067 ' SHEETS, Pure Iron American Rolling Mill Co- 1098 ' Powers Regulator Co- 1152-1153 Spence Engineering Co., 1154 H. A. Thrush & Co.. 1010-1011 Westinghouse Electric & Manu- factunng Co., 876 Wright-Austin Co., 1128 Chamberlin Metal Weather Strip Co.. 1032-1033 , SEPARATORS, Dust Air-Maze Corp- 924-925 American Air Filter' Co- 926-927 SHEETS, Special Finish American Rolling Mill Co., 1098 Republic Steel Corporation, 1071 SHEETS, Stainless Steel American Rolling Mill Co., 1098 REGULATORS, Furnace Air Controls, Inc., 878 .Barber-Colman Co., 1138-1139 American Blower Corp- 850-851 Carnegie-Illinois Steel Corp- 1100 Binks Manufacturing Co., 972-973 Republic Steel Corporation, 1071 Buffalo Forge Company, 981 . Coppus Engineering Corp- 928 SHEETS, Steel Detroit Lubricator Co., 1140-1141 Research Corporation, 870 American Rolling Mill Co., 1098 Fox Furnace Co- The, 893-897 Staynew Filter Corp- 932-933 Bethlehem Steel Co., 1099 ' . Fulton Sylphon Co- 1142-1143- B. F. Sturtevant Co., 985 Carnegie-Illinois Steel Corp-. 1100 General Controls, 1145 Unit Heater and Cooler Co- 944 - Jones & Laughlin Steel Corpora Hart & Cooley Manufacturing Co., Universal Air Filter Corp- 934 tion. 1070 . 1090-1091 . Westinghouse Elec. & Mfg. Co- 876 Republic Steel Corporation, -1071 Please mention THE GUIDE 1938 when wrlting to Advertisers Index to Modern Equipment SHUTTERS, Automatic Air Controls, Inc- 878 American Coolair Corp., 978-979 Autovent Fan & Blower Co- 977 ' Barber-Colman Co., 1138-1139 Champion Blower & Forge Co., 982 Ilg Electric Ventilating Co., 984 B. F. Sturtevant Co- 985 L. J. Wing Mfg. Co- 988-989 Young Regulator Company, 935 SLIME PREVENTION (See also Algae Prevention) Aquatic Chemical Laboratories, Inc- 1161 Oakite Products, Inc- 1162 SMOKE DENSITY ` RECORDING Bristol Company, The, 1012 ' Leeds & Northrup Company, 1015 Westinghouse Electric & Manu facturing Co., 876 SOOT DESTROYER B. F. Sturtevant Co- 985 . General Electric Companyr 902 Trane Company, The, 872-873 903, 1058-1059 Westinghouse Elec. & Mfg. Co., 876 .Kieley & Mueller, Inc- 1116 Yarnell-Waring Co., 1129 Milwaukee Valve Co., 1118-1119 York Ice Machinery Corp- 877 Mueller Steam Specialty Co- Inc- SPRAY NOZZLE SYSTEM COOLING 1120 Sarco Company, Inc- 1122-1123 Spence Engineering Co- 1154 American Blower Corp- 850-851 Staynew Filter Corp., 932-933 Baker Ice Machine Co- 854-855 Wright-Austin Co- 1128 Bayley Blower Co., 980 Binks Mfg. Co- 972-973 STRAINERS, Steam Buffalo Forge Co., 981 Clarage Fan Co., 858 Crane Co- 946-947 Detroit Lubricator Co., 1140-1141 Cooling Tower Co- 971 ^ General Controls, 1145 - Marley Company. 974 Illinois Engineering Co., 1114-1115 Niagara Blower Co- 868 Kieley & Mueller, Inc., 1116 B. F. Sturtevant Co., 985 Milwaukee Valve Co., 1118-1119 Trane Company, 872-873 Mueller Steam Specialty Co., Inc., York Ice Machinery Corp- 877 1120 STACKS, Steel Powers Regulator Co., 1152-1153 Sarco Company, Inc- 1122-1123 Bethlehem Steel Co- 1099 Spence Engineering Co., 1154 Brownell Co., 1130 Trane Company, The, 872-873 . E. Keeler Company, 958-959 Wright-Austin Co., 1128 Vinco Company, Inc- 936-937 STEAM HEATING SYSTEMS STRAINERS, Water SOUND DEADENING, Flexible (See Healing Systems, Steam) Crane Co- 946-947 Hose American Brass Co., 1062-1063 Chicago Metal Hose Corp., 1068 ' Gilbert &' Barker Mfg. Co- 904-906 Titeflex Metal Hose Co- 1069 STOKERS, Mechanical, An thracite Babcock & Wilcox Company, 954 Combustion Engineering Co., 1132 Delco-Frigidaire Conditioning Div- Detroit Lubricator Co., 1140-1141 General Controls. 1145 ` Illinois Engineering Co- 1114-1115 Kieley & Mueller, Inc- 1116 McDonnell & Miller, 938-939 Milwaukee Valve Co., 1118-1119 SOUND DEADENING, -Insula tion General' Motors 890-892 Sales Corp- Mueller Brass Co., 1064-1065 Mueller Steam Specialty Co., Inc- . Alfol Insulation Co- Inc- 1022-1023 Aluminum Aircell Insulation Corp., 1021 Armstrong Cork Products Com pany, 1024-1025 . Binks Mfg. Co., 972-973 Celotex .Corporation, The, 1029 1031 Cork Insulation Co., Inc- 1026 Eagle-Picher Lead Co., 1036 Ehret Magnesia Manufacturing Co- 1034-1035 Gilbert & Barker Mfg. Co., 904-906 ' Insulite Company, The, 1038-1039 Insul-Wool Insulation Corp- 1040 International Fibre Board Limited, 1041 Johns-Manville, 1042-1043 ' Mundet Cork Corp., 1027 Fairbanks. Morse & Co.. 860 Iron Fireman Mfg. Co., 1134-1135 Schwitzer-Cummins Co- 880, 1136 Vulcan Anthracite Stoker Co- 1137 STOKERS, Mechanical, Bitum inous 1120 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Staynew Company, Inc- 932-933 Wright-Austin Co., 1128 TANK COILS (See Coils, Tank) Babcock & Wilcox Company, 954 Brownell Company, 1130 Butler Manufacturing Co., 1131 . TANK COVERING (See Covering, Pipes and Surfaces) Combustion Engineering Co., 1132 Delco-Frigidaire Conditioning Div- TANK GAGES, Oil General Motors Sales Corp- Liquidometer Corp., 1016 890-892 Detroit Stoker Company, 1133 TANK HEATERS (See Heaters. Fairbanks, Morse & Company, 860 Tank) ! Iron Fireman Mfg. Co- 1134-1135 Kelvinator Div. of Nash-Kelvin- TANKS, Blow-off ator Corp- 907-911 ` Brownell Company, The, 1130 Pacific Lumber Co- The, 1046 Meyer Furnace Company, 917 Farrar & Trefts Incorporated, 955 Ruberoid Standard Co., The,-1044-1045 Lime & Stone Co- 1047- Herman Nelson Corp- 1004-1005 Schwitzer-Cummins'Co., 880, 1136 Kewanee Boiler Corp., 960-961 . United States Gypsum Co- 1048 Western Felt Works, 1049 ` Zonolite Company, 1050-1051 STOKER MOTORS, (See Motors, Electric) . TANKS, Pressure Baker Ice Machine Co., 854-855 Bell and Gossett Co., 1006-1007 SPRAY EQUIPMENT Binks Manufacturing Co- 972-973 Cooling Tower Co., Inc- 971 Unit Heater & Cooler Co- 994 SPRAY NOZZLES American Blower- Corp.,'850-851 Baker Ice Machine Co- 854-855 STRAINERS, Dirt Bethlehem Steel Co- 1099 Barnes & Jones, Incorporated, 1106 Crane Co- 946-947 Detroit Lubricator Co., 1140-1141 C. A. Dunham Co- 1108-1109 General Controls, 1145 GrinneU Co., Inc., 1000-1002, 1110 Hoffman Specialty Co- Inc- 1112-1113 . Binks Manufacturing Co- 972-973 Brownell .Company, The, 1130 ' Burnham Boiler Corp- 944-945 Butler Manufacturing Co- 1131 Farrar & Trefts Incorporated, 955 . Frick Company (Incorporated), 861 Kewanee Boiler Corp- 960-961 " H. A. Thrush & Co- 1010-1011 . Bayley Blower Company, 980 Binks Manufacturing Co- 972-973 Mueller Steam Specialty Co- Inc.1120 TANKS. Storage Buffalo Forge Company, 981 ' Sarco Company, Inc- 1122-1123 American Radiator Company, 884 Clarage Fan' Company, 858 Spence Engineering Co- 1154 885, 940-943. 1061 Cooling Tower Co., Inc- 971 ' Sterling Engineering Co- 1121 E. B. Badger & Sons Co., 976 Detroit Lubricator Co., 1140-1141 Warren Webster & Co., 1124-1127 Bethlehem Steel Co- 1099 \ : Marley Co., The, 974 . 'Wright-Austin Co., 1128 Brownell Company, The, 1130. ' Martocello, Jos. A. & Co., 866 Zonolite Company, The, 1050-1051 Burnham Boiler Corp- 944-945 . Mueller Brass Co- 1064-1065 Niagara Blower Company, 868 STRAINERS, Oil Butler Manufacturing Co- 1131 ` Farrar & Trefts Incorporated. 955 Parks-Cramer Co., 8C9 Crane Co- 946-947 ` Frick Company (Incorporated), 861 Streamline Pipe and Fittings Co., Detroit Lubricator Co- 1140-1141 Gilbert & Barker Mfg. Co- 904-906 . 1064-1065 General Controls, 1145. Kewanee Boiler Corp- 960-961 ' Numerals following Manufacturers' Names refer to pages In the Catalog Data Section . 1183 Heating Ventilating Air Conditioning Guide 1938 TEMPERATURE CONTROL Minneapolis-Honeywell Regulator Mueller Steam Specialty Co., Inc., Air Devices Corporation, Thermal Units Div., 849 Co., 1148-1149 Palmer Company, The, 1017 1120 Sarco Company, Inc., 1122-1123 American Radiator Company, 884 885. 940-943, 1061 Barber-Colman Co., 1138-1139 Barnes & Jones, Incorporated, 1106 Beaton & Cadweill Mfg. Co., 1104-1105 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Taylor Instrument Companies, 1018-1019 H. A. Thrush & Co., 1010-1011 United States Gauge Co., 1020 Sterling Engineering Co., 1121 Trane Company, The, 872-873 Warren Webster & Co., 1124-1127 Wright-Austin Co., 1128 TRAPS, Float and Thermostatic Bell & Gossett Co., 1000-1007 . American District Steam Co., Bristol Company, The, 1012 THERMOMETERS, Recording 975, 1052 Carrier Corporation, 853 Bristol Company, The, 1012 Armstrong Machine Works, 1102 Cochrane Corp., 1107 Consolidated Ashcroft Hancock 1103 Consolidated Ashcroft Hancock Co., Inc., 1013 Barnes & Jones, Incorporated, 1106 Co.. Inc., 1013 Julien P. Friez & Sons, Inc., 1144 C. A. Dunham Co., 1108-1109 Delco-Frigidaire Conditioning Di Leeds & Northrup Company, 1015 Grinnell Co.. Inc., 1000-1002, 1110 vision, General Motors Sales Liquidometer Corp., 1016 William S. Haines & Co., 1111 Corporation, 890-892 Minneapolis-Honeywell Regulator Arthur Harris & Co., 1066 Detroit Lubricator Co., 1140-1141 Co., 1148-1149 Hoffman Specialty Co., Inc., Dole Valve Company, The, 1158 Powers Regulator Co., 1152-1153 1112-1113 C. A. Dunham Co., 1108-1109 Preferred Utilities Corp.. 970 Illinois Engineering Co.. 1114-1115 Fox Furnace Co., The, 893-897 Taylor Instrument Companies, Milwaukee Valve Co., 1118-1119 Julien P. Fries & Sons, Inc., 1144 1018-1019 Mueller Steam Specialty Co., Inc., Fulton Sylphon Co., 1142-1143 H. A. Thrush & Co., 1010-1011 1120 v General Controls, 1145 Powers Regulator Co., 1152-1153 General Electric Company, 902 THERMOSTATS Sarco Company, Inc., 1122-1123 ' 903, 1058-1059 Illinois Engineering Co., 1114-1115 Illinois Testing Laboratories, Inc., 1014 Johnson Service Co., 1146-1147 Kieley & Mueller. Inc., 1116 Leeds & Northrup Company, 1015 Mercoid Corporation, The, 1150 Minneapolis-Honeywell Regulator Co.. 1148-1149 Penn Electric Switch Co., 1151 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Spence Engineering Co., 1154 Sterling Engineering Co., 1121 Taylor Instrument Companies, 1018-1019 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-973 Warren Webster & Co., 1124-1127 Westinghouse Electric- & Manu facturing Co., 876 L. J. Wing Mfg. Co.. 988-989 Yarnell-Waring Co... 1129 Young Regulator Co., 935 THERMOMETERS, Distance Type Bristol Company, The, 1012 American Radiator Company, 884 885, 940-943, 1061 Barber-Colman Co., 1138-1139 Bell & Gossett Co., 1006-1007 Bristol Company, The, 1012 , Carrier Corporation, 853 Consolidated Ashcroft Hancock Co., Inc., 1013 Detroit Lubricator Co., 1140-1141 Julien P. Friez & Sons, Inc., 1144 Fulton Sylphon Co., 1142-1143 General Controls, 1145 General Electric Company, 902 903, 1058-1059 Gilbert & Barker Mfg. Co.. 904-906 Illinois Engineering Co., 1114-1115 Johnson Service Co., 1146-1147 Mercoid Corporation, The, 1150 Minneapolis-Honeywell Regulator Co., 1148-1149 Penn Electric Switch Co.. 1151 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 H. A. Thrush & Co., 1010-1011 TOWERS, Cooling (See Cooling Towers) TRAPS, Bucket Sterling Engineering Co., 1121 Trane Company, The, 872-873 Warren Webster & Co., 1124-1127 Wright-Austin Co., 1128 TRAPS, Radiator Armstrong Machine Works, 1102 1103 . Barnes & Jones, Incorporated, 1106 C. A. Dunham Co., 1108-1109 William S. Haines & Co.. 1111 Hoffman Specialty Co., Inc., 1112 1113 Illinois Engineering Co., 1114-1115 Milwaukee Valve Co., 1118-1119- Sarco Company, Inc., 1122-1123 Sterling Engineering Co., 1121 Trane Company, The, 872-873 Warren Webster & Co., 1124-1127 TRAPS, Return Barnes & Jones, Incorporated, 1106 Crane Co.. 946-947 C. A. Dunham Co., 1108-1109 William S. Haines & Co., 1111 . Hoffman Specialty Co., Inc., 1112-1113 Illinois Engineering Co., 1114-1115 Kieley & Mueller, Inc., 1116 Consolidated Ashcroft Hancock Armstrong Machine Works, 1102 Milwaukee Valve Co., 1118-1119 Co., Inc., 1013 1103 Mueller Steam Specialty Co., Inc., Julien P. Friez & Sons, Inc., 1144 Cochrane Corp., 1107 1120 Illinois Testing Laboratories, Inc., Crane Co., 946-947 1014 . . C. A. Dunham Co., 1108-1109 Sarco Company, Inc., 1122-1123 Sterling Engineering Co., 1121 Johnson Service Co., 1146-1147 Illinois Engineering Co., 1114-1115 Trane Company,-The, 872-873 Leeds & Northrup Company, 1015 Kieley & Mueller; Inc., 1116 Warren Webster & Co., 1124^1127 . Minneapolis-Honeywell Regulator Mueller Steam Specialty Co., Inc., Co.. 1148-1149 Liquidometer Corp., 1016 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Taylor Instrument Companies, 1018-1019 United States Gauge Co., 1020 1120 TRAPS, Steam ' Sarco Company. Inc., 1122-1123 Trane Company, The, 872-873 Wright-Austin Co., 1128 American District Steam Company, 975, 1052 Armstrong Machine Works, 1102 TRAPS, Float ' 1103 Barnes & Jones, Incorporated, 1106 American District Steam Co., Cochrane Corp., 1107 , THERMOMETERS, Indicating 975, 1052 . Armstrong Machine Works, 1102 Crane Co., 946-947 Grinnell Co.. Inc., 1000-1002, 1110 Bell and Gossett Co., 1006-1007 , 1103 William S. Haines & Co., 1111 ' Bristol Company, The, 1012 Barnes & Jones, Incorporated, 1106 .Hoffman Specialty Co., Inc., Consolidated Ashcroft Hancock Crane Co.. 946-947 . . 1112-1113 ` Co.. Inc., 1013 C. A. Dunham Co., 1108^-1109 Julien P. Friez & Sons, Inc., 1144 Williams S. Haines & Co., 1111 Illinois Engineering Co., 1114-1115 Kieley & Mueller, Inc., 1116 Illinois Testing Laboratories, Inc., Arthur Harris & Co., 1066 Milwaukee Valve Co., 1118-1119 1014 .Hoffman Specialty Co., Inc., Mueller Steam Specialty Co., Inc., Johnson Service Co., 1146-1147 1112-1113 - 1120 Leeds & Northrup Company, 1015 Illinois Engineering Co., 1114-1115 -Powers Regulator Co., 1152-1153 Liquidometer Corp., 1016 Kieley & Mueller, Inc., 1116 ` Sarco Company, Inc., 1122-1123 .Martocello, Jos. A &.Co., 866 . Milwaukee Valve Co., 1118-1119 Sterling Engineering Co., 1121 Please mentio:n THE GUIDE 1938 when writing to Advertisers Index to Modern Equipment Trane Company, The, 872-873 TURBINES VALVES, Automatic - . Warren Webster & Co., 1124-1127 Wright-Austin Co., 1128 Yarnall-Waring Co., 1129 Coppus Engineering Corp., 928 B. F. Sturtevant Co., 985 Westinghouse Electric & Manu Alco Valve Co., Inc., 1155American Radiator Company, 884 885, 940-943. 1061 facturing Co., 876 Anderson Products, Inc., 1156-1157 TRAPS, Thermostatic L. J. Wing Mfg. Co., 988-989 Baker Ice Machine Co., 854-855 Barnes & Jones, Incorporated, 1106 C. A. Dunham Co., 1108-1109 Grinnell Co.. Inc., 1000-1002,1110 William S. Haines & Co., 1111 Hoffman Specialty Co., Inc., 1112-1113 Illinois Engineering Co., 1114-1115 Milwaukee Valve Co., 1118-1119 Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Trane Company, The, 872-873 Warren Webster & Co., 1124-1127 UNDERGROUND PIPE CON DUITS (See Conduits, Under ground Pipe) . UNIT HEATERS (See Heaters, Unit) UNIT VENTILATORS (See Ven tilators, Unit) UNITS, Air Conditioning, (See Air Conditioning Units) Barber-Colman Co., 1138-1139 Beaton & Cadwell Mfg. Company, 1104-1105 Bell & Gossett Co., 1006-1007 Bristol Company, The, 1012 Consolidated Ashcroft Hancock Co., Inc- 1013 Detroit Lubricator Co., 1140-1141 Frick Company (Incorporated), 861 Julien P. Friez & Sons, Inc., 1144 Fulton Sylphon Co- 1142-1143 General Controls, 1145 Kieley & Mueller, Inc- 1116 - ^ TRAPS, Vacuum V-BELT DRIVES Minneapolis-Honeywell Regulator Co- 1148-1149 ,, Armstrong Machine Works, 1102 1103 Barnes & Jones, Incorporated. 1106 C. A. Dunham Co., 1108-1109 William S. Haines & Co., 1111 Hoffman Specialty Co., Inc., 1112-1113 American Coolair Corp., 978-979 Binks Manufacturing Co., 972-973 Frick Company (Incorporated), 861 Worthington Pump & Machinery Co., 856-857 VACUUM HEATING SYSTEMS New York Air Valve Corp- 1160 Powers Regulator Co., 1152-1153 Sarco Company, Inc- 1122-1123 Spence Engineering Co- 1154 Sterling Engineering Co- 1121 ' H. A. Thrush & Co- 1010-1011 Trane Company, The, 872-873 Illinois Engineering Co., 1114-1115 (See Heating Systems, Vacuum) Kieley & Mueller, Inc., 1116 Milwaukee Valve Co., 1118-1119 VALVES, Air VALVES, Back Pressure Baker Ice Machine Co!, 854-855 Mueller Steam Specialty Co., Inc., American Radiator Company, 884 Cochrane Corp- 1107 ' ' 1120 885, 940-943. 1061 Crane Co- 946-947 Sarco Co., Inc., 1122-1123 Anderson Products, Inc., 1156-1157 Fedders Manufacturing Co- 991 Trane Company, The, 872-873 Beaton & Cadwell Mfg..Company, Illinois Engineering Co- 1114-1115 Warren Webster & Co., 1124-1127 1104-1105 Jenkins Bros- 1159 Wright-Austin Co., 1128 Bell & Gossett Co., 1006-1007 Kieley & Mueller, Inc., 1116 Binks Manufacturing Co., 972-973 Mueller Steam Specialty Co- 1120 TUBES, Boiler Bristol Company, The, 1012 Spence Engineering Co- 1154 Babcock & Wilcox Co., 954 Bethlehem Steel Co., 1099 Burnham Boiler Corp., 944-945 Taylor Instrument Companies, Carbondale Div., Worthington 1018-1019 Pump & Machinery Co., 856-857 Warren Webster & Co., 1124^1127 Carnegie-Illinois Steel Corp., 1100 Consolidated Ashcroft Hancock York Ice Machinery Corp- 877 . Jones & Laughlin Steel Corp., 1070 Co., Inc., 1013 Republic Steel Corporation, 1071 Curtis Refrigerating Machine Com VALVES, Balanced . TUBES, Pitot (See Air Measuring and Recording Instruments) pany, Division of Curtis Manu facturing Company, 859 ' . Detroit Lubricator Co., 1140-1141 Consolidated Ashcroft Co- Inc- 1013 Crane Co- 946-947 Hancock TUBING, Brass * American Brass Co., 1062-1063 Mueller Brass Co., 1064-1065 Dole Valve Company, 1158 C. A. Dunham Co., 1108-1109 Gilbert & Barker Mfg. Co., 904-905 Hoffman Specialty Co., Inc., Illinois Engineering Co- 1114-1115 Jenkins Bros- 1159 Kieley & Mueller, Inc- 1116 Mueller Steam Specialty Co., 1120 1112-1113 . ' Revere Copper and Brass, Incor- porated, 1067 Streamline Pipe and Fittings Co., 1064-1065 " V/ . TUBING, Copper American Brass Co., 1062-1063 ` American Radiator Company, 884 Jenkins Bros., 1159 Kieley & Mueller, Inc., 1116 Milwaukee Valve Co., 1118-1119 New York Air Valve Corp., 1116 Spence Engineering Co., 1154 Sterling Engineering Co., 1121 Trane Company, The, 872-873 Wright-Austin Co., 1128 VALVES, Blow-off . Cochrane Corp- 1107 Consolidated Ashcroft Hancock Co- Inc- 1013 Crane Co- 946-947 Detroit Lubricator Co- 1140-1141 Jenkins Bros- 1159 Kieley & Mueller, Inc- 1116 . , 885, 940-943, 1061 ' Mueller Brass Co., 1064-1065 Revere Copper and Brass, Incor porated, 1067 Streamline Pipe and Fittings Co., 1064-1065 TUBING, Flexible Metallic (See ' also Conduit, flexible; Hose, flexible) American Brass Co., 1062-1063 VALVES, Angle, Globe and Cross American Brass Co., 1062-1063 American Radiator Company, 884 885, 940-943, 1061. Baker Ice Machine Co., 854-855 Burnham Boiler Corp., 944-945 Carbondale Div., Worthington Pump & Machinery Co., 856-857 Consolidated Ashcroft Hancock Co.,- Inc., 1012 , Yarnall-Waring Co- 1129 VALVES, By-pass . Beaton & Cadwell Mfg. Co- 1104 1105 Consolidated Ashcroft Hancock. Co- Inc- 1013 Crane Co- 946-947 Jenkins Bros- 1159 .,, Johnson Service Co- 1146-1147 ' Kieley 8t:Mueller, Inc-1116 . . . Bethlehem Steel Co., 1099 Caraegie-Illinois Steel Corp., 1100 Crane Co., 946-947 . Detroit Lubricator Co., 1140-1141 VALVES, Check Chicago Metal Hose Co., 1068 Frick Company (Incorporated), 861 Cochrane Corp- 1107 ' ' ; . Titeflex Meta! Hose Co., 1069 Grinnell Co., Inc., 1000-1002, 1110 Consolidated Ashcroft . Hancock Jenkins Bros., 1159 ` Co., Inc- 1013 ' TUBING, Steel Milwaukee Valve Co., 1118-1119 Crane Co- 946-947 . Mueller Brass Co., 1064-1065 Fedders Manufacturing Co., 991 Babcock & Wilcox Co., 954 Streamline Pipe & Fittings Co., Frick Company (Tneorporated), 861 Jones & Laughlin Steel Corp., 1070 1064-1065 Gilbert & Barker Mfg- Co- 904-906 ' .Republic Steel Corporation, 1071 York Ice Machinery Corp., 877 Grinnell Co- Inc- 1000-1002, 1110 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section; - 1185 Heating Ventilating Air Conditioning Guide 1938 Illinois Engineering Co., 1114-1115 VALVES, Gate VALVES, Radiator, Electric Jenkins Bros., 1159 . Milwaukee Valve Co., 1118-1119 Taco Heaters, Inc., 1008-1009 Warren Webster & Co;, 1124-1147 York Ice Machinery Corp., 877 American Brass Co., 1062-1063 American Radiator Company, 884 885, 940-943, 1061 Consolidated Ashcroft Hancock Co., Inc., 1013 Motor Operated Barber-Colman Co., 1138-1139 Bristol Company, The, 1012 Julien P. Friez & Sons, Inc., 1144 Fulton Sylphon Co., 1142-1143 VALVES, Diaphragm Alco Valve Co., Inc., 1155 Consolidated Ashcroft Hancock Co.. Inc., 1013 Illinois Engineering Co., 1114-1115 Johnson Service Co., 1146-1147 Kieley & Mueller, Inc., 1116 Minneapolis-Honeywell Regulator Co., 1148-1149 Powers Regulator Co., 1152-1153 Taylor Instrument Companies, 1018-1019 Crane Co., 946-947 Detroit Lubricator Co., 1140-1141 Grinnell Co., Inc., 1000-1002, 1110 Jenkins Bros., 1159 Milwaukee Valve Co.,-1118-1119 VALVES, Hydraulic Consolidated Ashcroft Hancock Co.. Inc., 1013 Crane Co., 946-947 . Jenkins Bros., 1159 .. Yamall-Waring Co., 1129 General Controls, 1145 General Electric Company, 902 903, 1058-1059 Jenkins Bros., 1159 ` Minneapolis-Honeywell Regulator Co., 1148-1149 Sarco Company, Inc., 1122-1123 VALVES, Radiator Orifice American District Steam Company. 975, 1052 American Radiator Company, 884 H. A. Thrush & Co., 1010-1011 VALVES, Expansion . Alco Valve Co., Inc., 1155 Crane Co., 946-947 Delco-Frigidaire Conditioning Di vision, General Motors Sales Corporation, 890-892 Detroit Lubricator Co.,' 1140-1141 Fedders Manufacturing Co., 991 Frick Company (Incorporated), 861 Fulton Sylphon Co., 1142-1143 General Refrigeration Corp., 864 York Ice Machinery Corp], 877 VALVES. Float VALVES, Magnetic Alco Valve Co., Inc., 1155 Barber-Colman Co., 1138-1139 Detroit Lubricator Co., 1140-1141 Frick Company, 861 Julien P. Friez & Sons, 1144 General Controls, 1145 General Electric Company, 902 903, 1058-1059 Minneapolis-Honeywell Regulator Co., 1148-1149 Penn Electric Switch Co., 1151 VALVES, Mixing, Thermostatic Barber-Colman Co., 1138-1139 Fulton Sylphon Co., 1142-1143 885, 940-943, 1061 Barnes & Jones, Incorporated, 1106 Bell and Gossett Co., 1006-1007 Detroit Lubricator Co., 1140-1141 C. A. Dunham Co.. 1108-1109 Grinnell Co., Inc- 1000-1002, 1110 William S. Haines & Co., 1111 Hoffman Specialty Co., Inc- 1112-1113 Illinois Engineering Co- 1114-1115 Milwaukee Valve Co., 1118-1119 New York Air Valve Corp., 1160 Sarco Company, Inc., 1122-1123 . Sterling Engineering Co., 1121 Trane Company, The, 872-873 . Warren Webster & Co- 1124-1127 Alco Valve Co., Inc., 1155 Anderson Products, Inc., 1156-1157 'Baker Ice Machine Co., 854-855 Cochrane Corp., 1107 Johnson Service Co., 1146-1147 Powers Regulator Co., 1152-1153 'Sarco Company, Inc.,-1122-1123 Taco Heaters Inc., 1008-1009 . Crane Co.. 946-947 Detroit Lubricator Co., 1140-1141 Dole Valve Company, 1158 .-C.-A. Dunham Co., 1108-1109 VALVES, Non-Return American Brass .Co., 1062-1063 Consolidated Ashcroft Hancock Fedders Manufacturing Co., 991 Frick Company (Incorporated), 861 Co.. Inc., 1013 Crane Co., 946-947 ' General _ Electric Company, 902 903, 1058-1059 Arthur Harris & Co.. 1066 Fedders Manufacturing Co., 991 Frick Company, 861 Illinois Engineering Co., 1114-1115* VALVES, Radiator, Pneumatic Diaphragm - Bell and Gossett Co., 1006-1007 Bristol Company, The, 1012 . Johnson Service Co., 1146-1147 Minneapolis-Honeywell Regulator Co- 1148-1149 Powers Regulator Co., 1152-1153 . Taylor Instrument' Companies, 1018-1019 VALVES, Relief Illinois Engineering Co., 1114-1115 Jenkins Bros., 1159 - American Radiator Company, 884 Kieley & Mueller, Inc., 1116 - Kieley & Mueller, Inc., 1116 885, 940-943, 1061 McDonnell & Miller. 938-939 Mueller Steam Specialty Co., VALVES, Pressure Baker Ice Machine Co- 854-855 . Reducing Beaton & Cadwell Mfg. Company, 1120 {See Regulators, Pressure) 1104-1105 Spence Engineering Co., 1154 Sterling Engineering Co., 1121 VALVES, Pump Bell and Gossett Co- 1006-1007 Cochrane Corp- 1107 Trane Company, The. 872-873 ;York Ice Machinery Corp., 877 Crane Co., 946-947 ' Consolidated Ashcroft Hancock Jenkins Bros., 1159 Co- Inc- 1013 Trane Company, The, 872-873 Crane Co., 946-947 VALVES, Flow Control Frick Company (Incorporated), 861 - Bell & Gossett Co.. 1006-1007 VALVES, Radiator Bristol Company, The, 1012 American District Steam Co.', Consolidated Ashcroft Hancock 975, 1052 \ Co.. Inc., 1013 American Radiator Company, 884 Frick Company, 861 885, 940-943. 1061 General Controls, 1145 Barnes & Jones, Incorporated. 1106 General Electric Company, 902- Bell and Gossett Co., 1006-1007 . 903, 1058-1059 Burnham Boiler Corp., 944-945 . .Illinois Engineering Co., 1114-1115 Crane Co., 946-947 ' Johnson Service Co., 1146-1147 Detroit Lubricator Co., 1140-1141 Kieley & Mueller, Inc., 1116' C. A. Dunham Co., 1108-1109 Minneapolis-Honeywell Regulator Fulton Sylphon Co., 1142-1143 Illinois Engineering Co- 1114-1115 Kieley & Mueller, Inc- 1116 J. E. Lonergan Co., 1117 . Milwaukee Valve Co- 1118-1119 Mueller Brass Co- 1064-1065 Mueller Steam Specialty Co., Inc- 1120 New York Air Valve Corp- 1160 Taco Heaters Inc- 1008-1009 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 York Ice Machinery Corp., 877 Co., 1148-1149 Mueller Steam Specialty Co., Inc., Grinnell Co.. Inc., 1000-1002, 1110 William S. Haines & Co., 1111 VALVES, Safety 1120 Hoffman Specialty Co., Inc., American Radiator Company, 884 Powers Regulator Co., 1152-1153 1112-1113 885, 940-943, 1061 Preferred Utilities Corp., 970 Illinois Engineering Co., 1114-1115 Baker.Ice Machine Co., 854-855 Spence Engineering Co.. 1154 _ Jenkins Bros., 1159 . Beaton & Cadwell Mfg. Company, Sterling Engineering Co.. 1122 Milwaukee Valve Co., 1118-1119 1104-1105 . ... Taco Heaters Inc., 1008-1009 New York Air Valve Corp., 1160 Consolidated Ashcroft Hancock Taylor "'Instrument Companies, Sarco Company, Inc., 1122-1123 - Co- Inc- 1013 1018-1019 Sterling Engineering Co., 1121 Crane Co.. 946-947 H. A. Thrush & Co., 1010-1011 Trane Company, The, 872-873 Detroit Lubricator Co., 1140-1141. Warren Webster & Co., 1124-1127 Warren Webster & Co., .1124-1127 Frick Company (Incorporated), 861. Please mention THE GUIDE 1938 when writing to Advertisers' . 1186 Index to Modern Equipment General Controls. 1145 ' VENTILATORS, Attic (See also B. F. Sturtevant Co- 985 Jenkins Bros- 1159 - Fans, Electric, Propeller and Ex Trane Company, The, 872-873 J. E. Lonergan Co., 1117 haust) . - L. J. Wing Mfg. Co., 988-989 . New York Air Valve Corp., 1160 Spence Engineering Co- 1154 ' H. A. Thrush & Co., 1010-1011 VALVES, Solenoid Alco Valve Co- Inc., 1155 Anderson Products, Inc., 1156 Barber-Colman Co- 1138-1139 Detroit Lubricator Co., 1140-1141 Frick Company (Incorporated), 861 Julien P. Friez & Sons, Inc- 1144 General Controls, 1145 General Electric Company, 902 Air Controls. Inc- 878 American Blower Corp., 850-851 American Coolair Corp- 978-979 Autovent Fan & Blower Co- 977 Barber-Colman Co., 1138-1139 Binks Manufacturing Co., 972-973 Buffalo Forge Co- 981 Champion Blower & Forge Co- 982 Clarage Fan Co- 858 Coppus Engineering Co., 928 DeBothezat Division, American Machine and Metals, Inc., 983 Delco-Frigidaire Conditioning Div., Young Radiator Company, 995 VENTILATORS, Window American Air Filter Co., 926-927 American Coolair Corp- 978-979 Autovent Fan & Blower Co., 977 Buffalo Forge Company, 981 Coppus Engineering'Corp., 928 Ilg Electric Ventilating Co., 984 H. J. Somers, Inc., 931 Staynew Filter Corp- 932-933 B. F. Sturtevant Co- 985 Universal Air Filter Corp.,' 934 . 903, 1058-1059 Minneapolis-Honeywell Co- 1148-1149 Regulator General Motors Sales Corp- 890-892 - Gar Wood Industries, Inc., 900-901 VIBRATION, Absorbers {See also Sound Deadening) ' Penn Electric Switch Co- 1151 General Electric Co., 902-903, American Brass Co., 1062-1063 Spence Engineering Co- 1154 1058-1059 Chicago Metal Hose Corp., 1068 Fulton Sylphon Co- 1142-1143 Ilg Electric Ventilating Co., 984 Titeflex Metal Hose Co- 1069 Trane Company, The, 872-873 VALVES, Stop and Check {See Lau Blower Company, 879 Schwitzer-Cummins Co., 880, 1136 B. F. Sturtevant Co- 985 WARM AIR FURNACES Furnaces, Warm Air) {See Valves, Non-Return) VALVES, Thermostatic Alco Valve Co., Inc., .1155 American Radiator Company, 884 885, 940-943, 1061 Barber-Colman Co- 1138-1139 Beaton & Cadwell Mfg. Co., The. 1104-1105 Consolidated Ashcroft -Hancock Co., Inc- 1013 Detroit Lubricator Co- 1140-1141 Torrington Mfg. Co- 986-987 United States Radiator Corp- 950-951 Westinghouse Electric & Manu facturing Co- 876 L. J. Wing Manufacturing Co- 988-989 VENTILATORS, Floor and Wall American Blower Corp- 850-851 American Coolair Corp- 978-979 Anemostat Corp. of American, 1088 WARM AIR HEATING SYS TEMS {See Healing Systems, Furnace) ' WATER TREATMENT . American Blower Corp- 850-851 Aquatic Chemical Laboratories, Inc- 1161 Oakite Products, Inc- 1162 Cochrane Corp., 1107 Vinco Company, Inc- 936-937 C. A. Dunham Co., 1108-1109 Fedders Manufacturing Co., 991 Julien P. Friez & Sons, 1144 Fulton Sylphon Co., 1142-1143 Auer Register Co., The. 1089 Barber-Colman Co., 1138-1139 WATER COOLING, (See also Coppus Engineering Corp., 928 Hart & Cooley Manufacturing Co- Cooling Equipment, Water; Cool ing Termers) General Controls, 1145 1090-1091 Airtemp, Inc- 882-883 General Electric Company, 902 Independent Register Co- 1094 Baker Ice Machine Co., 854-855 903. 1058-1059 L. J. Mueller Furnace Co- 918-919 Binks Manufacturing Co., 972-973 Grinnell Co., Inc- 1000-1002, 1110 B. F. Sturtevant & Co- 985 Carbondale Div., Worthington ' Illinois Engineering Co., 1114-1115 Tuttle & Bailey, Inc., 1092-1093 Pump & Machinery Corp- 856 Johnson Service Co- 1146-1147 United States Register Co- 1095 857 Minneapolis-Honeywell Regulator Waterloo Register Co., 1096 Carrier Corporation, 853 Co., 1148-1149 Young Regulator Company, 935 Cooling Tower Co., Inc., 971 New York Air Valve Corp- 1160 Curtis Refrigerating Machine Com Perm Electric Switch Co., 1151 VENTILATORS, Mushroom pany, Division of Curtis Manu Powers Regulator Co., 1152-1153 Sarco Company, Inc., 1122-1123 Spence Engineering Co- 1154 . Sterling Engineering Co- 1121 Taylor Instrument Companies, American Blower Corp- 850-851 Clarage Fan Company, 858 L. J. Mueller Furnace Co., 918-919 Tuttle & Bailey, Inc., 1092-1093 facturing Company; 859 Delco-Frigidaire Conditioning Di vision, General Motors Sales, Corporation, 890-892 Fedders Manufacturing Co- 991' 1018-1019 Trane Company, The, 872-873 Warren Webster & Co- 1124-1127 Yarnall-Waring Co- 1129 VENTILATORS, Roof Air Controls, Inc., 878 '' Airtherm Manufacturing Co., 990 American Coolair Corp- 978-979 Frick Company (Incorporated), 861 General Refrigeration Corp., 864 Ingersoll-Rand Company. 862-863 Kelvinator Div. of Nash-Kelvin- ator Corp., 907-911 VALVES, Water Regulating Autovent Fan & Blower Co., 977 Butler Mfg. Co- 1131 Beaton & Cadwell Mfg. Company, De Bothezat Division American The, 1104-1105 Machine and Metals, Inc- 983 Bell and Gossett Co., 1006-1007 General Electric Company, 902 Binks Manufacturing Co- 972-973 903, 1058-1059 Consolidated Ashcroft Hancock Ilg Electric Ventilating Co., 984 Co- Inc- 1013 Johns-Manville, 1042-1043 Crane Co- 946-947 . Merchant & Evans Co- 867 Marley Co- Inc- 974 Servel, Inc- 871 . Universal Cooler Corp- 874 Vilter Manufacturing Co., 875 . York Ice Machinery Corp., 877 . WATER COOLING TOWERS (See Cooling Towers, Water) Detroit Lubricator Co.,-1140-1141 .Fulton Sylphon Co., 1142-1143 B. F. Sturtevant Co., 985 Gilbert & Barker Mfg. Co- 904-906 VENTILATORS, Unit WATER FEEDERS (See Feeders, Water) Johnson Service Co., 1146-1147 Kieley &'Mueller, Inc- 1116 Mueller Steam Specialty Co., 1120 American Blower Corp., 850-851 American Coolair Corp., 978-979 _ Penn -Electric Switch Co., 1151 Powers Regulator Co., 1152^1153 Preferred Utilities Corp- 970 H. A. Thrush & Co., 1010-1011 . York Ice Machinery Corp., 877 ^ Autovent Fan & Blower Co., 977 " Buffalo Forge Company, 981 Electrol, Inc- 898-899, 967 Ilg Electric Ventilating Co., 984 Herman Nelson Corp- 1004-1005 John J. Nesbitt, Inc.. 1003 WATER HEATERS (See Heaters, Hot Water Service) WEATHER INSTRUMENTS, Indicating and Recording Bristol Company, The. 1012 . ' Consolidated Ashcroft Hancock Co- Inc., 1013 VAPOR HEATING SYSTEMS Staynew Filter Corp- 932-933 Julien P. Friez & Sons. Inc- 1144 . (See Heating Systems, Vapor) . Schwitzer-Cummins Co., 880, 1136 Johnson Service Co- 1146-1147 . Numerals following Manufacturers' Names refer to pages in the Catalog Data Section Heating Ventilating Air Conditioning Guide 1938 Leeda & Northrup Company, 1015 Minneapolis-Honeywell Regulator Co., 1148-1149 Palmer Company, The, 1017 Powers Regulator Co., 1152-1153 Taylor Instrument Companies, 1018-1019 WEATHERSTRIPS, Metal Chamberlin Metal Weather Strip Co., 1032-1033 WELDING FITTINGS (See Fittings, Welding) WELDING ROD American Brass Co., 1062-1063 Camegie-Illinois Steel Corp., 1100 Mueller Brass Co., 1064-1065 Republic Steel Corporation, 1071 Revere Copper and Brass Incor porated, 1067 - Wickwire Spencer Steel Co., 1097 WHEELS, Blower Air Controls, Inc, 878 American Blower Corp., 850-851 Autovent Fan & Blower Co., 977 Bayley Blower Company, 980 . Buffalo Forge Company, 981 Champion Blower & Forge Co., 982 Clarage Fan Company, 858 Henry Furnace & Foundry Co., 912-913 Lau Blower Co., 879 L. J. Mueller Furnace Co., 918-919 Niagara Blower Company,'868 Schwitzer-Cummins Co., 880, 1136 B. F. Sturtevant Co., 985 Torrington Mfg. Co., 986-987 WINDOWS, Supplementary Sash . Chamberlin Metal Weather Strip Co., 1032-1033 Please mention THE GUIDE 1938 when writing, to Advertisers Roll of Membership ofAmerican society Heating W ventilating Engineers 1938 Contains Lists of Members Arranged Alphabetically and Geographically, also Lists of Officers and Committees, Past Officers and Local Chapter Officers \ A Corrected to January 1, 1938 Published at the Headquarters of the Society . 51 Madison Avenue, New York, N. Y. . Officers and Council American Society of Heating and Ventilating Engineers 51 Madison Ave., New York, N. Y. 1937-38 President...................................................................................................-.............. --D. S. Boyden First Vice-President...................... ................. ..... ............................ ...................E. Holt Gurney Second Vice-President................ ........ .......... ...... ................................................... J. F. McIntire Treasurer..................J.....:................................................................................................A. J. Offner Secretary..... 1.......................... ....................... .......... .......................................... !.......... A. V. Hutchinson One Year Albert Buenger F. E. Giesecke G. L. Larson W. E. Stark Council D. S. Boyden,- Chairman E. Holt Gurney, Vice-Chairman Two Years . R. C. Bolsinger S. H. Downs W. L. Fleisher C. M. Humphreys " Three Years j J. J. Aeberly ; M. C. Beman : E. 0. Eastwood - ; W. A. Russell ;: Committees of the Council ; Executive: G. L. Larson, Chairman; M. C. Beman, F. E. Giesecke Finance: J. F. McIntire, Chairman; W. L. Fleisher, W. E. Stark Meetings: C. M. Humphreys, Chairman; J. J. Aeberly, S. H. Downs Membership: R. C. Bolsinger, Chairman; Albert Buenger, W. A. Russell : . Advisory Council : G. L. Larson, Chairman; Homer Addams, R. P. Bolton, W. H. Carrier, S. E. Dibble, : W. H. Driscoll, H. P. Gant, John F. Hale, L. A. Harding, H. M. Hart, C. V. Haynes, ; E. Vernon Hill, J. D. Hoffman, John Howatt, W. T. Jones, D. D. Kimball, S. R. > Lewis, Thornton Lewis, J. I. Lyle, F. B. Rowley, F. R. Still and A. C. Willard. Cooperating Committees A.S.H.V.E. Representative" on National Research Council: J. H. Walker (one year). A.S.H.V.E. Representative on A. S. A. Sectional Committee' on Standardization of a Scheme for Identification of Piping Systems (A-1S): E. E. Ashley. 2 Special Committees . Committee on Admission and Advancement: E. J. Ritchie, Chairman (one year); T. H. Urdahl (two years), and M. F. Blankin (three years). Publication Committee: A. I. Brown, Chairman (one year); F. C. McIntosh (two years), and W. M. Sawdon (three years). Guide Publication Committee: Albert Buenger, Chairman; S. H. Downs, C. H. B. Hotchkiss, S. S. Sanford, W. H. Severns, and E. N. McDonnell, Advisory. Committee on Constitution and By-Laws: R. H. Carpenter, Chairman; W. T. Jones, and . O. W. Ott. F. Paul Anderson Award Committee: E. Holt Gurney, Chairman; E. O. Eastwood, John Howatt, G. L. Larson, and F. C. McIntosh. Committee on A.S.H.V.E. Code for Testing Stoker Fired Heating Boilers: C. E. Bronson, Chairman; L. A. Harding, H. M. Hart, F. C. Houghten, A. J. Johnson, J. F. Mc Intire, D. W. Nelson, Percy Nicholls, R. A. Sherman, and E. C. Webb. A .S.H. V.E.-A .S.R.E. Committee on National Standards for Air Conditioning Applica tions: L. A. Harding, Chairman; Glenn Muffly, Vice-Chairman; W. L. Fleisher, D. E. French, John Howatt, A. P. Kratz, H. J. Macintire, L. A. Philipp, C. W. Walton, Jr., and W. E. Zieber. " Chapter . Cincinnati Cleveland _ Illinois Kansas City Manitoba Massachusetts Michigan Western Michigan Minnesota Montreal New York Western New York Oklahoma City Ontario Pacific Northwest Philadelphia. Pittsburgh . St. Louis Southern California . Texas ' % Washington, D. C. Wisconsin COMMITTEES--1937 Nominating Committee for 1937 " ,' Representative H. E. Sproull G. L. Tuve . . J. J. Hayes L. R. Chase J. B. Steele James Holt R. K. Milward L. G. Miller N. D. Adams G. L. WlGGS G. E. Olsen P. S. Hedley F. X. Loeffler J. W. O'Neill S. D. Peterson H. H. Erickson M. L. Carr P. W. Sodemann H. M. Hendrickson R. K. Werner M. D. Kiczales Ernest Szekely Alternate C. E. Hust W. R. Beach C. E. Price A. H. Sluss William Glass W. T. Jones G H. Tuttle R. E. Backstrom L. H. Laffoley E. J. Ritchie B. C. Candee E. W. Gray H. R. Roth W. W. Cox M. F. Blankin J. F. Collins, Jr. L. W. Mooii E. H. Kendall W. E. Long T. H. Urdahl C. H. Randolph Committee on Research W. A. Danielson, Chairman . W. L. Fleisher, Vice-Chairman ' F. C. Houghten, Director Dr. A. C. Willard, Technical Adviser ' A. C. Fieldner, Ex-Officio Member One Year C. A. Dunham. W. L. Fleisher Elliott Harrington A. P. Kratz H. C. Murphy Two Years W. A. Danielson C. E. Lewis D. W. Nelson C. Tasker C.-E. A. Winslow Three Years H. E. Adams A. E. Stacey G. L. Tuve J. H. Van Alsburg J. H. Walker . Executive Committee ; . W. A. Danielson, Chairman . W. L. Fleisher J. H. Walker . Technical Advisory Committees, 1937-1938 Committee on Air Cleaning--IP-4: H. C. Murphy,* Chairman; M. I. Dorfan, C. E; Lewis,* S. R. Lewis, G. W. Penney, A. L. Simison, W. O. Vedder. Committee on Air Conditioning Requirements of Glass--IF.-18: M. L. Carr, Chairman; F. L. Bishop, A. N. Finn, E. H. Hobbie, R. J. Lillibridge, R. A. Miller, F. W. Parkinson, W. C. Randall, L.-T. Sherwood, J. T. Staples, C. Tasker,* G. B. Watkins, F. C. Weinert. Committee on Air Distribution--IP-21: Ernest Szekply, Chairman; S. H. Downs, M. K. Fahnestock, F. J. Kurth, D. W. Nelson,* C. H. Randolph, J. E. Schoen, G. L. Tuve,* J. H. Van >Usburg.* . Committee on Air Friction--IP-6: J. H. Van Alsburg,* Chairman; C. A. Booth, .S. H. Downs, C. M. Humphreys, R. D. Madison, L. B. Miller, L. G. Miller. . Committee on Atmospheric Impurities and Resulting Safety and Health Requirements-- IP-26: Theodore Hatch, Chairman; J. J. Bloomfield, C. A. Booth, Philip Drinker, Dr. Leonard Greenburg, Elliott Harrington,* H. B. Meller. Committee on Climate and Air Conditioning--C-24: Dr. C. A. Mills, Chairman; Major G. C. Dunham, James Govan, Dr. W. J. McConnell, C. F. Neergaard, Dr. F; M. Pottenger, Jr., E. L. Weber, Prof. C.-E. A. Winslow.* Committee on Comfort Air Conditioning--OH-22: C. Tasker,* Chairman; A. E. Beals, F. R. Bichowsky, Thomas Chester, F. E. Giesecke, Elliott Harrington,* R. E.; Keyes, A. B. Newton, C. P. Yaglou. . Committee on Cooling Load in Summer Air Conditioning--IP-30: J. H. Walker,* Chair man; C. M. Ashley, John Everetts, Jr., F. H. Faust, H. F. Hutzel, L. S. Morse, A.. E. Stacey, Jr.,* and R. M. Strikeleather. ' '. Committee on Corrosion in Air Conditioning Equipment--IF-14: A. E. Stacey, Jr,,* Chairman; A. F. L. Anderson, M. L. Diver, F. L. LaQue, C. E. Lewis,* R. M. Palmer, F. N. Speller, C. M: Sterne, R. T. Thornton, J. H. Young. Committee on Corrosion in Steam Systems^IF-2: A. R. Mumford, Chairman; J..F. Barkley, C. A. Dunham,* T. J. Finnegan, R. R. Seeber, F. N. Speller, G. M. Sterne: Committee on Effect of Water on Roofs--IF-29: A. B. Snavely, Chairman; M. R. Beasley,. J: B. Griffiths, Elliott Harrington,* E. H. Hyde, W. L. Murray, E. R. Queer, C. S. Reeve,: E. T. Selig, Jr. Committee on General Air Conditioning Comfort Requirements--OH-5: C. P. Yaglou, Chairman; J. J. Aeberly, R. R. Sayers, C.-E. A. Winslow.*^ Committee on Heat Requirements of Buildings--IF-8: O. W. Armspach, Chairman; P. D. Close, W. H. Driscoll, H. M. Hart, V. W.sHunter, H. H. Mather, E. C. Rack, F. B. Rowley, R. J. J. Tennant, J. H. Walker.* Committee on Heat Transfer of Finned Tubes with Forced Air Circulation--IP-10: F. B. Rowley, Chairman; H. F. Hutzel, R. H. Norris, C. H. Randolph, W. E. Stark, G. L. Tuve,* C. F. Wood. ' . Committee on Insulation--IF-23: L. A. Harding, Chairman;'E. A. Allcut,H. C. Bates, H. C. Dickinson, J. D. Edwards, E. C. Lloyd, W. E. McMullen, R. T. Miller, E. R. Queer, T. S. Rogers, F. B. Rowley, W. S. Steele, C. Tasker,* B. Townshend, G. B. Wilkes. . Committee on Intermittent Heating--IP-20: E. K. Campbell, Chairman; W. L. Cassell,. Prof. E. F. Dawson, N. W. Downes, F. E. Giesecke, J. M. Robertson, J. H. Kitchen, Prof. A. H. Sluss, G. L. Tuve.* . Member of Committee on Research. 4 Committee on Psychrdmetry--C~11: F. R. Bichowsky, Chairman; C. A. Bulkeley, J. A. Goff, Dr. E. V. Hill, F. G. Keyes, A. P. Kratz,* W. M. Sawdon. Committee on Radiation with Gravity Air Circulation--IP-9: M. K. Fahnestock, Chair man; B. C; Benson, H. F. Hutzel, J. P. Magos, J. W. McElgin, J. F. Mclntire, D. W. Nelson,* R. N. Trane, T. A. Novotney. . Committee on Relation of Body Changes to Air Changes--OH-3: Dr. E. V. Hill, Chairman; N. D. Adams, J, J. Aeberly, John Howatt, A. P. Kratz,* P. J. Marschall, V. L. Sherman. .. Committee on Sound Control--IF-1: J. S. Parkinson,' Chairman; C. M. Ashley, G. F. Drake, V. O. Knudsen, R. F. Norris, C. H. Randoplh, J. P. Reis, A. E. Stacey * G. T. Stanton, F. R.. Watson. Committee on Summer Air Conditioning for Residences--IP-7: M. K. Fahnestock, Chairman; E. A. Brandt, John Everetts, Jr., Elliott Harrington,* H. F. Hutzel, E. D. Milener, K. W. Miller, E. B. Newill, F. G. Sedgwick, J. H. Walker.* Committee on Transportation Air Conditioning--C-12: L. B. Miller Chairman; T. R. Crowder, F. B. Rowley, A. E. Stacey, Jr.,* L. W. Wallace. Committee on Treatment of Air with Electricity--C-17: Prof. C.-E. A. Winslow,* Chairman; R. D. Bennett, W. H. Carrier, L. W. Chubb, Major W. D. Fleming, R. F. James, L. R. Roller, Dr. C. A. Mills, Prof. E. B. Phelps, Prof. G. R. Wait, Prof. W.T. Wells. Committee on Weather Design Conditions--IF-31: W. E. Stark, Chairman; E. W. Good win, A. C. Grant, J. H; Kincer, A. P. Kratz,* L. S. Ourusoff. Member of Committee on Research. Officers of Local Chapters, 1937-38 Atlanta Headquarters, Atlanta. Ga. Meets: First Tuesday in Month i President, E. W. Klein 152 Nassau Street, N. W. . Secretary, C. T. Baker 713 Glenn Street, S..W_ / Cincinnati Headquarters, Cincinnati, Ohio Meets: Second Tuesday in Month President, I. B. Helburn 610 Chamber of Commerce Bldg.. Secretary, H. E. Sproull 1005 American Building Golden Gate Headquarters, Sah Francisco, Calif. Meets: First Tuesday in Month President, B. M. Woods University of California Berkeley, Calif. Secretary, G. J. Cummings 113 Tenth St., Oakland, Calif' Illinois Headquarters, Chicago, 111. Meets: Second Monday in Month President, S. I. Rottmaver 407 S. Dearborn Street Secretary, C. E. Price 6 N. Michigan Avenue ' . Iowa-Nebraska Headquarters, Omaha. Neb. President, M. J. Stevenson 1643 South 20th Street, Lincoln, Neb. Secretary, W. R. White 4339 Larimore Ave., Omaha. Neb: Kansas City Headquarters. Kansas City. Mo. Meets: Second Monday in Month President, A. H. Sluss 827 Mississippi Ave., Lawrence, Kan. Secretary, Gustav Nottberg 914 Campbell Street Manitoba Headquarters, Winnipeg, Man. Meets: Fourth Thursday in Month President, D. F, Michie 492 Wardlaw Avenue Secretary, E. J. Argue Ste. 23, Estelle Apts. Massachusetts Headquarters, Boston. Mass. Meets: Third Tuesday in Month President, James Holt Massachusetts Institute of Technology, . Cambridge, Mass. .- Secretary, H. C. Moore 69 Massachusetts Ave., Cambridge, Mass. Michigan . Headquarters. Detroit, Mich. Meets: First Monday after the 10th of the Month President, F. J. Feely , '' 950 Trombley Rd., Grosse Pointe Pk. Secretary, G. H. Tuttle 2000 Second Avenue . 5 .. . x Officers and List of Chapters, 1937-38--(Continued) Western Michigan Headquarters. Grand Rapids, Mich. Meets: Second Monday in Month President, W. W. Bradfield 901 Michigan Trust Bldg. Secretary, S. W. Todd, Jr. 309 Paris. S. E. . . Pacific Northwest Headquarters. Seattle, Wash. Meets: Second Tuesday in Month President, W. W. Cox 326 Columbia Street Secretary, M. N. Musgravb 314-9th Avenue, N. Minnesota Headquarters, Minneapolis, Minn. Meets: Second Monday in Month President, R. E. Backstrom Room 1981, First Natl. Bank Bldg. ' St. Paul. Minn, Secretary, F. C. Winterer 836 Juno St.. St. Paul; Minn. Philadelphia Headquarters, Philadelphia. Pa. Meets: Second Thursday in Month President. L. P. Hynes 240 Cherry Street Secretary, C. B. Eastman 530 Brookview Lane Brookline, Upper Darby, Pa. Montreal Headquarters, Montreal, Que. Meets: Third Monday in Month ' President, G. L. Wiggs - ' University Tower ' Secretary, C. W. Johnson 630 Dorchester St., W. . Pittsburgh Headquarters, Pittsburgh, Pa. Meets: Second Monday in Month President, M. L. Carr P. O. Box 1646 Secretary, T. F. Rockwell Carnegie Inst. Tech. New York Headquarters. New York, N. Meets: Third Monday in Month President, W. E. Heibel 11 West 42nd Street Secretary, T. W. Reynolds 100 Pinecrest Dr., Hastings-on-Hudson, N. Y. St. Louis ; Headquarters, St. Louis. Mo. Meets: First Tuesday in Month PresidentG. W. F. Myers 3947 W. Pine'Blvd. Secretary, D. J. FagiN 1344 Woodruff Avenue Western New York . Headquarters, Buffalo, N. Y. Meets: Second Monday in Month President. B. C. Candee 19 Tremont Ave., Kenmore, N. Y. Secretary, W. R. Heath 119 Wingate Ave. Northern Ohio Headquarters, Cleveland, Ohio Meets: Second Thursday in Month President, Philip Cohen 401 East Ohio Gas Bldg. .. Secretary, C. A. McKekman . Case School of Applied Science Oklahoma Headquarters,. Oklahoma City, Okla. Meets: Second Monday in Month President, E. F. Dawson ' University of Oklahoma, Norman, Okla. Secretary, E. W. Gray Box, 1498, Oklahoma City, Okla. Ontario Headquarters, Toronto, Ont. Meets: First Monday in Month President, G. A. Playfair 113 Simcoe Street Secretary, H. R. Roth 57 Bloor Street, W. ' . . Southern California Headquarters. Los Angeles, Calif. Meets: Second Tuesday in Month President, E. H. Kendall ` . 1978 S. Los Angeles Street Secretary, J. F. Park 1234 South Grand Texas i Headquarters. College Station, Texas President, R. F. Taylor 909 Banker's Mortgage Bldg.. Houston. Tex. Secretary, W. H. BaDCETT # Texas Engrg. Experiment Station, College Station, Tex. . , Washington, D. C. Headquarters, Washington. D. C.- Meets: Second Wednesday in Month President, L. Ourusoff ' 411 Tenth Street. N. W. Secretary. L. F. Nordine . Room 203, 734 Jackson Pl,, N. W. Wisconsin Headquarters, Milwaukee, Wis. Meets: Third Monday in Month President, J. H. Volk 1906 W. St. Paul Avenue Secretary, H. C. Frentzel 3000 W. Montana Street , 6 Roll of Membership American Society of Heating and Ventilating Engineers 1938 (Corrected to January 1, 1938) HONORARY MEMBERS VVM. J. (1915), New York, N. Y. (Deceased May 7, 1924.) J. S. (1896), New York, N. Y. (Deceased March 10, 1913.) BOLTON, REGINALD PELHAM (1897), New York, N. Y. '- BRECKENRIDGE, L. P. (1920), North Ferrisburg, Vt. . .. iOHN (charter Member), Norristown, Pa. (Deceased January 31, 1929.) NEWTON, C. W. (Charter Member), Baltimore, Md. (Deceased August 6, 1920.) HOOD, O. P. (1929), Washington, D. C. (Deceased April 22, 1937.) . JELLETT, STEWART A. (Charter Member), (Presidential Member), Philadelphia, Pa. (Deceased April 5, 1935.) . LIST OF MEMBERS Arranged Alphabetically (Asterisk indicates authorship of papers) ABRAMS, Abraham (Af 1927; J 1924), Pres Abbey Hearing Co., Inc., *81 Centre Ave., and . (for mail), TOO Clove Rd., New RocheJJe. N. Y. ACHESON, Albert R. (M 1919), Consulting Engr. (for mail), 501 Eckel Theatre Bldg., and 852 Ostrom Ave., Syracuse, N. Y. ADAMS) Benjamin (M 1919), Commercial Mgr. (for mail), American Blower Corp., Room 781 Broad Street Station Bldg., and 3006 W. Coulter St., Queen Lane Manor, Philadelphia, Pa. ADAMS, Benjamin C., Jr. (5 193G), Engrg. Student , (for mail), 724 Chautauqua, Norman, Okla., and 5127 Sunset Drive, Kansas City, Mo. ADAMS, Bruce P. (A 1936), Gen. Mgr. (for mail), McDonnell & Miller, 400 N. Michigan Ave., and 1432 Rascher Ave., Chicago, III. ADAMS, Charles W. (Af 1920), Salesman. U. S. Radiator Corp., 1221 West 11th St., Kansas City, Mo.. ADAMS, Harold E. (M 1930). Chief Engr. (for mail), Nash Engineering Co., Wilson Rd., South Norwalk and Merrill Heights, Norwalk, Conn. ADAMS. Neil D. (M 1929; A 1925; J 1922), Supt.. Franklin Heating Station (for mail), 220 Second Ave., S.W.,and 836 Eighth Ave., S.W., Rochester, Mmn. ADDAMS, Homer (Charter Member; Life Member) (Presidential Member), (Pres., 1924; 1st Vice- Pres., 1923; Treas., 1915*1922; Council, 1915^ 1925), Pres., Kewanee Boiler Co., Inc., and Fitzgibbons Boiler Co., Inc., 101 Park Ave.. New York, N. Y. ADLAM, T. Napier (Af 1932), Vice-Pres. and Gen. Mgr., Sarco Mfg. Co., 183 Madison Ave., New York, N. Y., and (for-mail), 64'Wellington Ave.. West Orange. N. J. ADLER, Alphonse A.* (Af 1921), Consulting Engr., 35 Stewart Ave., Arlington, N. J. ADLER, Jack C. (A 1937; J 1936), Sales Mgr., Air Cond. Dept., Frigidaire Corp., 224 West 57tb St., New York,.and (for mail), c/o B. W. Adler, 6952 Groton St.. Forest Hills, L. I.. N. Y. ADSHEAD, Bernard (J 1936), Tech.. Director, National Air Conditioning & Humidifying Co., Ltd., 46 Britannic Bldg., Manchester, and (for mail), 53 Shamrock Rd., Birkenhead, Cheshire, England. . AEBERLY, John J.* (M 1928). (Council, 1937), Chief of Div.' of Htg., Vtg. and Ind. Sanitation, Chicago Board of Health, 707 City Hall, and (for mail), 6225 N. Newcastle Ave., Norwood Park P. O., Chicago, 111. AHEARN, William J. (Af 1929), Htg. and Vtg. Engr., 21 Lake Rd., Cochituate, Mass. AHLBERG, Henry B. (A 1938; J 1933), Chief Engr., Anderson Products Co.: 17 Tudor St., . Cambridge, and (for mail), 146 Orlando St., Mattapan, Mass. AHLFF, Albert A. (Af 1923; A. 1918), Branch Mgr. (for mail). National Radiator Corp., 2124 Arch St., Philadelphia, and 43 Rock Glen Rd., Overbrook Hills, Philadelphia, Pa.' AIRMAN, Joseph M. (Af 1936), Consulting Air Cond. Engr., 2351 N. Cleveland Ave., Chicago, AITKEN, James (A 1935), 740 Gladstone Ave., Windsor, Ont., Canada. * ' . . * AKERMAN, Joseph Reid (J 1937), Htg. and Air Cond. Engr. (for mail), Phoenix Oil Co., 700 Twiggs St., and 831-15th St., Augusta, Ga. AKERS, George W. (Af 1929). Secy.-Treas., George W. Akers Co., 16525 Woodward' Ave.. Detroit, and (for mail), R. F. D. No. 2,Birming ham. Mich. - . ALBRECHT, Henry P..(/ 1937), Engr. (for mail). Reinhard Bros. Co.. Inc., 11 S. Ninth St., and 3521 Park Ave., Minneapolis, Minn. 7 Heating Ventilating Air Conditioning Guide 1938 ALEXANDER, Samuel W. (Af 1935), Mgr. Htg. Div., James Morrison Brass Co., 276 King St., S.W., and (for mail), 124 Kingsmount Park Rd., Toronto, Ont., Canada. ALFAGEME, Braulio (Af 1935), Engr., Mgr., B. Alfageme, Almagro I, Madrid, Spain. . ALFSEN, Nikolai (Af 1933), Civil Engr., Alfsen & Gunderson, A/S Oslo, Prinsensgate 2b, and (for mail), Shabekk near Oslo, Norway. ALGREN, Axel B.* (Af 1930), Asst. Prof. Mech. Engr., University of Minnesota, Exp. Engrg. Lab., and (for mail), 5109--17th Ave., S., Minne apolis, Minn. ALLAN, William (A 1937), Pres, and Treas. (for mail), Allan Engineering Co., 724 E. Mason St., and 2735 N. Farwell Ave., Milwaukee, Wis. ALLAIRE, Lucien (J 1937). Drainage Engr.. Department of Agnculture, Quebec City, and (for mail), 2182 Sherbrooke St., E.,. Montreal, Canada. * ALLGUT, Edgar A.* (if 1937), Prof, of Mech. Engrg. (for mail). University of Toronto, Dept, of Mech. EngTg., and 48 Foxbar Rd., Toronto, Ont., Canada. ALLEN, A. Walter (if 1936), Sales Engr., Pease Foundry Co., Ltd., Toronto, and (for mail), 151 Glen Ave., Ottawa, Ont., Canada.' ALLEN, Carl V. (if 1937), Engrg. Mgr., Midwest Air Conditioning Corp., 1909 Washington, and (for mail), 5562 Clemens, St. Louis, Mo.' ALLEN, DeWitt M. (if 1936; 7 1922), Dist. Mgr. (for mail), Ilg Electric Ventilating Co., 310 Board of Trade Bldg., and 5700 Olive St., Kansas City, Mo. ALLEN, William W. (A 1936), Pres, (for mail), American Coolair Corp., Box 2300, Jacksonville, and DaVinci St., Venetia, Fla. ALLONIER, Howard R. (A 1936), Dist. Mgr. (for mail). Buckeye Blower Co., Box 195 (425 W. Town St.), Columbus, and R. F. D. No. 1, Powell, Ohio. ALLSOP, Rowland P. (7 1934), Engr. (for mail), Mathers & Haldenby, Archts., 96 Bloor St., W., and 89 Neville Park Blvd., Toronto, Ont., Canada. ALT, Harold L.* (if 1913), 115-27-225th St., St. Albans, N. Y. AMES, Charles S. (7 1937), Sales Engr., BarberColman Co., Parker-Carpenter, Inc., 606 Mission St., and (for mail), 556 Judson Ave., San Fran cisco, Calif. AMMERMAN, Charles R. (M 1916), Consulting Engr. (for mail), 772 Century Bldg., and 3908 Guilford Ave., Indianapolis. Ind. . AMMERMAN, Andrew S., Jr. (7 1937), Sales Engr. (for mail). Aerofin Corp., Ill W. Wash ington St., Room 704, and 4737 N. Hermitage Ave., Chicago, 111. ANAYA, Marvin (if 1937), Mech. Designer and Draftsman, Bureau of Engineering, Room 367, San Francisco, Calif. ' ANDEREGG, R. H. (if 1920), Vice-Pres., The Trane Co., and (for mail), 420 N. Losey Blvd., LaCrosse, Wis. ANDERSON, Carroll S. (if 1920), Mgr. (for mail), American Blower Corp., 211 Architects Bldg., 816 W. Fifth St., Los Angeles, and 4267 Holly Knoll Drive, Hollywood, Calif. ANDERSON, David B. (7 1936; 5 1933), Engr., Wood Conversion Co., 1981 First National Bank Bldg., and (for mail), 1335 Grand Ave., Apt. 6., St. Paul, Minn. ANDERSON, George A. M. (7 1936), Secy, (for mail). King Ventilating Co., and 409 E. Main - St., Owatonna, Minn. ANDERSON, John W. (7 1937), Branch Engr. (for mail). Sidles Co., Airtemp.Div., 502 South 19th St., and 101 South 34th SL, Omaha, Nebr. ANDERSON, Sigurd H. (7 1936; 5 1935), Research Asst., Experimental Engrg. (for mail), University of Minnesota, 208 Exp. Eng. Bldg., and Veterans Adm. Facility, Bldg., No. 14, Minneapolis, Minn. ' ' ANDRESEN, Garwood C. (7 1938; 5 1936). Branch Engr. (for mail), York Ice Machinery Corp., 471 SL Paul St., and 55 Sommershire Drive, Rochester, N. Y. ANDREWS, George H. (A 1934). Partner and Supt., Frank P. Andrews & Son, 354 Neshanock Ave., and (for mail). 213 Meyer Ave., New Castle. Pa. ANGERMEYER, Albert H. (A 1936), Owner (for mail), 119 N. Commercial SL, and 705 E. Forest Ave., Neenah, Wis. ANGUS, Frank M. (Af 1937), Branch Mgr. (for mail). General Refrigeration Sales Co., 1931 Main St., Kansas City, Mo., and 3898 Parkdale St., Cleveland Heights, Ohio. ANGUS, Harry H.* (if 1918), (Council, 1927 1929), Consulting Engr., 1221 Bay St., and (for mail), 34 Farnham Ave., Toronto, Ont., Canada. ANNAS, Henry C. (A 1937), Sales-Engr. Air Cond. (for mail), R. L. Spitzley Heating Co.. 1202 W. Fort St., and 4801 Bedford Rd.. Detroit, Mich. ANSPACHER, Thomas H. (7 1936), Dist. Mgr., Buffalo Forge Co., Dallas, Texas. ANTHES, Lawrence L. (A 1935), Pres., Imperial ' Iron Corp;, Ltd., 30 Jefferson Ave., and (for mail), Anthes Foundry, Ltd., 64 Jefferson Ave., and 119 Dowling Ave., Toronto, Ont., Canada. APT, Sanford R. (if 1935). Mech. Engr., New York World's Fair 1939, Inc., Administration Bldg., and (for mail), 36-20-168th St., Flushing. N. Y. ARCHER, David M. (if 1934). Sales Repr. (for mail). Sarco Co., Inc., 143 Federal St., Boston, and 10 Thurlow St., West Roxbury, Mass. ARDEN, Irwin L. (7 1937), Engr., Gastonia Mill Supply Co., 804 Independence Bldg., and (for mail), 1136 Queens Rd., Charlotte. N. C. ARENBERG, Milton K. (A 1920), Pres, (for mail). Robert Barclay. Inc.. 122 N. Peoria St.. Chicago, and Wildwood Lane, Highland Park, III. ARGUE, Edgar J. (A 1935), Sales Engr., Anthes Foundry, Ltd., Saskatchewan Ave., and (for ' mail), Ste 11. Estelle Apts., Winnipeg, Man., Canada. ARMBRUSTER, Frank T. W. (if 1936), Sales Engr., Portsmouth Supply Co., 1532-34 Gallia Ave., Portsmouth, and (for mail), 105 First Ave., ` Waverly, Ohio. _ ARMISTEAD, William C. (if 1937), Sales Engr. (for mail), 205 Church SL, and Murfreesboro Rd., Nashville, Tenn. ARMSPACH, Otto W.* (if 1919), Vice-Pres. and Chief Engr., Kroeschell Engineering Co., 215 W. Ontario St., Chicago, and (for mail), 205 S. Summit Ave., Villa Park, 111. v ARMSTRONG, Robert W. (7 1937; S 1935), 2809 E. Lake of the Isles Blvd., Minneapolis, Minn. . ARNDT, Heinrich W. (A 1935), Mgr., Plbg. and Htg. Dept., Sears Roebuck & Co., 732 Broad St., and (for mail), 1114H Russell SL, Augusta, Ga. ' ARNOLD, Robert S. (A 1926; 7 1922), Pres.. Lowell Air Conditioning Corp., 127 S. Fifth St., Philadelphia, Pa. ARNOLDY, William F. (A 1930), Branch Mgr.. Minneapoli9-Honeywell Regulator Co., and (for mail). 415 Brainard St. Detroit, Mich. ARROWSMITH, John O. (M 1934). Plant Engr. (for mail). Canadian Kodak Co.. Ltd., and 9 Humberview Rd., Toronto 9, Ont., Canada. ARTHUR, John M., Jr. (Af 1923). Commercial Sales Mgr. (for mail), Kansas City Power & Light Co., 1330 Baltimore. Kansas City, Mo.. and 3311 State Ave.. Kansas City. Kan. ASHLEY, Carlyle M.* (Af 1931), Dir. of Develop ment (for mail). Carrier Corp-. and 207 Brattle Rd., Syracuse, N. Y. ASHLEY, Edward E. (if 1912), Consulting Engr. (for mail). 10 East 40th St.. New York. N. Y.. and Middlesex Rd., Norton Heights. Conn. ATHERTON, Alfred E. (A 1937), Director (for mail). A. E. Atherton & Sons, Pty. Ltd.. 383 Latrobe St., and 39 Esplanade, Melbourne, Victoria, Australia. 8 Roll of Membership ATKINS, Thomas J, (Af 1931). Mgr. Air Cond. Div., Carbondale Machine Corp., Harrison, and (for mail), 22 S. Munn Ave., East Orange, N. J. ` AUGHENBAUGH, Harry E. (Af 1935), York Ice Machinery Corp., 1238-46 North 44th SL. Philadelphia, and (for mail), 7105 Penarth Ave., Upper Darby, Pa. AUSTIN, William H. (S 1937), York Ice Ma chinery Corp., 200 Causeway SL. Boston, and (for mail), 630 Adams St.. East Milton, Mass. AVERY, Lester T. (Af 1934), Pres, (for mail), Avery Engineering Co., 2341 Carnegie Ave., Cleveland, and 21149 Colby Rd., Shaker Heights. Ohio. AXEMAN, James E. (Af 1932; A 1931; 7 1925), Gen. Sales Mgr. (for mail), Spencer Heater Div. of Lycoming Mfg. Co., Box 660, and N. Camp bell St.,'Williamsport, Pa. AYERS, Earl H. (A 1938; 7 1935), Supt., D. W. Hickey & Co., 1631 University Ave., and (for mail), 1846 Palace St., SL Paul, Minn. BAKER, Richard H. (S 1936), Junior Engr., Chrysler Motor, and (for mail), 3765 W. Chicago Blvd., Detroit, Mich. BAKER, Roland H. (Af 1928; A 1924), Pres., R H. Baker Co., Elkins, New Hampshire. BAKER, William H., Jr. (A 1935), Mgr. Western Air Cond. Div. (for mail), American Radiator Co., 816 S. Michigan Ave., and 1211 N. State St.. Chicago, 111. BALDI, Giuseppe (A 1936), Engr. (for mail), Compagnia Italians Westinghouse, via Pier Carlo Boggio 20 and Corso Racconigi, 39, Torino, Italy. BALDWIN, William H. (Af 1921), Sales Engr. (for'mail), 5757 Cass Ave., and 2432 Atkinson Ave., Detroit, Mich. BALL, William (A 1936), Pre9. (for mail). Inter state Heating & Plumbing Co., 521 Southwest Blvd., Kansas City, Mo., and 1026 Shawnee Rd., Kansas City, Kan. BALLANTYNE, George L. (A 1936), Mgr., Htg. . Sales Dept, (for mail). Crane, Ltd., P. O. Box B 840, Montreal, and 141 Bedbrook Ave., Montreal. West, P. Q., Canada. BACHMAN, Fred (Af 1936), Contractor (for BALLMAN, William H. (Af 1937), Division mail), 3004 North 21st St., Philadelphia, and Engr., Nash Kelvinator Corp., 2012 Chanin 906 Bell Ave., Yeadon, Pa. Bldg., New York, N. Y. ' BACKSTROM, Russell E.* (A 1931; 7 1928), Mgr., Sales Engrg. Dept, (for mailt, Wood BALSAM, Charles P. (Af 1932), 324 Fourth St.. Brooklyn, N. Y. Conversion Co., First National Bank Bldg., and 1655 Hiilcrest, St. Paul, Minn. BACKUS, Theodore H. L. (Af 1916), Htg. and Vtg. (for mail), 200-208 Hill St., and 1018 Vaughn St., Ann Arbor, Mich. ' BADARACCO, John A. (A 1937), Owner (for mail), Badaracco Appliance Co., 115 W. Monroe St., and 2 Southmor St., Mexico, Mo. BADGETT, W. Howard* (Af 1937; 7 1932), Research Asst:, Texas Engineering Experiment Station, Agricultural and Mechanical College of Texas, P. O. Box 213 Faculty Exchange, College BAMOND, Manuel J. (Af 1936), Engr., Reynolds Corp., 609 N. LaSalle St., and (for mail), 4715 Magnolia Ave., Chicago, 111. - BANKS, John B. (A 1937), Branch Mgr., Minne- apolis-Honeywell Regulator Co., 2405 N. Mary land Ave., and (for mail), 4544 N. Larkin St.. Milwaukee, Wis. BANNER, F. L. Dan (Af 1937). Branch Mgr.. Minneapolis-Honeywell Regulator Co.,'and (for mail), 5523 Corby St., Omaha, Nebr. . BANNON, Lucas E. (A 1935), Archt., 18 Church Station, Texas. .. St., and (for mail), 16 Church St., Paterson, N. J. BAENDER, Frederick G. (Af 1937), Pres, (for BARBIERI, Patrick J. (7 1936; S 1933), AssL mail). Thermo Air Conditioning Institute, Inc., Engr.. Armo Cooling & Ventilating Co., 30 186 S. Alvarado St., and 3621 Boyce, Los Angeles, Calif. West 15th St., and (for mail), 2166 Belmont Ave., New York, N. Y. BAHNSON, Frederick F * (Af 1917), Vice-Pres. and Chief Engr. (for mail), The Bahnson Co., 1001 S. Marshall St., Pres., Southern Steel . . Stampings, Inc., P. O. Box 1942, and 28 Cascade Ave., Winston Salem, N. C. BAILEY, Edward P., Jr. (Af 1925), Dist. Repr., Iron Fireman Corp., 3170 West 106th St., Cleve land, Ohio, and (for mail), 151 Crocker Blvd., Mt. Clemens, Mich. BAILEY, W. Mumford (Af 1930), Managing Dir., Mumford Bailey & Preston, Ltd., and Joint Managing Dir., British Trane Co., Ltd. (for mail), "Newcastle House" Clerkenwell Close, London, E. C. 1, and "Oldbury Court," Dainesway, Thorpe Bay, Essex, England. BARNARD. M. Everett (A 1931; 7 1929). Sales Engr. (for mail). Carrier Corp., 12 South 12th St., and 341 Vernon Rd., Philadelphia, Pa. BARNES, Arthur R. (Af 1924), Chief Engr. (for mail), U. S. Supply Co., 1315 West 12th St., and 326 East 70th Terrace, Kangag City, Mo. BARNES, Harry P. (A 1936), Mgr., Construction Dept, (for mail), Johns-Manville Sales Corp., 2030 Walnut St., and 6101 Walnut St., Kansas City, Mo. BARNES, Herbert (Af 1936), Mgr. (for mail), Herbert Barnes Plumbing & Heating, Delta Block, and 114 Grosvenor Ave., S.t Hamilton, Ont., Canada. BAIRD, S. Alan (Af 1935), Consulting Engr. (for BARNES, Lewis L. (7 1937). Engr., Carrier mail), 621 Commercial Merchants National Bank Bldg., and 911 E. Virginia Ave., Peoria, III. Atlanta Corp., 348 Peachtree St., and (for mail), 3995 N. Stratford Rd., Atlanta, Ga. BAKER, C. T. (Af 1935), Consulting Engr. (for BARNES, Walter E. (Af 1933), Pres., Barnes & mail), 713 Glenn St., S.W., and 892 Piedemont Ave., Atlanta, Ga. Jones, Inc., 128 Brookside Ave., Jamaica Plain (Boston), and (for mail), 7 Woodlawn Ave., BAKER, George R. (Af 1936), Pres, (for mail), Wellesley Hills, Mass. G. R. Baker Co., Ltd., 224 Adelaide St., W., and BARNEY, William E. (Af 1936). Mgr. and 37 Lappin Ave., Toronto, Canada. Research Engr. (for mail), Hydraulic-Press BAKER, Harold S. (A 1937), Sales Engr. Refrig Brick Co., South Park, and 4929 East 108th St., eration, 2015 Chester Ave., and (for mail), 241 Cleveland, Ohio. Jefferson St., Bakersfield, Calif. BARNS, Amos A. (Af 1933), Owner (for mail), BAKER, Harry L., Jr. (7 1935), Sales Engr. (for 440 W. State SL, and. 318 W. State SL, Ithaca, mail), American Blower Corp., 50 West 40th St., N. Y. 3 New York, and 9935 Third Ave., Brooklyn, N. Y. BARNSLEY, Frank R. (A 1936), Mgr., Air BAKER, Howard C. (Af 1921), Pres, (for mail). Cond. Div. (for mail), Canadian General Electric The Howard C. Baker Co., 128 S. St. Clair St., Co., Ltd., 1000 Beaver Hall Hill, and 5245 and 4604 Manorwood Rd., Toledo, Ohio. Byron Ave., Montreal, Que., Canada. .: BAKER, Irving C. (Af 1921), Vice-Pres. and Operating Mgr., 1119 Leo SL and Mad River Rd., Dayton, Ohio. BAKER, Lome P. (7 1937), Engr., Canadian General Electric Co., Ltd., and (for mail), 669 Spadina Ave., Toronto, Ont., Canada. BARNUM, Charles R. (A 1938; S 1935), 1494 C^apitol Ave., St. Paul, Minn. BARNUM. Marvin C. (Af 1930; A 1928), Eastern Repr. (for mail), Waterman-Waterbury Co., 1133 Broadway, New York, and Cherry Lane, Monsey, N. Y. . s' 9 Heating Ventilating Air Conditioning Guide 1938 BARNUM, Willis E., Jr. (Af 1933; A 1933; 7 1930). Mgr., Air Cond. Div., York Ice Ma chinery Corp., and (for mail), 36 N. Vernon St., York, Pa. BARR, George W. (Af 1905), (Board of Gpver. nors, 1910), Dist. Mgr., Aerofin Corp., Land Title Bldg., Philadelphia, and (for mail). Woods End, Villa Nova, Pa. BARRON, John T. (7 1937). Kinney Mfg. Co.. 3529 Washington St., Jamaica Plains, and (for mail), 1867 Beacon St.. Brookline, Boston, Mass. BARRY, James G., Jr. (Af 1933), Vice-Pres. (for mail), Elliott & Barry Engineering Co., 4060 W. Pine Blvd., and 5051 Queens Ave., St. Louis, Mo. BARRY, Patrick I. (Af 1920), (Peace Commis sioner), MIHVE (for mail), M. Barry, Ltd., 4 Marlboro St., and Budaka, Sidney Park, Cork, Ireland. BARTH, Herbert E. (Af 1920). Vice-Pres. (for mail), American Blower Corp., 6000 Russell St., and 700 Seward, Detroit, Mich. BARTLETT, Amos C. (Af 1919), Mgr., Htg. and Vtg. Dept, (for mail), B. F. Sturtevant Co., Damon St., Hyde Park, Boston, and 30 Hollings worth Ave., Braintree, Mass. ` BARTLETT, C. Edwin (Af 1922), Pres, (for mail), Bartlett & Co., Inc., 3223 Arch St., and 3111 W. Coulter St., Philadelphia, Pa. BARTON, Delbert H. (J 1936; S 1935), Box 44-B, * Somerville, Texas. . BARTON, Jay (Af 1937), Mgr., National Mtg. & Engineering Co., 628 E. Forest Ave., and (for mail). Box 221, Detroit, Mich. BASTEDO, Albert E. (Af 1919), Vice-Pres.- Treas.-Mgr. (for mail), Burnham Boiler Corp., Irvington-on-Hudson, and 55 Burnside Drive; Hastings-on-Hudson. N. Y. ' BASTEDO, George R. (7 1937), Lab. Asst., Standard Air Conditioning, Inc., New Rochelle, and (for mail), 102-36-86 Road, Richmond Hill, N. Y. BATES, H. Clifford (Af 1937), Chief, Fibre Prod. Lab. (for mail). Corning Glass Works and 8 W. Sixth St., Coming, N. Y. ' BAUER, Albert E. (Af 1935), U. S.` Air Con ditioning Corp., N. W. Terminal, Minneapolis, and (for mail), 59 S. Victoria St., St. Paul, Minn. BAUGHMAN, L. R. (Af 1935), Htg. Engr., . Helms & Baughman, 103 N. Sheridan Rd., Waukegan, and (for mail), 2706 Eschol Ave., Zion, 111. BAUM, Albert L. (Af 1916), Member of Firm (for mail). Jaros, Baum & Bolles, 415 Lexington Ave., and 601 West 113th St., New York, N. Y. BAUMGARDNER, Carroll M. (Af 1928), Branch' Mgr. (for mail), U. S/ Radiator Corp., 3254 N. . Kilbourn Ave., Chicago, and 602 Michigan Ave., Evanston, 111. BAUR, John W. (7 1936; 5 1935), 2517 Leland Ave., Chicago, 111. BAYSE, Harry V. (Af 1923), Pres, (for mail), American Furnace Co., 2719-31 Delmar Blvd., and 6959 Hancock Ave., St. Louis. Mo. BEACH, Walter R. (A 1936), Sales Engr. (for mail). Cleveland Electric Illuminating Co., 75 Public Square, Cleveland, and 1185 Yellowstone - Rd., Cleveland Heights, Ohio. ' BEAN, George S. (A 1935), Mgr., Stoker Div. (for mail). North Western Fuel Co., E-1203 First National Bank'Bldg., St. Paul, and 4949-16th Ave.. S., Minneapolis, Minn. BEARMAN, Alexander A. (Af 1937), Engrg. .Dept, (for mail). Twentieth Century-Fox Film . -Corp., 444 West 56th St.. New York, and 47 : Edward St., Baldwin, L. I., N. Y. ' BEAULIEU, Adrian A. (Af 1937), Utilization Engr., Boston Edison Co., 39 Boylston St., Boston, and (for mail), 535 N. Eim SL, W., Bridgewater, Mass. ' BEAURRIENNE, Auguste* (Af 1912), Consulting : Engr.,'25 Rue des Marguettes, Pans, France. BEAVERS, George R. (Af 1929). Chief Engr.. Canadian Blower & Forge Co.. Ltd., Woodside Ave., and (for mail), 60 Church St., Apt. `D,* Kitchener, Ont., Canada. . BECHTOL, Jack J. (7 1937), Conditioner (for mail), Jos. E. Seagram & Sons, Inc., Lawrence- ' burg, Ind., and 397 Elberon Ave., Cincinnati, Ohio. BECKER, Walter A. (Af 1935), Sales Engr.. Grinnell Co., Inc., 4425 S. Western Ave., and (for mail), 5531 N. Artesian Ave., Chicago. 111. BEEBE, Frederick E. W. (A 1915). Johnson Service Co., 28 East 29th St:, New York, N. Y. BEECHLER. Jack S. (7 1937). Div. Repr., Kelvinator Corp., 1714 Rhodes Haverty Bldg., Atlanta, Ga. . BEERY, Clinton E. (Af 1913), Owner-Pres. (for mail). Heat & Fuel Engineering Co., 40 N. Dearborn St., and 4042 Greenview Ave., Chicago, IU. BEGGS, William E. (Af 1927),: Pres., W. E. Beggs Co., 907 Lloyd Bldg., and (for mall), 3639 Palatine Ave., Seattle, Wash. BEIGHEL, Howard A. (A 1927), Sales Repr. (for mail), Herman Nelson Corp., 503 Columbia Bldg., Pittsburgh, and 207 Puritan Rd., Rosslyn Farms, Carnegie, Pa. ' ' BEITZELL, Albert E. (A 1933; 7 1930), Mgr., Air . Cond. Div., Garnett, Eastman & Fleming, Inc., 2100 Arch St., Philadelphia, and (for. mail), 114 Crestview Rd., Bywood Heights, Upper Darby, Pa. - .. BELDING, Harry H. (A 1937), Chief. Engr. (for mail), Gathright, Inc., 1840 W. Broad St., and 2616 Chamber Layne Ave., Richmond, Va. - DELING. Earl H.* (Af 1936; A 1930; 7 1925). Proprietor, Beling Engineering Co., 2414-16th St., and (for mail), 242S-13th St.; Moline, 111. BELL, E. Floyd (Af 1933), Branch Mgr. (for mail), Buffalo Forge Co., 619 Foshay Tower, and 5337 Girard Ave., S., Minneapolis, Minn. BELSKY, George A. (A 1937), Air Cond. Engr., Majestic Refrigerator Corp., 333 West 52nd St., ' and (for mail); 3042 Grand Concourse, New . York, N. Y. ' BELT, Newton O. (Af 1929), Engrg. Dept, (for mail), E. I. Du Pont de Nemours & Co., and 824 West 10th St., Wilmington, Del. .. BEMAN, Myron C. (Af 1926), (Council, .1934 1937), Consulting Engr. (for mail), Beman & Candee, 374 Delaware Ave., and 699 Richmond ' Ave., Buffalo, N. Y. ... BENHAM, Colin S. K. (7 1937), Asst..Mgr.-Htg. and Vtg. Section (for mail), Benham & Sons, 4 . Ltd., 66 Wigmore St., London W. 1, and 31 Ormonde Terrace, London, N.W. 8, England. BENNETT, Charles A. (Af 1936), 1750 Harvard St., N.W., Washington. D. C. BENNETT, Edwin A. (Af 1936; A 1936; 7 1929). Sales Engr. (for mail), American Blower Corp., 50 West 40th St., New York, and 45 Pondfieid Rd., W., Bronxville. N. Y. BENNITT, George E. (Af 1918), Consolidated Edison Co. of N. Y., 4 Irving Place, New York, and (for mail), 81 N. Broadway, White Plains, N. Y. ` BENOIST, LeRoy L. (Af 1934), Mgr. (for mail), ' Benoist Bros. Supply Co., 117 S. Tenth St., and 1500 Main St., ML Vernon, III. ^ BENOIST, Raymond E. (A 1936), Mgr., Benoist Bros. Supply Co., and (for mail), 811 North 12th St., Mt. Vernon, 111. ' BENSEN, Clarence L. (7 1935), Engr. (for mail). McQuay, Inc., 1600 Broadway, N. E., and 2722 Benjamin St., N.E., Minneapolis, Minn. ' BENS1NGER, Mark (7 1936), Sales Engr., Com- bustioneer Stoker Corp*. 10th and D Sts., S.W., and (for mail), 2737 Devonshire Place, Wash ington, D. C. BENSON, Bernard C. (Af 1937),.Sales Promotion . Mgr., Chicago Branch (for mail), American Radiator Co., 816 S. Michigan Ave., and 8127 . Clyde Ave., Chicago, 111. - ` ... 10 Roll of Membership BENTLEY, Clyde E. (Af 1937), Consulting Mech. Engr., G. M. Simonson, Room 436, 74 New Montgomery, and (for mail), 1875 San Antonio Ave., Berkeley, Calif. BENTZ, Harry (Af 1915), Vice-Pres. (for mail), Davis Engineering Corp., 1064 E. Grand St., Elizabeth, and 18 Holland Terrace, Montclair, N. J. BERCHTOLD, Edward W. (Af 1927; A 1925), Rate Engr. (for mail), Boston Consolidated Gas Co., 100 Arlington St.. Boston, and 20 Randolph St., S., Weymouth, Mass. BERGAN, John R. (7 1937), Repr. (for mail), Minneapolis-Honeywell Regulator Co., 1220 Madison St., and 3815 Monroe SL, Toledo, Ohio. BERGIIOEFER, Victor A. (Af 1936; 7 1926). Vice-Pres-, Sterling Engineering Co., 3738 N. Holton St., and (for mail), 5446 N. Kent Ave., Milwaukee, Wis. BERGLUND, Niels W. (A 1936), Draftsman (for mail). York Ice Machinery Corp., 5051 Santa Fe Ave., and 729 S. Bonnie Brae SL, Los Angeles, Calif. '- BERMAN. Louis K. (Af 1908), Pres, (for mail). Raisler Heating Co., 129 Amsterdam Ave., and 285 Central Park West. New York, N. Y. BERMEL, Alfred H. (A 1933; 7 1928). 16 William St., North Arlington, N. J. . BERNERT, Lawrence A. (A 1937), Mgr. Htg. and Air Cond. Dept, (for mail). The Maag Co., 831 N. Milwaukee St., Milwaukee, and 381 Perkins Blvd., Burlington, Wis. BERNHARD, George (Af 1935; A 1929), Manag ing Engr., Associated Heating & Power Corp.. . 1 Hanson Place, and (for mail). 985 Park Place, Brooklyn, N. Y. BERNSTROM, Bert* (Af 1930). Mech. Engr., B. Bemstrom Air Conditioning Consultant, 844 Rush St., Chicago, III. * BERZELIUS. Carl E. (Af 1936), Captain, Com manding Officer CCC Camp (for mail), Co. 784 CCC, and 101 Wisconsin St.. Neodesha. Kan. BEST, Millard W. (A 1933), Pres, (for mail), Kolelectric Underfeed Stoker. Co., Ltd., 245 Kenilworth Ave. S., and 1750 King SL E., Hamilton, Ont., Canada. BETLEM, Henriette T. (7 1934), Air Cond. Engr. (for mail). Betlem Heating Co.. 1926 East Ave., and 1293 Park Ave., Rochester, N. Y. BETTS, Howard M. (Af 1927), Senior Mech. *" Engr., Htg. and Vtg. (for mail), DepL of Build ings, 213 City Hall, and 4923 Russell Ave. S., Minneapolis, Minn. - BETZ, Harry D. (Af 1928), Pres, (for mail), Betz Air Conditioning Corp., 6 W. Ninth SL, and. . 1610 Valentine Rd., Kansas City, Mo. BEVINGTON, Curtis H. (Af 1936), Director of Sales (for mail). Marsh Tritrol Co., 720 N. Michigan Ave., Chicago, and Park Ridge, 111. BIANCULLI, Vincent A. (7 1937), Engr.. Carrier Corp., Chrysler Bldg., and (for mail), 557 Broome St., New York, N. Y. BIBER, Herbert A. (A 1937). Engr., Mellon National Bank, Fifth Ave. and Smithfield St., and (for mail), 1950 San Juan SL, E. Liberty. . Pittsburgh. Pa. BICHOWSKY, F. Russell (Af 1935), Consultant, (for mail), Dow Chemical Co., 204 Nickels Arcade, and 1508 Granger SL, Ann Arbor, Mich. BILLINGSLEY, Oliver F., 2nd (7 1937). Sales and Design Engr., C. E. Wilson, Inc. (Westing- house Dist.), 810 Broadway, and (for mail). No. 3 Lincoln Apts., 127 W. Craig Place, San Antonio, Texas. BINDER, Charles G. (Af 1920), Mgr. Htg. DepL, Warren Webster & Co., 17th and Federal Sts., Camden, and (for mail). 115 Oak Terrace. Merchantville, N. J. ` * BIRD, Charles (A 1934), Treas.-Gen. Mgr (for mail), Doermann-Roehrer Co., 450-456 E. Pearl St., and Box 179-D, R. R. 6, Section Rd., Cincinnati. Ohio. BIRD, George L. H. (7 1937), Chief Engr., Refrigeration. Ltd., Transport House, Broad St., and (for mail), Highfield, 128 Selly Park Rd., Birmingham. England. BISCH, Bernard J. (Af 1931), Engr., St. Mary- of-the-Woods College, SL Mary-of-the-Woods, Ind. BISHOP, Charles R. {Life Member; M 1901), 22 Sagamore Rd., Bronxville, N. Y. BISHOP. Frederick R. (Af 1921), Mfrs. Agent, 8011 Dexter Blvd., Detroit, Mich. BISHOP, Marion W. (7 1935), Sales Engr. (for mail), American Blower Corp., 228 N. LaSalle SL, and 7024 Sheridan Rd., Chicago, III. BJERKEN. Maurice H. (Af 1937; A 1927), Sales Engr., Hoffman Specialty Co., and (for mail). 4952-17th Ave. S., Minneapolis. Minn. BLACK, Edgar N., 3rd (Af 1922), Philadelphia Mgr., Fitzgibbons Boiler Co., Inc., 1215-6 Land Title Bldg., Philadelphia, and (for mail). 111 Woodside Rd., Haverford, Montgomery Co., Pa. BLACK, Frank M. (A 1937), Chief Engr., U. S. Government, Army Medical Center, Washing- ton, D. C., and (for mail), P. O. Box 164, Silver Spring, Md. BLACK, F. C. (Life Member; M 1919), Pres..(for mail), F. C. Black Co.. 622 W. Randolph St., and 4535 N. Ashland Ave., Chicago, 111. . BLACK. Harry G. (Af 1917), Prop, (for mail). P. Gormly Co., 155 N. Tenth SL, and 927 North 65th St., Philadelphia, Pa. BLACKBURN, Edwin C., Jr. (Af 1929), Con sulting Engr., Crow, Lewis & Wick, Archts., 200 Fifth Ave., New York, and (for mail), 5 Kenwood Rd., Garden City, L. I., N. Y. " BLACKHALL, Lewis C. (Af 1935), Engr., Gurney Foundry Co., Ltd., 4 Junction Rd., and (for .mail), 234 Brock Ave., Toronto, OnL, Canada. BLACKHALL, Wiimot R. (Af 1922), Partner (for mail), McKellar & Blackhall, 1104 Bay St., and ' 332 Waverly Rd., Toronto, Canada. BLACKMAN, Alfred O. (Af 1911), Consulting Engr., 145 West 45th St., and (for mail), 450 West 24th SL. New York, N. Y. BLACKMORE, F. H. (Af 1923), Mgr., Operating Dept, (for mail), U. S. Radiator Corp., Box 686, Detroit, and 515 Tooting Lane, Birmingham, Mich. BLACKMORE, George C. (Charter Member; Life Member), Pres, (for mail), Automatic Gas Steam Radiator Co., 301 Brushton Ave., and Cathedral Mansions, Pittsburgh, Pa. ` BLACKMORE, J. J.* (iCharter Member; Life Member), 32 West 40th SL, New York, N; Y. BLACKMORE, James S. (7 1931), Philadelphia Dist. Mgr.. H. A. Thrush & Co., Peru, Ind.. and (for mail), 728 Manoa Rd., Upper Darby, Pa. " BLACKMORE, Joseph J. (7 1937), Sales Engr. (for mail). McDonnell & Miller and' Bell & Gossett, 4006 Papin, St. Louis, Mo., and 312 S. Fillmore, Edwanlsville, 111. BLACKSHAW, J. L * (Af 1937; 7 1929), Engr., Air and Refrigeration Corp., 11 West 42nd SL. New York, and (for mail), 59 Joralemon SL, Brooklyn, N. Y. - BLAIR, Howard A. (A 1937; 7 1935). Air Cond. Service Engr., Westinghouse Electric & Mfg. . Co., 653 Page Blvd., and (for mail), 105 Edendale St., Springfield, Mass. ' BLAKELEY, Hugh J. (Af 1935). Consulting Engr. (for'mail), Hubbard, Rickerd & Blakeley, 1109 Chapel St.. New Haven, Conn., 110 State St., Boston, Mass., and 5 Doty Place, New Haven, Conn. . BLAKESLEE, Donald (A 1935), Pres, (for mail), Donald Blakeslee. Inc., 89 E. Main St., Patcho- gue, and Main Rd., Bellport, N. Y. - BLANDING, George H. (Af 1919), Salesman. Johnson Service Co., 1355 W. Washington Blvd., .Chicago, and (for mail), 729 Hayes Ave., Oak Park, 111. BLANKIN, Merrill F. (Af 1927; A 1926; 7 1919), . Pres, (for mail), Haynes Selling Co.', Inc., S: E. - Cor. Ridge Ave. and Spring Garden SL, and 528 E. Gates St., Roxboro-tn.,-Philadelphia, Pa. BLAS, Romualdo J. (Af 1936), Apartado Postal, 1006 Caracas. Venezuela. " BLEDSOE, Raymond P. (7 1937). Design.Engr., Trane Co., and (for mail), 2201. George St., LaCrosse. Wis. ' uS Heating Ventilating Air Conditioning Guide 1938 BLESSED, William A. (A 1935). Sales Engr. (for mail). Mueller Brass Co., 1925 Lapeer Ave., and 1407 Court St., Port Huron, Mich. BLISS, George L. (A 1933), Engr. and Sales (for mail), Allis-Chalmers Mfg. Co., 11th and' Main St., Room 1410 Waldheim Bldg., and 7041 Brooklyn Ave., Kansas City, Mo. BLOOM, Louis (M 1935), Partner, B. Bloom & Son, and (for mail), 1450-52nd St., Brooklyn, N. Y. BLUM, Herman, Jr. (J 1936), Engr., Leo S. Weil & Walter B. Moses, Cons, Engrs.. 425 S. Peters St., and (for mail), 6131J Hurst St., New Orleans, La. BLUMENTHAL, Moritz 1. (Af 1936), Engrg. In structor, (for mail). Air Cond. and Refrigeration. National Schools, 4000 S. Figueroa SL, and 648 W. Santa'Barbara Ave., Los Angeles, Calif. BOALES, William G. (Af 1935; A 1923), Mgr. ' (for mail), Wm. G. Brales and Associates, 6439 Hamilton Ave., Detroit, and 195 McMillan Rd., Grosse Pointe Farms. Mich. BOCK, Bernard A. (A 1929; J 1927), Mech. Engrg. Draftsman, 57 Elizabeth Ave., Arlington, N. J. BOCK, 1. 1. (A 1934), Pres, (for mail), Carrier- Bock Corp., 2022 Bryant St., and 2500 South Blvd., Dallas, Texas. - BODEN, Walter F. (A 1937), Branch Mgr. (for mail), Modine Mfg. Co., 420 E. Wells St., Mil waukee, and 628 Michigan St., South Mil waukee, Wis. BODDINGTON, William P. (Af 1927). Mgr. (for mail), Canadian Powers Regulator Co., Ltd., ' 195 Spadina Ave., and 280 Clendenan Ave., Toronto, Ont., Canada. BOD1NGER, Jacob H. (Af 1931), Pres, (for mail). Bodinger & Co., Inc., 530 Tenth Ave., New York, and 1429 Easi 19th St., Brooklyn, N. Y. BODMER, Emmanuel (Af 1937), Engr., Oil Htg.. Williams-Oil-O-Matic Burners, 223 Boule vard Pereire, and (for mail), 5 Rue Lagrange, Paris, France. BOEHMER, Andrew P. (J 1937; S 1935), Sales Engr., Mills Novelty Co., 4100 Fullerton Ave., and (for mail), 3012 N. Kostner Ave., Chicago, 111. BOESTER, Carl F. (A 1936), Air Cond. Engr. (for mail); 220 N. Kingshighway, and Park Plaza Hotel, St. Louis, Mo. ' BOGATY, Hermann S. (Af 1921), 735 E. Phil- ellena St., Philadelphia, Pa. BOLSINGER, Raymon C. (Af 1916), (Council, ' 1936-1937), Prop., Automatic Florzone Heating Co., Conshohocken, Pa., and (for mail), 238 E.. Madison Ave., Collingswood, N. J. BOLTE, E. Endlcott (A 1929), Salesman, National Radiator Corp., 1111 East 83rd St., and (for mail), 6516 Kenwood Ave., Chicago, 111. BOLTON, Reginald P.* {Honorary Member; Life Member), {Presidential Member), (Pres., 1911; 1st Vice-Pres., 1905-1910; 2nd Vice-Pres., 1903; Board of Governors, 1901, 1905, 1910, 1911, 1912, 1913), The R. P.. Bolton Co.. 116 East 19th St., New York, N. Y. BOND, Horace A. (Af 1930), DisL Mgr., Warren Webster & Co., 152 Washington Ave., and (for mail), 12 Ramsey Place, Albany, N. Y. BONTHRON, Robert C. (A 1935), Syndicate Headquarters Repr. (for mail), Westinghouse Electric & Mfg. Co., Room 1208-150 Broadway, New York, and 44 Ingraham Blvd., Hempstead. ' N. Y. ' ' ' BOOTH, Charles A. (Af 1917), Vice-Pres. (for mail), Buffalo Forge Co., 490 Broadway, and 142 Summit Ave., Buffalo, N. Y. BORAK, Eugene (Af 1937), Chief Draftsman (for mail), Buensod-Stacey Air Conditioning, Inc., 60 East 42nd St., New York. N. Y., and 1245 Second Ave., North Bergen, N. J. . BORKAT, Philip {J 1936). Engr., Weiss Hearing & Plumbing Co., 5604 Cedar Ave., and (for mail), 843 East 100th St.. Cleveland, Ohio. . BORLING, John R. (A .1934), Engr.-Custodian (for mail), Chicago Boaird of Education. 9510 S. Prospect Ave., and 953 East 84th Place, Chicago. III. BORNEMANN, Walter A. (Af 1924; J 1923). Sales Engr. (for mail), Carrier Corp., 12 South 12th St., Philadelphia, and 123 W. Wharton Ave., Glenside, Pa. BORNSTE1N, William (A 1937). Pres, and Treas., William Bornstein, Inc., 1000 W. Broad St., Bethlehem, Pa. BORUCH, Edwin R. (A 1935), Vice-Pres. (for mail). Standard Electric Mfg. Co., 2020 Richard son, and 835 N. Bishop, Dallas, Texas. BOTELHO, Nanto J. (A 1937), Engr. and Mgr., Ceibrasil. Representacoes Ltda. (for mail), Rua General Camara, 64--70 andar, Rio de Janeiro, Brazil (S. A.). BOUCHERLE, Henry N. (Af 1934), Secy, (for mail). The Scholl-Choffin Co., Mahoning Ave., and Hogue St., and 3412 Hudson Ave., Youngs town, Ohio. ` BOUEY, Angus J. (A 1937; J 1930), Sales Engr. (for mail), B. F. Sturtevant Co., 553 Monadnock Bldg., and 4810 Fulton SL, San Francisco, Calif. BOUILLON, Lincoln (Af 1933), Consulting Engr. (for mail), 1411 Fourth Ave. Bldg., and 2211-32nd South, Seattle, Wash. BOWDITCH, Robert P. {J 1936; 5 1935), 504 S. Race St., Urbana, 111. BOWERMAN, Everett L. (A 1937), Sales Engr.. Canadian General Electric Co., Ltd., 212 King St. W., and (for mail), 175 Crescent Rd., Toronto, Ont., Canada. - BOWERS, Arthur F. (A 1919), Pres., Industrial Heating & Engineering Co., 828 N. Broadway, Milwaukee, Wis. BOWLES, Edmund N. (A 1937), Air Cond. Supv. N.W. Dist. (for mail), Westinghouse Electric & Mfg. Co., 20 N. Wacker Drive, and 6043 N. Paulina St., Chicago, 111. BOWLES, Potter (A 1928), Pres, (for mail), Hoffman Specialty Co., Inc., Room 3324-500 Fifth Ave., New York, N. Y., and P. O. Box 61, New Canaan, Conn. BOXALL, Frederick (Af 1937), 36 Kenwood ' Ave., Verona, N. J. BOYAR, Sidney L. {J 1937), Estimating Super visor, Sears Roebuck Co., Chicago, and (for mail), 1515 Schilling Ave., Chicago Heights, 111. BOYD, Spencer W. (Af 1937; J 1931), Consulting Engr. {for mail), Newcomb & Boyd, 708 Walton Bldg., and 887 Juniper SL, Atlanta, Ga. BOYD, Thomas D. (Af 1937), Sales Engr. (for mail). Johnson Service Co., 1113 Race St., and 4220 Erie Ave., Cincinnati, Ohio. BOYDEN, Davis S.* (Af 1909), (Pres.. 1937; 1st Vice-Pres., 1936; Treas., 1933-1934; Council, 1917-1930-1937), Supt., Steam Utilization DepL (for mail), Boston Edison Co., 39 Boylston St., Boston, and 1496 Commonwealth Ave., Brighton, Mass. % . . BOYKER, Robert O. {J 1935), Contractor; Mac Boyker & Son, Kent, Wash. BOYLE, John R. (Af 1936), Asst. Traveling Sales Mgr., Westerlin & Campbell Co., 1113 Cornelia Ave., and (for mail), 6858 Osceola Ave., Chicago, 111. BOZEMAN, Richard W. (Af 1936; J 1929), 450 S. Ashland Ave., Lexington, Ky. BRAATZ, Chester J.* (Af 1930), Sales Mgr.. Temperature Control and Uni-Flo ;DepL, Barber-Colman Co., and (for mail), 718 King SL, Rockford, 111- ' ' ' BRABB&E, Dr. Charles W * (Af 1925). (for mail), American Radiator Co., 40 West 40th St., New York, and 50 Lincoln Ave., Tuckahoe, N. Y. BRACKEN, John Hi (Af 1927), Mgr., Industrial Uses DepL (for mail). Celotex Corp., 919 N.^ Michigan Ave., and 455 Oakdale Ave.,.Chicago, 111. .... BRADF1ELD, William W. (Af 1926), Consulting Engr. (for.mail), 341 Michigan Trust Bldg., and 1352 Franklin St. S.E.,`Grand.. Rapids, Mich. 12 Roll of-Membership BRADFORD, Gilmore G. (Af 1936), Mgr., Frigidaire Div., General Motors China, Ltd., 201 Route Cardinal Merrier, Shanghai, China. BRADLEY, Eugene P. (Af 1906). Pres, (for mail), Hester-Bradley Co., 2835 Washington Ave., and 6935 Pershing Ave., SL Louis, Mo. BRANDI, O. H. (Af 1930), Dipl. Ing., Rud. Otto Meyer, Hamburg 23, and (for mail), Reinbek/ Hamburg, Hamburgerstr. 14, Germany. BRANDT, Ernst H., Jr. (Af 1928), Pres., Reliance Engineering Co.. Inc. (for mail), P. O. Box 1292, and 1101 Providence Rd., Charlotte, N. C. BRATT, Hero D. (Af 1937), Sales Engr., Warren Webster &-Co., 228 Ottawa Ave., N.W., and (for mail), 2259 Stafford Ave., S.W., Grand Rapids, Mich. ' BRAUER, Roy (Af 1926), Prop, (for mail). Ventilating Equipment Co., Magee Bldg., and 576 Austin Ave., Ml. Lebanon, Pittsburgh, Pa. BRAUN, John J. (Af 1932), Factory Mgr., U. S. Playing Card Co., Norwood Station, Cincinnati, and (for mail), 4305 Floral Ave., Norwood, Ohio. BRAUN, Louis T. (Af 1921), Executive Secy, (for mail), Chicago Master Steamfitters Association, 228 N. LaSalle St, and 1548 Pratt Blvd., Chicago, 111. BRAYMAN, Albert I. {J 1937), Draftsman and Estimator, Edw. Brayman, Hearing Contractor, 81 Chambers St., Boston, and (for mail), 2 Page St., Dorchester, Mass. BRECKENRIDGE, L. P.* {Honorary Member; Life Member; M 1920), The Brackens, North Ferrisburg, Vt. BREDESEN, Bernhard P. (A 1931), Engr. (for mail), Reese & Bredesen, 410 Essex Bldg., and 3319 Knox Ave., N., Minneapolis, Minn. BRENEMAN, Robert B. {A 1931; J 1927), Sales Engr. (for mail), Armstrong Cork & Insulation Co., 191 Orchard Lane, Columbus, Ohio.. BREZINAi Edwin A. {J 1937; S 1936), 3731 East 131st St., Cleveland, Ohio. BRIDE, William T. (Af 1928; J 1925), Supt. Engrg., Bride-Grimes & Co., 9 Franklin SL (for mail), P. O. Box 777 Lawrence, and 50 High SL, Methuen, Mass. BRIGHAM, Clare M. (Af 1935), Vice-Pres. in charge of sales (for mail), C. A. Dunham Co., 450 E. Ohio St., Chicago, and 420 Maple Ave.,. Winnetka, 111. BRIGHTLY, Frederick C., Jr. {A 1936), Vice '' Pres., Standard Galvanizing Co., 2619 W. Van Buren St., and (for mail), 917 S. Austin Blvd., Chicago, 111. BR1NKER, Harry A.. (Af 1934), 524 Village St., Kalamazoo, Mich. BRINTON, Joseph W. (Af 1920), DisL Mgr. (for mail), American Blower Corp., 1003 Statler Bldg., Boston, and 42 Gleason SL, West Med ford, Mass. BRISSETTE, Leo A. (Af 1930), Treas. (for mail), Trask Hearing Co., 4 Merrimac St., Boston, and 168 Florence St., Melrose, Mass. BROCHA, John F. (Af 1936), Buyer of Plbg. and Htg., Montgomery Ward & Co., 619 W. Chicago Ave., and (for mail), 5475 Hirsch SL, Chicago, 111. BROCKINTON, C. E. (A 1937), Air Cond. Sales Engr. (for mail). Advanced Refrigeration, Inc., ''SSO Peachtree SL, N.E., and 1384 W. Peachtree St., N.E., Atlanta, Ga. BRODERICK, Edwin L* (Af 1933), Research AssL in Mech. Engrg. (for mail). University of Illinois, 213 M. E. Lab., Urbana, and 909 S. First SL, Champaign, III. BRONSON, Carlos E.* (Af 1919), Mech. Engr. (for mail), Kewanee Boiler Corp., and 311 McKinley Ave., Kewanee, III. . BROOKE, Irving E. (Af 1937), Consulting Engr.' (for mail), 189 W. Madison SL, .Chicago, and 830 Keystone Ave., River Forest, 111. `' BROOKS, Herbert B. (A 1937). Sales Engr.i - Smith Distributing Co., 831 E. Broadway, Louisville, and (for mail). Anchorage, Ky. . BROOM, Benjamin A. (Af 1914), Sales Promo tion Engr., Weil-McLain Co., 641 W. Lake St., and (for mail), 1534'Fargo Ave., Chicago,-111. BROOME, Joseph H. (A 1936), Sales Engr., Minneapolis-Honeywell Regulator Co., 801 Second Ave., New York, and (for mail), 1556 Pacific St., Brooklyn, N. Y. BROWN, Alfred P. (Af 1927), Vice-Pres. (for mail), Reynolds Corp., 609 N. LaSalle SL, Chicago, and 551 Hill Terrace, Winnetka, 111. BROWN, Aubrey I.* (Af 1923), Prof, of Htg. and Vtg. (for mail), Ohio State University, and 169 Richards Rd., Columbus, Ohio. BROWN, David (Af 1936), Owner (for mail), 67 Cooper Square, and- 54 West 174th SL, New York, N. Y. BROWN, Foskett* (Af 1926), Vice-Pres. (for mail). Gray & Dudley Co., 222 Third Ave., N,, P. O. Box 722, and 2314 West End Ave., Nash ville. Tenn. BROWN, John S., Jr. {J 1937), Sales Engr., Delco-Frigidaire Conditioning Division, General Motors Sales Corp., and (for mail), 35 E. Norman Ave., Dayton, Ohio BROWN, Mack D. (A 1938; J 1936), Mech. Engr. (Htg. and Vtg.), (for mail). Northrup & O'Brien, Archts., 602-03 Reynolds Bldg., and 915 East 21st St., Winston-Salem, N. C. BROWN, Norman A. (A 1938; J 1936; S 1935), 4723 West 19th St., Cicero, III. Brown, Ronald E. G. (Af 1933), 5501 Woodward Ave., Detroit, Mich. BROWN, Tom (Af 1930), Vice-Pres.-Gen. Mgr. (for mail). Autovent Fan & Blower Co., 1805-27 N. Kostner Ave., and 5325 N. Laramie, Chicago, 111. BROWN, William (A 1937), Vice-Pres.-Gen. Mgr. (for mail), Carey Co., 6197 Hamilton Ave., and 660 Virginia Park, Detroit, Mich. BROWN, William H. (A 1923), Mgr., Brown Bros., Inc., 3015 North 22nd SL, Milwaukee, Wis. BROWN, W. Maynard (A 1930), Warren Webster . & Co.. 17th and Federal Sts., Camden, N. J. BROWNE, Alfred L. (Af 1923), 253 Highland Ave., South Orange, N. J. BRUNETT, Adrian L. (Af 1923), Assoc. Mech; Engr., U. S. ' Supervising Architects Office, Treasury Dept., Washington, D. C-, and (for mail), P. O. Box 36, Rockville, Md. BRUST, Otto (Af 1930), Consulting Engr., Lufttechnische GesellschafL Ing. Broz & Co., Praha 1. Revolucni 13, and (for mail), Praha, VII, Mala Vinarska 4, Czechoslovakia. BRYANT, Dr. Alice G. (Life Member; Af- 1921), 405 Marlborough SL, Boston, Mass. BRYANT, Percy J. (Af 1915), Chief Engr. (for mail), Prudential Insurance Co. of America, 763 Broad St., Newark, and 754 Belvidere Ave.. Westfield, N. J. BUCK, David T. (A 1936), Pres, (for mail). Buck Engineering Co., Inc., 37-41 Marcy SL, and 116 W. Main SL, Freehold, N. J. BUCK, Lucien (Af 1928), Engr., Proctor & Schwartz, Inc., Seventh St. and Tabor Rd., Philadelphia, and (for mail), 101 Waverly Rd., Wyncote, Pa. BUENGER, Albert* (Af 1920; J 1917), (Council. 1934-1937), Mgr., Comm. Sales and ApplicationEngrg. (for mail), Delco-Frigidaire Conditioning . Div., 1420 Wisconsin Blvd., and 224 Schantz Ave., Oakwood, Dayton, Ohio. BUENSOD, Alfred C. (Af 1918), Pres., BuensodStacey Air Conditioning, Inc., 60 East 42nd St., and (for mail), 33 Fifth Ave., New York, N. Y. BULKELEY, Claude A. (Af 1923), Chief Engr., Niagara Blower Co., and (for mail), 265 Sanders Rd., Buffalo, N. Y. BULLEIT, Charles R. (M 1932; J 1930), 1811 Bayard Park Drive, Evansville, Ind. > BULLOCK, Howard H. (A 1933). Commercial Engr.- (for. mail). General Electric Co., 212 N.' .Vignes St., Los Angeles, and 2442 Cudahy:St-, Huntington Park, Calif. . BULLOCK, Thomas A. (Af 1930), Engr. (for mail),* Densmore LeCIear & Robbins, : 31 SL5 James Ave.,-Boston, and 35 Everett St.,'Arling ton, Mass. ' .! 13 Heating Ventilating Air Conditioning Guide 1938 BUR, Jullen R. C. (A 1936; 7 1931). Chief Engr. CAMERON. William R. (A 1936). Dist. Mgr.. (for mail). Bur & Co.. 10 rue du Chapeau Rouge, L. J. Mueller Furnace Co., Milwaukee, Wis., and and 1 Place Francois Rude, Dijon, France. (for mail), 3337 Highland Ave., Kansas City, Mo. BURCH, Laurence A. (Af 1934). Sales Mgr., CAMPBELL, Alfred Q.. Jr. (7 1933), Spec. R. L. Deppmann Co., 957 Holden Ave., Detroit, Repr., Huttig Sash & Door Co., Charlotte, and (for mail), 78 Amherst Rd., Pleasant Ridge N. C. (for mail), 1083 MeriwetherAve., Memphis, (Royal Oak), Mich. Tenn. BURKE, James (7 1930), Engr., Carrier Corp., CAMPBELL, Everett K* (Af 1920), (Council, 12 South 12th St., Philadelphia, Pa. 1931-1933), Pres.-Treas. (for mail). E. K. BURKHART, Elder M. (7 1935), Sheet Metal Campbell Heating Co., 2445 Charlotte St., and Estimator, Overly Mfg. Co.. 574 W. Otterman 3717 Harrison Blvd., Kansas City, Mo. St., and (for mail), 22 Westminster Ave.. Greens- CAMPBELL, E. Kirker, Jr. (A 1938 ; 7 1930), burg. Pa. BURKS. Roland H. (7 1936; S 1935), 120 Second Secy, (for mail), E. K. Campbell Heating Co., - 2445 Charlotte St., and 3717 Harrison Blvd., St., Detroit, Mich. Kansas City, Mo. - BURNETT, Earl S. (Af 1920), Mech. Engr., CAMPBELL, Frank B. (A 1927). Sales Engr.. Amarillo Helium Plant. U. S. Bureau of Mines, American Radiator Co., 40 West 40th St., and (for mail), 4223 West 11th Ave., Amarillo, New York. N. Y. Texas. CAMPBELL, George S. (7 1937), Sales Engr.. BURNHAM, C. M., Jr. {A 1937). Engrg. Editor John Bouchard & Sons Co., Nashville, and (for (for mail), Keeney Publishing Co., 6 N. Michigan mail), 1906 Ivy St., Chattanooga, Tenn. Ave., and 10621 Hale Ave., Chicago. 111. CAMPBELL, Ralph L. (A 1937). Sales Engr... BURNS, Edward J. (Af 1923), Harris Bros. Chrysler Airtemp, 1316 Nicollet Ave., S., and Plumbing Co., 217 W. Lake St., and (for mail), (for mail), 4418 W. Lake Harriet Blvd., Minne 4716 Aldrich Ave.. Minneapolis Minn apolis, Minn. - BURNS, John R. (7 1936; S 1933), Htg. Engr., CAMPBELL, Robert E. (7 1935; 5 1934), U. S. Delius Co., 43 N. Main St., and (fpr mail), 504 N. Air Conditioning Corp., 2100 Paramount Bldg.; Main St., Wallingford, Conn. . New York, and (for mail), 538 East 21st St.. BURR, Griffith C. (Af 1937), Pres., Controlled Brooklyn, N. Y. Heat, Inc., 569 Main St., Poughkeepsie, and (for CAMPBELL, Thomas F. (Af 1928). T. F. mail), Hyde Park, N. Y. Campbell Co. (for mail), 1013 Penn Ave., and BURR, Kimball (A 1936). Mgr. Air Cond. Div. 8927 Francstown Rd., Wilkinsburg, Pa. (for mail). American Radiator Co., 40 West 40th CANDEE, Bertram C. (Af 1933), Partner, St., New York, and Ardsley Park, Dobbs Ferry, Beman & Candee, 374 Delaware Ave-, Buffalo, N. Y. and (for mail), 19 Tremont Ave., Kenmore, N. Y. BURRITT, Charles G. (A 1916), Branch Mgr. CAPPS, Edgar Lee (A 1937). Sales Engr. (for (for mail), Johnson Service Co., 922 Second Ave., mail). Tidewater Electric Corp., 137 E. Olney S., and 615 Second Ave., S., Minneapolis, Minn. - Rd., and 619 Pennsylvania Ave., Norfolk, Va. BUSHNELL, Carl D. (A 1921), Pres, (for mail), CARBONE, James H. (Af 1937), Htg.-Vtg. Engr., Bushnell Machinery Co., 311 Ross St., Pitts L. J. Wing Mfg. Co., 154 West 14th St., New burgh, and 94 Pilgrim Rd., Rossiyn Farms, York, and (for mail), 29 Grove St., Baldwin. Carnegie, Pa. L. I., N. Y. BUTLER, Peter D. (Af 1922), Salesman, U. S. Radiator Corp., Detroit, Mich., and (for mail), 127 Edgewater Rd., Cliffside Park, N. J. BUTT, Roderick E. W. (A 1936; 7 1930), Air Cond. Engr., Frigidaire, Ltd.. The Hyde, Hendon, London, N.W. 9, and (for mail), 605 Beatty House, Dolphin Square, London, S.W. 1, England. BUTTARAVOLI, Frank (7. 1937; 5 1935), 2425 Kings Highway, Brooklyn, N. Y. BYRD, Tom (A 1936), Salesman (for. mail), American Rolling Mill Co., 703 Curtis St., and 2403 Fleming Rd., Middletown, Ohio. CAREY, James A. (Af 1928), Carrier Con>., Syracuse, N. Y., and (for mail). Villa Nova, Pa. CAREY, Paul C. (Af 1930), Consulting Engr. (for mail), Runyon & Carey, 33 Fulton St., Newark, and 31 Claremont Drive, Maplewood. N. J. CARLE, William E. (Af 1926), Pres, (for mail), Carl. Boehling Co., Inc., 1641 W. Broad St., and 2220 Floyd Ave., Richmond, Va. CARLOCK, Marion F. (Af 1936). Dist. Repr., American Foundry & Furnace Co. (for mail), 505 Henry, Alton, 111. CARLSON, C. O. (A 1937), Owner (for mail). 1627 Washington Ave., N., and 1806 Thomas Ave., N., Minneapolis, Minn. c CARLSON, Conrad V. (7 1937), Engr. (for mail). CABOT, Mathew A. (7 1937), Mech. Engr. (for mail). University of Kentucky, Building Pro gram, College of Engrg., Lexington and R. R. ' No. 1, Brannon Pike, Nicholasville, Ky. CADY, Edward F. (7 1937), Engr., 1003 Euclid Ave., Syracuse, N. Y., CAIRNS, John H. (A 1936). Asst. Sales Engr., Clarence A. Flarsheim, Inc., B. M. A. Bldg;, Kansas City, Mo., and Axtell, Nebr. CARLSON, Everett E. (Af 1932; A 1929), Branch Mgr. (for mail). Powers Regulator Co., 1010 Louderman. Bldg., and 6652 Washington Ave., St. Louis, Mo. CARNAHAN, John H. (7 1937), Design Engrg. Dept, (for mail), Oklahoma Gas Electric Co., Frigidaire Corp., and (for mail), 127 Scarboro * Third and Harvey, and 3116 Northwest 26th St., Rd., Toronto, Ont., Canada. Oklahoma City, Okla. CALDWELL, Arthur C. (Af 1930), Engr. and Estimator, P. Gormly Co., 155 N. Tenth St., and . (for mail), 550 South 48th St.. Philadelphia, Pa. CARPENTER, R. H. (Af 1921), (Council, 1930 1935), Mgr., New York Office (for mail), Nash Engineering Co., Graybar Bldg., 420 Lexington CALEB, David (Af 1923), Eng. (for mail), Kansas Ave., New York, and 20 Jefferson Ave., White City Power & Light Co., 1330 Baltimore Ave., Plains, N. Y. and 141 Spruce St.. Kansas City, Mo. CARR, Maurice L. (Af 1931), Director, Pittsburgh CALL, Joseph (A 1938; 7 1936), Air Cond. Engr., Testing Laboratory, Stevenson and Locust Sts., EUiott-Lewis Co., 2518 N. Broad St.. Phila Pittsburgh, Pa. - delphia, and (for mail), 669 Jamestown St., CARRIER, Earl G. (Af 1936; 7 1929). Gen. Mgr. -Roxborough, Philadelphia, Pa. and Chief Engr. (for mail). Carrier Engineering, CALLAHAN, Peter J. (Af 1934), Inspecting Engr., , S. A., Ltd., P. O. 7821 and 13 Victoria Ave., Central Hanover Bank & Trust Co.. 60 Broad Melrose, Johannesburg, South Africa. ^ way, New York, and (for mail), 4057 Amboy CARRIER, -Willis H.* (Af 1913). {Presidential Rd., Great Kills. S. 1., N. Y. . Member), (Pres., 1931; 1st-Vice-Pres., 1930; 2nd CALVER, Robert W. (A 1937), Prop, (for mail). Vice-Pres-, 1929; Council. 1923-1932), Chairman Box 832, and 77 Queen St., Kirkland Lake, Ont., of the Board (for mail). Carrier Corp., and 2570 Canada, Valley Drive, Syracuse, N. Y. 14 Roll of Membership CARTER, Alexander W. (7 1936), Heating Engr. CHENOWETH, Dale M. (7 1938; S 1936). (for mail). Monarch Brass Mfg. Co., Ltd., 71 Junior Project Engr., Armstrong Cork Co.,' and Browns Ave., and 2178 Queen St., E., Toronto, (for mail), 536 W. James St., Lancaster, Pa. Canada. CHERNE, Realto E. (A 1938; 7 1929), Engr., CARTER, Doctor (Af 1934), Hollycombe, 359 Carrier Corp., and (for mail), 105 Columbia Croydon Rd.. Caterham, Surrey, England. Ave., Syracuse, N. Y. CARTER, John H. (Af 1936), Special Repr. (for CHERRY, Lester A.* (Af 1921), Consulting Engr. mail), Frick Co., 100 N. Broadway, St. Louis, (for mad). Industrial Planning Corp., 271 and 529 Atalanta Ave., Webster Groves, Mo. Delaware Ave., and 155 Euclid Ave., Buffalo, CARY, Edward B. (Af 1935), Partner (for mail), N. Y. John Paul Jones, Cary & Millar, Inc., 448 CHERRY, Vireil H. (Af 1937). Instructor, Uni Terminal Tower, Cleveland, and Chillicothe Rd., versity of California, Dept, of Mech. Engrg., and Aurora, Ohio. (for mail), 1269 Hearst, Berkeley, Calif. CASE, Delbert V. (Af 1937). Mgr. Air Cond. CHESTER, Thomas* (Af 1917), Consulting Dept., B. D. R. Engineering Corp., 402 Midland Engr., c/o Davidson & Co., Ltd., Central House, Bldg., and (for mail), 3727 Brooklyn, Kansas Kingsway, London. England. City, Mo. CHEYNEY, Charles C. (A 1913). Asst. Sales CASE, Roy H. (A 1936), Resident Mgr. (for mail), Mgr. (for mail), Buffalo Forge Co., 490 Broad 417 Central Bldg., and 3322 Hunter Blvd., way. and 255 Lincoln Parkway, Buffalo, N. Y. Seattle, Wash. CHRISTENSON, Harry (A 1931), Secy.-Treas. CASE, Walter G. (A 1930), Asst. Mgr., Ideal (for mail), Hunter-Prell Co., 38 S. Madison St., Boilers & Radiators, Ltd., Ideal House, Great and R. F. D. No. 1, Battle Creek, Mich. Marlborough St., London, W.I., and (for mail), CHRISTIE, Alfred Y. (A 1933), Salesman. U. S. 66 The Ridgeway, Kenton, Harrow., Middlesex, Radiator Corp., 233 Vassar St., Cambridge, and England. (for mail), 715 LaGrange St., West Roxbury, CASEY, Byron L. (Af 1921), Sales Engr. (for Mass. mail). Jig Electric Ventilating Co., 182 N. CHRISTMAN, William F. (A 1932; 7.1931), LaSalle St., Chicago, and 307 Vine Ave., Park Engr. (for mail), Kroeschell Engineering Co., Ridge. 111. 215 W. Ontario St., and 2803 Lunt Ave., Chicago, CASPERD, Henry W. H. (A 1938; 7 1930), Engr., 111. Carrier Co., Ltd., 24 Buckingham Gate. London, CHRISTOPHERSEN, Andrew E. (Af 1935), and (for mail), 21 Robin Hood Lane, Sutton, Engr.-Custodian (for mail). Board of Education, Surrey, England. Franklin & Waller Br. High Schools, 226 W. CASSELL, John D* {Life Member; Af 1913), Goethe St., and 2923 N. Kilpatrick Ave., Chicago, . Retired (for mail), 2008 Walnut St., Philadelphia, III. Pa., and 740 Garfield Ave., Palmyra, N. J. CHROUCH, Richard B. (7 1936; S 1935), CASSELL, William L. (Af 1936), Owner (for Consumers Power Co., and (for mail), 225 S. - mail), 2501 Telephone Bldg., Kansas City, and Butler Blvd., Lansing, Mich. . R. F. D. No. 6, Independence, Mo. CHURCH, Herbert J. (Af 1922), Mgr. (for mail), CAWBY, Elmer L. (A 1938; 7 1935), Sales Engr. Darling Bros., Ltd., 137 Wellington SL,"-W., (for mail), Carrier Corp., 748 E. Washington Room 904, Toronto, and 358 Main* St... N., Blvd., and 2315 S. Flower St., Los Angeles, Calif. Weston, Ont., Canada. - * CHAMBERS, Fred W. (Af 1936), Pres, (for mail), F. W. Chambers & Co.. Ltd., 96 Bloor St., W., Toronto 5, and 122 Garfield Ave., Toronto, Ont.; Canada. * - . CHAPIN, C. Graham (Af 1933). Treas. (for mail). Hopson & Chapin Mfg. Co., 231 State St., and 65 Faire Harbour Place, New London. Conn. . CHAPIN, Harvey G. (Af 1935), Sales Engr. (for - - mail), Westerlin & Campbell Co., 1113-23 Cor nelia Ave., and 8136 Ingleside Ave., Chicago, 111. CHAPMAN, William A., Jr. (Af 1936), Sales Planning Div. (for mail), Delco-Frigidaire Con ditioning Div.-General Motors Sales Corp., 1420 ' Wisconsin Blvd., and 2515 Shafor Blvd., Dayton, Ohio. ` CHARLES, Thomas J. (Af 1934), 175 Marine CLARE, Fulton W. (Af 1927), 935 Plymouth Rd.. N.E., Atlanta, Ga. * CLARK, E. Harold (Af 1922), Mfrs. Agt.. 600 Michigan Theatre Bldg., and (for mail), 2539 Lakewood, Detroit, Mich. CLARKE, Joseph G. (Af 1936). Sales Engr., Frigidaire Div., General Motor Sales Corp., and (for mail), 1233 Carlisle Ave., Dayton, Ohio. CLEGG, Carl (Af 1922), Dist. Mgr. (for mail), American Blower Corp., 311 MuLual Bldg., and 3513 Gillham Rd., Kansas City, Mo. CLEGG, Robert R. (A 1933), Zone Mgr., Owens- Illinois Glass Co., 1538 LaSalle Wacker Bldg., and (for mail), 3270 Lake Shore Drive, Chicago, 111. . . ' Ave., Brooklyn, N. Y. CLERICUZIO, Gerald P. (7 1935), 87 Grove St.; CHARLET, Louis W. (Af 1934). Mgr., N. Y. Bloomfield, N. J. Branch (for mail), Kewanee Boiler Corp., 37 CLEVELAND, Clyde G. (A 1936). Htg. Engr.; West 39th St., New York, and 427 Rich Ave., Johnson & Cleveland, 192 Main St., and (for - Mt. Vernon, N. Y. . mail), 64 E.*Main St., Bradford, Pa. CHARTERS, William A. (A 1937), Salesman and Field Engr., Canada Foundries & Forgings; Ltd., Brockville, and (for mail), 57 Newton Ave., ' Hamilton. Ont., Canada. CHASE, Chauncey L. (Af 1931). Partner (for mail), Edward E. Ashley, Consulting Engr., 10 East 40th St., New York, and 8829 Fort Hamil ton Parkway, Brooklyn. N. Y. CHASE, Louis R. (A 1938; 7 1931), Dist. Super visor (for mail), Carter-Waters Corp., 2440 CLINE, Edward A. (Af 1937), Sales Engr., Genera] Electric Air Conditioning Co., 1510 S. Los Angeles St., Los Angeles, Calif. . CLIPPINGER, J. Verne (3 1936), Student Engr., York Ice Machinery Corp., and (for mail), Yorkco Club, York. Pa. . CLODFELTER, John L. (A 1932), Supt. (for mail), Carolina Sheet Metal Corp., 17th St. and Chelten Ave., Philadelphia, and West Chester Pike and Brief Ave., Elizabeth Manor Apt., Pennway, and 214 Brushcreek, Kansas City, Mo. Upper Darby, Pa. CHEATWOOD, William H. (7 1937), Com CLOSE, Paul D.* (Af 1928), Asst. Mgr., Metuchen mercial Engr. (for mail), Straus-Bodenheimer Div., Celotex Corp., 101 .Park Ave., New York, Co., 1513 Prairie Ave., and 2705 Louisiana, N. Y., and (for mail), 564 Meadow Rd., Win- Houston, Texas. . netka, 111. * CHEESEMAN, Evans W. (7 1937; 5 1934), Engr.. * COCHRAN, Charles C. (A 1935), Asst. Sales . Perfection Stove Co., 7609 Platt Ave., and (for Mgr., Midwest Region (for mail), Minneapolis- ' --mail), 2200 Prospect Ave., Cleveland, Ohio. Honeywell Regulator Co., 433 E. Erie, and 5221 CHEN, Sarcey T. (Af 1936). Director and Partner ' N. Kenmore Ave.. Chicago. III. ' (for mail). American Engineering Corp., 989 COCHRAN, Lex H. (Af 1934). Dist. Mgrl (for Bubbling Well Rd., and 122 Route Frelupt, mail), American-Blower Corp., 625 Market St., Shanghai, China. - and 130 Camino Del Mar, San Francisco, Calif. Heating Ventilating Air Conditioning Guide 1938 COCHRAN, William B. (V 1936; 5 1935), Air Cond. Engr. (for mail). Cochran Air Conditioning Co. (Westinghouse), 1303 Lamar Ave., and 3316 Telephone Rd., Box 16, Houston, Texas. COCKINS, William W. (7 1937), Sales Engr. (for mail), Trane Co., 1129 Folsom St., San Fran cisco, and 2466 Virginia St., Berkeley, Calif. CODY. Henry C. (Af 1936), Sales Engr., Pierce. Butler Radiator Corp., 19th and Glenwood Ave., and (for mail). 7336 North 21st St., Philadelphia, Pa. COGHLAN, Sherman F. (A 1937), Metropolitan Water Dist. of So. Calif., 306 W. Third St., Los Angeles, and (for mail), 414 Ninth St., Santa Monica, Calif. COHAGEN, Chandler C. (Af 1919), Archt., 211 Hedden Bldg, (for mail). Box 2100, and 235 Avenue G.. Billings, Mont. COHEN. Harry (7 1937; 5 1936), 3630 East 140th St.. Cleveland, Ohio. , COHEN, Philip (Af 1932), Dist. Mgr. (for mail). B. F. Sturtevant Co., 401 E. Ohio Gas Bldg., Cleveland, and 3681 Lynnfield' Rd., Shaker Heights, Ohio. COLBY, Clyde W. (Af 1915). Consulting Engr. (Air Cond.), 1215 Main St., Springfield, Mass., 578 Madison Ave., New York, N. Y., and (for 1 mail), 80 N. Pleasant St., Holyoke, Mass. COLCLOUGH, O. T. (A 1933), Custodian. American Legation, American Government Bldg., and (for mail), 180 Lisgar St.. Ottawa, Canada. COLE, Charles B. (7 1937), Chief Engr., General Air Conditioning Co., 160 Peachtree St., and (for mail), 1843 Flagler Ave., N.E., Atlanta, Ga. COLE, Grant E. (A 1925). Vice-Pres. and Gen. Mgr. (for mail), Trane Co. of Canada, Ltd., 4 Mowat Ave., and 117 Royal York Rd., Toronto, and Ont., Canada. -- COLEMAN, John B. (Af 1920), Chief Engr. (for mail), Grinnell Go., Inc., 260 W. Exchange St., and 237 Cole Ave., Providence, R. I. COLFORD. John (A 1937), Pres.. John Colford, Ltd., 2007 Guy St.. Montreal, and (for mail),. 51 Upper BeUevue Ave., Westmount, Que.,. .Canada. . COLLIER, William I. (Af 1921), Pres, (for mail). W. I. Collier & Co., 522 Park Ave., Baltimore, and Ellicott St., Ellicott City, Md. COLLINS, John F. S., Jr. (Af 1933), Supervisor of Steam Utilization (for mail), Allegheny - County Steam Heating Co., Philadelphia Company Bldg., 435 Sixth Ave., and 827 N. Euclid Ave., Pittsburgh, Pa. COMB, Fred R., Jr. (7 1938; S 1937), Sales Engr., Delco-Frigidaire Conditioning Div., 2446 University Ave., St. Paul, and (for mail), 2425 Bryant Ave., S., Minneapolis, Minn. COMPTON, Warren E. (7 1936; 5 1935), Engr., 904 W. Green St., Urbana. 111. COMSTOCK, Glen M. (A 1926), Dist. Repr., (for mail), 604 Chamber of Commerce Bldg., Pittsburgh, and 154 College Ave... Beaver, Pa. CONATY, Bernard M. (Af 1935), Sales Mgr. (for mail), American District Steam Co., N. Tona- wanda, and P. O. Box 342, Eden, N. Y. CONE, William E. (J 1937), Air Cond. Engr.,. Shook & Fletcher Supply Co., 1814 First Ave., N., and (for mail), 1037 Tenth Ave., S., Birming ham, Ala. CONNELL, Harold (Af 1935), Engr. and Esti mator, Armo Cooling & Ventilating Co., Inc., 30 West 15th St., New York, and (for mail), 12 Donald Place, West New Brighton, S. I., N. Y. CONNELL, Richard F. (Af 1916), Mgr., Capitol Testing Lab. (for mail), U. S. Radiator Corp., 1056 National Bank Bldg., and 2970 Burlingame, Detroit, Mich. CONNER, Raymond M. (Af 1931), Director, Testing Laboratories (for mail). American Gas . Association, 1032 East 62nd St., Cleveland,-and 271 East 216th St., Euclid. Ohio. CONRAD, Roy (Af 1935), Comm. Dist. Mgr., Kelvinator Div. . (for mail), Nash-Kelvinator Corp., 1355 Market St., and 751--20th. Ave., San Francisco, Calif. CONSTANCE, John D. (7 1937), Draftsman. York Ice Machinery Corp., 42nd St. and Second Ave., Brooklyn, N. Y., and (for mail), 407-27th St., North Bergen, N. J. CONSTANT, Earl S. (7 1935), Air Cond. Sales Engr., Viking Air Conditioning Co., 1818 Main St., and (for mail), 825 N. Crawford St., Dallas. Texas. COOK, Benjamin F. (Af 1920), Consulting Engr., 114 W. Tenth St. Bldg., Kansas City, and (for mail), 1720 Overton Ave., Independence, Mo. COOK, George E. (A 1937), Vice-Pres. (for mail), Airconditioning, Inc.. 2324 Hampden Ave., St. Paul, and 2115 Blaisdell Ave., Minneapolis, Minn. COOK, Harris R. (A 1935), Dist. Mgr. (for mail), American Foundry & Furnace Co., 709 North 11th St,, and 2325 North 50th St., Milwaukee, Wis. . COOK, Ralph P. (Af 1930), Asst. Supt., Engrg. and Maintenance Dept, in charge of Engrg. Div., Eastman Kodak Co. (for mail), Kodak Park Works, and 663 Seneca Parkway, Rochester, N. Y. COOKE, Thomas C. (A 1937), Salesman (for mail). Tomlinson Co., Inc., 400-402 Peabody St., and 305 Monmouth Ave., Durham, N. C. COOMBE, James (A 1932), Vice-Pres. (for mail). William Powell Co.. 2525 Spring Grove Ave., and 2363 Grandin Rd., Cincinnati, Ohio. COOLEY, Edgerton C. (Af 1937), Mfrs. Agent (for mail), 625 Market St., San Francisco, and Box 789 B, Rte. 1, Los Altos, Calif. COON, Thurlow E. (Af 1916), Pres, (for mail),.. Coon-DeVisser Co., Inc., 2051 W. Lafayette, and 826 Edison Ave., Detroit. Mich. COOPER, Albert W. (Af 1935), Branch Mgr. (for mail). Johnson Service Co., 153 W. Ave. 34, Los Angeles, and 2614 Hermosita Drive, Glen dale. Calif. COOPER, Dale S. (A 1937), Air Cond. Engr: (for mail). Air Conditioning Co., 4304 Main St., and 2237 Bellaire Blvd., Houston, Texas. COOPER, John W. (Af 1932; A 1025; 7 1921). Repr. (for mail), Buffalo Forge Co., 1598 Arcade Bldg., St. Louis, and 612 Hawbrook Drive, Kirkwood, Mo. COOPER, Tom E. (7 1937; 5 1936), 309 West 50th St., Minneapolis, Minn. COOPER, William B. (7 1937), Engr., Lamneck Products, Inc., 416*36 Dublin Ave., and (for mail), 2394 Neil Ave., Columbus, Ohio. COPPERUD, Edmund R. (7 1933), Asst. Mgr. (for mail), Minneapolis Plumbing Co., 1420 Nicollet Ave., and 17 West 25th St., Minneapolis, Minn. COREY, George R. (Af 1936), Sales Engr., Massachusetts Wharf Coal Co., 60 Devonshire St., Boston, and (for mail), 106 Central Ave., Milton, Mass. CORNISH, Donald F. (7 1936), Consulting Engr.. Dominion Heating Specialty Co., and (for mail), 95 Dinnick Cres., Toronto, Ont., Canada. CORNWALL, Charles C. (7 1935), Research Engr., Bahnson Co., 1001 S. Marshall St., and (for mail), 473 Carolina Circle, Winston-Salem, N. C, CORNWALL, George I. (Af 1919), Salesman (for mail). Burnham Boiler Corp., 701 Spring St., and' 633 Madison Ave., Elizabeth, N. J. CORRAO, Joseph (A 1936; 7 1933), Engr., City and County of San Francisco, City Hall, and (for mail), 854-31st Ave., San Frandsco, Calif. CORRIGAN, James A. (7 1935; 5 1930), Engr. (for mail). Corrigan Co., 2501 St. Louis Ave., and 6130 McPherson, St. Louis, Mo. COTTER, Robert P. (7 1937; 5 1935), Carrier Air Cond. Engr., Martin Wright Electric Co., 1001 Navarro SL_, and (for mail), 935 W. Summit Ave., San Antonio, Texas. COVER, E. B. (Af 1937), Sales Engr., York Ice Machinery Corp., 115 South 11th St., St. Louis, Mo.,and (formail), 3252 Waverly, E.St. Louis; 111. 16 j Roll or Membership COVER, Richard R. (A 1936), Carrier Corp., 301 Tower Bldg., and (for mail), 1302 Gallatin St., N.W., Washington, D. C. COWARD, Charles W. (Af 1935), Pres, (fof mail), Coward Engineering Co., 411 Cooper St., Camden, and 812 Lincoln Ave.; Palmyra, N. J. COX, Harrison F. (A 1930), Htg. and Air Cond., 243 Carroll St., Paterson, N. J. COX, Thomas M., Jr. (7 1937), Sales Engr., Neal & Massy Engineering Co., Ltd-, Port of Spain, Trinidad, B. W. I. COX, William W. (Af 1923), Pres.-Mgr. (for mail), Heating Service Co., 326 Columbia St., and 6232-31st Ave., N.E., Seattle, Wash. CRANSTON, William E., Jr. (Af 1931), VicePres. and Gen. Mgr. (for mail), Thermador Electric Mfg. Co., 2821 E. Pico St., Los Angeles, and 240 Hadenda Drive, Arcadia, Calif. CRAWFORD, John H,, Jr. (A 1936; 7 1930), Air Cond. Engr., Hitchen Engineering Co., 441 Lex ington Ave., New York, N. Y., and (for mail), 433 Lincoln Ave., Orange, N. J. CRIBARI, Hugo (A 1937), Salesman, American Radiator Co., 40 West .40th St., New York, and (for mail), 560 Gramatan Ave., Mt. Vernon, N. Y. . CRICHTON, Howard C. (7 1938; S 1936), 769 Beaver Ave., Midland, Pa. CRIQUI, Albert A* (Af 1919), Chief Engr., Htg. and Vtg. Dept., Buffalo Forge Co., 490 Broadway, Buffalo, and (for mail), 39 St. Johns Ave., Kenmore, N. Y. CRONE, Charles E., Jr. (Af 1922), Secy.-Treas. (for mail), Wendt & Crone Co., 2124 N. South port Ave., and 1320 N. State St., Chicago, 111. CRONE, Thomas E. (Life Member; M 1920), Sales Engr., Pelham Coal & Oil Co., and (for mail). 205 Pelhamdale Ave., Pelham, N. Y. CROSBY, Edward L. (Af 1936), Pres, (for mail), Henry Adams. Inc., Consulting Engrs., 1263-69 Calvert Bldg., and 5811 Merville* Ave., Balti more, Md. ` CROSS. Freeman G. (Af 1936);*. Sales Mgr., Controls Div. (for mail),' Fulton Sylphon Co.,. 19 Rector St.,-New York, N; Y., dnd 11 Inwood Place, Maplewood, N. J. CROSS, Robert C.* (Af 1937), Fuel Engr. (fdr mail). Battelle Memorial Institute, 505 King Ave., and 1740 King Ave., Columbus, Ohio. CROSS. Robert E. (A 1931), 95 State St.. Spring field, Mass. CRUMP, Alvin L. (Af 1937), Sales Engr. (for mail). Powers Regulator Co., 2720 Greenview Ave., Chicago, and 2701 Payne St.. Evanston, III. CUCC1, Victor J. (Af 1930), Consulting Engr. (for mail), 347 Madison Ave., New York, and 451 55th St., Brooklyn, N. Y. CULBERT, William P. (A 1929), Secy, (for mail), Culbert-Whitby Co., 2019 Rittenhouse St., Philadelphia, and 929 Alexander Ave., Drexel Hill, Pa. CULLEN, Augustine C. (A 1936), Pres, (for mail), Cullen, Inc., 20 L. St.. S.W., and 1301 Massachusetts Ave., N.W., Washington, D. C. CUMMING, Ford J. (Af 1936), Pres, (for mail). Beecher-Cumming, Inc., 820 Second Ave., S., Minneapolis, and 120 Interlachen Rd., Interlachen Park, R. R. 1, Hopkins, Minn. CUMMING, Robert W. (Af 1928), Engr.-Sales Executive, Sarco'Co., Inc., 183 Madison Ave., New York, and (for mail), 81 Alkamont Ave., Scarsdale, N. Y. CUMMINGS, Carl H. (A 1927; 7 1926), Pres, (for mail). Industrial Appliance Co. of New England, 110 Arlington St., Boston, and 41 Edgehill Rd... Chestnut Hill, Mass. CUMMINGS, G. J. (M 1923), Mgr. (for mail). The Scott Co., 113 Tenth St., and 2001 Hoover Ave.. Oakland, Calif. CUMMINS, George H. (Af 1919). Dist. Mgr. (for mail), Aerofin Corp., 918 United Artist's Bldg., and 16210 Ashton Rd., Detroit, Mich. CUNLIFFE, Jack A. (A 1937), Western Can. Mgr. (for mail), A. P. Green Co. of Canada, Ltd., 1034 Arlington St., and 133 Arlington St., Winnipeg, Man., Canada. CUNNINGHAM, John S. (7 1937; 5 1935). Htg. Engr., Rudy Furnace Co., and (for mail), 311 N. Front St., Dowagiac, Mich. CUNNINGHAM, Thomas M. (Af 1931; 7 1930), Production Mgr., Carrier Corp., 7-122 Mer chandise Mart, Chicago, 111. CURRIE, Francis J. (A 1935), Prop., Plbg.-Htg. Contractor, 16 South 39th St., Philadelphia, and (for mail), 9 Montrose Ave., Kirklyn, Upper Darby, Pa. - CURRIER, Charles H. (Af 1919), Vice-Pres. (for mail), Ross Heater & Mfg. Co., Inc., 1407 West Ave., and Park Lane Apts., 33 Gates Circle. Buffalo, N. Y. CURTICE, Jean M. (A 1936), Repr., House Htg. Engr., Public Service Co. of Colorado, W. Moun tain Ave., and (for mail), 309 Locust St., Fort Collins, Colo. CURTIS, Herbert F. (A 1934). Chief EngJ. (for mail), Henry Furnace & Foundry Co., 3471 East 49th St., Cleveland, and 59 Fourth Ave., Berea, Ohio. CURTIS, Walter A. (7 1938; 5 1936), Sales Engr.. B. F. Sturtevant Co., 220 Delaware Ave., and (for mail), 2429 Delaware Ave., Buffalo, N. Y. CUTHBERTSON, Merle W. (A 1937). Supt. . Mech. Equip, and Bldgs., Hardware Mutual Fire Insurance Co., 2344 Nicollet Ave., Minne apolis, and (for mail), 1466 Hague Ave., St. Paul, Minn. ` CUTLER, Joseph A. (Af 1916), (Council, 1920 1926), Vice-Pres. (for mail). Johnson Service Co., 1355 Washington Blvd., Chicago, and 649 Hinman Ave., Evanston, 111. D DAHLSTROM, Godfrey A. (A 1927), Htg. Sales Engr., Central Supply Co., 312 S. Third St., and - (for mail), 3721--47th Ave., S., Minneapolis, Minn. . - DAILEY, James A. (A 1920), 31-64-30th St., Astoria, L. I., N. Y. . DA1TSH, Abe (7 1937), Ppst-Grad. Student'(for mail), Massachusetts Institute of Technology, Graduate House, Cambridge. Mass., and 87 King Edward Rd., Parow, C. P., Union of South Africa. DAKIN, Harold W. (7 1934), General Electric Co., Woodlawn Ave., Pittsfield, and (for mail), 169 Park Ave., Dalton, Mass. DALY, Charles P. (A 1935), Member of Firm (for mail), Rautman Plumbing & Heating Co., 115 Jackson St., and 2438 Queen Anne Ave., Seattle, Wash. DALY, Robert E. (Af 1931), Dir. of Engrg. (for mail), American Radiator Co., 40 West 40th St., New York, and Bronxville, N. Y. DAMBLY, A. Ernest (Af 1924; 7 1921), (for mail), c/o H. B. Hackett, 901 Architects Bldg., Phila delphia, Pa., and Harvey Cedars, N. J. DAMM, Daniel A. (7 1937), Air Cond. Engr., Surface Combustion Corp., 1435 Dorr St., and (for mail), 1908 Joffre Ave., Toledo, Ohio. DANIELSON, E. B. (A 1936), Owner-Mgr. (for mail), Air Conditioning Co., 627 Main St., and 819 Main St., Russell, Kan. DANIELSON, Lloyd C. (7 1938; S 1936), Test Dept- (for mail). General Electric Co., and 223- .Robinson St.. Schenectady. N. Y. DANIELSON, Wilmot A. (Af 1935), Lieut.-Col., Q. M. C., U. S. Army, Fort Knox, Louisville, Ky. DARBY, Marion H. (A 1938; 7 1930), Chief Engr., Air Cond. Dept., General Electric, S. A., Avenida Rio, Branco No. 114, Rio de Janeiro, Brazil. ' DARLING, Arthur B. (A 1929), Asst. Sales Mgr. (for mail). Darling Bros., Ltd., 140 Prince St., Montreal, P. Q., and 4326 Sherbrooke St., Westmont, P. Q., Canada. DARLING, John K. (7 1937), Engr., Sidles Co., Airtemp Div., and (for mail), 1414 C St., Lincoln, Nebr. DARLINGTON, Allan P. (Af 1930), Dist. Sales ' Mgr. (for mail), American Blower Corp., 6000 Russell St., and 5200 Haverhill, Detroit, Mich. 17 Heating Ventilating Air Conditioning Guide 1938 DARTS, John A. (M 1919), Kewanee Boiler Co., DAY. Harold C. (A 1934), Mgr. (for mail), Inc., 101 Park Ave., New York, N. Y. American Radiator Co., 1807 Elmwood Ave., and DASING, Emil (Af 1937), Designing Engr., Sears Stuyvesant Hotel, Buffalo, N. Y. Roebuck & Co.. 925 S. Homan Ave., and (for DAY, Irving M. (A 1936), Sales Engr. (for mail), mail). 4729 N. Talman Ave., Chicago, 111. 709 .Mills Bldg., Washington, D. C., and 405 DAUBER, Oscar W. (Af 1937), Owner (for mail)/ Cumberland Ave., Chevy Chase, Md. 224 S. Michigan Ave., Chicago, and 366 Winneta DAY, V. S.* (Af 1924), Engr. (for mail). Carrier Ave., Winnetka, 111. ' Corp.. 306 Highland Ave., Syracuse, N. Y. DAUBERT, LeRoy L. (7 1937), Branch Mgr., DEAN, Carl H. (Af 1936), Htg. Engr. (for mail), Sidles Co. Airtemp Div., 805 Walnut St., and Oklahoma Natural Gas Co., P. O. 871, and 1007 (for mail), 2315 Grand, Des Moines, Iowa. N. Main, Tulsa, Okla. DAUCH, Emil O. (Af 1921). Secy.-Treas. (for DEAN, Charles L. (Af 1932). Asst. Prof, of Mech. mail). McCormick Plumbing Supply Co., 1675 Engr., University of Wisconsin. 305 University Bagley Ave., and The Whittier Hotel, Detroit, Extension Bldg., and (for- mail). 102 Grand Ave., Mich. DAVENPORT, R. F. (A 1933), Furnace Sales Madison, Wis. . DEAN, David (Af 1937), Htg. Engr. and Salesman, Mgr., Canada Foundries & Forgings, Ltd., and New York Specialties Co., Inc., 334-6 East 98th (for mail), 258 Melrose Ave., Toronto, Ont., St., New York, and (for mail), 171 Radford St., Carlada. DAVEY, Geoffrey I. (Af 1937), Consulting Engr., Yonkers, N. Y. - DEAN, Frank J., Jr. (7 1935; S 1934), Sales Engr., Haskins & Davey, 60-66 Hunter St., Sydney, Gustin-Bacon Mfg. Co., 1412 West 12th St., and N.S.W., Australia. (for mail), 6028 Walnut St., Kansas City, Mo. DAVIDSON, John C. (7 1936), Warm Air Htg. DEAN, Marshall H. (7 1938; 5 1936), 1030 West and Air Cond. Inspector, City of Minneapolis, 213 City Hall, and (for mail). 4233 Nicollet .Ave., Minneapolis, Minn. , 55th St., Kansas City, Mo. DEE, Leo H. (7 1937), Engr., Carrier Corp., Syracuse, and (for mail), 1026 W. Onondaga St., DAVIDSON, L. Clifford (Af 1927), Associate Dist. Mgr. (for mail), Buffalo Forge Co., 220 South 16th St., Philadelphia, and 439 Anthwyn Syracuse, N. Y. DEELY, James J. (A 1937; 7 1933), Supervisor House Htg. Div. (for mail), Brooklyn Union Gas Rd.. Merion, Pa. DAVIDSON, Philip L. (M 1924; J 1921), Con Co., 180 Remsen St.. Brooklyn, and 61 College - Ave., N.t Tarrytown, N. Y. sulting Engr. (for mail), 1204 Commercial Trust DeLAND, Charles W. (Af 1924; 7 1923), Secy.- . Bldg., Philadelphia, and 14 Radnor Way, Treas. (for mail), C- W. Johnson, Inc., 211 N. Radnor, Pa. . DAVIES, George W. (Af 1918), Mgr. (for mail), G. W. Davies & Co., 19 Maclaggan St., Dunedin, Cl, and Colinswood, Macandrew Bay, New Zealand. . DAVIS, Arthur C.* (Af 1920), Supt. of Matn- ' tenance. Port of New York Authority. Ill Eighth Ave., New York, N. Y., and (for mail). 73 Preston St., Ridgefield Park, N. J. DAVIS^ Arthur F. (Af 1934), Pres, (for mail), Johnson & Davis Plumbing & Heating Co., 2235 Arapahoe St., and 1901 Ivanhoe St., Denver, Colo. DAVIS, Bert C. (Life Member; M 1904), (Council, 1917), Pres -Treas. (for mail). American Warming .& Ventilating Co.; 317-19 Pennsylvania Ave., ' Desplaines St., and 2021 Estes Ave.. Chicago. 111. DENISE. John R.. (A 1937; 7 1935). Engr., Surface Combustion Corp., 400 Dublin Ave., Columbus, Ohio. ... - DENNY, Harold R. (A 1934), Eastern Mdse. Mgr. (for mail), American Blower Corp., 50 West 40th St., New York, N. Y., and 429 Edgewood Ave., Westfield, N. J. .. - DEPPMANN, Ray L. (A 1937), Pres, (for mail). R. L. Deppmann Co., 957 Holden Ave.,-*1320l Cloverlawn Ave., Detroit, Mich. .. DeSOMMA, Anthony E. (7 1937), Sales Engr.. Oliver & McClellan. Inc., 30 Church St., New York, and (for mail). 827--40th St., Brooklyn,- N. Y. . DES REIS, John F. (Af 1936), Mgr., West Indies and Caribbean Div., Carrier Corp., and. (for and 603 W. Church St., Elmira, N. Y. mail), 507 S. Beech, Syracuse, N. Y.... DAVIS, Calvin R. (Af 1927). Branch Mgr. (for DETERLING, William C. (A 1937), Salesman mail), Johnson Service Co., 2328 Locust St., and (for mail). General Electric Co., 570 Lexington 7534 Westmoreland Drive, St. Louis. Mo. Ave., New York, and 32 W. Milton St., Free DAVIS, George C. (7 1936), Sales Engr. (for mail). port, N. Y. Northern Public Service Corp., Ltd., 307 Power DEVER, Henry F. (Af 1936; A 1935), Branch Bldg., Winnipeg, and 923 Somerset Ave., Fort Mgr., Minneapolis-Honeywell Regulator Co., Garry, Man., Canada. Wayne and Roberts Aves., Philadelphia, and (for. DAVIS, Joseph (Af 1927; A 1926), Owner-Htg. mail), 502 Merwyn Rd.. Narberth, Pa. ' ' Engr. and Contractor (for mail), 316 Root Bldg., DeVILBISS, Parker T. (A 1937), Chief Engr. and `70 w. Chippewa, and 166 Huntington Ave., Secy, (for mail), U. S. Air' Conditioning Sales Buffalo. N. Y. . DAVIS, Keith (M 1937), Engr. (for mail), L. J. Mueller Furnace Co., 2005 W. Oklahoma Ave., and 2426 N. Cramer St., Milwaukee, Wis. DAVIS, Otis E. (Af 1929; A 1925), Sales Engr. (for mail). Hoffman Specialty Co., Box 98, and 1402 . Third Ave.. Scottsbluff, Nebr. DAVIS, Rowland G. (A 1921), Sales Repr., 887 Nela View Rd., Cleveland Heights, Ohio. Corp., 1701 Grand Ave., and 5545. Tracy, Kansas City, Mo. - DEVORE,'Angus B. (A 1937), Sales Engr. (for mail), James A. Messer Co., Inc., 1206 K St., N.W., and 247 Quackenbos St., N.W., Wash ington, D. C. . . DEWAR, William G. (A 1936), Purchasing Agt., Construction Equipment Co., Ltd., 1200 Benoit St., and (for mail), Apt. 4, 5550 Cote St. Luc, Montreal, Que., Canada. DAVISON, Robert L. (Af 1934), Director of DEWEY, Ritchie P. (Af 1934), Mgr., Temp. Housing Research (for mail). John B. Pierce Control and Uni-Flo Depts., Barber-Colman Foundation, 37 West 39th St., New York, and Co.. River and Loomis Sts./ and (for mail). Meadow Glen Rd.-, Fort Salonga, L. I., N. Y. 2301 Oxford St.. Rockford, 111. DAWSON, Eugene F. (Af 1934), Asst. Prof., DeWITT, Earl S. (A 1936), Branch Mgr. (for Mech. Engr. (for mail). University of Oklahoma, mail), American Blower Corp., 438 Woodward and 916 S- Flood St., Norman, Okla. Bldg., and 3224 Oliver St., N.W., Washington, DAWSON, G. Stewart (A 1935), Mdse. Sales D. C. Engr. (for mail), British Columbia Electric DEXTER, Ernest R. (7 1937), Junior Engr. (for Railway Co.. Ltd.. 425 Carroll St., and 1860 mail). Sidles Co., Airtemp Div., 425 Stuart Barclay St., Vancouver, B. C., Canada. Bldg., and 136 South 17th St., Lincoln, Nebr. DAWSON, Thomas L. (Af 1930), Pres, (for mail), Thomas L. Dawson Co., 2035 Washington St., Kansas City, Mo., and 56th and Shawnee Mis DIAMOND, David D. (7 1937), Designing Engr., Twin City Furnace Co. of Minneapolis, 410 W. Lake St., and (for mail). 118 E. Congress St., sion Rd., Rosedale Station, Kansas City, Kan. St. Paul. Minn. 18 Roll of Membership DIBBLE, S. E. (M 1917), (Presidential Member), (Pres., 1925; 1st Vice-Pres.. 1924; 2nd VicePres.. 1923; Council, 1921-1926), Supt., Thomas Ranken Patton School, Elizabethtown, Pa. DICK, Andrew V. (7 1935), Pres., A. V. Dick Heating Co., 141 Jay St., Albany. N. Y. DICKENSON, Frederick R. (Af 1936; A 1934), Asst. Sales Mgr. (for mail), American Blower Corp., 6000 Russell St., Detroit, and 284 Pilgrim Rd., Birmingham, Mich. DICKENSON. Malcolm E. (Af 1936), Gen. Mgr. (for mail), Livingston Stoker Co., Ltd.. 78 Catherine St., N., and 964 Cumberland Ave., Hamilton, Canada. DICKEY, Arthur J. (Af 1921), Vice-Pres.-Gen. Mgr., C. A. Dunham Co., Ltd., 1523 Davenport Rd., and (for mail), 9 Mossom Place, Toronto, Ont., Canada. DICKINSON, Tom (A 1936). Draftsman. York Ice Machinery Corp., and (for mail), 419 West 65th St.. Los Angeles, Calif. DICKSON, George P. (Af 1919), Dist. Mgr. (for mail), B. F. Sturtevant Co., 89 Broad St., ` Boston. Mass., and P. O. Box 22. Canterbury, New Hampshire.. DICKSON, Robert B. (Af 1919), Pres, (for mail), Kewanee Boiler Corp., Franklin St., and Q Tracks, and 145 E. Division St.. Kewanee, 111. DIETZ, C. Fred (Af 1937), Sales Engr. (for mail), Haynes Selling Co., Inc., 1124 Spring Garden St., and 4028 Neilson St., Philadelphia, Pa. DION, Alfred M. (Af 1937), Air Cond. Engr. (for mail), Trane Co. of Canada, Ltd., King and Mowat Sts., and 133 Cottingham St., Toronto, Out., Canada. DISNEY, Melvin A. (A 1934), Pres., DisneyLeffel Co.. Inc., 629 New York Life Bldg., and (for mail), 6648 Kenwood, Kansas City, Mo. DIVER, M. L. (Af 1925), Consulting Engr., P. O. Box 1016, San Antonio, Texas. DIXON, Arthur G. (Af 1928). Sales Mgr. (for mail), Modine Mfg. Co., and 442 Wolff St., Racine, Wis. DIXON, Meredith F. (A 1937), Combustion Engr., Fuel Oil and Oil Burner Div., Imperial Oil, Ltd., P. O. Box 1440, and (for mail). 2281 - Wilson Ave., Montreal, Que., Canada. DOBIE, Thomas K. (A 1936), Supt. of Bldgs., . .London Life Insurance Co., and (for mail), 969 Colbome St., London, Ont., Canada. DODDS. Forrest F. (Af 1920). Mgr., K. C. Branch (for mail), American Radiator Co., 1023 Grand Ave., and 229 Ward Parkway. Kansas City, Mo. DODGE, Harry A. (Af 1936), Elec. Engr., S. H. Kress & Co.. 114 Fifth Ave.. and (for mail), 425 East 86th St.. New York. N. Y. DOERING, Frank L. (Af 1919), Sales Engr., American Radiator Co., 238 Boston Ave., Lynchburg, Va. DOLAN. Raymond G. (Af 1926; 7 1922), Secy.Treas. (for mail), Tom Dolan Heating Co., Inc., 614 W. Grand, and 2112 West 20th. Oklahoma City, Okla. DOLSON, Charles N. (A 1937). Sales Engr., Illinois Iron & Bolt, 908 S. Michigan Ave., and (for mail). 46 Hawkins Ave., Chicago. 111. DOME. Alan G. (A 1938; 7 1936), Engr., Bryant Air Conditioning Corp., 230 Park Ave., New York, and (for mail), 448 River Ave., North Pelham, N. Y. DONELSON, William N. (7 1937). Engr. (for mail), T. J. Conners, Inc., 3290 Spring Grove, Cincinnati, Ohio, and 1558 Madison Ave., Covington, Ky. DONNELLY. James A.* (Life Member; Af 1904). (Treas., 1912-1914), Largent, W. Va. DONNELLY, Martin A. (7 1937), Salesman. McArdle & Cooney, 519 Arch St.. Philadelphia, and (for mail), 500 Manoa Rd., Brookline, Del. Co., Pa. DONNELLY, Russell, (Af 1923), Sales Engr , Nash Engineering Co., Graybar Bldg., 420 Lexington Ave., New York, N. Y. . DONOHOE. John B. (A 1937; 7 1935), Engr.Estimator (for mail), B. F. Donohoe Co.. 51 Albany St., Boston, and 24 Primrose St., Roslindale. Mass. DONOVAN. William J. (A 1930). 2239 North 27th St.. Philadelphia, Pa. DORFAN, M. I. (Af 1929), Dust Control Special ist. Pangbom Corp.. 604 Chamber of Commerce Bldg., and (for mail), 1217 Malvern Ave., Pittsburgh. Pa. DORNHEIM. G. A. (Af 1912; 7 1906), 15 Hamil ton Ave.. Bronxville, N. Y. DORSEY, Francis C. (Af 1920), Engr.-Contractor (for mail). Francis C. Dorsey. Inc., 4520 Schenley Rd., Roland Park, and 212 Gittings Ave., Baltimore, Md. DOSTER, Alexis (A 1934). Vice-Pres.-Secy. (for mail). Torrington Mfg. Co., 70 Franklin St., Torrington and South Plains, Litchfield, Conn. DOUGHTY, Charles J. (Af 1925). Fres.-Managing Director (for mail), C. J. Doughty & Co., Fed. Inc.. U. S. A., 30 Brenan Rd., and 1920 Ave., Joffre, Shanghai, China. DOUGLAS, Howard H. (A 1936). Air Cond. Engr. (for mail). Southern California Edison Co., 601 W. Fifth St., and 2317 Kelton Ave., Los Angeles, Calif. DOVOLIS, Nick J. (7 1936; S 1935), 3403 Chicago Ave., Minneapolis, Minn. DOWLER, Edward A. (Af 1937), Sales Engr., B. F. Sturtevant Co. of Canada. Ltd.. 137 Wellington St., W., and (for mail), 9 Prince Arthur Ave., Toronto, Ont.,-Canada. DOWNE, Edward . R. (Af 1927). Vice-Pres.. American Gas Products Corp., 40 West 40th St., New York, and (for mail), 35 Howell Ave., Larchraont, N. Y. DOWNE, Henry S. {Life Member; M 1895), Cie Nationale des Radiateurs, 149 Boulevard Haussman, Paris, and 5. rue Verdi, Paris, 16e, France. - DOWNES, Alfred II. (A 1937), Draftsman, 1342J4 Bond St., Los Angeles, Calif. DOWNES, Henry H. (Af 1923), Dist. Mgr. (for mail), American Blower Corp., 438 Woodward Bldg., Washington, D. C., and 4621 Chevy Chase Blvd., Chevy Chase, Md. DOWNES, Nate W. (Af 1917), (Council. 1928 1930, 1937), Chief Engr.-Supt. of Bldg, (for mail). School District of Kansas City, Mo., 317 Finance Bldg., and 2119 East 68th St., Kansas City, Mo. DOWNS, Charles R. (Af 1936). Vice-Pres.-Treas. (for mail), Weiss & Downs, Inc., 50 East 41st St., New York. N. Y., and Sylvan Lane, Old Green wich, Conn. DOWNS, Sewell H. (Af 1931), (Council. 1937), Chief Engr., Clarage Fan Co., and (for mail), 211 Creston Ave., Kalamazoo, Mich. DOXEY, Harold E. (A 1937), Engr. (for mail). Ocean Accident & Guarantee Corp., Ltd., 308 Phoenix Bldg., and 4251 Quincy St., N.E., Minneapolis. Minn. DOYLE, William J. (Af 1920), Designing Engr., Williamson Heater Co., 335 W. Fifth St., and (for mail), 3766 Hyde Park Ave., Cincinnati, Ohio. - . DRAKE, G. Forrest* (Af 1937). Development Engr., Barber-Colman Co., and (for mail), 709 CamlinAve., Rockford, III. DRAKE, George M. (7 1936). Vice-Pres. (for mail), George H. Drake, Inc., 218 Lexington Ave.. and 351 Norwood Ave., Buffalo, N. Y. . DRIEMEYER, Ray C. (7 1937). Prod. Engr., Airthenn Mfg. Co., 1474 S. Vandeventer Ave., and (for mail), 5410 Vernon Ave., St. Louis, Mo. DRINKER, Philip* (Af 1922). Prof, (for mail). Harvard School of Public Health, 55 Shattuck St.. Boston, and 40 Puddingstone Lane, Newton Center. Mass. DRISCOLL, Marvin G. (Af 1937), Vice-Pres. (for mail), Bryant Equipment Co., Inc., 1725 Rhodes Haverty Bldg., and 20 Collier Rd., Atlanta, Ga. 19 Heating VentiiiAting Air Conditioning Guide 1938 DRISCOLL, William H-* (M 1904), (Presidential EARL, Warren (A 1936), Sales Engr., Howard E. Member), (Pres., 1926; 1st Vice-PTes., 1925; Melton, Inc., 207 N.W. Tenth St., and (for mail), 2nd Vice-Pres., 1924; Treas., 1923; Council, 1421 N. Ellison St., Oklahoma City, Okla. 1918-1927), Vice-Pres. (for mail). Carrier Corp., EARLE, Frederic E, (M 1937), Sales Engr. (for S. Geddes St., Syracuse, N. Y.. and 50 Glenwood mail), 520 Howard Ave., Bridgeport, and 1536 Ave., Jersey City, N. J. Main St., Stratford, Conn. DROPPERS, C. J. (A 1937), Sales Supervisor, EARLEY, Thomas J. (A 1935), Sales Engr., Home Insulation Co. of St. Louis, 2504 Texas Jennison Co., Putnam St., and (for mail), 46 Ave., St. Louis, Mo., and (for mail), 2111 Yale Elizabeth St., Fitchburg, Mass. Ave., Maplewood, Mo. EASTMAN, Carl B. (M 1932; J 1929), Mgr., DuBOIS. Louis J. (M 1931), Air Cond. Engr., Philadelphia Sales Office, C. A. Dunham Co., York Ice Machinery Corp., 117 South 11th St., 1500 Walnut St.. Philadelphia, and (for mail), St. Louis, and (for mail), 7451 Bland Drive, 530 Brookview Lane, Brookline, Upper Darby. Pa. Clayton. Mo. EASTWOOD, E. O. (M 1921), (Council, 1931 DUBRY, Ernest E. (M 1924), Asst. Supt., Central 1934; 1937), Prof, of Mech. Engrg. (for mail). Htg., Detroit Edison Co., 2000 Second Ave., and University of Washington, and 4702 12th Ave., (for mail), 9116 Dexter Blvd., Detroit, Mich. N.E., Seattle, Wash.' DUFAULT, Felix H. (A 1936), Mgr. Furnace Div. EATON, Byron K. (M 1920), Zone Mgr., Delco- (for mail). General Steel Wares, Ltd., 2355 Frigidaire Conditioning Div., General Motors Delisle St., and 1277 Visitation St., Montreal, Sales Corp., 1420 Wisconsin Ave., Dayton, Que., Canada. Ohio, and (for mail), 240 S. Brainard Ave., DUFF, Kennedy (M 1915), Mgr. Eastern Ter LaGrange, 111. ritory (for mail), Johnson Service Co., 28 East ' EATON, William G. M. (A 1934). Sales Engr., 29th St., New York, N. Y., and 9 Park Ave., Pease Foundry Co., Ltd., 227 Victoria St., Maplewood. N. J. Toronto 2, and (for mail), 59 Symington Ave., DUGAN, Thomas M. (M 1920), Sanitary-Htg. Toronto 9, Canada. Engr.. National Tube Co., Fourth Ave. and EBERT, William A. (M 1920), Mech. Contractor Locust St., and (for mail), 1308 Freemont St., (for mail), 1026 W. Ashby, and 2151 W. Kings McKeesport, Pa. Highway, San Antonio, Texas. DUGGER, Earl R. (J 1936; 5 1934), Service- ECKERT, E. Kendall (J 1935), Engr. (for mail); Installation Engr., Oklahoma Refrigerating Co., American Blower Corp., 6000 Russell. St., and 18 W. Grand, and (for mail), 3409 Classen, 91 E. Kirby, Detroit, Mich. Oklahoma City. Okla. EDELMAN, Bernard P. (A 1935), Asst. Sales DULL, Edgar J. (A 1937), Engr.-Contractor (for Mgr. (for mail), U. S. Air Conditioning Corp., mail), 218 Water St., Baltimore, and 3614 Third 2101 Kennedy St.. - N.E., and 4233 Nicollet St., Brooklyn, Baltimore, Md. Ave., Minneapolis, Minn. DULLE, Wlllferd L. (J 1936), Asst. Secy., E. E. EDWARDS, Arthur W. (M 1936), Dist. Mgr., Southern Iron Co., St. Louis, and (for mail), 2910 The Trane Co/, 626 Broadway, and (for mail), Lincoln Ave., Normandy,-Mo. 3423 Paxton Ave., Cincinnati, Ohio. ' DUNCAN, James R. (M 1923), Sales .Engr., Air EDWARDS, Daniel F. (M 1920), 2340-42 Pine' Cond., Carrier Corp., Room 408, Chrysler Bldg., St., St. Louis, Mo. New York, N. Y. EDWARDS, Don J. (A 1933), Vice-Pres. (for DUNCAN, William A. (A 1930), Dist. Service mail). General Heat & Appliance Co;, 596 Engr. (for mail), Dominion Oxygen Co., Ltd., Commonwealth Ave., and 8 Devon Terrace, 92 Adelaide St., W., and 20 TyreU Ave., Toronto, Boston, Mass. Ont., Canada. EDWARDS, Henry B. (J 1935), Chief Engr. (for DUNHAM, Clayton A.* (M 1911), Pres, (for mail), Refrigeradon y aire Acondidonado, S. A., mail), C. A. Dunham Co., 450 E. Ohio St., Oficios 18, and Calle 4, No. 10, Habana, Cuba. Chicago, and 150 Maple Hill Rd., Glencoe, 111. EDWARDS, Junius D. (M 1936), Asst. Director DUNNE, Russell V. D. (M 1937), Engr. (for mail). of Research (for mail). Aluminum Company of Carrier Corp., Russian-American Chamber of America, P. O- Box 772 (Freeport Rd.), New Commerce, ul. Kuibisheva 6, Moscow, U.S.S.R., Kensington, and 536 Sixth St., Oakmont, Pa. and 43 E. Park St., East Orange, N. J. EDWARDS, Paul A. (M 1919), Pres, (for mail). DUPUIS, Joseph R. (A 1936), Dist. Mgr. (for G. F. Higgins Co., 608 Wabash Bldg., and 3074 ' mail), Trane Co. ox Canada, Ltd., 660 St. Pinehurst Ave., Pittsburgh 16, Pa. Catherine W., Montreal, Que., and 331 Clarke EHLERS, Jacobus (J 1937), Engr. (for mail), Ave., Westmount, Que.. Canada. Carrier Engineering South Africa, Ltd., Box DURKEE, Merritt E. (A 1930), Sales Engr., 7821, and Jacwal Court, Quartz St., Johannes Dunham Heating Service, 121 Grandview Ave., burg, South Africa. White Plains, N. Y. EHRLICH, M. William* (M 1916), Chief Engr,, DURNING, Edward H. (A 1936; J 1931). Com Commodore Heaters'Corp., 11 West 42nd St., mercial Sales, Dallas Gas Co., Harwood and New York, N. Y., and (for mail), 56 Ridge Rd., Jackson Sts., and (for mail), 1830 Moser St., Lyndhurst, N. J. Oa.lIa&. Texas EICHER, HuBert C. (M. 1922), Chief, Div. of DWYER, Thomas F. (M 1923), Mech. Engr. (for School Plant, Pennsylvania State Dept, of mail). Board of Education, 49 Flatbush Ave. Public Instruction State Capitol, and (for mail), Ext., Brooklyn, and 1163 Clay Ave., New York, 207 North 30th St.. Harrisburg, Pa. . N. Y. EILS, Lee C. (J 1936), Asst. Supt., George J. DYKES, James B. (J 1936), Estimator (for mail), Meyer & Son, 3223 Kennett Square, Pittsburgh, T. A. Morrison & Co., Ltd., 1070 Bleury St., P. O. No. 13, Pa. . and 3141 Maplewood Ave., Montreal, P. Q., EISELE, Lewis G. (A 1937), Secy, (for mail), Canada. Eisele Automatic Heating Co., Box 309, and 602 W. Hughitt St., Iron Mountain, Mich. E EISELE, William S. (A 1937), Supv. Engr. (for mail). Ideal Heating & Air Conditioning Co., EADE, Hugh R. (M 1935). Archt. (for mail), 551 Seneca St., and 836 Tacoma Ave., Buffalo, Eade & Co.. 2 Imperial Bank Bldg., and 163 N. Y. Cheriton Ave., North Kildonan, Winnipeg, EISS, Robert M. (M 1933; J 1930). Engr., Man., Canada. Kimberly-Clark Corp., and (for. mail), 714 EADIE, John G.. (M 1909), Consulting Engr., Hewitt St., Neenah, Wis. Eadie, Freund & Campbell Co., 110 West 40th . ELBERT, Ben F. (/ 1937), Sales Engr., Sidles St., New York, N. Y. '- Co.. Airtemp Div., 805-Walnut St-, and (for EAGLETON, Sterling P. (M 1930), Assoc. Air mail), 1008 Eighth St., Des Moines, Iowa.. Cond. Engr., National Park Service (Bldgs. ELLINGWOOD, Elliott L..(Jf 1909), Consulting .Branch), Navy Bldg.; and (for mail), 3522 "S" . Mech. Engr.,, 124 W. Fourth St., Los Angeles, SL,, N.W., Washington, D. C.. . - . Calif. ... - 20 Roll of Membership ELLIOT, Edwin (M 1929), Edwin Elliot & Co. (for mail), 560 North 16th St., Philadelphia, and 403 W. Price St., Germantown, Philadelphia; Pa. ELLIOTT, Irwin (A 1937), Chief Engr., Universal Oven Co., 271 Broadway, New York, and (for mail), 103 Penfield Ave., Croton, N. Y. ELLIOTT, Louis (M 1932), Consulting Mech. Engr., Ebasco Services; Inc., 2 Rector St.. Room 1530, New York. N. Y. ELLIOTT, Norton B. (A 1934), Branch Mgr., American Blower Corp., 1011 Majestic Bldg., Milwaukee, Wis. ' ELLIS, Frederick E. (M 1923). Sales Mgr. (for mail). Imperial Iron Corp., Ltd., 30 Jefferson Ave., Toronto, and 9 Princeton Rd., Kingsway P. O., Toronto 3, Ont., Canada. ELLIS, Frederick R. (M 1913), Sales Engr., Buerkel & Co., Inc., 18-24 Union Park St., Boston, and (for mail), 131 Beacon St., Hyde Park, Boston, Mass. `' ELLIS, Gershom P. (M 1935), Chief Engr. (for mail). Board of Public Education, 341 Bellfield Ave., and 6601 Dalzell Place, Pittsburgh, Pa. ELLIS, Harry W. (Life Member; M 1923; A 1909). Pres.-Gen. Mgr., Johnson Service Co., 507 E. Michigan St., Milwaukee, Wis. ELWOOD, Willis H. (M 1936), Branch Mgr., Holland Furnace Co., 209 King St.. Ithaca, N. Y. EMERSON, Ralph R. (M 1922), Pres., Emerson Swan Goodyer Co., 107 Arlington St., Boston, and (for mail), 44 Whitney Rd., Newtonville, Mass. . EMERY, Gordon W. (A 1935), Service Engr., H. H. Van Saun, Inc-, 190 Moore St., Hacken sack, and (for mail), 65 Birk St., Rochelle Park, N. J. EMMERT, Luther D. (M 1919), Repr. (for mail). Buffalo Forge Co.. Room 1909, 20 N. Wacker Drive. Chicago, and 1704 Hinman Ave., Evans ton, 111. . EMSWILER, John E * (M 1917), Prof. of-Mech. Engrg. (for mail). University of Michigan, 221 W. Engrg. Bldg., and 1303 Granger Ave.. Ann Arbor, Mich. . ENGLE, Alfred (A 1923), Secy, (for mail) Jenkins Bros., 80 White SL, New York, and 1 Edgewood Rd., Scarsdale, N. Y. ' ENGLISH, Harrold (M 1935; A 1930). Pres, (for mail), English & Lauer, Inc., 1978 S. Los Angeles St., and 515 S. Norton, Los Angeles, Calif. ENSIGN. Willis A. (M 1935), Vice-Pres. and Chief Engr., Frontier Fuel Oil Corp., 986 EUicott Square Bldg., Buffalo, and (for mail), Revere Drive, Derby, N. Y. EPPLE, Arnet B. (J 1934), 201 Benjamin Ave., S.E., Grand Rapids, Mich. ERICKSON, E. Vincent (M 1936), Mgr., New York Export Office (for mail). Carrier Corp., 405 ' Lexington Ave., and 143 East 39th St., New York, N. Y. ERICKSON, Harry H. (A 1929), Sales Engr. (for mail), Haynes Selling Co., 1124 Spring Garden St., and 217 W. Tulpehocken St., Philadelphia, Pa. ERICKSON, Martin E. (A 1926), Supt., Main tenance, Board of Education, and (for mail), 1533 South 74th St., West Allis, Wis. ERICSSON, Eric B. (M 1933), Engr., Board of Education, and (for mail), 605 West 116th St., Chicago, 111. ER1SMAN, Percival H., Jr. (M 1936), . Chief Engr., Washington Refrigeration Co., 1731-14th St., N.W., and (for mail), 2240-40th St., N.W., 2, Washington, D. C. ERRATH, Edward O. (J 1936). Htg. and Air Cond. Engr. (for mail), Heil Co., 3000 W. Montana St., and 2646 North 45th St., Mil waukee. Wig. '' ESCHENBACH, Samuel P. (/ 1935), Sales Engr., American Blower Corp., 135 Spring St., and 268 Dartmouth St,, Rochester, N-. Y. ., ' ESKIN, Samuel G. (A 1936), Development and Research Engr. (for- mail), Edison General Electric Appliance Co., 5600 W. Taylor St., and 1656 Jonquil Terrace, Chicago; III. -' ESTEP, Leslie G. (M 1936), Asst. Sales Mgr. in charge of Residential Air Cond., Kelvinator Div., Kelvinator-Nash Corp., 14250 Plymouth Rd.,and (for mail), 14909 Marlowe Ave., Detroit, Mich. ESTES, Edwin C. (A 1936), Mech. Draftsman (for mail). Railroad Transportation, Room 820, Northern Pacific Bldg., and 1690 Marshall Ave., St. Paul, Minn. ETLINGER, Martin J- (J 1936), Pres., Contempory Public Relations Co., 55 West 42nd St., and (for mail), 2979 Marion Ave., New York, N. Y. EVANS, Bruce L. (A 1937), Designing Engr. (for mail), Langenberg Heating Co., 3800 W. Pine Blvd., and 5920 Nina Place, St. Louis, Mo. EVANS, Edwin C. (M 1919), Branch Mgr., B. F. Sturtevant Co., 504 Eckel Theatre Bldg., and 307 Montgomery St., Apt. 6, Syracuse, N. Y. EVELETH, Charles F-* (M 1911), 2030 East 115th St., Cleveland, Ohio. EVEREST, R. Harry (M 1935), Sales Engr., Sheldons, Ltd., Galt, and (for mail), 235 Water loo St., Preston, Ont., Canada. EVERETTS, John, Jr* (A*1935; J 1929), Engr. (for mail). Air & Refrigeration Corp., 11 West 42nd St., New York, N. Y., and 55 Sound Beach Ave., Old Greenwich, Conn. - EVLETH, Everett B. (A 1927), Vice-Pres. and Gen. Mgr. (for mail). Brown Instrument Co., Wayne and Roberts, Philadelphia and Fishers Rd., and Radnor, Bryn Mawr, Pa. EWENS, Frank G-* (M 1937), Engr., Canadian Air Conditioning Co., Ltd., 989 Bay St., and (for mail), 83 Madison Ave., Toronto, Canada. F FABER, Dr. Oscar (M 1934), Consulting Engr. (for mail), Romney House, Marsham St., . Westminster, London and Hayes Court, Kenley, Surrey, England. FABLING. Walter D. (A 1937), Owner. 722 N. Broadway, and (for mail), 2121 Glendon Ave., W. Los Angeles. Calif. FAGIN, Daniel J. (M 1932), Htg. Engr., Laclede Gas Light Co., 1017 Olive St., and (for mail), 1344 Woodruff Ave., St. Louis, Mo. - FAHNESTOCK, Maurice K.* (M 1927). Research Asst. Prof, (for mail). University of Illinois, 214 M. E. Laboratory, and 701 W. California St., Urbana, 111. ' FAILE, Edward H. (M 1934), Designing and Construction Engr. (for mail), 608 Fifth Ave., New York, N. Y.. and R. F. D. 1, Westport, Conn. FAIRBANKS, Frank L. (M 1937), Prof. Agri cultural Engrg., Agric. Engrg. Exp. Station. Cornell University, and (for mail), 424 E. State St.. Ithaca, N. Y. ' FALK, David S. (J 1937), Sales Engr. (for mail). The Trane Co., 8316 Woodward Ave., and 79 E. Philadelphia, Detroit, Mich. FALTENBACHER, Harry J. (M 1930), Pres., H. J. Faltenbacher, Inc., 235 E. Wister St., Philadelphia, Pa. FALVEY, John D. (M 1922), Consulting. Engr., ' 316 N. Eighth St., St. Louis, and (for mail), . 6636 Pershing Ave., University City, Mo. FAMILETTI, A. Robert (A. 1938; J 1930), Chief Engrg. Draftsman, Industrial DeptTM, Navy Yard, and (for mail), 6735 Guyer Ave., Phila delphia, Pa. FARBER, Louis M. (J 1936), Engr., Natkin & Co., 1800 Baltimore, and (for mail)', 3714 Flora, Kansas City, Mo. - FARLEY, W. F. (M 1930). Salesman, American Radiator Co., 40 West 40th St., New York, and (for mail), 28 Elm St.,- New Rochelle, N. Y. FARNHAM, Roswell (M 1920), (Council, 1927 1933),' Dist. Mgr., Engrg. Sales (for mail), Buffalo Forge Co., P. O. Box 985, and 5 Claren don Place. Buffalo, N. Y. - . FARNSWORTH, John G. (A 1936; J 1931),. Gas House Htg. Engr. (for mail), .Central Illinois Light.Co.. 316 S. Jefferson St., and 1283 Monroe St., Peoria, 111. '* Heating Ventilating Air Conditioning Guide 1938 FARRAR, Cecil W. (M 1920; A 1918), (Treas.. 1930; Council, 1930), Pres, (for mail), Excelso Products Corp., 65 Clyde Ave., and 29 Oakland Place. Buffalo, N. Y. FARROW. Hollis L. (/ 1937). Engr. Air Cond. Dept., Kelly Sales Corp., Arlington, and (for mail), 60 Essex St., Lynn, Mass. FATZ, Joseph L. (M 1935), Htg.-Vtg. Engr. (for mail), Board of Education, 228 N. LaSalle#St., Room 536. and 1634 N. Mason Ave., Chicago, 111. FAULKNER, Gordon (J 1937; 5 1935), Junior Engr., Standard Oil Development Co., Linden, and (for mail), 43 Bellewood Place, Elizabeth. N. J. FAUST. Frank H * (M 1936; J 1930), Air Cond. Dept, (for mail). General Electric Co., 5 Lawrence St., Bloomfield, and 202 Vreeland Ave., Nutley, N. J. FAXON, Harold C. (M 1937), Engr., Appliance Section (for mail), Borneo Co., Ltd., Mercantile Bank Bldg., and 73 Grange Rd., Singapore. S. S. FAY, Donald P. (S 1936), 91-38-115th St., Richmond Hill, L. I., N. Y. FAY, Frank C. (M 1925), Engr. (for mail), Raisler Heating Co., 129-31 Amsterdam Ave., New York, and 9217-54th Ave., Elmhurst. L. I.. N. Y. FEBREY, Ernest J. (Life Member; M 1903), E. J. Febrey & Co. (for mail), 616 New York Ave., N.W., and 2331 Cathedral Ave., N.W., Wash ington, D. C. FEEIIAN, John B. (M 1923), Pres.-Treas. (for mail), John B. Feehan, Inc., 58 Spring St., Lynn, and 4 Long View Drive, Marblehead, Mass. FEELY, Frank J. (M 1935; A 1929), Mgr. of Sales. Taylor Supply Co., 700 Monroe Ave., Detroit, and (for mail), 950 Trombley Rd., Grosse Pointe Park, Mich. FEHLIG, John B. (Life Member; M 1918), Pres.- Treas. (for mail). Excelsior Heating Supply Co., 528 Delaware St., and 2927 Brooklyn Ave., Kansas City. Mo. FE1NBERG, Emanuel (J 1937), Dist. Sales Engr. (for mail), Ilg Electric Ventilating.Co.. 415 Brainard, and 3255 Cortland Ave., Detroit, Mich. . FE1RN, William H.'(Af 1937), Htg. and .Vtg. Contractor, C. A. Hooper Co., and (for mail), Shorewood, Madison, Wis. FELDERMANN, William (A 1937), Mgr. Air Cond. Div., American Gas Accumulator Co., Newark 'Ave., Elizabeth, and (for mail), 357 Irving Ave., South Orange, N. J. FELDMAN, A. M.* (Life Member; M 1903), Consulting Engr., 40 West 77th St., New York, N. Y. - FELS, Arthur B. (M 1919), Pres, (for mail). The Fels Co., 42 Union St.. Portland and Gilman St., Yarmouth, Maine. FELTWELL, Robert H. (Life Member; M 1905), Htg. Engr., U. S. Radiator Corp., 2321 Fourth St., N.E., and (for mail), 1370 Oak St., N.W., Washington, D. C. FENKER, Clement M. (M 1937), Designing Mech. Engr. (for mail), Edward J. Shulte, Archt., 920 E. McMillan. Cincinnatti, and 2268 Feldman Ave., Norwood, Ohio. FENNER, Everett M. (M 1936; A 1928). Chief Engr. (for mail). Staples Coal Co., 92 Pleasant St., Fail River, Mass., and 83 Colonial Ave., Cranston, R. 1. FENNER, N. Paul (A 1928), (for mail). John G. . Kelly, Inc., 210 East 45th St., New York, and 15 De Mott Place, Rockville Center, L. I.' N. Y. FENSTERMAKER, Sidney E. (M 1909), Pres, (for mail), S. E. Fenstermaker & Co., 937 Architects and Builders Bldg., and 3102 Wash ington' Blvd., Indianapolis, Ind. FERCESTAD, Marvin L. (A 1938; J 1935), Field Engr., Pacific Lumber Co., Bark Prod. Div., 100 Bush'St., San Francisco, Calif., and (for mail), 3509 S. Colfax Ave., Minneapolis, Minn. - FERGUSON, Ralph R. (M 1934; A 1927; J 1925), Mgr. Air Cond. Dept., American Blower Corp., 50 West 40th St., New York. N. Y., and (for mail). 160 Prospect St.. East Orange, N. J. FERRARINI, Joseph (J 1937), Testing Engr., Washington Gas Light Co.. 411 Tenth SL, N.W., Washington, D. C., and (for mail), 1728 Queens Lane, Colonial Village, Apt. 180, Arlington, Va. FEYGE, Harold (M 1937), Mgr. Htg. Dept, (for mail), Walworth California Co., 665 Sixth St., and 835 Turk St., Sian Francisco, Calif. FIDELIUS, Walter R. (M 1936), Sales Engr., Fitzgibbons Boiler Co., Inc., 101 Park Ave., New York, and (for mail), 135 Amersfort Place, Brooklyn, N. Y. FIEDLER, Harry W. (M 1923), Pres, (for mail). Air Conditioning Utilities, Inc., 8 West 40th St., New York, and 77 Hillside Ave., Mt. Vernon, N. Y. FIFE, G. Donald (M 1937; A 1931; J 1929), Air Cond. Engr., Architect of the Capitol, and (for mail), 211 Delaware Ave., Washington, D. C. FIGGIS. Thomas G. (A 1937; J 1936), Tech. Sales Engr., J. & E. Hall, Ltd., Dartford Iron works. Kent, England. FILLO, Frank B. (A 1934). Dist. Mgr.,.Minne- apolis-Honeywell Regulator Co., 1134 N. Pennsylvania Ave., Indianapolis, Ind. . FINAN. James J. (M 1923), Supervising Engr., Board of Education, 228 N. LaSalle St., Room 530, and (for mail), 7149 Euclid Ave., Chicago. HI. F1NERAN, Edward V. (J 1935), Asst. Engr. of Utilization, Washington Gas Light Co., 411 Tenth St., N.W., Washington, D. C., and (for mail), 305 Edgewood Ave., Silver Spring. Md. FINNERTY, John A. (J 1937), Sales Engr., Herman Nelson Corp., Room 839, 101 Park Ave., New York, and (for mail), 531 E. Lincoln Ave., Mt. Vernon, N. Y. FINNEY, Brandon (M 1937), Htg.-Vtg. Engr. (Inspector), City of Los Angeles, City Hall, Los Angeles, and (for mail), 721 Via de La Paz, Pacific Palisades, Calif. . FISCHER, Ladislav (J 1937), Engr. in charge of Mfg., Anemostat Corp. of America, 10 East 39th St., New York, and (for mail), Crosby St., Sayville, L. I., N. Y. FISHER, John T. (J 1936), Chief Engr., United Equipment & Supply Co., 1812 M St., N.W., and (for mail), 3228 Rittenhouse St., N.W., Washington, D. C. FITCH, Howard M. (J 1936), Sales Engr., American Air Filter Co., 215 Central Ave., and (for mail), 201 Clare Ave., Louisville. Ky. FITTS, Charles D. (M 1920), Branch Mgr. (for mail), American Radiator Co., 692 Prior Ave., St. Paul, and 2807 Dean Blvd., Minneapolis, Minn. FITTS, Joseph C. (M 1930), Secy.. Heating, Piping & Air Conditioning Contractors National Association, 1250 Sixth Ave., New York, N. Y., and (formail), 215 Kenilworth Rd., Ridgewood, N. J. FITZ, Jean Chandler (M 1924), Mgr., Arco Thermo System Div. (for mail). American Radiator Co., 40 West 40th St., New York, N. Y. FITZGERALD, Matthew J. (M 1934), Secy.- Treas., Standard Asbestos Mfg. Co., `820 W. Lake St., Chicago, and (for mail), 1117 N. Linden Ave., Oak Park. 111. .1 FITZGERALD, William E. (J 1936; 5 1935),. Secy.-Treas., Fitzgerald Plumbing & Heating Co., Inc., 939-41 Louisiana Ave., and (for mail), 210 Vine St., Shreveport, La. . FITZSIMONS, J. Patrick (J 1934; 5 1932), Mgr., Air Cond. Dept, (for mail), Trane Co. of Canada, Ltd., 4 Mowat Ave., and 151 Dowling Ave., Toronto. Canada. FLARSHEIM, Clarence A. (J 1933), Pres., C. A. Flarsheim, Inc., 201-7 Pershing Rd., Union Station Plaza (for mail), P. O. Box 56, and 3720 Holmes St., Kansas City, Mo. FLEISHER, Walter L.* (M 1914), (Council, 1937). Consulting Engr: (for mail), 11 West 42nd St., New York, and New City, N. Y. 22 Roll of Membership FLEMING, James P. (M 1923), Engr.-Custodian, Board of Education, 5045 N. Kimball Ave., .Chicago, 111. FLEMING, Thomas F. (J 1936; 5 1935), Safety Engr., Liberty Mutual Insurance Co., 122 N. Seventh St., St. Louis, Mo., and (for mail), 7004 Eggleston Ave., Chicago, 111. FLINK, Carl H. (M 1923), Research Engr. (for mail), American Radiator Co., 8007 Joseph . Campau Ave., and 5959 Yorkshire Rd., Detroit. Mich. FLINN, George S. (J 1936), Chief Engr., Mcr Gregor's, Inc., 1071 Union Ave., and (for mail), 190 N. Avalon, Memphis, Tenn. FLINT, Coll T. (M 1919), Sales Mgr. (for mail), H. B. Smith Co., 640 Main St., Cambridge, and 56 Brantwood Rd., Arlington, Mass. FLYNN, Frank J, (M 1936), Secy.-Treas., Missouri Water & Steam Supply Co., 816-20 Sixth St., and (for mail), 920 Ridenbaugh St., St. Joseph, Mo. ' FOGARTY, Orville A. (M 1934), Engr., Rivers Salvage Co., Ltd., 2245 St. James St., W., Montreal, and (for mail), Rigaud. Que., Canada. FOLEY, Daniel F, (A 1937), Sales (for mail), W. B. Young Supply Co., 208 Delaware St., Kansas City, Mo., and 25 Wint Ave., Fort ' Leavenworth, Kan. FOLLETT, Thomas L. (5 1936). 10900 Euclid Ave.. Cleveland, and (for mail). 306 N. Main St., Hudson, Ohio. . FOOTE, A. G. (M 1937), Dist. Engr., Frigidaire Div., General Motors Sales Corp., Oakland, and (for mail), 2466 Virginia SL, Berkeley, Calif. FOOTE, Earl E. (M 1936), Gen. SupL, Consumers Central Heating Co., 108 East 11th St., and (for mail), 3412 North 28th St., Tacoma, Wash. FORD, Edward F. (A 1937), Sales Repr. (for mail), American Radiator Co., 8019 Joseph Campau Ave., Detroit, and 288 Ann St., Ply mouth, Mich. FORFAR, Donald M. (M 1917), Mech. Engr., Grinnell Co., Inc., 240 Seventh Ave., S., and (for mail), 4817 Emerson Ave., S., Minneapolis, Minn. FORRESTER, Charles M. (A 1937), Air Cond. Sales Mgr. (for mail), Gurney Foundry Co., Ltd., 4 Junction Rd., and 77 Collegeview Ave., Toronto, Ont., Canada. FORRESTER, Norman J. (A 1936), Mgr. ' Contract Div., Garth Co., 750 Belair Ave., -Montreal, and (for mail), .316 Westminster Ave., N., Montreal, W., Que., Canada. FORSBERG, William (M 1919), Hopson & Chapin Mfg. Co., 231 State SL, New London, Conn. '. FORSLUND, Oliver A. (M 1936), Gen. Mgr., Forslund Pump & Machinery Co., 1717-19 Main St., and (for mail), 1109 West 75th Terrace, Kansas City, Mo. FOSS, Edwin R. (A 1936), Branch Mgr. (for mail). Powers Regulator Co., 407 Bona Alien Bldg., and 257 Bolling Rd., N.E., Atlanta, Ga. FOSTER, Charles (M 1923), Consulting Engr. (for mail), Foster & Wahlberg, 316 Medical Arts Bldg., and 2831 E. First St., Duluth, Minn. FOSTER, James M. (M 1930; A 1920), Owner , (for mail), 4526 Olive St., St. Louis, and 7021 Lindell Ave., University City, Mo. FOSTER, Philip H. (A 1937), Business Mgr., . Hudson Bay Plumbing Co., Flin Flon, Man., Canada. FOULDS, P. A. L. (M 1916), Consulting Engr. (for mail), Hubbard, Rickerd & Blakeley, 110 State .St., Room 709, Boston, and 72 Whitin Ave., Revere, Mass. . FOWLES, Harry H. (J 1934), Htg.-Vtg. Engr. (for mail), Carman-Thompson Co., 12-14 Lincoln St., Lewiston, and 176 Summer St., Auburn, Maine. FOX, Edward L, (J 1936), Engr., American Foundry & Furnace Co., Bloomington, and (for .mail), 715 Sanford SL, Peoria, 111. FOX, Ernest (M 1935), Asst, to Engr. (for mail), -C. A. Dunham Co., Ltd., 1523 Davenport Rd;, and 409 Glenholme Ave., Toronto, OnL, Canada. FOX, John H. (M 1935), Sales Engr. (for mail), Minneapolis-Honeywell Regulator Co., Ltd.,T17 Peter St., and 37 Macdonell Ave., Toronto, Canada. . FRANCE, Clarence N. (A 1936), Service Mgr., Colonial Fuel Oil, Inc., 1709 De Sales St., N.W., Washington, D. C. FRANCIS, Paul E. (M 1937). Asst. Mgr. of Sales. Northwestern Fuel Co., E-1203 First National Bank Bldg., SL Paul, and (for mail), 5115 S. Colfax Ave., Minneapolis, Minn. FRANK, John M. (M 1918; A 1912), Pres, (for mail), llg Electric Ventilating Co., 2850 N. Crawford Ave., Chicago, and 1152 Chatfield Rd., Hubbard Woods, 111. FRANK, Olive E * (M 1919). Pres, (for mail). Frank Engineering Co., 11 Park Place, and 610 West 110th St., New York, N. Y. FRANKEL, Gilbert S. (M 1926), Mgr., Federal and Marine Dept, (for mail), Buffalo Forge Co., 820-24 Woodward Bldg., and 2749 Macomb St.; N.W., Washington, D. C. ` FRANKLIN, Ralph S. (M 1919), Pres.-Treas. (for mail), Albert B. Franklin, Inc., 38 Chauncy St., Boston, and 320 Grove St., Melrose, Mass. FRASER, James J. (A 1936), Director (for mail), Honeywell-Brown, Ltd., 70 St. Thomas St., London, S.E. 1, and 60. The Grove, St. Mar garet's, Twickenham, Middx., England. FRAZIER, J. Earl (A. 1936), Secy.-Treas. (for mail), Frazier-Simplex, Inc., Washington Trust Bldg., and 417 E. Beau SL, Washington, Pa. FREAS, Royal B. (M 1928), Vice-Pres., Freas Thermo Electric Co., 1750 N. Springfield Ave., Chicago, ill., and (for mail), Schodack Landing, N. Y. FREDERICK, Holmes W. (M 1937), Asst. SupL. Engrg. Div., Harvard University, Lehman Hall, Cambridge, and (for mail), 69 Kingswood .Rd., Aubumdale, Mass. ' FREDERICK, Walter L. (A 1937), Pres, (for mail), Bryant Air Conditioning Corp., 1340 Connecticut Ave., and 3016 Tilden St., Wash ington, D. C. FREEMAN, Edwin M. (A 1937), Vice-Pres. (for mail), Canadian Asbestos Co., Ltd., 316 Youville Square, and 37 Sunset Ave., Montreal, Que., Canada. FREEMAN, John C. (J 1936), Assoc. Mech. Engr., Div. of Architecture, Sacramento, Calif. FREITAG, Frederic G. (M 1932), Chief Engr,, Sylvester Oil Co., Inc., 703 S. Columbus Ave., and (for mail), 9 Harrison St., Mt. Vernon, N. Y. FRENCH, Donald (M 1926), Vice-Pres. (for mail). Carrier Corp., 302 S. Geddes St., Syracuse, N. Y., and 114 Hobart Ave., Summit, N. J. FRENTZEL, Herman C. (M 1936), Chief Engr., Htg. and Water Systems Divs., The Heil Co., 3000 W. Montana $L, and (for mail), 4363 N. Wildwood Ave., Milwaukee, Wis. FRIED, Harold V. (A 1935), Air Cond: Specialist (for mail), Birmingham Electric Co., 2100 N. First Ave., and 1585 Druid Hill Drive, Birming ham, Ala. FRIEDLINE, James M. (J 1937), Sales Engr.. General Air Conditioning Corp., Room 304 Paramount Bldg., and (for mail), *1811 Fifth Ave.. S.E., Cedar Rapids, Iowa. FRIEDMAN, Arthur (A 1936), Pres, (for mail), Cleveland Heater Co., 1933 West 114th St., Cleveland, and 15700 S. Moreland Blvd., Shaker Heights, Ohio. FRIEDMAN, D. Harry, Jr. (M 1936), Engr. (for mail), Peoples Water & Gas Co.. 15th and Wash ington Ave., and 330 58th SL, Miami Beach, Fla. FRIEDMAN, Ferdinand J.* (M 1921), Consult ing Engr. (for mail), McDougall & Friedman, 1221 Osborne SL, Montreal, Que., Canada, and 31 Union Square, New York, N. Y. FRIEDMAN, Milton (7 1935; 5 1933), 470 West End Ave., New York, N. Y. FR1MET, Maurice (J 1936), Pres.-Owner, Ace Refrigerating Co., 62 Sherman Ave., Tompkins-, ville, and (for mail), 120 Osgood Ave.. Stapleton, S. I., N. Y. '! 23 Heating Ventilating Air Conditioning Guide 1938 FRISSE, John L. (J 1937; S 1935), 5538 Forbes St., Pittsburgh, Pa. FRITZ, Charles V. (7 1936; 5 1933), Designer and Estimator, Chas. F. Fritz (for mail), 67 W. Merrick Rd., and 26 Cottage Court, Freeport, N. Y. FUKU1, Kunitaro (Af 1926), Auditor (for mail). Oriental Carrier Engineering Co., Ltd., Osaka Mitsui Bldg., Nakanoshima, Osaka, Japan. G GALE, Hamilton A. (7 1936), Sales Engr., Hudson Air Conditioning Corp., 1727 Pennsyl vania Ave., Washington, D. C.t and (for mail). Murray Hill, Annapolis, Md. GALLAGHER, Paul (7 1937; 5 1935), 1209 Sixth St.. Peru, 111. ` GALLIGAN, Andrew B. (Af 1921), 716 South 51st St., Philadelphia, Pa. GALLOWAY, James F. (A 1938; 5 1934), General Electric Co., 570 Lexington Ave., Netf York, and (for mail), 117-01 Park Lane, S., Kew Gardens, L. L, N. Y. GAMBLE, Cary B. (A 1935), Consulting Engr. (for mail), Leo S. Weil & Walter B. Moses, 427 S. Peters St., and 732 St. Peter St., New Orleans, La. GAMBLE, Claude L. (Af 1937), 12 Riverside, Fort Leavenworth, Kans. GAMMILL, Oscar E., Jr. (A 1937; 7 1930},'Sales Engr. (for mail). Carrier Corp., 1413 Hibernia Bank Bldg., and 2133 Calhoun St., New Orleans, La. GANGE, Frank B. (Af 1937), Managing Director, Gordon & Co., Ltd., 185 Yuen Ming Yuen Rd., Shanghai, China. ' GANT, H. P.* (Af 1915), (Presidential Member), (Pres., 1923; 1st Vice-Pres., 1922; 2nd Vice- Pres., 1921; Council, 1918-1924), Vice-Pres; (for mail), Carrier Corp., 12 South 12th St., Phila delphia. and R. D. 1, Glen Moore, Pa. GARDNER, Clifton R. (A 1937), Vice-Pres. (for mail), Martyn Bros., Inc., 911 Camp St., and 5506 Mercedes, Dallas. Texas. GARDNER, S. Franklin (Af 1911), Pres, (for mail). Standard Engineering Co., 2129 Eye St., N.W., and 4901 Hiilbrook Lane. Washington, D. C. GARDNER, William (A 1921), Vice-Pres. (for mail). Garden City Fan Co., 1842 McCormick Bldg., and 7836 Loomis Blvd.. Chicago, 111. - GARNEAU, Leo (A 1938; 7 1930), Sales Engr., C. A. Dunham Co., Ltd., Room 931 Dominion Square Bldg., and (for mail), 2541 Maplewood Ave., Apt. 2, Montreal, P. Q., Canada. GARNETT, Ralph E. (A 1936), Sales Engr. (for mail). Standard Asbestos Mfg. & Insulating Co., 10 N. Olive St., and 3114 Benton Blvd., Kansas City, Mo. GATES, Robert A. (Af 1936), Sole Owner, Gates Engineering Co., 510-77 Sheet St., and (for mail), 248 Bay 38th St., Brooklyn. N. Y. GAULEY, Ernest R. (A 1935), Salesman (for mail). Age Publications, Ltd., 31 Willocks St., and 110 Lee Ave., Toronto, Ont., Canada. GAULT, George W. (7 1937; 5 1934). Standard Steel Works Co., and (for mail), C. C. C. Co. 2340, Camp No. 5-118, Clearfield, Pa. GAUSE, H. Chester (Af 1937), Power Sales Engr. (for mail). Alabama Power Co., 600 North 18th St., and 905 South 38th St., Birmingham, Ala. GAUSEWITZ, William H. (A 1937), Owner and Mgr., Conditionedaire, Inc., 513 Third Ave., N.E., and (for mail), 1321 W. Minnehaha Park way, Minneapolis, Minn. GAUSMAN, Carl E. (Af 1923), Consulting Engr., Gausman & Moore, 1526 First National Bank Bldg., E., and (for mail), 23G0 Chilcombe Ave., St. Paul, Minn. GAWTHROP, Fred. H. (Af 1919), Pres., Gaw- throp & Bro. Co.. 705 Orange St., and (for mail), 2211 Shallcross Ave., Wilmington, Del. GAYLOR, William S. (Af 1919), 6 West Ave., Larchmont, N. Y. ' GAYLORD, Frank H. (Af 1921), Western Sales Mgr. (for mail), Hoffman Specialty Co., Inc., 130 N. Wells St., Chicago, and 362 N. York St., Elmhurst, ill. GAYNER, James (Af 1937), Mech. Engr., G. M. Simonson, Cons. Engr., 74 New Montgomery St., San Francisco, and (for mail), 239 Park View Ave., Piedmont, Calii. GEIGER, Irvin H. (Af 1919), Registered Prof. Engr. and Mfrs. Repr. (for mail), 319 Telegraph Bldg. (P. O. B. 83), and 240 Maclay St., Harris burg, Pa. GEISSBUHLER, John O. (7 1936; S 1934), Student Engr., General Electric Co., Glass Machine, 1133 East 152nd St., and (for mail), 9820 Zimmer Ave., Cleveland, Ohio. ' GELTZ, Ralph W. (7 1936), Air Cond. Engr., York Ice Machinery Corp., 2700 Washington Ave., N.W., Cleveland, and (for mail), 1400 Lakefront Ave., E. Cleveland, Ohio. GENDRON, Henri (A 1937), Chemical Engr., Canadian General Electric Co., Ltd., 1000 Beaver Hall Hill,'and (for mail), 2049 Maplewood, Apt. C, Montreal, Que., Canada. GERHARD, David H. (A 1937), Power Sales Engr. (for mail). Consumers Power.Co., 212 W. Michigan Ave., and 121 S. Higby St., Jackson, Mich. , GERMAIN, Oscar (Af 1935), Foreman, Germain & Frere, Ltd., 237 St. Antonie St., and (for mail), 1343 Blvd. St. Louis, Three Rivers, P. Q., Canada. GERRISH, Grenville B. (A 1936; 7 1930), Mgr. (for mail), Fitzgibbons Boiler Co.. Inc., 31 Main St., Cambridge, and 89 Warwick Rd., Melrose Highlands, Mass. GERRISH, Harry E. (Af 1910), (Council. 1919), Partner (for mail), Morgan-Gerrish Co., 84 S. Tenth St., 307 Essex Bldg., and 4534 Fremont S., Minneapolis, Minn. ' GETSCllOW, Roy M. (Af 1919), Pres, (for mail). Phillips-Getschow Co., 32 W. Hubbard St., Chicago, and 122 Woodstock, Kennilworth, 111. GH1LARD1, Fernand (Af 1937), Chief Engr., Minneapolis-Honeywell Regulator Co., 34 Rue Govot de Mauroy, and (for mail), 26 Rue de la ' Pepiniere, Paris, France. GIANN1NI, Mario G. (Af 1935), Asst. Prof, of Mech. Engrg., New York University, University Heights, New York, and (for mail), 31 French Ridge, New Rochelle, N. Y. GIBBONS, Michael J. (Af 1914), Owner, M. J. Gibbons Supply Co., 601-31 E. Monument Ave., and (for mail), 22 Oxford Ave., Dayton, Ohio. GIBBS, Edward W. (Af 1919), Owner, The Smith-Gibbs Co. (for mail), 201 S. Main St., and 39 President Ave., Providence, R. I. GIBBS, Frank C. (Af 1921), Gen. Supt. (for mail). National Regulator Div.-Minneapolis-Honeywell Regulator Co., 2301 N. Knox Ave., Chicago, and 538 N. Cuyier Ave., Oak Park, III. G1ESECKE, Frederick E.* (Af 1913), (Council, 1932-1937), Director, Texas Engrg. Experiment Station, Agricultural and Mechanic! College, College Station, Texas. GIFFORD, Clarence A. (A 1934), Salesman, American Radiator Co., 374 Delaware Ave., and (for mail), 758 Parkside Ave., Buffalo, N. Y. GIFFORD, Robert L. {Life Member; Af 1908), Pres., Illinois Engineering Co., 21st St. and Ratine Ave., Chicago, 111., and (for mail), 1231 S. El Molino Ave., Pasadena, Calif. GIFFORD, William R. (Af 1938 ; 7 1936), Sales Engr., American Radiator Co., Fourth and - Channing Sts., N.E., Washington, D. C., and (for mail), Box 295, College Park, Md. GIGUERE, George H. (Af 1920), Consulting Engr., 17205 Fairport Ave., Detroit, Mich. GILBERT, Leslie S. (Af 1937), Owner (for mail), Gilbert Engineering Co., 1314 Liberty Bank Bldg., and 2719 N. Haskell, Dallas, Texas. GILES, Alfred F. (Af 1936; 7 1934), 3537 Beech- wood Blvd., Pittsburgh, Pa. GILES, J. C. (7 1938; 5 1935), 546 South Blvd., Norman, Okla. 24 Roll of Membership GILFRIN, George F. (Af 1932). Climas Artifidales, S. A. (for mail), Edifido "La National" 608, and Esplanada No. 715 Lomas de Chapultepec, Mexico. D. F. GILL, Eric F. (Af 1936), Chief Draftsman. Drayton Regulator & Instrument Co., Ltd., and (for mail), 30 Warwick Rd., West Drayton, Middlesex, England. - GILLE, Hadar B. (Af 1930), Consulting Engr. (for mail), Hugo Theorell9 Ingeniorsbyra, Skoldun- gagatan 4, Stockholm, and Svanhildsvagen 19, Nockeby, Sweden.' ' GILLETT, M. C. (Af 1916), Engr., Hoffman Spedalty Co.. 500 Fifth Ave., New York, N. Y., and (for mail), 6600 Rising Sun Ave., Phila delphia, Pa. GILLHAM. Walter E. (Af 1917), (Treas., 1926 1929; Council, 1926-1929), Consulting Engr. (for mail), 337 Law Bldg., and 3427 Bellefontain Ave., Kansas City, Mo. GILMAN, Franklin W. (Af 1935). Plant Engr. (for mail), Atwater Kent Mfg. Co., 4700 Wis- sahickon Ave., and 514 W. Coulter St., Phila delphia, Pa. ' GILMORE, Louis A. (7 1935; 5 1930), Vice- Pres. (for mail), John Gilmore & Co., 13 N. Tenth St., and 6186 Westminster Place,-St. Louis, Mo. CINI, Aldo (Af 1933), via Correggio 18, Milano, . Italy. GINN, Tony M. (Af 1935), Gen. Mgr., Tony M. Ginn Co., 214-24 Fifth St., S., Great Falls. Mont. GITTERMAN, Henry (A 1937), Dist. Repr. (for ' mail). Independent Air Filter Co.. Inc., 55 West 42nd St., New York and Baptist Church Rd., Yorktown, N. Y. . GITTLESON, Harold (A 1936), Sales Mgr., Lariviere, Inc., 3715 St. Lawrence Blvd., and (for mail), 1125 Lajoie Ave., Montreal. Que.! Canada. GIVIN, Albert W. (A 1925), Vice-Pres. (Stove Sales), Gurney Foundry Co., Ltd. (for mail), 4 Junction Rd., Toronto, Ont., Canada. GLASS, William (Af 1934), Mgr. (for mail), Partridge-Halliday, Ltd., 144 Lombard St., Winnipeg, and 190 Braemar Ave., Norwood, Manitoba, Canada. GLEASON, Gilbert H. (Af 1923), Partner (for mail), Gilbert Howe Gleason & Co.. 28 St. Botolph St., Boston, and 10 Edgehitl Road, Winchester, Mass. GLORE, Evins F. (A 1916), 644 Riverside Drive, New York, N. Y. . GODDARD, William F. (A 1936), Gov't. Repr., American Radiator Co., Fourth and Channing . Sts.. N.E., and (for mail), Apt. 34, 3150-16th St., '' N.W., Washington, D. C. GOELZ, Arnold H. (Af 1931), Pres.-Treas. (for mail), Kroeschell Engineering Co., 215 W. Ontario St., Chicago, and 827 Greenwood Ave., Wilmette, 111. GOENAGA, Roger C. (Af 1931), Tech. Director, Ateliers Ventil (for mail), 109 Cours Gambetta, Lyon, and 33 Avenue Valioud-Ste-Foy-les-Lyon, Rhone, France. GOERG, Bernhard (Af 1928), Director Inst. Thermal Research (for mail), American Radiator Co., 675 Bronx River Rd., Yonkers, and Eton Lodge. Scarsdale, N. Y. GOLDBERG, Moses (A 1934), Pres., Electric Motors Corp., 168 Centre St., New York, and (for mail), 885 E. Eighth St., Brooklyn, N. Y. GOLDSCHMIDT. Otto E. (Af 1915), Consulting Engr. (for mail), 22 East 40th St., New York, N. Y., and Greens Farms, Conn. GOLDSMITH, F. Willlus (Af 1936), Pres, (for mail), W. Clasmann Co., 324 E. Wisconsin Ave., and 629 E. Day Ave., Milwaukee, Wis. GOLL, Willard A. (A 1937), Sales Engr., Standard Furnace Supply Co., 407 S. Tenth, and (for mail), 418 North 38th Ave., Omaha, Nebr. GOMBERS, Henry B. (Life Member; A 1901), Secy. Emeritus, Heating, Piping and Air Con ditioning Contractors National Assodation, 1250 Sixth Ave., New York, N. Y,, and (for mail), 160 Halsted St., East Orange, N. J. GONZALEZ. Rafael A. (Af 1936), Mgr., Applica tion Engrg. (for mail), Airtemp, Inc., and 434 Delaware St., Dayton, Ohio. GOODMAN, Daniel J. (7 1937; 5 1935), 2704 Filbury St., Pittsburgh, Pa. GOODRAM, William E. (A 1936), Partner, Goodram Bros., 88 King SL, W., Hamilton, and (for mail), R. R. 2. Freeman, Ont., Canada. GOODRICH, Charles F. (Af 1919), Andrews & Goodrich, Inc., Boston, and (for mail), 336 Adams St., Dorchester, Mass. . GOODWIN, Eugene W. (Af 1936). Sr. Mech. Engr., U. S. Treasury Dept., Procurement Bldg., Washington, D. C., and (for mail), 7024 Hampden Lane, Bethesda, Md. GOODWIN, Samuel L. (Af 1924), Consulting Engr., John Eberson, 1560 Broadway, New York, and (for mail), 247 Madison Ave., Has- brouck Heights, N. J. GORDON, Edward B., Jr. (Af 1908), Pres., Pillsbury Engineering Co., 1200 Second Ave., S., and (for mail), 2450 West 24th St., Minneapolis, Minn. . GORDON, Peter B. (A 1938; 7 1935), Engr. (for mail), Wolff & Munier. Inc., 222 East 41st St., New York, N. Y., and 35 Park Ave., Bloomfield, N. J. GORDON, William D. (A 1935), Air Cond. and Sales Engr., Hart & Cooley Mfg. Co. of Canada, Ltd., Fort Erie, N., and (for mail), 71 Chilton Rd., Toronto, Ont., Canada. GORNSTON, Michael H. (A 1923), Stationery Engr. (for mail), Thomas Jefferson High School, 402 Pennsylvania Ave., Brooklyn, and 90-11 149th St., Jamaica, N. Y. GOSSETT, Earl J. (Af 1923), Pres, (for mail). Bell & Gossett Co.. 3000 Wallace SL, Chicago, and 314 Woodland Ave., Winnetka, III. GOTHARD, William W. (A 1936), Editorial Director (for mail), Domestic Engineering, 1900 , Prairie Ave., Chicago, and 1027 Arlington Ave., LaGrange, 111. . GOTSCHALL, Hairy C. (Af 1935), Air Cond. Instructor, Lane Technical High School, 2501 Addison SL, and (for mail), 2953 Eastwood Ave., Chicago, lit. GOTTWALD, C. (A 1916), Pres, (for* mail), Ric-wiL Co., Union Trust Bldg., Cleveland, and 2225 Stillman Rd., Cleveland Heights, Ohio. GOUEDY, Kenneth E. (A 1935), Member of Firm and Engr. (for mail). Modem Building Insulating Co., 411 Bona Allen Bldg., Atlanta, and 218 Columbia Drive, Decatur, Ga. GOULD, Henry E. (7 1936), Secy, (for mail), Natkin & Co., 1800 Baltimore, and 6528 Summit, Kansas City, Mo. GOULDING, William (A 1933), Air Cond. Engr., World Broadcasting Co., 711 Fifth Ave., New York, and (for mail), 782 Westminster Rd., Brooklyn, N. Y. GRABENSTEDER, Louis (A 1937; 7 1935)* 3206 Linnet Rd., Louisville, Ky. GRABER, Ernst (7 1936), Engr.. Minneapolis- Honeywell Regulator Co., 801 Second Ave., New York, and (for mail), 42-12 Ditmars Blvd., Astoria, L. I., N. Y. ' . GRAFF, William F. (A 1937), Salesman-Engri,' Standard Sanitary Mfg. Co., and (for mail), 940 Jefferson, S.E., Grand Rapids, Mich. GRAHAM, Charles H. (Af 1934), Sales Repr., Lennox Furnace Co., Inc., 400 N. Midler Ave., Syracuse, and (for mail) 377 Highland Ave., Hamburg, N. Y. GRAHAM, Earl W. (7 1935), Student Engr. (for mail), Carrier Corp., Merchandise Mart Bldg., Chicago, 111., and Bristow, Ky. GRAHAM, John M. (A 1937; 7 1936), Sales Engr. (for mail), B. F. Sturtevant Co., 528 Kentucky Home Life Bldg., and Puritan Apts., Louisville, Ky. . ' GRAHAM, William D. (Af 1929; A 1925; 7'1923), Sales Dept., Carrier Corp., and (for mail), 129 Circle Rd., Syracuse, N. Y. - 25 y Heating Ventilating Air Conditioning Guide 1938 CRANSTON, Ray O. (J 1935; S 1930), Engr. (for mail). University Plumbing & Heating Co.. 3939 University Way, and 4014 Brooklyn Ave., Seattle Wssh GRANT,'Walter A. (A 1933; J 1929), Dist. Chief Engr., Carrier Corp., and (for mail), 236 Shotwell Park. Syracuse, N. Y. GRAVES. Willard B. (Life Member; M 1906), Pres.. W. B. Graves Heating Co., 162 N. Des- plaines St., Chicago. 111. GRAY, Earle W. (A 1934), In charge of Air Cond., Commercial- Dept, (for mail). Oklahoma Gas & Electric Co., Third and Harvey Sts., and 2125 Northwest 18th St., Oklahoma City, Okla. GRAY, Everett W. (M 1936), Mgr. (for mail). The Trane Co., 1900 Euclid Ave., Cleveland, and . 17545 Madison Ave., Lakewood, Ohio. GRAY, George A. (M 1924), Branch Mgr. (for mail), C. A. Dunham Co., Ltd., 404 Plaza Bldg., and 114 Belmont Ave., Ottawa, Ont., Canada. GRAY, William E. (M 1922), Air Cond. Engr., . Ross Engineering Corp., 350 Madison Ave., New York, N. Y., and 718 W. Farris Ave., and (for . mail). Box 264, High Point, N. C. . GREBEN, David (M 1936), Mech. Engr., 29 W. 71st St., New York, N. Y. GREEN, Arthur W. (A 1935). 37-60-88th St., . Jackson Heights. L. I., N. Y. GREEN, William C. (Life Member; M 1906), Dist Mgr. (for mail), Warren Webster & Co., 704 Race St., Room 602-5, and 244 Erkenbrecher Ave., Cincinnati, Ohio. GREENBERG, Irving (S 1937), Estimating and Drafting. S. Greenberg, 80 West 102nd St., and (for mail), 1565 Grand Concourse, New York, N. Y. ' GREENBURG, Dr. Leonard* (M 1932), Exec. Director, Div. of Industrial Hygiene (for mail). New York State Department of Labor, 80 Centre St., and 241 West 97th St., New York, N. Y. GREENLAND, Sidney F. (M 1934), Engr., Gee. Walker & Slater, Ltd., Fitzmaurice Place, Berkeley Square. London W.l, and (for mail), 8, Averley Court, Averley Park, London, S.E 20. England. . GREENLEAF, Robert P. (M 1937), Consulting and Designing Engr., 2804 East 132nd St., Cleveland, Ohio. GREER, Willis R. (/ 1934), Air Cond. Engr., Arkansas Power & Light Co., and (for mail), 1401 Linden St., Pine Bluff, Ark. GREGG, Scranton H. (A 1936), Pres., Shellen- berger-Gregg Co., 2203 N. Prospect Ave., and (for mail). 5134 N. Woodbum St., Milwaukee,Wis. GREGG, Stephen L. (J 1936), Sales Engr. (for ' mail), Potomac Electric Power Co., Tenth and E Sts., N.W., and 3614 Connecticut Ave., N.W., Washington, D. C. GREINER, George E., Jr. (J 1938; 5 1935), Engr., Wayne Crouse. Inc., 4647 Centre Ave., and (for mail), 5515 Claybourne St., Pittsburgh, Pa. GRIESS, Philip G. (M 1937). Mech. Engr., Voorhees, Gmelin & Walker, 101 Park Ave., -New York, N. Y., and (for mail), 189 Walnut Ave., Bogota, N. J. . GRIESSER, Charles E. (A 1936). Owner, Electric Contractor Dealer, Bryan, Texas.- CRIEST, Kermit (J 1936). Sheet Metal Worker and. Sales, Frank-Limbach & Co., 1722 E. Ohio St., and (for mail), 134 Groveland St., Pitts- bureh Pa . GRIEVES, Thomas R. (A 1930), Branch Mgr. (for mail), U. S. Radiator Corp., 303 Crosby Bldg., Buffalo. N. Y. GRIMES, Fenner M. (J 1935), Junior Engr., T. H. Urdahl, Consulting Engr., 726 Jackson Place, N.W., and (for mail), 7705 Alaska Ave., N.W.. Washington, D. C. GROOT, Harry W. (M 1937), Engr.. Home Com fortable, Inc., 230 w. Walnut St., and (for mail), 3728 Western Parkway, Louisville, Ky. GROSS, Lyman C. (M 1931), Sales Engr., Minneapoli9-Honeywell Regulator Co., 2727 Fourth Ave., S., and (for mail), 5324 Oaklawn Ave., Linden Hills Sta., Minneapolis. Minn. GROSSMAN. Franklin A. (S 1937), Experi mental Engr., Serve!, Inc., Engrg. Dept., 119 N. Morton Ave., and (for mail). 1161 E. Illinois St., Evansville, Ind. GROSSMAN, Harry E. (A 1933; J 1927), Sales Repr., Haynes Selling Co.. Inc., Ridge and Spring Garden Sts., Philadelphia, and (for mail). 218 Parham Rd., Springfield, Pa. GROSSMANN. Harry a. (M 1931), Owner. H. A. Grossmann Co., 3138 Cass Ave., and (for mail), 3122 Geyer Ave., St. Louis, Mo.' . GROVES, Samuel A. (J 1935), Salesman. American Radiator Co., 40 West 40th St., New York, and (for mail), 21 Cassilis Ave., Bronxville, N. Y. GULER, George D. (A 1937), Modutrol Mgr., Minneapolis-Honeywell Regulator Co.,' Wayne and Roberts St., Philadelphia. Pa. - GUMAER, P. Wilcox (M 1937), Consulting Engr.. Toxic Vapors & Dusts, 40 Rector St., New York, N. Y., and (for mail), 25 Garden St., West Englewood, N. J. - GUNNELL, George T. (M 1937). Chief Htg. Engr. (for mail). Sunbeam Heating & Air Con * ditioning Co., 346 Peachtree-St., N.E., and 595 Ashby, S.W., Atlanta, Ga. GURNEY, E. Holt (M 1929), (1st Vice-Pres., 1937; 2nd Vice-Pres., 1936; Council, 1931-1937), Pres, (for mail), Gurney Foundry Co., Ltd., 4 Junction Rd., and 347 Walmer Rd., Toronto, Ont., Canada. ' GURNEY, Edward R. (/ 1937), Asst. Engr., Gurney Foundry Co., Ltd., 4 Junction Rd., and (for mail), 50 Eastbourne Ave.. Toronto, Canada. H HAAS, Emil, Jr. (A 1936; J 1929), T*eas. (for mail), Natkin & Co., 1800 Baltimore, and 5526 Crestwood Drive, Kansas City, Mo. ` HAAS. Richard B. (J 1937; 5 1935), Htg. Engr.. c/o L. C. Pemberton, 406 S. Washington Ave., Lansing, Mich. "' HAAS. Samuel L. (M 1923), Pres.-Treas. (for mail). Advance Heating & Air Conditioning Co. 117-19 N. Desplaines St., and 1513 Fargo Ave., Chicago, 111. HACKETT, H. Berkeley (M 1921), Consulting Engr... 901 Architects Bldg., 17th and Sansom Sts., Philadelphia, Pa. - HADDOCK, Isaac T. (A 1926), New England Gas & Electric Association, 719 Massachusetts Ave., Cambridge, Mass. HADEN, G. Nelson (M 1934; A 1928; J 1922), Managing Director (for mail), G. N. Haden & Sons, Ltd., 60 Kingsway, London. W.C.2, and 36 Wildwood Rd., Hampstead Heath, London, N.W. 11. England. : HADEN, William N. (Life Member; M 1902); Late Chairman, G. N. Haden & Sons, Ltd., St. Georges Works, and (for mail), Arnolds Hill, Trowbridge, Wilt, England. HADJISKY. Joseph N. (M 1930), Consulting Engr., 744 Bates St., Birmingham, Mich. HAGAN, William V. (A 1933; J 1926), Secy., V. J; Hagan Plumbing & Heating Co., 506 Pearl - St., and (for mail), 1811 Jones St., Sioux City, Iowa. ' HAGEDON, Charles H. (M 1919), Secy.-Treas. (for mail), S. E. Fenstermaker & Co., 937 Architects and Builders Bldg., and 4156 Broad way, Indianapolis. Ind. HAHN, Roy F. (J 1936), Air Cond. Engr. (for mail). Advance Refrigeration, Inc., 350 Peach tree St., and 1211 Fairview Rd., Atlanta, Ga. HAINES, John J. (M 1915), Pres, (for mail). The Haines Co., 1933 W. Lake St., Chicago, and 623-17th Ave.. Maywood. 111. HAJEK. William J. (M 1932), Branch Mgr., Minneapolis-Honeywell Regulator Co., 420 S. San Pedro St.. Los Angeles, Calif. HAKES. Leon M. (M 1932; J 1929), Dist. Repr. (for mail), Warren Webster & Co., 410 Reynolds Arcade Bldg., and 327 Lone Oak Ave., Rochester, N. Y. 26 Rou. or Membership HALE, Fred J. (M 1936), Mgr. (for mail). Empire Sheet Metal Works, Ltd., 1606 W. First Ave., and 3606 Point Grey Rd., Vancouver, B. C., Canada. - HALE, John F. (Life Member; M 1902), (Presi dential Member), (Pres., 1913; 1st Vice-Pres., 1912; Board of Governors. 1908-1910,' 1912 1913), Dist. Mgr. (for mail), Aerofin Corp., Room 704. Ill W. Washington St.. Chicago, and 400 S. LaGrange Rd.. LaGrange, 111. HALEY, Harry S * (M 1914), Consulting Engr., Partner (for mail), Leland & Haley, 58 Sutter St., and 735-21st Ave., San Francisco, Calif. HALL, George (A 1937), Secy.-Treas. and Mgr. (for mail), Hyland, Hall & Co., 115 E. Doty St., and 2632 Chamberlain Ave., Madison, Wis. HALL, John R. (M 1937; J 1932). Mech'. Engr., U. S. Air Conditioning Corp., 2101 N.E. Kennedy St., and (for mail), 1416 Lakeview Ave., Minne apolis. Minn. HALL, Mora S. (M 1934), Development Engr. (for mail), Anthracite Industries, Inc., Primos, Pa., and R. F. D. 3, Westminster, Md. HALLAR, Edgar V. (A 1937). Mgr. (for mail), Coglteer Insulation Co., 207 Reliance Bldg., and Ambassador Hotel. Kansas City, Mo. HALLECK, Leon P. (A 1937), Vice-Pres. and Sales Mgr. (for mail), Allen Corn., 9751 Erwin Ave., and 12049 Roselawn Ave., Detroit, Mich. HALLER, Arthur L. (M 1920), Pres.-Treas. (for mail). Haller Appliance Sales Co., Inc., 3321 Washington Blvd., St. Louis, and 124 W. Cedar Ave., Webster Groves, Mo. HAMAKER, Ambrose C. (A 1937). Sales Engr. (for mail), Mayflower-Lewis Corp., 63 W. Milwaukee Ave., and~18624 Santa Rosa Drive, Detroit, Mich. HAMENT, Louis (A 1933), Gen. Mgr. (for mail). Aquatic Chemical Laboratories, Inc., 118 East 28th St., and 1352 Franklin Ave., New York, N. Y. HAMERSKI, Francis D. (J 1934), Sheffield Inn, - Indianapolis, Ind. HAMIG, Louis L. (J 1935), Engr., Controlled Air Corp., 3319 Olive St., and (for mail), 3514 Utah SL, St. Louis, Mo. HAMILTON, James E. (A 1933), Branch Mgr. (for mail), U. S. Radiator Corp., 4004 Duncan Ave., St. Louis, and 7701 Shirley Drive, Clayton, Mo. HAMJE, Milton C. (J 1936). Engr., Syska & Hencessy, Consulting Engrs., 420 Lexington Ave., New York, and (for mail), 198 Hancock St., Brooklyn, N. Y. HAMLET, Francis A. (A 1936), Branch Mgr. (for mail), C. A. Dunham Co., Ltd., Room 931, Dominion Square Bldg., 1010 St. Catherine St., W., and 3550 Shuter St., Montreal, Que., Canada. HAMLIN, James B.. Jr. (A 1937), Htg. Engr., Crane CO., 14 W. Broad St., and (for mail), 1207 East 37th St., Savannah, Ga. HANCE, W. Wayne (A 1935), Draftsman, E. I. DuPont de Nemours Co.. Wilmington, Del., and (for mail), 6017 Baynton St., Germantown, Philadelphia, Pa. ' HANLEIN, Joseph H. (M 1937), Secy.-Treas. (for mail), Wilberding Co., Inc., 808-17th St., N.W., Room 13, and 5420 Connecticut Ave., Wash ington, D. C. ' HANLEY, Edward V. (A 1933), Pres, (for mail), ' S. V. Hanley Co.. 1653 N. Farwell Ave., Mil waukee, and 844 E. Birch Ave., Whitefish Bay, Wis. HANLEY, Thomas F., Jr. (M 1933), Pres, (for mail), Hanley & Co., 1503 S. Michigan Ave., and 4940 East End Ave., Chicago, 111. ' HANSLER, John E. (M 1937), Zone Service Mgr., Automatic Heat and Air Conditioning. Delco- Frigidaire, and (for mail), 203 Hadley Ave., Dayton, Ohio. HANSON, Leslie P. (M 1937; A 1936; J 1935; S 1933), Engr., U. 5. Air Conditioning Corp., 2101 Kennedy, N.E., and (for mail), 4336-46th Ave., S., Minneapolis, Minn. HARBAUGH. Jacob W. (M 1937), Supt. of Erection, Kupferle-Hicks Heating Co., 3974 Delmar Blvd.. St. Louis, and (for mail), 607 Lilac St., Webster Groves, Mo. " HARBORDT, Otto E. (A 1936), Sales Mgr. (for mail), U. S. Supply Co., 1315 West 12th St., and 303 Brush Creek Blvd., Kansas City, Mo. HARDING. Edward R. (M 1936), State Sales Mgr. and Engr. (for mail). Kewanee Boiler Corp., P. O. Box 536. 704 Jefferson Bldg., and 2603 Sherwood St., Greensboro, N. C. HARDING, Louis A.* (M 1911), (Presidential . Member), (Pres., 1930; 1st Vice-Pres., 1929; 2nd Vice-Pres., 1928; Council, 1922-1931), (for mail). L. A. Harding Construction Corp., Prudential Bldg., and 85 Cleveland. Ave., Buffalo, N. Y. ` HARDY, Frank L. (J 1937), Sales Engr. (for mail), York Ice Machinery Corp., P. O. Box 182, and 2312 Highland Ave.. Apt. 3, Birmingham, Ala. HARE, W. Almon (M 1930), Consulting Engr., 2002 National Bank Bldg., and (for mail), 1237 Chilver Rd., Windsor, Ont., Canada. HARMONAY, William L. (A 1935), Mgr. (for mail), M. J. Harmonay, Inc., 124 Elm St., and 34 Alida St., Yonkers, N. Y. HARRIGAN. Edward M. (M 1915), Gen. Mgr. (for mail), Harrigan & Reid Co., 1365 Bagley Ave., and 7450 LaSalle Blvd., Detroit, Mich. HARRINGTON, Charles (M 1923), 43 Indian Grove, Toronto, Ont., Canada. HARRINGTON, Elliott* (M 1932; A 1930), Mgr., Commercial Engrg. Div.. Air Cond. Dept, (for mail). General Electric Co., 5 Lawrence St., Bloomfield, and 5 Wilson Terrace, Caldwell, N. J. HARRIS, Jesse B. (M 1918), Co-Partner (for mail), Rose & Harris Engineers, Inc., 416 Essex Bldg., and 3620 Colfax Ave., S., Minneapolis, Minn. HARRIS. John G. (M 1936). Dist. Repr. (for mail), Frigidaire Div., General Motors Sales Corp., Terminal Tower Bldg., Cleveland, and 14432 Delaware Ave., Lakewood, Ohio. HARRISON. George G. (M 1937). Chief Engr., S. T. Johnson Co., 940 Arlington Ave., Oakland, and (for mail), 10 El Toyonal, Orinda, Calif. HARROWER, William C. (A 1937), Draftsman, Gar Wood Industries. 409 Connecticut Ave., and (for mail), 12561 Third Ave., Apt. 411, Highland Park, Mich. - HART-BAKER, Henry W. (M 1918), Hart Engineering Co., 451 Kiangse Rd., Shanghai, China. HARSCH, Richard J. (M 1936). Assoc. Naval Archt., U. S. Government, and 142 Avenue O, Brooklyn, N. Y. HART, F. Donald (J 1937), Junior Htg., Vtg. and Air Cond. Engr. (for mail). Rayon Dept., E. I. Du Pont deNemours & Co., Station B, Buffalo, and 254 Tremaine Ave.. Kenmore, N. Y. HART, Harry M* (M 1912), (Presidential Member), (Pres., 1916; 1st Vice-Pres., 1915; Council, 1914-1917), Pres, (for mail), L. H. Prentice Co., 1048 Van Buren St., and 3730 Lakeshore Drive, Chicago, 111. HARTIN, William R., Jr. (J 1935), Htg. Engr., Vice-Pres.-Secy., W. R. Hartin & Son, Inc., 2123 Green St., and (for mail), 212 S. Saluda Ave., Columbia, S. C. HARTLINE, William R. (A 1936), Vice-Pres. and Treas. (for mail), Combustioneer Stoker Corp.,` 409 Tenth St., S.W.. and 3112 Mt. Pleasant St., N.W., Washington, D. C. - HARTMAN, John M. (M 1927), Engr. (for mail). Kewanee Boiler Corp., and 719 Henry St., Kewanee, 111. HARTON, A. J. (A 1935), Sales Engr., St. Joseph Railway, Light. Heat & Power Co., Sixth and Francis, and (for mail), 730 E. Hyde Park Ave., St. Joseph, Mo. HARTWEIN, Charles E. (M 1933), Supervisor, House Htg. Dept., St. Louis County Gas Co., 231 W. Lockwood, Webster Groves, and (for mail), 135 Peeke Ave., Kirkwood, Mo. HARTWELL, Joseph C. (M 1922), Pres, (for . mail), Hartwell Co., Inc., 87 Weybosset St., and 16 Freeman Parkway, Providence, R. I. Heating Ventilating Air Conditioning Guide 1938 HARVEY, Alexander D. (A 1928; 7 1925). Sales Mgr. (for mail), Nash Engineering Co., Wilson Rd., South Norwalk, and West St., New Canaan, Conn. HARVEY, Lyle C. (Af 1928). Vice-Pres. (for mail). ' Bryant Heater Co., 17825 St. Clair Ave., and 3388 Glencarin Rd., Cleveland, Ohio. HARVEY, Robert A. (7 1937; 5 1936), 3260 Braemar Rd., Shaker Heights, Ohio. HASHAGEN, John B. (Af 1930), Plant Engr.. General Seafoods Corp., 1-15 Fish Pier, Boston, Mass. HATEAU, William M. (7 1934), Draftsman and Designer, J. O. Ross Engineering Corp., 350 Madison Ave., and (for mail), 1530 Sheridan Ave., New York, N. Y. HATTIS, Robert E. (Af 1926), Consulting Engr. (for mail), 820 N. Michigan Ave., and 1454 W. Fargo Ave., Chicago, 111. HAUAN, Merlin J. (Af 1933), Consulting Engr., 3412-16th, S., Seattle. Wash. HAUER, Fred (A 1937), Pres, (for mail), Fred Hauer & Co., Ill N. Water St., and 3i5 Het- tinger Place, Peoria, 111. HAUCK, Elden L. (7 1936), Sales Mgr. and Engr. (for mail), Hauck Brothers, 232 S. Center St., Springfield, and 54 S. June St., Dayton, Ohio. HAUS, Irvin J. (A 1937; 7 1935), Engr., Everett Smith Automatic Temperatures, Inc., 789 N. Water, Milwaukee, and (for mail)-, 925 Division St., Green Bay, Wis. HAUSMAN, Louis M. (M 1935), Pres., L. M. Hausman & Co., 440 Dasmaxinas, and (for-matl), P. O. Box 1729, Manila, P. I. HAUSS. Charles F* (Charter Member; Life Member), via Gesd, No. 8. Milan, Italy. HAWK, Joseph K. (7 1936), Engr. (for mail). General Air Conditioning Co., Inc., 3096 Main St., and 111 Florence,.Buffalo, N. Y. HAWK1NSON, C. F. (7 1936), Mech. Engr., U. S. Air Conditioning Corp., 2101 N.-E. Kennedy St., and (for mail), 4805 Columbus Ave., Minneapolis, Minn. HAYDEN, Carl F. (A 1930), Dist. Repr. (for mail), Askania Regulator Co.. 1603 S. Michigan . Ave., Chicago, and 1106 Seward St., Evanston, 111. HAYES. James J. (M 1920), Sales Engr. (for mail), Stannard Power Equipment Co., Room 925-53 W. Jackson Blvd., and 7443 Jeffery Ave., Chicago, 111. ' - HAYES, Joseph G.{Life Member; M 1908), Pres, and Engr. (for mail). Hayes Bros., Inc., 236 W. - , Vermont St., and 2849 N. Capitol Ave., India napolis, Ind. HAYMAN, A. Eugene, Jr. (7 1935; 5 .1930), Engr., 2500 Washington St., Wilmington, Del. HAYNES, Charles V. (Af 1917), {Presidential Member), (Pres., 1934;-1st Vice-Pres., 1933; 2nd- Vice-Pres., 1932; Council. 1926-1999; 1932 ' 1935), Vice-Pres., Hoffman Specialty Co., 500 Fifth Ave., Room 3324, New York, N. Y., and (for mail), 115 Llanfair Rd., Ardmore, Mont. Co., Pa. HAYS, Charles A. (A 1937), Mfgrs. Agent. Fitzgibbons Boiler Co. (for mail). 828 N. Broad way, and 4868 N. Woodburn St., Milwaukee, Wis. HAYTER, Bruce (Af 1934), Chief Engr., Institute of Thermal Research (for mail), American Radi ator Co., 675 Bronx River Rd., Yonkers, arid 114 Birchall Drive, Scarsdale, N. Y. HEARD, John A. E. (A 1938; 7 1930), Asst. Mgr. (for mail). Carrier Corp., Ltd., Connaught Place, New Delhi, India, and 28, Leighcliff Rd., Leigh on Sea, Essex, England. HEARD, Roderick G. (A 1933), Oil Burner Sales Dept, (for mail). Imperial Oil, Ltd., 56 Church St., and 81 Braemar Ave., Toronto, Ont., Canada. HEATH, WUllam R. (Af 1931), Asst. Chief Engr., Buffalo Forge Co., 490 Broadway, and (for mail), 119 Wingate Ave., Buffalo, N. Y. HEBERL1NG, C. W. (A 1934). Box 115, Wayzata, Minn. HF.BLEY, Henry F. (Af 1934), Advisory Engr., Commercial Testing & Engineering Co., 307 N. Michigan Ave., and (for mail), 636 Wrightwood Ave., Chicago. 111. -HECKLER, Samuel (7 1937), Engr. (for mail) Westchester Square Plumbing Supply Co., Inc., 4617 White Plains Ave., and 3040 Cruger Ave., New York, N. Y. HECHT, Frank H. (Af 1930), Sales Engr. (for mail), B. F. Sturtevant Co., 2635 Koppers Bldg., and 1467 Barnesdale St., Pittsburgh, Pa. HECKEL, E. P. (Af 1918), Vice-Pres. (for mail). Carrier Corp., Merchandise Mart Bldg., Chicago, and 314 Cuttriss Place, Park Ridge, 111. HEDDEN, Willard M. (A 1937), Treas. (for mail). Hedden Co., 17-25 S. Warren St., and 7- Reservoir Ave., Dover, N. J. HEDGES, H. Berkley (Af 1919), Mgr. of In dustrial Sales (for mail), J. J. Nesbitt, Inc., Holmesburg, Philadelphia, and 311 Jericho Rd.. Abington, Pa. HEDLEY, Park S. (Af 1923), Park S. Hedley Co., 361 Delaware Ave., Buffalo, N. Y. HEDLUND, Richard A. (7 1938; S 1937), Hartsdale, N. Y. HEEBNER, Walter M. (Af 1922), Sales Engr.. Warren Webster & Co., 95 Madison Ave., New York, N. Y., and (for mail), 282 Highwood Ave., Teaneck, N. J. HE1BEL, Walter E. (Af 1917), Dist. Mgr. (for mail). Aerofin Corp., 11 West 42nd St, New York, N. Y., and Old Greenwich, Conn. HEILMAN, Russell H* (Af 1923), Senior In dustrial Fellow (for mail), Mellon Institute of Industrial Research, 4400 Fifth Ave., and 5637 Wilkins Ave,. Pittsburgh, Pa. HEISTERKAMP, Herbert W. (7 1937), Engr., Bryant Heater Co., 17825 St. Clair Ave., and (for mail), 10801 St. Mark St., Cleveland, Ohio. HELBURN, I. B. (Af 1929; 7 1927), Junior Assoc, (for mail), Wyman Engineering, 1306 Chamber of Commerce Bldg., and 3815 Winding Way, Cincinnati, Ohio. HELLMERS, Charles C., Jr. (7 1937), Sales and Installation Engr., Airtemp Div., Sidles Co., 425 Stuart Bldg.', and - (for mail), 2554 Woodsdale Blvd., Lincoln, Nebr. HELLSTROM, John (A 1929), Vice-Pres. (for mail), American Air Filter Co., Inc., 215 Central Ave., and 3015 Brownsboro Rd., Louisville, Ky. HELMR1CH, G. Bernard (Af 1936), Detroit . Edison Co., 2000 Second Ave., Room 750, Detroit, and (for mail), 26590 Dundee Rd.; Huntington Woods, Royal Oak, Mich. HELSTROM, Herman G. (Af 1928),. Boiler and Stoker Div. (for mail), Wm. Bros. Boiler & Mfg. . Co., Nicollet Island, and 4608 Arden Ave., S., Minneapolis, Minn. HENDRICKSON, Harold M. <Af 1933), Engr. (for mail), York Ice Machinery Corp., ^5051 Santa Fe Ave., Los Angeles, and 3901 Liberty Blvd., South Gate, Calif. HENION, Hudson D.. (A 1923), Sales Mgr. (for mail), C. A. Dunham Co., Ltd., 1523 Davenport Rd., and 45 Ridge Drive, Toronto, Ont., Canada. HENNESSY, William J. (Af 1937), Design Engr., Green Foundry & Furnace Works, and (for mail), ' 1826 South 23rd St., Lincoln, Nebr. HENRY, Alexander S., Jr, (Af 1930), 300 Central Park West, New York, N. Y. HENSZEY, William P. (7 1935), Pres., W. P. Henszey Co., Lemont, Pa. HER1NG, Alfred (Af 1935), Pres., Hering Heating Co., Inc., 304 East 87th St.. New York, N. Y. HERKIMER, Herbert (Af 1934), Director (for mail), Herkimer Institute, 1819 Broadway, and 25 Central Park West, New York, N. Y. HERLIHY, Jeremiah J. (Life Member; Af 1914), 3751 Eddy St., Chicago, 111. HERMAN, Neil B. (7 1937; 5 1936), Dist. Repr. (for mail), Minneapolis-Honeyweli Regulator Co., 713 Maritime Bldg., New Orleans, La., and 4217 Garfield Ave., S., Minneapolis, Minn. HERRING, Edgar (Af 1919), Chairman and Governing Director (for mail), J. Jeffreys & Co., Ltd., Barrens Place, Waterloo Rd., London, S.E., .and "Kenia," Keswick Rd., Putney,. London, SW., England. - 28 Roll of Membership HERSH, Franklin C. (A 1933; 7 1930), Air Cond. Engr., Pennsylvania Power & Light Co., 901 Hamilton St., and (for mail), 47 S. St. Cloud St., Allentown, Pa. HERSKE, Arthur R. (Af 1926), Vice-Pres.-Gen. Mgr. Sales (for mail), American Radiator Co., 40 West 40th St., New York, and 101 Brookfield Rd., Mt. Vernon, N. Y. HERTY, Frank B. (Af 1933), Retail Sales Super visor (for mail), Brooklyn Union Gas Co., 176 Remsen St., Brooklyn, and 106 Pinehurst -Ave., New York, N. Y. HERTZLER, John R.* (Af 1936; 7 1928), Gen. Repr. (for mail), York Ice Machinery Corp., Roosevelt Ave., and 863 S. George St., York, Pa. HESS, Arthur J. (Af 1937), Engr., English & Lauer, Inc., 309 West 12th St., and (for mail), 2616 West 70th St., Los Angeles, Calif. HESS. David K. (7 1936; 5 1932), 5824 Harper Ave., Chicago, III. HESSELSCHWERDT, August L., Jr. (7 1937). Instructor-Mech. Engrg., Wayne University, Cass Ave., and (for mail), 15722 Kentucky Ave., Detroit, Mich. HESSLER, Lester W. (Af 1936), Branch Mgr., Trane Co., 125 E. Wells St., and (for mail), 6034 N. Bayridge, Milwaukee, Wis. HESTER, Thomas J. (Af 1919), Vtee-Pres.-Treas. (for mail), Hester Bradley Co., 2835 Washington Blvd., St. Louis, and 67 Aberdeen Place, Clayton, Mo. HEWETT, John B. (Af 1937; A 1935), Engr. (for mail), Quinby Air Conditioning Corp., 618 E. Main St., and 295 Meigs St., Rochester, N. Y. HEXAMER, Harry D. (Af 1931), Sales Engr. (for mail), Excelso Products Corp., 65 Clyde Ave., and 163 E. Delavan Ave., Buffalo, N. Y. HEYDON, Charles G. (A 1923), Mgr. Sales of Western Div., Wright-Austin Co., 315 W. Woodbridge St., and (for mail), 2681 Nebraska, Detroit, Mich. HIBBS, Frank C. (Af 1917), Salesman, H. B. Smith Co., 2209 Chestnut St., and (for mail), 846 North 65th St., Philadelphia, Pa. HICKEY, Daniel W. (A 1931), Pres., D. W. Hickey & Co., Inc. (for mail), 1631 University Ave., and 1874 Highland Parkway, SL Paul, Minn. HICKS, H. Kimble (7 1936; 5 1935). Sales Engr., American Radiator Co., 2212 Walnut St., Philadelphia, and (for mail), 33 Windemere Ave., Lansdowne, Pa. HIERS, Charles R. (Af 1929; 7 1927), Sales Engr., Minneapolis-Honeyweli Regulator Co., 801 Second Ave., New York,-and' (for mail), 19 Westminster Rd., Great Neck, N. Y. HIGDON, Harry S. (A 1937). Sales (for mail), Andrews Heater Co., 2231 Market, and 231 Byxbee, San Francisco, Calif. H1LDER, Frederick L. (Af 1937), Chief Engr., Electric Furnace-Man, Inc., 780-788 East 138th St., New York, N. Y.. and (for mail), 162 Trenton Ave., Clifton, N. J. HILDRETH, Egbert S. (A 1936), Air Cond. Engr. (for mail), Indianapolis Power & Light Co., 17 N. Meridian St., and 5734 E. New York St., Indianapolis, Ind. HILDRETH, Lane W. (Af 1935), Secy, (for mail). Anthracite Institute. 19 Rector St., New York, N. Y., and 221 Wheatsheaf Lane, Abington, Pa. HILL, Charles F. (7 1936), Carrier Repr., United Engineers, Ltd., River Valley Rd., Singapore, Straits Settlements. * HILL, Dr. E. Vernon* <Af 1914; A 1912), (Presi dential Member), (Pres., 1920; 1st Vice-Pres., 1919; 2nd Vice-Pres.. 1918; Council, 1915-1921). . -Owner (for mail). 179 W. Washington St., and . 6826 Newell Ave., Chicago, III.- HILL, Fred M. (Af 1930), 225 East Ave. 39, Los Angeles, Calif. HILL. Harold H. (Af 1935), Branch Mgr. (for - mail). 1211 Commercial National Bank Bldg., and 1705 E. Boulevard, Charlotte, N. C. HILL, Jared A. (Af 1937), Gas Htg. and Air Cond. Engr. (for mail). Pacific Gas & Electric Co., 245 Market St., San Francisco, and 717 Laurel Ave., Burlingame, Calif. HILLIARD, Charles E. (Af 1932; 7 1927), Htg.-Vtg. Engr. (for mail), E. C. Hilliard Co., 27 B St., South Boston, and 341 Hunnewell St., Needham Heights, Mass. HILLS, Arthur H. (Af 1924), Mgr., Sarco Canada, Ltd., 725-6 Federal Bldg., 85 Richmond St., W.. Toronto, Ont., Canada. HINCKLEY, Harlan B. (A 1934), Engr.-Custo- dian, Chicago Board of Education. 8510 S. Green St., and (for mail), 6933 Princeton Ave., Chicago, 111. HINES, Guy M. (A 1937), Chief Engr., Texas Agricultural & Mechanical College Power Dept., College Station, Texas. HINES, John C. (Af 1937). Vice-Pres., Treas. and Air Cond. Engr. (for mail), R. B. Hayward Co., 1714 Sheffield Ave., and 6629 Ramona Ave., Chicago. 111. HINKLE. Edwin C. {Life Member; M 1911), 170 N. Franklin St,, Hempstead, N. Y. H1NRICHSEN, Arthur F. (Af 1928), Pres.-Treas. (for mail). A. F. Hinrichsen, Inc., 50 Church St., New York, N. Y., and Mountain Lakes, N. J. HINTZ, Harvey P. (7 1936; S 1935), 211 E. Armory Ave., Champaign, 111. HIRSC1IMAN, WUllam F. (Af 1929). Pres, and Chief Engr., W. F. Hirschman Co., Inc., 220 Delaware Ave., and (for mail), 165. Le Brim Circle, Buffalo, N. Y. HITCHCOCK, Paul C. (Af 1931), Vice-Pres.- Treas., Burlingame, Hitchcock & Estabrook, Inc., 521 Sexton Bldg., and 5130 Harriet Ave., S., Minneapolis, Minn. .. HITT. John C. (A 1936), Branch Mgr. (for mail), Holland Furnace Co., 34-17th St., and 301 Valley View Ave., Wheeling, W. Va. HOBB1E, Edward H. (A 1937), Mgr. Sales Promotion and Research (for mail), Mississippi Glass Co., 220 Fifth Ave., New York, N. Y., and Ridgedale Ave., Florham Park, N. J. HOBBS, J. Clarence (Af 1920), Gen. Mgr., and Mfg. Operations (for mail). Diamond Alkali Co., and 60 Wood St., Painesville. Ohio. HOBBS, William S. (A 1936), Owner and Mgr. (for mail), P. O. Box 269, and 327 Park Ave., Swarthmore, Pa. HOCKENSMITH, Francis E. (Af 1936), Chief Engr. (for mail), Lennox Furnace Co., Inc., 400 N. Midler Ave., and 124 Ludington St., Syracuse, N. Y. HODEAUX, Walter L. (Af 1931), Owner (for mail), W. L. Hodeaux Plumbing & Heating Co., 215-17 N. Flagler Drive, and 310 Tenth St.. West Palm Beach. Fla. HODGDON, Harry A. (Af 1919), Pres., Stone- Underhill Co.-, 78 Woodbine St., and (for mail), 122 Sherman St., Wollaston, Mass. HODGE, William B. (Af 1934), Vice-Pres.. Parks - Cramer Co., and (for mail), P. O. .Box 1234, Charlotte, N. C. HOEHL, Edward R. (7 1935), Engr. (for mail). Carrier Corp., 405 Lexington Ave., New York, N. Y., and 645 Jefferson St., West New York, N. J. HOFFMAN, Charles S. (Af 1924), Vice-Pres. (for mail). Baker, Smith & Co., Inc., 576 Greenwich St., and 108 East 38th St., New York, N. Y. HOFFMAN, James D * {Life Member; M 1903), {Presidential Member), (Pres., 1910; 1st Vice- Pres., 1908; Board of Governors, 1911-1912), Prof, of Practical Mechanics, Head of Dept., Director of Practical Mech. Lab. (for mail), Purdue University, and 323 University St., West Lafayette, Ind. HOGAN, Edward L.* (Af 1911), Consulting Engr. (for mail), American Blower Corp., 6000 Russell St., and 700 Seward Ave., Detroit, Mich. HOGUE, William M. (A 1935), Sales Engr. (for mail), U. S. Electrical Motors, Inc., 200 E. Slauson Ave., and 4839 Keniston Ave., Los Angeles, Calif. 29 S Heating Ventilating Air Conditioning Guide 1938 HOLBROOK, Frank M.* (Af 1923), Engr., ApL J-l-5, 10 Lexington St., Newark, N. J. ' HOLLAND, Robert B. (Af 1937), Sales Engr. (for mail), York Ice Machinery Corp., 1275 Folsom St., and 3820 Scott St., San Francisco, Calif. HOLLISTER, E. Wallace (Af 1936; 7 1931). Owner (for mail), Hollister's, 31 Ridge SL, and 69 Staple St., Glens Falls ,N. Y. HOLLISTER, Norman A.* (Af 1933). 7101 Colonial Rd., Brooklyn, N. Y. HOLMES. Arthur D. (Af 1935). Vice-Pres. (for mail). Plumbers Supply Co., 323 W. First, and 1848 East 18th St., Tulsa. Okla. HOLMES, Paul B. (A 1936), Branch Mgr. (for mail). National Radiator Corp., 600 W St., N.E., and 4525 Fessenden St., N.W., Washington, D.C. HOLMES, Richard. E. (A 1938; 7 1934). Air Cond. Design Engr., Westingbouse Electric & Mfg. Co., 653 Page Blvd., and (far mail), 11 Bushwick St., Springfield, Mass. HOLT, James (Af 1933), Assoc. Prof, of Mech. Engrg. (for mail), Massachusetts Institute of Technology, Charles River Rd., Cambridge, and 1062 Massachusetts Ave.. Lexington, Mass. HOLYFIELD, Earl F. (A 1937), Air Cond. Engr., Oklahoma Electrical Supply Co., and (for mail), 121 E. Park. Oklahoma City, Okla. HONERKAMP, Fritz (Af 1937), Chief Engr. (for mail), Anemostat Corp. of America, 10 East 39th St., and 362 Riverside Drive, New York, N. Y. HOOK, Frank W. (Af 1937). Branch Mgr. (for mail), Johnson SeiVice Co., 814 Rialto Bldg., and 2363 Larkin St., San Francisco, Calif. HOPP, Herbert K. (5 1935), 530 McLean Ave., Yonkers, N. Y. HOPPE, Albert A. (Af 1935), Design and Applica tion Engr., Carrier Corp., 213 N.W. First St., and (for mail). 1941 Northwest 17th St., Okla homa City, Okla. HOPPER, Garnet H. (Af 1923), Engr., Taylor Forbes, Ltd., 1088 King St., W., and (for mail), 19 Brummell Ave., Toronto, OnL, Canada. HOPSON, William T. {Life Member; Af 1915), Tht Hopson & Chapin Mfg. Co., New London, Conn. HORNER, Samuel D. (J 1937), Engr., Carrier Corp., Merchandise Mart, and (for mail), 5054 Winthrop Ave., Chicago, 111. HORNUNG, John C. (Af 1914) .Engr., Retired. 854 Bluff St., Glencoe, ill. HORTON, Homer F. (Af 1925), Sales Repr., 1301 Judson Ave., Evanston, 111. HOSHALL, Robert H. (Af 1930). Associate (for mail). Thos. H. Allen, Consulting Engr., 65 McCall Place, and 1844 Cowden Ave., Memphis, Tenn. HOSKING, Homer L. (Af 1930), Sales Mgr. (for mail). Pacific Steel Boiler Corp., 101 Park Ave., New York, and 5 Church Lane, Scarsdale, N. Y. HOSTERMAN, Charles O. (Af 1924), SupL, McMurrer Co., 303 Congress St., Boston, and (for mail), 25 Batesweil Rd., Dorchester, Mass. HOTCHKISS, Charles H. B. (Af 1927), Editor. Heating and Ventilating, 148 Lafayette St., New York. N. Y. HOUGHTEN, Ferry C.* (Af 1921). Director (for mail). Research Lab., A.S.H.V.E., U. S. Bureau of Mines, 4800 Forbes StM and 1136 Murray Hill Ave., Pittsburgh, Pa. HOULIS, Louis D. (Af 1935), Chief Engr., Master Baker Ovens, and (for mail), 655 Pedretti Rd., West Price Hill, Cincinnati. Ohio. HOULISTON, G. Baillie {A 1928), Secy, (for mail), W. C. Green Co., 704 Race St., Cincinnati, Ohio, and 33 Tremont Ave., Ft. Thomas, Ky. HOUSKA, Arthur D. (7 1937). Sales Engr. (for mail), Clowe & Cowan, Inc., and 1417 Harrison St., Amarillo, Texas. HOWARD, Fenton L. (Af 1037). Chief-Engrg. -Staff (for mail), Refrigeration & Air Con ditioning Institute, 2130 Lawrence Ave.. and 2417 W. Greenleaf Ave., Chicago, 111. HOWATT, John* (Af 1915), {Presidential Member) (Pres., 1935; 1st Vice-Pres., 1934; 2nd Vice . Pres., 1933; Council, 1927-1936), Chief Engr. (for mail). Board of Education, 228 N. LaSalle St., and 4940 East End Ave., Chicago, 111. HOWE, Willis W. (Af 1936; A 1917). Div. Sales Engr., Pacific Gas & Electric Co., and (for mail), 108 Central Ave., Sausalito, Calif. HOWLETT, Ira G. (Af 1935; 5 1934). Consulting . Engr. (for mail), I. G. Howlett Co.. 120 E. Main St., and 2132 N. FonshiH Ave., Oklahoma City, Okla. HOWELL, Lloyd (Af 1915), Engr.. Industrial Dept., Peoples Gas Light & Coke Co., 122 S. Michigan Ave., and (for mail), 7605 Yates Ave., Chicago, 111. HOYT, Charles W. (A 1931), Pres.-Treas. (for mail). Wolverine Heating & Ventilating Equip ment Co.. 31 Main St.. Cambridge, and 45 Thaxter Rd., Newtonville, Mass. HOYT, Leroy W. (Af 1930), N. Stamford Ave., Stamford, Conn. HUBBARD, George W.* (Af 1911), Chief Mech, Engr. (for mail), Graham, Anderson, Probst & ' White, 1417 Railway Exchange, Chicago, and 710 Bonne Brae, River Forest, ill. HUBBARD, Nelson D. (Af 1919), Engr.-Partner, Hubbard & Wagschal, 243 W. Congress St., and (for mail). 2985 Blaine Ave., Detroit, Mich. HUCH, A. J. (Af 1919), Secy.-Treas. (for mail). Central Supply Co., 312 S. Third St., and 4037 Harriet Ave., Minneapolis, Minn. HUCKER, Joseph H. (Af 1921). Partner, HuckerPryibil Co., 1700 Walnut St., Philadelphia, and (for mail). 715 Stanbridge St.. Norristown, Pa. HUDEPOHL, Louis F. (Af 1936). Pres, (for mail), T. J. Conner, Inc., 3290 Spring Grove Ave., and 4395 Haight Ave., Cincinnati, Ohio. HUDSON, Robert A. (Af 1934), Partner (for mail). Hunter St Hudson, Room 710, 41 Sutter St., and Route 2, Box 51, Cordilleras Rd., Redwood City, San Francisco, Calif. HUETTNER, Henry F. (7 1938; 5 1934), Engr. (for mail). National Radiator Corp., Central Ave.. Johnstown, Pa., and 124 Jerusalem Ave., ' Hickesville, L. I., N. Y. HUFF, James M. (Af 1936), Mgr. Air Cond. Dept, (for mail). Silkensen Sc Co., inc.t 401-23rd St., and 1705~35th St., Apt. C.. Galveston. Texas. HUGHES, Lewis K. (7 1936), Gen. Mgr., Howard Furnace Co., 881 Yonge SL, and (for mail), 43 Rivercourt Blvd., Toronto, Canada. HUGHES, William U. (Af 1936), Vice-Pres.Managing Dir. (for mail), Lewis-Brown Co., Ltd., 1409 Crescent St., and 1610 Sherbrooke St., W.f Montreal, P. Q.. Canada. HUGHEY, Thomas M. (A 1935), Sales Engr.' (for mail), Westerlin St Campbell Co., 906 N. Fourth St., and 2350 North 58th St., Milwaukee. Wis. HUGHSON, Harry H. (Af 1937), Sales Engr. (for mail), Coon-DeVisser Co., 2051 W. Lafayette Blvd., and 58 Florence Ave.; Detroit, Mich. HUGONIOT, Victor E. (Af 1935), Zone Engrg. Mgr. (for mail), Airtemp Sales Corp., 3717 Washington Ave., and 1347 Kingsland Ave^ - St. Louis, Mo. HULL, Harry B. (Af 1931), Mgr. Research Engr. (for mail). Frigidaire, Div. of General Motors Corp., and 1430 Glendale Ave., Dayton, Ohio. .. HUMMEL, George W. (Af 1937), Field Engr. and Sales (for mail). Trane Co., Room 211. Industrial Bldg., and 327 E. McDowell Rd . Phoenix, Ariz. HUMPHREY, Dwight E.* (Af 1921). Htg.-Vtg. Engr., Goodyear Tire 8t Rubber Co., 1144 E. . Market SL, Akron, and (for mail), 2499 Sixth St., Cuyahoga Falls, Ohio. HUMPHREYS, Clark M. (Af 1931), (Council. 1937), Asst. Prof, of Mech. Engrg. (for mail), Carnegie Institute of Technology, Schenley Park, and 1934 Remington Drive, Pittsburgh. Pa. HUNGER, Robert F. (M 1927), Assoc. Dist. Mgr. (for mail). Buffalo Forge Co., 220 South lfith St., and 4618 Chester Ave., Philadelphia. Pa. 30 Roll of Membership HUNCERFORD, Leo (Af 1930), Mgr. Air Cond. Dept, (for mail), Delco-Frigidaire Corp.. 1057 ' J N. Le Brea Ave., Los Angeles, and 2360 Laurel JACKES, Herman D. (Af 1915), Mgr.-Sales (for Canyon Blvd., Hollywood, Calif. mail), Aerofin Corp., 410 S. Geddes St., Syracuse, HUNT, MacDonald (A 1936), Mfrs. Agent (for N. Y., and 1 Clinton Rd., Glen Ridge; N. J. mail), McDonnell Miller Co., 12 W. Madison St., JACKSON, Charles H. (Af 1923), Vice-Pres. (for and Windsor Court Apts., Baltimore, Md. mail). Blower Application Co.. 918 N. Fourth HUNT, Noel P. (Af 1934), Managing Dir. (for mail). Carrier Australasia, Ltd., 41-49 Forbes St., and 52 Lang Rd., Centennial Park, Sydney. N.S.W., Australia. HUNTER, Louis N. (Af 1936), Mgr. of Research (for mail). National Radiator Corp., 221 Central Ave., and 403 Wayne St., Johnstown. Pa: . HUNZIKER, Chester E. (A 1934), Branch Mgr. (for mail), American Blower Corp., 331 State St., Schenectady, and 422 Reynolds St., Scotia, N. Y. HUSKY, S. T. (7 1936; 5 1934), Engr., Zenith Gas System, Box 397, Alva, Okla. St., and 2706 N. FarweU Ave., Milwaukee, Wis. JACKSON, Marshall S. (Af 1919), Repr. (for mail). Powers Regulator Co., 250 Delaware Ave., and 108 Larchmont Rd., Buffalo, N. Y. JACOBUS, Dr. David S. {Life Member; M 1916), Advisory Engr. (for mail). The Babcock & Wilcox Co., 85 Liberty St., New York, N. Y., and 93 Harrison Ave.. Montclair, N. J. JALONACK, Irwin G. (A 1933; S 1930), Engrg. Mgr. (for mail), c/o A. L. Hart, 82 Railroad Ave., Patchogue, and Beaver Dam Rd., Brookhaven, N. Y. JAMES, Hamilton R. (Af 1931), Service Equip. Engr., United Engineers & Constructors, Inc., HUST, Carl E. (Af 1932), Supv. Htg Engr. (for 1401 Arch St., Philadelphia, and (for mail), mail), Cincinnati Gas & Electric Co., Fourth and 55 W. Drexel Ave., Lansdowne. Pa. Main Sts., and Hillcrest Apts., 15 Mason St., JAMES. John W * (Af 1937; 7 1933), Tech. Asst., Cincinnati, Ohio. i American Society of Heating & Ventilating HUSTOEL, Arnold M. (A 1930). 2414 N. Kedzie Engineers, 51 Madison Ave., New York, N. Y. Blvd., Chicago, III. JAMES, Richard E. (Af 1936), Mgr. Htg, Dept., HUTCHINGS, Robert L. (7 1937). Hughes Heating & Air Conditioning Co., 125 N. Jefferson St., Dayton, Ohio. , '' Harry Cooper Supply Co., and (for mail), 597 E. Elm St.. Springfield, Mo. JANET, Harry L. (Af 1920), Mech. Engr., Buensod- HUTCHINS, William H. (Af 1934), Chief Engr., Delco Appliance Div., General Motors Corp., and (for mail). 88 Magee St., Rochester, N. Y. HUTZEL, Hugo F. (Af 1918), Air Cond. Applica tions Dept., Kelvinator Corp., and (for mail), 2635 Woodstock Drive, Detroit. Mich. HVOSLEF, Frederick W. (Af 1931; A 1921), Htg.. Research Engr. (for mail), Kohler Co., and 523 Audubon Rd., Kohler, Wis. Stacey Air Conditioning, Inc., 60 East 42nd St., New York, and (for mail), 688 Decatur SL, Brooklyn, N. Y. - JARCHO, Martin D. (7 1936), Vice-Pres. (for mail), Jarcho Bros., 215 East 37th St., New York, and 941 Washington Ave., Brooklyn, N. Y. JARDINE. Douglas C. (Af 1929; A 1926), Pres, (for mail), Jardine & Knight Plumbing & Heating Co., 516 S. Tejon St., and 1512 E. Platte Ave., Colorado Springs, Colo. HYDE, Elmer H. (A 1937), Tech. Repr., Koppers JEFFREY, Thomas G. (A 1935), Mgr., Ruud Co., Tar and Chem. Div., 501 Flannery Bldg., Mfg. Co., 474 Bathurst SL, and (for mail). and (for mail), 442 Sulgrave Rd.,-Chatham 478 Windemere Ave., Toronto, Canada. Village, Pittsburgh, Pa. JEHLE, Ferdinand (A 1937). Dir. of Labora- HYDE, Eric F. (Af 1937), Consulting Engr*. 512 : tones (for mail), Hoffman Specialty Co., Inc., Free Press Bldg., Detroit, and (for mail). 708 Oakland Ave., Birmingham, Mich. 575 Pacific St., Stamford, and New Canaan, Conn. - HYDE, Lawrence L. (A 1937; 7 1934), Gen. Mgr., M. J. O'Neil, and (for mail), 54 S. Cretin St., St. Paul, Minn. ' HYMAN, Wallace M. (Af 1920), Pres, (for mail), ' Reis & O'Donovan, Inc., 12 West 21st St-, and 23 West 73rd St., New York, N. Y. HYNES, Lee P* (Af 1919), Pres, and Chief Engr. (for mail), Hynes Electric Heating Co., 240 Cherry St., Philadelphia, Pa., and 127 West End . Ave., Haddonfield, N. J. JELINEK, Frank R. (7 1937). Sales Engr., (for mail), Johnson Service Co., 2505 Commerce St., and 605 N. Ervay SL, Dallas, Texas. JENNEY, Hugh B. (A 1933). Gen. Sales Mgr. (for mail). Dominion Radiator & Boiler Co., Ltd., Royce and Lansdowne Aves., and 96 Dawlish Ave., Toronto, OnL, Canada. JENNINGS, Hal K. (Af 1937), Sales Engr., Avery Engineering Co., 2341 Carnegie, Cleve- - land, and (for mail), 844 Chestnut Blvd., Cuyahoga Falls, Ohio. .' JENNINGS, Irving C. (Af 1924), Pres, (for mail), I Nash Engineering Co., and 138 Flax Hill Rd., ICKERINGILL, John C. (Af 1923), Sales Engr.! Spencer Heater Co.. 2020 N. Broad St., and (for mail), 477 Flamingo St., Rox., Philadelphia, Pa. 1LLIG, Walter R. (Af 1935; A 1927), Owner. ' South Norwalk, Conn. JENNINGS, Richard A. (A 1937), Chief Engr. (for mail), R. K. O. Keith Memorial Theatre, 539 Washington St., and 695 Atlantic Ave., Boston, Mass. 1 Cushing St., and (for mail), 242 Blossom St., JENNINGS, Stanley A. (Af 1935). Chief Drafts Fitchburg, Mass. man, Trane Co. of Canada, Ltd., 439 King SL, INGALLS, Frederick D. B. (Af 1906), Consulting W., and (for mail), 80 Glen Manor Drive, Engr., 1 Hopkins St., Reading, Mass. Toronto, OnL, Canada. INGELS. Margaret* (Af 1923; 7 1918), Mech. Engr. (for mail). Carrier Corp., and 600 James St., Syracuse, N. Y. JENNINGS, Warren G. (A 1930), Resident VicePres. (Tor mail), Minneapolis-Honeywell Regu lator Co., 797 Beacon SL, Boston, and Long- IRWIN, Robert R. (7 1937), Air Cond. Engr. (for mail), York Ice Machinery Corp., 117 South 11th . St., and 754 Westgate Ave., St. Louis, Mo. dTSSERTELLE, Henry G.* {Life Member M 1913; A 1912), Consulting Engr., 31 Park Terrace,-W., Apt. A-8, New York, N. Y. . ISETT, William M. (A 1936), Pres, (for mail), C. B. Isett & Son. Inc., 3035-37 N. Rockwell St., and 4236 N. Drake Ave., Chicago, 111. wood Towers, Brookline. Mass. JENNINGS, Henry H. {Life Member; Af 1901), 15 Grange View, Chapeltown Rd., Leeds, EnglandJENSON, Jean S. (Af 1912), Consulting Engr. (for . mail), 431 S. Dearborn SL, and 1634 West 106th St., Chicago, 111. JEPERTINGER, Richard C. (A 1934), Secy, (for mail), Syncromatic Air Conditioning Corp.. 3373 N. Holton St., and 1628 W. Vienna St., IVERSON, Henry R. (Af 1936; A 1936), Sales Milwaukee, Wis. ' Engr. (for mail), Trane Co.. 734 Jackson Place JESSUP, Benjamin H. (Af 1937), Pres, (for mail), N.W., and 1601'Argonne Place, N.W.; Wash Richards & Jessup Co., Inc., 615 Main SL, ington, D. C. . Stamford, and 48 Field St., Glenbrook, Conn. Heating Ventilating Air Conditioning Guide 1938 JEX, John, Jr. (A 1936), Sales Engr. (for mail), Mercoid Corp., 1035 Cathedral St., Baltimore, and Earleville, Cecil County, Md. JIMENEZ, Joaquin G. (Af 1935), Engr. Director (for mail), Ave. Edwardo Dato, 34, Madrid, Spain. JOHN, Victor P. (Af 1931), Mgr., Buffalo Branch, American Blower Corp., 822 White Bldg., Buffalo, and (for mail), 136 Berryman Drive, Snyder, N. Y. JOHNS, Harold Byron* (Af 1928; 7 1927), (for mail), Peoples Gas Light & Coke Co., 122 S. Michigan Ave., Chicago, and 543 N. Elmwood ' Ave., Oak Park, 111. JOHNSON, Allen J.* (Af 1935), Director Anthra cite Industries Laboratory, Primos, Del. Co., Pa. JOHNSON, Car! W. (Af 1912), Pres, (for mail), C. W. Johnson, Inc., 211 N. Desplaines St., and 1809 Morse Ave., Chicago, 111. JOHNSON. Clarence W. (Af 1933; 7 1931), Dist. Mgr. (for mail), Canadian Sirocco Co., Ltd., 630 Dorchester St., W., and 333 Dresden Ave., Mt. Royal, Montreal, Que., Canada. JOHNSON, Edward B. (Af 1919), Sales Engr., Staten Island Supply Co., and (for mail), 154 Wardwell Ave., West New Brighton, S- L, N. Y. JOHNSON, Helge S. (A 1933; 7 1927). Dist. Mgr. (for mail), Buffalo Forge Co. (112 State St.), 611 Standard Bldg., and 20 Fleetwood Ave., Albany, N. Y. JOHNSON, Leslie O. (A 1938; 7 1930), Sales Engr., H. Y. Keeler Co., 910 Hines Bldg., and (for mail), 3015 Staunton Rd., Huntington, W. Va. JOHNSON, Louis H. (Af 1931). 918 LaSalle Ave., Minneapolis. Minn. JOHNSON, Oliver W. (Af 1937), Chemical Engr., Standard Oil Co. of California, San Francisco, and (for mail), 1831 Waverly St., Palo Alto, Calif. JOHNSON. Walter A. (7 1936; 5 1935), Asst. Instructor in Mech. Engrg. (for mail), Columbia University, Mech. Engrg. Dept., and 1138 John Jay Hall. New York, N. Y. JOHNSON. Wayne G. (7 1937; 5 1936), Research Dept., Herman Nelson Corp., 1824 Third Ave., and (for mail), 810-20th Ave., Moline, 111. JOHNSTON, Hugo D. (A 1934), Engr. and Contr., Box 282, Wellington, Ont., Canada. JOHNSTON, J. Ambler (Af 1912), Partner, Carneal, Johnston & Wright, 809 Electric Bldg., and 2616 Hanover Ave., Richmond, Va. JOHNSTON, Robert E. (Af 1929; A 1926), Managing Dir. (for mail), R. E. Johnston Co., Ltd.. 1070 Homer St., and 3342 West 33rd Ave., Vancouver, B. C.. Canada. , JOHNSTON, Robert McC. (J 1937), Instructor, Dept, of Mech. Engrg., Virginia Polytechnic Institute (for mail). Box 548, and 707 Main St., Blacksbutg. Va. - JOHNSTON, William H. (Af 1924), 306 East 26th St., New York, N. Y. JONES, Alfred (Af 1928), Chief Consulting Engr. (for mail), Armstrong Cork Co., P. O. Box 540, and 402 President Ave., Lancaster, Pa. JONES, Alfred L. (Af 1926), Plbg. and Htg. Contr. (for mail), 431 Greenwich Ave., Green wich. and Breezemont Ave., Riverside, Conn. JONES. Allan T. (Af 1937; 7 1935), Mech. Engr. (for mail), S. A. Armstrong, Ltd., 720 Bathurst St., and 325 Kingswood Rd., Toronto, Ont., Canada. JONES, Andrew P. (J 1936; 5 1935), Elec, and Mech. Engr., 504 E. Fifth, Hereford, Texas. JONES, Bernard G. (Af 1928), Mgr. (for mail). Acme Fan & Blower Co., Ltd., 868 Arlington St., and 542 Raglan Rd., Winnipeg, Man., Canada. JONES, Charles R. (A 1928), Pres., Jones Supply Co., Siloam Springs, Ark. JONES, David J. (Af 1936), Control Engr., Vapor Car Heating Co., Inc., Railway Exchange Bldg., Chicago, and (for mail), 391 Poplar Ave., Elra- . hurst. 111. JONES, Edwin (Af 1933; 7 1924), Engr. and Estimator (for mail). Watt Plumbing, Heating & Supply Co., 608 S. Cincinnati, and 1436 East 17th Place. Tula, Okla. JONES, Edwin A. (Af 1919), Chief Engr. (for mail), L. J. Mueller Furnace Co., 2005 W. Oklahoma; and 4381 N. Alpine Ave., Milwaukee, Wis. JONES, Edwin F. (Af 1923), Utilities Engr., City of St. Paul, 216 Courthouse, and (for mail), 220 Montrose Place, St. Paul, Minn. JONES, Harold L. (Af 1920). Supt. (for mail), W. W. Farrier Co., 44 Montgomery St., Jersey City, and 11 Cambridge Rd., Glen Ridge, N. J. JONES, John P. (Af 1937), Pres, (for mail), John Paul Jones, Cary and Millar, 448 Terminal Tower, Cleveland, and 3161 Scarborough Rd., Cleveland Heights,.Ohio. JONES, Norman R. (A 1935), Sales Mgr., Orr & Sembower, Inc., Reading, and (for mail), 109 Rutledge Ave., Rutledge, Pa. ' JONES, Sprague (Af 1936), Pres.-Mgr. (for mail), Sprague Jones, Inc., 1116 Madison Ave., and 3769 S. Lockport Ave., Toledo, Ohio. JONES, William T. (Af 1915), {Presidential Member), (Pres., 1933; 1st Vice-Pres., 1932; 2nd Vice-Pres.. 1931; Council, 1925-1933). Treas.. Barnes & Jones, 128 Brookside Ave., Jamaica Plain, and (for mail), 16 Harvard St., Newton- ville. Mass. JOPSON, John M. (Af 1936), Engr.. W. M. Anderson Co., 600 Schuylkill Ave., Philadelphia, and (for mail), 8455 W. Penn St., East Falls, Philadelphia, Pa. JORDAN. Richard C* (7 1935; S 1933), In structor, University of Tulsa, and (for mail), 1004 S. College, Tulsa, Okla. JORDAN, W. D. (Af 1935), Mgr., Air Cond. Div. (for mail). Savage Arms Corp., 100 East 42nd St., New York, and 132 Overlook Rd., New Rochelle. N. Y. JOSEPHSON. Simon (J 1936), Engr. (for mail), Astor Plumbing & Heating Corp., 1134 Bedford Ave., and 525 Linden Blvd., Brooklyn, N. Y. JOYCE, Harry B. (Af 1922), Consulting Engr. (for mail). 616 Commerce Bldg., and 501 Liberty St., Erie, Pa. JUNG, John S. (Af 1930; A 1923), Htg., Piping and Air Cond. Contr. (for mail), 2409 W. Green- held Ave., and 1516 S. Layton Blvd., Milwaukee, Wis. JUNKER. William H. (Af 1936), Chief Mech. Engr., Thos. Emery's Son9, Inc., 2109 Carew Tower, and (for mail), 6068 Dryden Ave., Cincinnati, Ohio. K KACZENSKI, Chester (7 1933), P. O. Box 155. Bridgehampton, L. I., N. Y. ' KAERCHER, C. M. H. (Af 1937), Managing Dir. (for mail), Central Bureau for Heating and Air Conditioning, 3030 Euclid Ave., Cleveland, and 2560 Ashurst Rd., University Heights, Ohio. KAGEY, I. B * (A 1937; 7 1929), Sales Engr. (for mail). Carrier Corp., 404 Bona Allen Bldg., and Atlanta Athletic Club, Atlanta. Ga. KAIN, Edward M. (7 1937; 5 1936). Draftsman, Babcock & Wilcox Co., Stirling Ave., Barberton, and (for mail), 3656 East 146th St., Cleveland, Ohio. KAISER, Fred (Af 1935), Branch Mgr. (for mail), Minneapolis-Honeywell Regulator Co., 45 Allen St., and 481 Starin Ave., Buffalo, N, Y. KAJUK, Andrew E. (Af 1936), Engr., Austin Co., 16112 Euclid Ave., Cleveland, and (for mail), 6907 Theota Ave., Parma, Ohio KALINSKY, Alex G. (7 1936; 5 1934), Htg. Engr., Fox Furnace Co., and Y. M. C. A., Elyria, and (for mail), 9114 Fuller Ave., Cleveland, Ohio. KAMMAN, Arnold R. (A 1925; 7 1921), Arnold R. Kamman Co. (for mail), 493 Franklin St., Buffalo, and R. F. D. No. 3, Hamburg, N. Y. . KAMPISH, Nick S. (7 1935; 5 1934), Air Cond. Engr., Air Temp. New York Sales Corp., Chrysler Bldg., New York, N. Y., and (for mail), 214 E. Lincoln Ave., Roselle Park, N. J. KAPPEL, George W. A. (Af 1921), Pres, and Treas. (for mail), Camden Heating Co.,. Wilson . Blvd. and Waldorf Ave., Camden, and 347 W. Kings Highway, Haddonfield. N. J. . 32 Roll of Membership KARAKASH, Todori (7 1936), Engr. (for mail), G. & A. Baker, Ltd., Carrier Div., Prevuayans Han, Tahtakale, and Engin Apt., Ferus-Aga, Galatasaray, Istanbul, Turkey. KARCHMER, Jacob H. {A 1936), Mgr. (for mail), Karchmer Co., 600-14 N. Jefferson Ave., and 1316 Roanoke Ave., Springfield, Mo. KARGES, Albert (A 1935), Vice-Pres. and Managing Dir., James Stewart Mfg. Co., Ltd., Tecumseh St., and (for mail). 37 Perry St., Woodstock, Ont., Canada. . KARLSON, Allred F. (Af 1918), Chief Engr. (for mail), Parks-Cramer Co., 970 Main St., Fitch burg, and 186 Prospect St., North Leominster, Mass. KARLSTEEN, Gustav H. (Af 1935), Plant Engr., Dunlop Tire & Pubber Corp., Buffalo, and (for mail), Box 55, Route 1, Tonawanda, N. Y. KARTORIE, V. T. (7 1935; S 1933), Engr. (for mail), York Ice Machinery Corp., Air Cond. Div., and 1513 Third Ave., Elmwood, York, Pa. KASTNER, George C. (7 1935; 5 1933), 654 East 226th St., New York, N. Y. KAUFMAN, Charles W. (7 1935), Engr. (for mail). Carrier Corp., Hibernia Bank Bldg., and 5532 S. Liberty St., New Orleans, La. KAUFMAN, Hiram J. (Af 1937). Htg.-Vtg. Engr., Commonwealth & Southern Corp., Consumers Power Bldg., Jackson, Mich., and (for mail), 13215 Rosetawn Ave.. Detroit, Mich. KAUP, Edgar O. (Af 1937), Engr., Air Cond. Div., W. R. Ames Co., 150 Hooper, San Francisco, and (for mail). 1129 Curtis, Albany. Calif. KAWASE, Sumlo (Af 1936), Chief Htg. Engr., Eizen Juhin Kyoku--Manchoukuo, and (for mail), 614 Suchikodo, Hsinking, Manchoukuo. KEATING, Arthur J. (Af 1937), Air Cond. Engr. (for mail). Cooling & Air Conditioning Corp., Room 404, Wrigley Bldg., and 4429 W. Congress St., Chicago, III. KEEFE, Edmund T. (Af.1931), Pres, (for mail). Underground Steam Construction Co., 75 Pitts St., Boston, and 185 Commonwealth Ave., Newton, Mass. KEENEY, Frank P. (A 1915), Pres, (for mail), Keeney Publishing Co., 6 N. Michigan Ave., and 7059 South Shore Drive, Chicago, III. KEHM, Horace S. (Af 1928), Pres., Kehm Bros. Co. & Stevens-Root Co. (for mail), 51 E. Grand - Ave., and 3000 Sheridan Rd., Chicago, 111. KELBLE, Frank R. (Af 1928), Vice-Pres. and Mgr. (for mail), Huffman-Wolfe Co. of Phila delphia, 4660 North 18th St., Philadelphia, and 305 Pleasant Ave., Glenside Gardens, Pa. KELLEY, James J. (A 1924), Vice-Pres. and Gen. Mgr. (for mail), Arthur H. Ballard, Inc., 535 Commonwealth Ave., Boston, and 142 Governors Ave., Medford, Mass. KELLEY, Robert D. (Af 1937), Pres, (for mail). Sunbeam Heating & Air Conditioning Co., 346 Peachtree St., N.E., and 668 Elmwood Drive, N.E., Atlanta, Ga. KELLNER, Day C. (7 1937; S 1933), Cuba City, Wis. KELLOGG, Alfred {Life Member; M 1916), (Council, 1920-1921; 1923-1924), Consulting Engr. (for mail), 585 Boylston St., Boston, and 6 Hawthorne St., Belmont. Mass. KELLY, Charles J. (Af 1931), Treas. (for mail), Kelly & Kenney, Inc., 551 Fifth Ave., New York, N. Y., and 96 Duncan Ave., Jersey City, N. J. KELLY, John G. (A 1919), 374 Park Ave., Yonkers, N. Y. KELLY, Wilbur C. (Af 1935). Field Engr. (for mail). Iron Fireman Mfg. Co. of Canada, Ltd., 602 King St., W., and 58 Elmsthorpe Ave., Toronto, Ont., Canada. KENDALL, Edwin H. (Af 1930), Engr., English & Lauer, Inc., 1978 S. Los Angeles St., Los Angeles, Calif. KENNEDY, Maron (A 1936; 7 1930), Sales Engr.. York Ice Machinery Corp., 5051 Santa Fe Ave., Los Angeles, Calif.` KENNEDY, Owen A .(7 1938; 5 1933). Vent. Engr. (for mail), H. H. Robertson Co., 5134 Margaret Morrison St., Pittsburgh, Pa., and 112 Dixie Highway, South Fort Mitchell, Ky. KENNEDY. Paul V. (7 1936; S 1934), 105 Avon St., New Haven, Conn., and (for mail), 4915 Forbes St., Pittsburgh, Pa. KENNEY, Thomas W. (Af 1937), Pres, (for mail). Kelly & Kenney, Inc., 551 Fifth Ave., New York, ' and 16 Point Circle, Malba, Whitestone, N. Y. KENT, J. King (A 1938; 7 1928), Pres, (for mail). J. King Kent Co., Inc., 6477 Manchester, St. Louis, and 2012 Urban Drive, Brentwood, Mo. KENT, Laurence F. (A 1927; 7 1924), Pres, (for mail), Moncrief Furnace Co., P. O. Box 1673, Atlanta, and R. F. D. No. 2, Smyrna, Ga. KENT, Richard L. (Af 1936). Dist. Mgr. (for mail), Trane Co. of Canada, Ltd., 138 Portage Ave., and 830 Wolseley Ave., Winnipeg, Man., Canada. KEPLER, Donald A. (7 1936; 5 1934), Vent. Engr., New York Stock Exchange Bldg. Co., 20 Broad St., New York, N. Y., and (for mail), 30 Maplewood Ave., Maplewood, N. j. KEPLINGER, William L. (Af 1929), Combustioneer Corp., 409 Tenth St., S.W., and 1437 . Rhode Island Ave., N.W., Washington, D. C. KERN, Joseph F., Jr. (A 1937), Asst. Editor, Heating & Ventilating, 148 Lafayette St., New York, and (for mail), 42-15-79th St., Elmhurst, N. Y. KERN, Raymond T. (Af 1927). Chief Engr., Jennison Co., 17 Putnam St., Fitchburg, and (for mail), 51 Claflin St., Leominster, Mass. KERR, William E. (Af 1937). Sales Repr., Barnes 6 Jones, Inc. (of Boston, Mass.), College Place, Columbia. S. C. KERSHAW, Melville G. (Af 1932; A 1926; 7 1921), Vtg. and Air Cond. Engr. (for mail), E. I. DuPont de Nemours & Co., Wilmington, Del., and 7313 North 21st St., Philadelphia, Pa. KESSLER, Jacob (Af 1936). Pres, (for mail). Jacler Heating Co., Inc., 3810 Third Ave., and 2115 Ryer Ave., New York, N. Y. . KESSLER, Maurice E. (Af 1937). Mgr., Pioneer . Heating-Cooling Co., 1304 Niagara St. (for mail), P. O. Box 664, and 696 Orchard Parkway, Niagara Fall3, N. Y. a KETTER, Jack W. (7 1937). Sales Engr. (for mail). Badger Refrigeration & Eng. Co., 706 W. Wisconsin Ave., and 3042 N. Second St., Mil waukee, Wis. KEYES, Robert E. (Af 1913), Chief Engr., B..F. Sturtevant Co., Hyde Park, Boston, Mass. KEYSER, Herman M. (A 1937), Sales Engr., Murray W. Sales & Co., and (for mail), 3007 Whitiiey Ave., Detroit, Mich. KIGZALES, Maurice D. (Af 1935). Mech. Engr., ' U. S. Army Motion Picture Service, 726 Jackson Place, N.W., and (for mail), 3000 Connecticut Ave., Washington, D. C. KIEFER, Carl J. (Af 1922), Vice-Pres. (for maU), Schenley Products Co., 607 Schmidt Bldg., and 984 Lennox Place, Avondale, Cincinnati, Ohio. * KIEFER, E. J., Jr. (A 1932; 7 1928), Treas. and Gen; Mgr., H. C. Archibald Co., 406 Main St., and (for mail), 108 N. Sixth St., Stroudsburg, Pa. KIESLING, Justin A. (Af 1930), Pres, (for mail). Robischung Kiesling, Inc., 4848 Main St., P. O. Box 1295, and 1602 Stuart St., Houston, Texas. KILLIAN, Thomas J. (A 1937). Htg. Contractor (for mail); 118 Belvidere St.-. Waukegan, 111. KILLIAN, Vic. J. (A 1937), V. J. Killian Co. (for mail), 907 Linden Ave., and 1348 Edgewood Lane. Winnetka, 111. ` KILNER, John S. (Af 1929), Mfrs.* Agent (for mail), Kilner Co., 7310 Woodward Ave., and ` 1091 Seminole Ave., Detroit. Mich. ' KILPATRICK. W. S. (Af 1923), W. S. Kilpatrick & Co. (for mail), 1682 W. Washington Blvd., and 943 S. Cochran St., Los Angeles, Calif. - .33 Heating Ventilating Air Conditioning Guide 1938 KIMBALL, Charles W. (M 1915), Treas. (for mail), Richard D. Kimball Co., 6 Beacon St., Boston, and 65 Prescott St., West Medford, KLIE, Walter (M 1915), Pres, (for mail). The Smith & Oby Co., 6107 Carnegie Ave., Cleveland, and 18411 S. Woodland Ave., Shaker Heights, Ohio. KIMBALL, Dwight D.* (M 1908), (Presidential Member), (Pres., 1915; 2nd Vice-Pres., 1914; Board of Governors, 1912-1916), Consulting Engr. (for mail), Room 1728 Grand Central Terminal Bldg., and 145 West 58th St., New KNAB, Edward A. (M 1930; A 1927), Prop., E. A. Knab, Heating Contractor, 4823 N. Bartlett Ave.. Milwaukee, Wis. KNAPP, Andrew E. (M 1937), Engr. (for mail), Nasb-Kelvinator, 14250 Plymouth Rd., and York. N. Y. 8059 Sorrento, Detroit, Mich. KIMMEL, Walter G. (J 1937), Commercial Field Engr., York Ice Machinery Corp., 117 KNAPP, Donald S. (A 1936), Branch Mgr. (for mail), Chamberlin Metal Weather Strip Co., South 11th St., St. Louis, Mo. ' KIMMELL, PhlUp M. (J 1936), Dist. Engr., L. R. Krumm Co., (Delco-Frigidaire Cond. Inc., 2400 Hennepin Ave., and 4607 Wooddale Ave., Minneapolis. Minn. ` KNAPP, Joseph H. (M 1936), Designing, Htg. Corp.), 121 E. Gay St., Columbus, Ohio. KINCAIDE, Merrill C. (A 1937; J 1936), Air Cond. Engr. (for mail), Timken Silent Automatic Division, 10CM00 Clsirk Ave., and 1160 Seward Ave., Detroit, Mich. KINDORF, Harry L. (M 1937). Chief Engr. (for and Vtg. Equip.. Utica Products Corp., and (for mail). Ill Lowell Ave., Utica, N. Y. . KNIBB, Alfred E. (M 1930), Htg. Engr. (for mail), L. L. McConachie Co., 1003 Maryland Ave., and 9333 E. Jefferson Ave., Detroit, Mich. KNOPF, Charles (A 1936; J 1935; 5 1933). 1201 mail), Edward B. Ward & Co., 270 Fremont St., and 46 Oakwood St., San Francisco, Calif. KING, Arthur C. (M 1936), Consulting Engr. (for mail), 35 S. Dearborn St., and 2018 Lane Court, Chicago. III. . KING, Harry K. (A 1937), Dist. Mgr., Tube- Turns, Inc., 224 E. Broadway, Louisville, Ky., Liberty Ave., Brooklyn, N. Y. KNOWLES, Elwin L. (A 1937). Prop., Marshall Heating Co., 1647 Hennepin Ave., and (for mail), 36 Oliver Ave., S., Minneapolis, Minn. ' . KNOWLES, Frank R. (A 1937), Dir. Commercial Engrg. Dept, (for mail), Pennsylvania Electric Co.. 535 Vine ot., and 719 Linden Ave., Johns . and (for mail), 10356 Morrow Circle, S., Dear born, Mich. KING, Lon D. (A 1937), Air Cond. and Htg. (for mail), Sidles Co., Airtemp Div., 425 Stuart Bldg., and 2325 R St., Lincoln, Nebr. KING, Roy L. (J 1936; S 1933), Engr.. Lewis Air _ Conditioners, Inc., 1600 Broadway, N.E., and (for mail), 2538 Clinton Ave., S., Minneapolis, Minn. KINGSLAND, George D. (M 1935). Vice-Pres. (for mail), Minneapolis-HoneyweU Regulator Co.. 2753 Fourth Ave., S.f and 2036 Queen Ave., S., Minneapolis, Minn. KINGSWELL, William E. (M 1935), Pres, (for mail), W. E. Kingswell, Inc., 3707 Georgia Ave., N.W., and 2739 Macomb St., N.W., Washington, D. C. KINNEY, AJdon M. (if 1936), Pres.-Treas. (for mail), A. M. Kinney, Inc., 1820 Carew Tower, Cincinnati, and 3812 Beech St., Mariemont, town, ra. KNOWLES, Mahlon G. (M 1935), Instructor in Applied Science, Wentworth Institute, 550 Huntington Ave., Boston, and (for mall), 255 Burrill St., Swampscott, Mass. KNOX, James R. (M 1930), Consulting Engr., 26 Commercial St., Dundee, Angus, Scotland. KNUDSEN, William R. (M 1937), Mgr., Frigidaire Div., General Motors, 2031 Calumet, and (for mail), 7834 Ridgeland Ave., Chicago, 111. KOCH, Richard G. (A 1935), Htg. and Ait Cond. Engr., Milwaukee Gas Light Co., 626 E. Wis consin Ave., and (for mail), 734 North 34th St., Milwaukee, Wis. KOEHLER, C. Stewart (A-1936), Sales Engr. (for mail), Minneapolis-HoneyweU Regulator Co., 801 Second Ave., and 4374 Richardson Ave.; New York. N. Y. KOFOED, V. Beckwith (A 1937), Dist. Mgr. (for mail). Fox Furnace Co., 6505 Euclid Ave., Cleveland, and R. F.'D. No. 3, Chagrin Falls, Ohio. KIPE, J. Morgan (M 1919), Director of Educa OIIIO. , KOHLER, Walter J., Jr. (A 1933), Secy. (for. tion, Anthracite Merchandising School, Primes, ' mail), Kohler Co., and "Windway," Kohler, Wis. and (for mail), 801 Homestead Ave,, Beechwood, KONZO, Seichl* (M 1937; A 1936; J 1932), Del. Co.. Pa. Special Research Asst. Prof., University of KIPP, Theodore (M 1937), Pres., Kipp-Kelly, Illinois, 102 Mech. Engrg. Lab., and (for mail), Ltd., 68 Higgins Ave., and (for mail), 1030 1108 W. Stoughton St., Urbana, III. Wellington Crescent. Winnipeg, Man., Canada. KOOISTRA, John F. (M 1933), Sales Engr. (for KIRKPATRICK, Arthur H. (M 1935; J 1931), Salesman, Ilg Electric Ventilating Co., 415 Brainard, and (for mail). Hotel Webster Hall, Detroit, Mich. KISTLER, Milton L. (A 1936). Owner-Engr., Kistler's Sheet Metal Works, Route 2, Box 167-A, Mobile, Ala. KITAURA, Shigeyukl (M 1918), 191 Gotanda 6 Chrome, Shanagawa-ku, Tokyo, Japan. KITCHEN. Francis A. (A 1927; J 1923), Pres, (for mail), American Warming & Ventilating Co., 1514. Prospect Ave., and 2077 Campus Rd., South Euclid, Cleveland, Ohio. KITCHEN, John H. (Life Member; M 1906), Owner and Mgr. (for mail), John H. Kitchen Co., 1016 Baltimore Ave., and 5015 Westwood Ter race, Kansas City, Mo. mail), Carrier Corp., Room 701, 625 Market St., San Francisco, and 1245 Laguna St., Burlin- . game, Calif. . KORN, Charles B. (M 1922), Member of Firm. Reber-Kom Co., 817 Cumberland St., and (for mail), 1022 S. Eighth St., Allentown, Pa. KOTHE, Frederick H. (A 1937). Resident Engr. (for mail). Carrier Engineering South Africa, Ltd., Box 2421, and 258 Florida Rd., Durban, oouui rtinca. KOTZEBUE,. Robert W. (A 1937), Mgr. Air Cond. Dept, (for mail), Straus-Frank Co., 301 S. Flores, and 118 Carolina, San Antonio, Texas. KOZU, Tamiichiro (M 1930), Chief Engr. (for mail), Japan Radiator Industrial Association, 506 Marunouchi Bldg., and 1701 Yonchome Shimoochiai, Yodobashiku, Tokyo, Japan. KRAMIG, Robert E-, Jr. (A 1933), Vice-Pres., KLEIN, Albert R. (M 1920), Managing Dir. (for Treas. (for maU), R. E. Kramig & Co., Inc., mail). Lufttechnische GeseUschaft m.b.H., 222-4 East 14th St., Cincinnati, and 115 Linden Stuttgart W., Konigstrasse 84, and Stuttgart N., Drive, Wyoming, Ohio. . Panoramstr. 23, Germany. KRAMINSKY, Victor (M 1936), Managing Dir. KLEIN, Edward W. (M 1917), Dist. Repr. (for mail), Warren Webster & Co.. 152 Nassau St.,' N.W., and 456 Peachtree Battle Ave., Atlanta, (for mail). Air Conditioning & Engineering, Ltd., 4-12 Palmer St., Westminster, London. S.W. 1, and 36 Manor Court, Aylmer Rd., Highgate, Ga. KLEINKAUF, Henry (7 1937), Branch Mgr. (for mail), Natkin & Co., .1726 St. Mary's Ave., and 6312 Florence Blvd., Omaha, Nebr. London, England. . KRATZ, Alonzo P.* (M 1925), Research Prof, (for mail). Dept, of Mech. Engrg., University of Illinois, and 1003 Douglas Ave., Urbana. 111. 34. Rou. or Membership KRAYENHOF, Harold G. (A 1937). Mgr. Htg. and Air Cond. Div. (for mail), Home-Wilson, Inc.. 163 Peters St., S.W., and 756 Sherwood Rd., N.E., Atlanta, Ga. KRENZ, Alfred S. (M 1937; A 1935). Pres, (for mail),. Krenz & Co., 5114 W. Center St., Mil waukee, and 1766 North 74th St., Wauwatosa, Wis. KREZ, Leonard (A 1935), Secy, (for mail), Paul J. Krez Co., 444 N. LaSalle St., and 4716 N. Paulina St., Chicago, 111. KRIBS. Charles L., Jr. (M 1935), Pres., Kribs & Landauer, 200 Houseman Bldg., and (for mail), 4209 Shenandoah Ave.. Dallas, Texas. KRIEBEL, Arthur E. (M 1920). Sales Engr. (for. mail), Haynes Selling Co., Inc., Ridge Ave. and Spring Garden SL, Philadelphia, and Warren Ave., Berwyn, Pa. KRINTZMAN, Harry (5.1936), Air Cond. Engr. (for mail), Dubin & Co., 182 Ann St., Hartford, Conn., and 19 S. Lenox St., Worcester, Mass. KROEKER, J. Donald (M 1936), Consulting Engr. (for mail), Columbia Engineering Co., 619 Failing Bldg., and 6831 N.E. Siskiyou St., Portland, Ore. KRUEGER, James I. (M 1921), Mfrs. Repr.. Illinois Engineering Co., and Whitlock Coil Pipe Co. (for mail), 357 Ninth St., and 1920 Sacra mento St,, San Francisco, Calif. KUBASTA, Robert W. (J 1936), Sales Engr., Carrier Corp., Syracuse, N. Y.p and (for mail), 1088 Summit Ave., Lakewood, Ohio. KUECHENBERG, William A. (M 1937), Pres, (for mail). R. B. Hayward Co., 1714 Sheffield Ave., Chicago, and 427 Elmore Ave., Park Ridge. 111. . KUEHN, Walter C. (A 1933). Kuehn Heating & Ventilating Co., 915 Seventh Ave., S., Minne apolis, Minn. KUEMPEL, Leon L. (M 1936; J 1929). Zone Engr., Delco-Frigidaire Cond. Div., General Motors Sales Corp., and (for mail), 927 Cumber land Ave., Dayton, Ohio. KUHLMANN, Rudolf (M 1928), Engr., 122 East 42nd St., New York, N. Y. KUNTZ, Edward C- (J 1937). Engr., Hammond Sheet Metal Co., 119 Cass Ave., and (for mail), 4014 Loughborough Ave., St. Louis, Mo. KURTH, Franz J. (M 1937), Vice-Pres.-(for mail), Anemostat Corp. of America, 10 East 39th St., and 875 West 181st St., New York, N. Y. KURTZ, Robert W. (J 1936). Air Cond. and Sales Engr.. (for mail), Robischung-Kiesling, Inc., 4848 Main SL, and 901 Isabella, Houston, Texas. KWAN. I. K. (M 1933), Gen. Mgr., China Engi neering Co., 30 Brenan Rd., Shanghai. China. KYLBERG, V. C. (A 1934), Contr. Engr., Lan caster Iron Works, 122 East 42nd SL, New York, N. Y., and (for mail), 66 Maple Ave., Maple wood, N. J. KYLE, W. J. (A 1935). Power Sales Engr. (for mail). Public Utility Engineering & Service Corp., 231 S. LaSalle St., and 1239 Jarvis Ave., Chicago, III. L LABOV, Milton (A 1937; 5 1930). Vice-Pres. (for mail), Benj. E.Labov & Son, 212 Adriatic Ave., and 114 N. LaClede Place, Atlantic City. N. J. LAFFOLEY, Laurence H. (M 1937; A 1936), AssL Engr. of Bldgs, (for mail), Canadian Pacific Railway, Room 401, C. P. R. Windsor Station, ` and 175 Woodlands Ave., Montreal, Que, Canada. ' LAGODZINSKI, Harry J. (A 1927; J 1920), Sales Engr. (for mail), Ilg Electric Ventilating Co., 182 N. LaSalle St., Chicago, and Crystal Lake, III. LAMBERT, Robert D. (M 1936), Design Engr. - (Air Cond.), American Radiator Co. (for mail)-, P. O. Box 356, New Rochelle, and 89 Young Ave., Pelham, N. Y. LaMONTAGNE, Arthur F. (A 1936). Sales Mgr., Htg. Div. (for mail), Gurney Foundry Co., Ltd., P. O. Box 1149, Montreal, and 24 Prince Arthur SL, St. Lambert, Que., Canada. LANDAU, Mitchel (M 1937), Mgr., Htg. and Air Cond. DepL. ABC Oil Burner & Engineering Co., 2012-14 Chestnut St., and (for mail), 5965 Kemble Ave., Philadelphia, Pa. LANDAUER. Leo L. (M 1937; J 1932), Member of Firm (for mail), Kribs & Landauer. 200 Houseman Bldg-, and 5707 Velasco, Dallas, Texas. LANDERS, John J. (M 1930; J 1924), Mfrs. Agent (for mail), 701 Crosby Bldg., Buffalo, and 120 Burroughs Drive; Snyder, N. Y. LANDES, Benjamin D. (A 1937), Mgr., Engrg. Service Dept., A. M. Byers Co., .Clark Bldg., Pittsburgh, Pa. ' LANDEWIT, Caslmir J. (J 1937), 115-95-226th St.. St. Albans. L. L. N. Y. LANE, D. Duffy (M 1934). Mgr., Weber & Merritt, Inc., 75-12 Roosevelt Ave., Jackson Heights, and (for mail), 87-65-52nd Ave., Elmhurst, N. Y. LANG, J. Clifford (J 1937), Sales Engr.. York Ice Machinery Corp., 118 Southwest Blvd., Box 17, Kansas City, Mo. . LANGE, Fred F. (A 1934), Pres, (for mail). Mechanical Service Co., 602 Pence Bldg., and King Cole Hotel, Minneapolis, Minn. LANGE. Raymond T. (M 1936), Engr.. Hartzell Propeller Fan Co., Box 909, and (for mail), 1700 N. Broadway St., Piqua, Ohio. LANGENBERG, Everett B. (AT 1914), (Council, 1926-1931), Pres, (for mail), Langenberg Heating Co., 3800 W. Pine Blvd., SL Louis, and 338 Brentwood Blvd., Clayton, Mo. *. LANNING, E. K. (A 1927), Asst. Secy, and Sales Mgr. (for mail), Warren Webster & Co., Camden, and Box 311, Clayton, N. J. LANOU, J. Ernest (M 1931), Mgr. (for mail), F. S. Lanou &. Son, 90 St. Paul St., and 48 Brookes Ave., Burlington, Vt. LARKIN, Paul (A 1937), Service and Installation. Mgr. (for mail), Minneapolis-HoneyweU Regu lator Co.. 378 Saunders-Kennedy Bldg., and . 4667 Pierce, Omaha, Nebr. LaROCQUE, Paul E. (A 1937), Heating Con tractor, 86 D'Abraham Hill, Quebec, Canada. LaROI, George, II, (J 1936), Engrg. Correspon dent and Asst. Adv. Mgr. (for mail), McDonnell & Miller, Room 1316, Wrigley Bldg., and 4443 N. Monitor Ave., Chicago, 111. 1 LARSON, Carl W. (M 1936), Service Engr., Barnes & Jones, Inc., 12S Brookside Ave., Jamaica Plain, and (for mail), 641 Hyde Park Ave-, Rosiindale, Mass. ' LARSON, Clifford P. (J 1936), Sales Engr. (for mail), Insuiite Co., 205 W. Wacker Drive, and Chicagoan Hotel, Chicago, 111. LARSON, Gustus L * (M 1923), (Presidential Member), (1st Vice-Pres., 1935; 2nd Vice-Pres., 1934; Council, 1929-1937), Prof., Steam and Gas Engrg., and Chairman of DepL of Mech. Engrg; (for mail). University of Wisconsin, Mech. Engrg. Bldg., and 1213 Sweetbriar Rd., Shorewood Hills, Madison, Wis. LaSALVIA, James J. (if 1930). Mech. Engr.. Frigidaire Corp.. and (for mail). 2250 Emerson Ave., Dayton, Ohio. . LAUER, Harold B. (M 1930), Vice-Pres. (for mail). English & Lauer, Inc., 1978 S. Los Angeles SL, and 1121 S. Hayworth Ave., Los Angeles, Calif. LAUER, Rodney F.- (7 1936), Sales Engr., York Ice Machinery Corp., 1238 North 44th SL, Philadelphia, and (for mail), 236 Glentay Rd., Lansdowne. Pa. LAUFKETTER, Fred C. (if 1936). SupL and Chief Engr. (for mail), Hotel -Jefferson. 415 North 12th St., and 7056 West Park Ave., St. Louis, Mo. 35 Heating Ventilating Air Conditioning Guide 1938 LrAUTERBACH, Henry, Jr. (M 1935). Asst. . ` Chief Engr. (for mail). Carrier Corp., Mer chandise Mart, and 6959 Merrill Ave., Chicago, III. LAUTZ, Fritz A. (Af 1936), Dist. Engr., Nash- Kelvinator Corp., 710 North 12th St., and (for mail), 1005 Hi-Pointe Place, St. Louis, Mo. LAWLOR, John J. (AT 1935), Mgr. Htg. Div., James Robertson Co., Ltd., 215 Spadina Ave., and (for mail). 35 Tennis Cres., Toronto, Ont., Canada. LEACH, Leland S. (7 1937), Asst. Chief Engr.. Sidles Co.. Airtemp Div., and (for mail), 1130 South 14th St., Lincoln, Nebr. LEDGETT, F. Donald (S 1936), 108 CUnton St., Toronto, Ont., Canada. LEE, James A. (A 1937). Commercial Air Cond. Dept., Nash-Kelvinator Corp., Kelvinator Div., 14250 Plymouth Rd., and (for mail), 17527 Indiana, Detroit, Mich, LEE, Robert T, (7 1937; 5 1936), Mech. Engr., Plant Engr's. Office, Eastman Kodak Co., 333 ' State St., and (for mail), 131 S. Plymouth Ave., Rochester, N. Y. LEEK, Walter (Life Member; M 1903), Pres, (for mail). Leek & Co., Ltd., 1111 Homer St., and 4769 W. Second Ave., Vancouver, B. C., Canada. LEFEBVRE, Eugene J. (Af 1937). Engr., Warden King, Ltd., 2 Bennett Ave., Montreal, and (for mail), 38 Third St., St. Lambert, Que., Canada. LEGLER, Frederick W. (Af 1935; A 1933), Pres, (for mail), Waterbury Co., 2754 Hennepin Ave., and 2919 Johnson St., N.E., Minneapolis, Minn. LEHMAN, M. G. (A 1937), Owner (for mail). . M. G. Lehman, 720 O St., and 2011 Worthington, Lincoln. Nebr. LEHMANN. Matt (7 1937), Engr., Ralph E. Phillips, Mechanical & Electrical Consultants, 603 Architects Bldg., and (for mail). 1569 Midvale Ave., W. Los Angeles, Calif. LEICHNITZ, Robert W. (7 1936), Estimator. Leichnitz-Johnson Co., 14 E. A St., and (for mail), 2506 W. Chestnut St., Yakima, Wash. LEILICH, Robert K. (Af 1937), Western Mgr. (for mail). The Marley Co., 1144 S. Grand Ave., Los Angeles, and 1024 Tiverton Ave., West Los Angeles, Calif. LEILICH, Roger L. (Af 1922), Pres, (for mail). Baltimore Heat Corp., 2000 W. Pratt St., and 2810 Elsinor Ave., Baltimore, Md. . LEINROTH, J. Paul (Af 1929), Gen. Industrial Fuel Repr. (for mail). Public Service Electric & Gas Co., 80 Park Place, Newark, and 37 The Fairway, Montclair, N. J. LEITCH, Arthur S. (M 1908), Pres, and Manag ing Director (for mail), Arthur S. Leitch Co., Ltd., 1123 Bay St., and 421 Russell Hill Rd., Toronto, Ont., Canada. . LELAND, Warren B. (Af 1929), Sales Engr., H. B. Smith Co., Westfield (for mail), P. O. Box 1522, and 159 Sumner Ave., Springfield, Mass. LELAND, WIlUam E. (Af 1915), Consulting Engr. (for mail), Leland & Haley, 58 Sutter St., San Francisco, and 704 The Alameda, Berkeley, Calif. LENIHAN, William O. (A 1936), Vice-Pres. (for mail), Laverack & Haines, Inc., 718 White Bldg., and 703 W. Ferry St., Buffalo, N. Y. LEONARD, Lorcan C. G. (7 1937), Draftsman- Designer, Messrs. J. Jeffreys & Co., Ltd., Waterloo Rd., London S.W.1, England, and (for mail), 265 Clontarf Rd., Dollymount, Dublin, Ireland. LEONHARD. Lee W. (Af 1936), Supv., Eastman Kodak Co., Kodak Park, and (for mail). 1075 Winona Blvd., Rochester, N. Y. LEOPOLD, Charles S. (Af 1934). Consulting Engr. (for mail), 213 S. Broad St., Philadelphia, and 7600 West Ave., Elkins Park, Pa. LESER, Frederick A. (A 1937), Distl Mgr. (for mail), Ilg Electric Ventilating Co.. 608 Mills Bldg., and 4711 Chesapeake St., N.W., .Wash ington, D. C. .. LEUPOLD, George L. (A 1937), Sales Engr., Minneapolis-Honeywell Regulator Co., 561 Reading Rd., Cincinnati, Ohio, and (for mail), 137 Burnet Rg., Fort Thomas, Ky. LEUPOLD, Herbert W. (7 1933), Engr., Prod. Dev. Dept., Stanley Rule & Level Plant, Elm . St., and (for mail), 61 Lincoln St., New Britain, Conn. LEUTHESSER, Fred. W,, Jr. (M 1937), Secy., National Metal Products Corp., 21 N. Loomis St., Chicago, 111. LEVENTHAL, Bernard (7 1937; 5 1935), Esti- . mating and Designing Engr., Gene Meenan. Inc., 44 East 23rd St., New York, and (for mail), 3913-13th Ave., Brooklyn, N. Y. * LEVERANCE, Herbert J. (A 1935), Salesman (for mail)! J. M. O'Connor Co., 434 N. Rock Island. Wichita. Kans- . LEVY, Marion I. (A 1936; 7 1931), Pres, (for mail), Viking Air Conditioning Corp., Main and Center Sts., IJJ.W., and 2834' Ludlow Rd., Cleveland, Ohio. LEWIS, Carroll E. (Af 1930), Chief Engr., Delco- Frigidaire Conditioning Division, General Motors Corp., 1420 Wisconsin Blvd., and (for mail). 2724 Fairmont, Dayton, Ohio. LEWIS, Clyde A. (7 1937), Engr., Carrier Corp., Syracuse, and (for mail), 24-40 Kindred St., Astoria, L. I., N. Y. . LEWIS, George M. (M 1937). Chief Engr., Penobscot Bldg., Simon J. Murphy Co.. 1366 Penobscot Bldg., and (for mail), 14414 Grand- mont Rd., Detroit, Mich. ' LEWIS, H. Frederick (A 1937), Vice-Pres. (for mail), Harvey A. Dwight Oil Heat & Supply Co., Inc.. 147 Dongan Ave., Albany, and Sweats Crossing, Nassau, N. Y. LEWIS, L. Logan* (Af 1918), Vice-Pres., Chief Engr. (for mail). Carrier Corp.v South Geddes . St., and 207 Sedgewick Drive, Syracuse, N. Y. LEWIS, Samuel R* (M 1905). (Presidential Member), (Pres., 1914; 2nd Vice-Pres.. 1910; Board of Governors, 1909-19.10-1912; Council, 1914-1915), Consulting Mech. Engr. (for mail). 407 S. Dearborn St., and 4737 Kimbark Ave. Chicago, 111. ' LEWIS, Thornton* (Af 1919). (Presidential Member), (1st Vice-Pres., 1928; 2nd Vice-Pres.. 1927: Council, 1923-1930). Pres., Pulp Products Co., Inc., 60 East 42nd St., New York, N. Y., and (for mail). Holiday Hill Newton R. D. 2, Pa. LIBBY, Ralph S. (7 1933), Air Cond. Engr.. Arthur S. Leitch Co., Ltd., 1123 Bay St., and (for mail), 56 Spadina Rd., Toronto, Ont., Canada. LICHTY, Charles P. (Af 1920), Pres, (for mail), C. P. Lichty Engineering Co., Inc., 400> South 21st St., and 100 Devon Drive, Birmingham, Ala. LIEBRECHT, Walter J. (7 1936), Sales Engr. (for mail), American Radiator Co:,' Fourth and Channing Sts., N.E., and 3032 Rodman St., N.W., Washington, D. C. LIGHTHART, Charles H. (Af 1935), Mfrs. Sales Engr. (for mail), 254 Court St., and 19 E. Winspear Ave., Buffalo, N. Y. . LILJA, Oscar L. (A 1937; 7 1936), Mech. Engr.. Toltz, King & Day, Inc, 1509 Pioneer Bldg., St. Paul, and (for mail); 5000-16th Ave., S., Minneapolis, Minn. ' LINCOLN, Roland L. (Af 1935), Engr., Hoffman Specialty Co., 193 Grand St., Waterbury, and (for mail). Breakneck Hill.-Middlebury, Conn. LINDBERG, Arthur F. (A 1937; 7 1935; 5 1933), Inspector, National Park Service, 300 Keeline Bldg., Omaha, Nebr.' . LINDSAY, Griffith W., Jr. (Af 1937), Chief Engr., Air Cond. and Autom. Heat Dept, (for mail), Chicago District, Frigidaire Div., General Motors Sales Corp., 2031 S. Calumet Ave.; and 10440 S. Eberhart Ave., Chicago, 111. LINEBAUGH, John E. (M 1937), Chief Engr.. Frigidaire. Ltd-, Edgeware. Rd., The Hyde, Hendon, London, N.W.,.9, and (for- mail), 93 __ Hodford Rd., Golders Green, N.W. 11, London, England. . ' . : -. Roll of. Membership LINGO, Charles K. (A 1936; 7 1935), Air Cond. Engr. (for mail), Florida Power & Light Co., and 2224 aw. Sixth St., Miami, Fla. LINN, Homer R. (Af 1914), Consulting Engr., Brooke & Linn, 189 W. Madison Ave., Chicago, and (for mail), 321 S. Ashland Ave., LaGrange, LINSENMEYER, Francis J. (M 1935). Head. Dept. Mech. Engrg. (for mail). University of . Detroit, Livernois & McNichols, and 17375 Prairie Ave., Detroit, Mich. LINTON, John P. (Af 1927), Mech. Engr., 247 Brock Ave., N., Montreal, W., P. Q., Canada. LITTLE, David, H. (7 1937), Engrg. Inspector (for mail), Boston Edison Co., 39 Boylston St., . Boston, and 27 Rangeley St., Dorchester, Mass. LITTLE, Kenneth B. (A 1935), Mfrs. Repr., Kenneth B. Little Co., 736 Dixie Terminal, Cincinnati, Ohio. LITTLEFORD, Wallace H. (Af 1936), Estimating Engr. (for mail), E. J. Febrey & Co., 616 New York Ave., N.W., Washington, D. C.. and Hyattsville R. F. D. No. 1, Md. LIVAR, Allen P. (Af 1935), Chief Engr., Htg. Div. (for mail), Airtemp, Inc., 1119 Leo St., and 44 Ivanhoe St., Dayton, Ohio. LLOYD, Edmund H. (7 1936), Sales Engr., . Washington Gas Light Co., 411 Tenth St., N.W., and (for mail), 2601 Calvert St., N.W., Wash .. ington, D. C. . ' LLOYD, Edward C. (Af 1927), Director of Tech. Service (for mail), Armstrong Cork Products Co., . and R. D. 5, Lancaster, Pa. LOCKE, Robert A. (M 1935), Mgr., Steel Hearing Boiler Institute, and (for mail), 500 N. Union St., Middletown, Pa. ' LOCKHART, Harold A. (A 1936; 7 1935), Chief . Engr., Bell & Gossett Co., 3000 Wallace St., and . (for mail), 11749 Hale Ave., Chicago, 111. LOCKHART, William R. (7 1936), Dist. Sales Mgr. (for mail), York Ice Machinery Corp., 215 . Investment Bldg., and 3430-30th St., N.W;, Washington, D. C. . LOEFFLER, Frank X. (M 1914), Pres, (for mail), LoeflUer-Greene Supply Co., 1604 N.W. Fifth St., and 1811 Northwest 19th St., Oklahoma City, Okla. LOEFFLER, Louis, Jr. (7 1936; S 1934), 1815 W; Ninth St., Oklahoma City, Okla. LOFTE, John A. (7 1936; S 1933). Engr., Pflugradt ' Co., 215 W. Kilbourn Ave., and (for mail), 3117 W. Highland Blvd., Milwaukee, Wis. LOGAN, Thomas M. (7 1937; 5 1935), 113 Delaware St., Peoria, 111. LOH, Nan-Shee (Af 1933; A 1931;. 7 1927), Mgr. (for mail). New Shanghai Hearing & Plumbing Co., Room 330, National Commercial Bank Bldg., 400 Kiangse Rd., Shanghai,' China. LONG, Dewey J. (A 1937), Sales Engr. (for mail), . Wm. G. Boales Co., 6439 Hamilton Ave., Detroit, and 466 Pearson Ave., Femdale, Mich. LONG, Wayne E. (Af 1935), Assoc. Prof, of Mech. - Engrg., Texas Agricultural & Mechanical Col . lege. College Station, Texas. LONGCOY, Grant B. (Af 1933), Engr., Joseph Breslove, Cons. Engr., 1101 Hippodrome Bldg., Cleveland, and (for mail), 1215 Ramona Ave., . Lakewood, Ohio. LONGWELL, James Cooper ($ 1937), Student (for mail), Massachusetts Institute of Tech nology, 400 Memorial Drive, Cambridge, Mass., and 330 Second Ave., Westmont, Johnstown, Pa. LOO, Ping Yok (Af 1933), Gen. Mgr. (for mail), . China' Engineering Co., 774 N. Chung San Rd., Nanking, and 271-73 Dumbarton Rd., Tientsin, China. - LOUCKS, David W. (A 1930), Supv., Com'mercial Electric and. Steam Sales (for mail), . Duquesne Light Co., 435 Sixth Ave., and 535 Shelbourne Ave., Pittsburgh (21) Pa. LOUGHRAN, Patrick H,, Jr. (7 1937), Asst. Testing Engr., Washington Gas Light Co., 411 . Tenth St., N.W., and (for mail), 4513-49th St., N.W., Washington, D. C. .. LOVE, Clarence H. (Af 1919), Mfrs. Agent, Nash ' Engineering Co., 317 Chamber of Commerce, and (for mail), 289 Norwalk Ave., Buffalo, N. Y. . LOVING, William H. (7 1936), Htg. Engr., Washington Gas Light Co., 411 Tenth St., N.W., and (for mail). 3901 Fulton St., N.W., Wash ington, D. C. LOWER, Henry G. (A 1937), Sales Engr., Account Exec., J. J. Gibbons, Ltd., 259 Bay St., Toronto 2, and (for mail), 649 Lakeshore Rd., Toronto 14, Ont., Canada. LOWNSBERY, BanjamJn F. (Af 1920), Htg. Engr., Benjamin F. Shaw Co., Second and Lombard Sts., and (for mail), 21 S. Sycamore St., Wilmington, Del. ' LUCK, Alexander W.* (Life Member; M 1919), Pres, and Gen. Mgr. (for mail), Reading Heater & Supply Co., Church and Woodward Sts., Reading, and Reiffton, Pa. . LUCRE, Charles E. (Af 1924), Stevens Prof, of Mech. Engrg., Columbia University, and Con sulting Engr., Babcock & Wilcox Co; (for mail), Pupin Laboratories Bldg., Columbia University, . and 186 Riverside Drive, New York, N. Y. . LUDERS, Richard H. (7 1937; 5 1936), Main tenance Engr., Quaker Oats Co., 345 East 25th- St., and (for mail), 2410 N. Kilbourn Ave., Chicago, 111. LUND, Clarence E. (Af 1936; 7 1935; S 1933), Research Engr., University of Minnesota, Engrg. Exper. Sia., 108 Experimental Bldg., and (for mail), 4817-12th Ave., S., Minneapolis, Minn. LUTY, Donald J. (Af 1933), Asst. Gen. Mgr. (for mail). Gar Wood Industries, Inc., 7924 Riopelle . St., and 13661 Cloverlawn Ave., Detroit, Mich. LYCAN, Larb K. (A 1937), Sales Mgr. (for mail), Allison Insulation Co., 4801 Levenworth St., and 2712 North 64th St., Omaha, Nebr. LYLE, Ernest T. (Af 1919), P. O. Box 1550, Orlando, Fla. . LYLE, J. I.* (Af 1911), (Presidential Member), (Pres., 1917; Council, 1917-1918), Pres., Carrier Corp., Syracuse, N. Y. . LYMAN, Samuel E. (A 1924), Buensod, Stacey Air Conditioning, Inc., 60 East 42nd St., New York, N. Y., and (for mail), 820 Canton St., Elizabeth, N. J. LYNCH, William L. (Af 1928). Treas.-Gen. Mgr. (for mail), Rome Turney Radiator Co., Canal St., and 1413 N. George St., Rome, N. Y. LYON, P. S. (Af 1929), Gen. Mgr., Cochrane Corp., 17th St~, and Allegheny Ave., Phila delphia, Pa., and 42 Hawthorne Place, Summit, N. J. LYONS, Cornelius J. (A 1932), Sales Engr. (for mail), Nash Engineering Co., Wilson Ave., and 22 Haviland St., South Norwalk, Cohn. - ' LYONS, Michael A. (Af 1935), Htg. Contr., 238 West 20th St., New York, N. Y. ' M ' MABLEY, Louis C. (Af 1937), Salesman (for mail), Surface Combustion Corp., 122 S. Michi gan Ave., and 2317 N. Commonwealth Ave., Chicago, 111. MACCUBBIN, Howard A. (Af 1934), Buyer, Htg. Materials, Montgomery Ward & Co., Chicago, and (for mail), 2135 Ridge Ave., Evanston, 111. . . MacDADE, Ambrose H. (Af 1923), Sales (for . mail), Burnham Boiler Corp., S.E. Cor. 31st and Jefferson Sts., Philadelphia, Pa., and 225 Haddon Ave., Westmont, N. J. MacDONALD, Donald B. (Af 1930). Sales Engr., Donald B. MacDonald Co., 101 E. Walnut St., . Kingston, Pa. MacDONALD, Douglas J. (Af 1935), Vice-Pres. . (for mail). Dominion Radiator & Boiler Co., Ltd., 1322 Dufferin St.,' and 96 Hudson Drive, Toronto, Ont., Canada. - MacDONALD, Everett A. (A 1933), Branch Mgr. . (for mail), Spencer Heater. Co., 145 Broadway, Cambridge, and 154 Standish Rd., Watertown, - Mass. . 37 X Heating Ventilating Air Conditioning Guide 1938 MACHEN. James T. (A 1938; J 1934). Chicago MALONE, James S. (A 1936), Dist. Sales Repr. Branch Mgr., (for mail). The Ric-wiL Co., Ill (for mail). Hoffman Specialty Co., 411 N. Tenth W. Monroe St., and 420 Diversey Parkway, St., and 7124 Waterman Ave., St. Louis, Mo. Chicago, 111. MACHIN, Donald W. (J 1935), Fuel Engr,, MALVIN, Ray C. (if 1929), Pres, (for mail), Malvin & May, Inc., 2427 S. Michigan Ave., Pittsburg & Midway Coal Mining Co., 810 and 8220 Dante Ave., Chicago, III. . Dwight Bldg.. Kansas City, Mo., and (for mail), MANDELL, Thomas P. (A 1937), Salesman, 2029 Vermont St., Lawrence, Kans. Carrier Corp., 1201 Statler Office Bldg., Boston, MACK, Ludwig (M 1935), Dist. Mgr.. Cooling & . and (for mail), South Hamilton, Mass. Air Conditioning Corp., Cresmont and Haddon MANN, Arthur R. (if 1930), Owner, Mann & Co., Aves., Camden, N- J., and (for mail), 246 W. Archt.-Engrs., 902 Wiley Bldg., and 122 West Upsal St., Germantown, Philadelphia, Pa. 15th St., Hutchinson, Kans. MacLEOD, Kenneth F. (A 1933), Mgr. Htg. MANNING, Charles E. {J 1937), Air Cond. Sales Dept., Crane Co., 419 Second Ave., S., and (for Engr. (for mail), von Hamm Young Co., Ltd., mail), 7703 First Ave., N.E., Seattle, Wash. and 4087 Black Point Rd., Honolulu, Hawaii. MacMLLLAN, Alexander. R. {M 1936). Mgr., MANNING, Walter M. (if 1930). Htg. Engr., Educational Dept., Delco-Frigidaire Condition Crane Co., 115 E. Front SL, Grand Island, and ing Div., General Motors Sales Corp., and (for (for mail), P. O. Box 112, Clarks, Nebr. mail), 130 Beverly Place, Dayton, Ohio. MANNY, J. Harvey (A 1936), Vice-Pres., Secy, MACRAE, Robert B. (J 1935), Air Cond. Engr., (for mail), Robinson Furnace Co., 213 W. E. J. Nell Co., Manila, P. I. MACROW, Lawrence (J 1936), 27 Arborough Hubbard St., and 5950 Midway Park, Chicago, 111. Road, Boston, Mass. MADDEN, John J. (A 1937), Owner (for mail). MARCONETT, Vernon G. (A 1936), Engr., Factory Supt., Farquhar Furnace Co., and (for Madden Co., 339 Warren St., Roxbury, and 16 mail), Wilmington, Ohio. Brown Ave., Roslindale, Mass. MARIN, Axel* (if 1935), Assoc. Prof., Mech. MADDUX, Oliver L. (if 1935; A 1933), Owner, Engrg. (for mail). University of Michigan, 241 53 Park Place, Newark, and (for mail), 95 West Engrg. Bldg., and P. O. Box 175, Ann Washington St., East Orange, N. J. Arbor, Mich. MADELY, Frederick J.'(A 1936), Asst. Contract MARKS, Alexander A. (A 1930). Chief Engr., Engr., Eastern Steel Products, Ltd., 1335 Richmond Radiator Co., and (for mail), 818 Delorimier Ave., and (for mail), 6408 LouisHemon St., Montreal, Que., Canada. Fayette Title and Trust Bldg., Uniontown, Pa, MARKUSH, Emery U. (if 1931), Consulting MADISON, Richard D. (M 1926), Research Engr. (for mail), 225 East 21st St., New York, Engr. (for mail), Buffalo Forge Co., 490 Broad - way. Buffalo, and 218 Brantwood Rd., Snyder, ` and 8442-85th Rd., Woodhaven, L. I., N. Y. MAROTTA, John A. (S 1936). 11116 Tuscora N. Y. MAEHLING, Leon S. (if 1932), Service Dir., Equitable Gas Co., 427 Liberty Ave., and (for Ave., Cleveland, Ohio. ' MARRINER, John M. S. (if 1934), Vice-Pres.. Taylor Engineering & Construction Co., Ltd., mail), 448 Sulgrave Rd., Pittsburgh, Pa. 80 Richmond St., W., and (for mail), 111)4 MAGINN, Peter F. {Life Member; M 1908), Mfrs. Agent, P. F. Maginn & Co., 207 Fulton Bldg., Pittsburgh, Pa. MaGIRL, Willis J. (if 1934; A 1931; J 1927), Chief Engr. (for mail), P. H. MaGirl Foundry & Furnace Works, 401-13 E. Oakland Ave., and 108 Warner Ave., Bloomington, III. MAHER, Thomas F., Jr. (A 1937), Salesman, Balsam Ave., Toronto, Ont., Canada. MARSCHALL, Peter J. (if 1930; J 1927). Engr., Kroeschell Engineering Co., 215 W. Ontario St., and (for mail), 6434 N. Seeley Ave., Chicago, 111. MARSHALL, Albert W. (if 1937), Asst. Supt.. Chief Engr.. Soho Public Baths, 2408 Fifth Ave., and (for mail), 2410 Fifth Ave., Pitts burgh, Pa. MARSHALL, Alexander G. (A .1936), Sales Kewanee Boiler Corp., 37 West 39th St., New Engr. (for mail), Trane Co. of Canada. Ltd., 660 York, and (for mail), 116-48-218th St., St. St/ Catherine St., W., and 2353 Wellington St., Albans, L. I., N. Y. Montreal, Que., Canada. * MAHON, B. B. (if 1935), Principal. School of Air MARSHALL, Orville D. (A 1931), Mfrs. Agent Cond. (for mail). International Correspondence (for mail), 514 Anderson Bldg., and 1350 Calvin Schools, Ash St. and Wyoming Ave., 'and 433 Ave., S.E., Grand Rapids, Mich. Fig St., Scranton, Pa. . MARSHALL, Thomas A. {J 1937), Sales Engr. MAHON, Frank B. (if 1937}, Air Cond. Spec., (for mail), York Ice Machinery Corp., 1275 Duquesne Light Co., 435 Sixth Ave., and (for Folsom St., and 155 Hyde St., San Francisco, mail), 1241 Illinois Ave., Pittsburgh, Pa. MAHONEY, David J. (if 1930: A 1926), Branch Mgr. (for mail). Johnson Service Co., 503 Franklin St., and 140 Linwood Ave., Buffalo, N. Y. MAIER, Albert H. {A 1936), Chief Engr. (for mail). Board of Education, Baltimore and Girard Ave., and 1021 Kuntz Ave., Middletown, Ohio. MAIER, George M. (if 1921), Asst, to VicePres. and Gen. Mgr. of Mfg. (for mail), American Radiator Co., 8007 Jos Campau, Detroit, Mich. MAILLARD, Albert L. (M 1934), Consulting Engr., Head of Air Cond. Div. (for mail), Kansas City Power & Light Co., 1330 Baltimore Ave., P. O. Box 679, and 3740 Washington St., Kansas City, Mo. MALCOLM, Bernard L. {J 1937), Sales Engr., Sidles Co., Airtemp Div., 502 South 19th, and (for mail), 4960 Military Ave., Apt. 7, Omaha, UUli. MARSHALL, William D. (if. 1935), Branch Mgr. (for mail), Noland Co., Inc., 1823 N. Arlington Ridge Rd., and 1307 N. Wakefield St., Arlington, Va. . MARSTON, Anson D.* (A 1937), Industrial Engr. (for mail), Kansas City Power & Light Co., 1330 Baltimore, Box 679, and 4943 Central, Kansas City, Mo. MARTEL, Charles L., Jr. (J 1937), Pres., Martel Heating Co., 13534 Cedargrove Ave., Detroit, Mich. MARTENS, Edward D. (if 1937), Mech. Engr. (for mail), Thompson Starrett Co., Inc., 444 Madison Ave., New York, and 89 Eldridge Ave., Hempstead, L. I., N. Y. MARTIN. Albert B. (if 1917), Branch Mgr. (for mail), Kewanee Boiler Corp., 1858.S. Western Ave., Chicago, and 977 Vine St., Winnetka, 111. Nebr. MARTIN, George W.* (if 1911). Supervising MALLIS, William (if 1914), Owner (for mail). 330 Lyon Bldg., and' 723 Federal Ave., Seattle, Wash. MALONE. Dayle G. (if 1929; A 1925). Branch Mgr., Petroleum Heat & Power Co., 1725 S. . Michigan Ave., and 7337 Merrill Ave., Chicago, 111. . . Engr. (for mail), U. S. Realty & Improvement Co., Ill Broadway, New York, N. Y., and 340 Prospect St., Ridgewood, N. J. MARTIN, Leonard {J 1936), Sales Engr. (for mail), H. L. Peiler & Co., Ltd., 459 New Birks Bldg., and 3777 Decarie Blvd., Montreal, Que.. Canada. . 38 Roll of Membership MARTIN, Raymond (A 1937), Sales Engr., Heal Dept, (for mail). Vapor Car Heating Co. of Canada. Ltd.. 65 Dalhousie St., Montreal, and 825 Moffat Ave., Verdun, P. Q., Canada. MARTINEZ, Juan J. (J 1929), Research and Rate Engr., Mexican Light & Power Co., Ltd., Gante 20, and (for mail), Paseo de la Reforma 183, Mexico City, Mexico. MARTINKA, Paul D. (J 1937; 5 1934), 13703 Chautauqua Ave., Cleveland, Ohio. MARTOCELLO, Joseph A. (if 1934), Pres.. Jos. A. Martocello & Co., 229 North 13th St., Phila delphia, Pa. MARTY, Edgar O. (if 1916), Pres, and Gen. Mgr., Indian Head Anthracite, Inc., Thompson Bldg., and (for mail), 1775 Howard Ave., Pottsville, Pa. MARTYN, Henry J. (A 1937), Pres, (for mail), Martyn Bros., Inc., 911 Camp St., and 5306 Ridgedale St., Dallas, Texas. MARZOLF, Frank X. (A 1937), Sales Engr., Minneapolis-Honeywell Regulator Co., 415 Brainard St., and (for mail), 15046 Mettetal, Detroit, Mich. MASON, Gall C. (A 1937). Air Cond. Engr. (for mail), Williamson Heater Co., 337 W. Fifth St., and Hotel Sinton, Cincinnati, Ohio. MATCHETT, James C. (if 1923), Vice-Pres. (for mail), Illinois Engineering Co., Racine Ave. at 2ist.. and 9936 S. Winchester Ave., Chicago, 111. MATHER, Harry H. (A 1929), Industrial Promo tion (for mail). Philadelphia Electric Co., 1000 Chestnut St., Philadelphia, and 373 Lakeview Ave., Drexel Hill, Pa. MATHEWSON. Marvin E. (M 1937). Secy, (for mail), A. M. Kinney, Inc., 1820 Carew Tower, and 1355 Cryer Ave., Cincinnati, Ohio. MATHIS. Eugene* (if 1922), (for mail). New York Blower Co., 32nd St. and Shields Ave., Armour P. O. Station, and 9151 S. Hoyne Ave., Chicago, 111. MATHIS, Henry (if 1921), New York Blower Co., 32nd and Shields Ave., and (for mail), 10317 Oakley Ave., Chicago, 111. MATHIS, Julien W. (A 1921), New York Blower Co., 32nd St. and Shields Ave., Chicago, 111. MATOUSEK, A. G. (if 1937), Air Cond. Engr., York Ice Machinery Corp., 117 South 11th SL, * and (for mail), 1528 Locust St.. St. Louis, Mo. MATTHEWS, John E. (if 1934; A 1934), Dist. Mgr., B. F. Sturtevant Co., 1106 Commerce Bldg., and (for mail), 5642 Lydia SL, Kansas City, Mo. MATTHEWS, Wesley M. (J 1937), Sales Engr., Sidles Co., Airtemp Div., 425 Stuart Bldg., and (for mail), 1324 South 35th, Lincoln, Nebr. MATZEN. Harry B. (if 1919), York Ice Ma chinery Corp., 42nd St. and Second Ave., Brooklyn, and (for mail), 16 Addison Place, Rockville Centre. L. I., N. Y. MAURER, Frederick J. (A 1937). Mgr. Ind. Sales Dept, (for mail). Crane Co., 6215 Carnegie Ave., Cleveland, and 14679 Elderwood Ave., East Cleveland, Ohio. MAUTSCH, Robert (A 1928), Engr., Managing Dir. (for mail), Compagnie Beige Des Freins Westingbouse, 97 Avenue Louise, Brussels, Belgium. MAWBY, Pensyl (if* 1934), Distr. Sales Mgr.. Lehigh Navigation Coal Co., 1421 Chestnut St., Philadelphia, and (for mail), 15 Golf Rd., Lansdowne. Pa. - MAXWELL, George W. (if 1935; S 1932), Engr., Kenealy & Maxwell, Main SL, and (for mail), P. O. Box 422, Harwich Port, Mass. - MAXWELL, Robert S. (if 1937). Branch Mgr., Bennett & Wright, Ltd., 72 Queen St.. E.. and (for mail), 560 Briar Hill Ave., Toronto, OnL, Canada. MAY, Clarence W. (if 1933), Consulting Engr. (for mail). Smith Tower, and 902 W. Halladay, Seattle, Wash. MAY, Edward M. (if 1931), Engr., Steel Products Engineering Co., 1601 S. Michigan Ave., and (for mail), 848 N. Ridgeland Ave., Chicago, 111. MAY, George E. (if 1933), Utilization Engr. (for mail), New Orleans Public Service. Inc., 317 Baronne St., and 2031 Short SL, New Orleans, La. MAY, James W. (A 1938; J 1935), Asst. Prof., H. V. & A. C. (fr mail). College of Engrg., University of Kentucky, and 261 Lyndhurst SL, Lexington, Ky. MAY, Maxwell F. (if 1929), Secy.-Treas. (for . mail), Malvin & May, Inc., 332 S. Michigan Ave., Chicago, and Palos Park, 111. MAYER, Robert W. (A 1937), DisL Mgr. (for mail), Minneapolis-Honeywell Regulator Co., 561 Reading Rd., and 3980 Rosehill Drive, Avondale, Cincinnati, Ohio. MAYES, Curtis (J 1937; S 1936), National Supply Co., Toledo, Ohio. MAYETTE, Charles E. (if 1926), Principal Mech. Engr., U. S. Housing Authority, North Interior Bldg., and (for mail). 701-19th SL, N.W., Washington. D. C. MAYNARD, Herbert R. (J 1936; S 1935), Hotel Northern, Rochester, Minn. MAYNARD, J. Earle (if 1931), Chief Htg. Engr., Fox Furnace Co., Woodford SL, and (for mail), 324 Fifth St., Elyria, Ohio. MAYNE, Walter L. (if 1937), Branch Mgr. (for mail), U. S. Radiator Corp., Cor.-Wayne and C. L. & N. R. R., and 1239 Delta Ave., Cincin nati, Ohio. McCAFFERTY, Joseph E. (A 1937), Engr., Petroleum Heat & Power Co., 419 Boylston SL, Boston, and (for mail), 196 Manthorne Rd., West Roxbury, Mass. McCAIN, H. King (A 1938; J 1937), Sales Engr.. Frigidaire Div., General Motors Sales Corp., 675 Greenwood Ave., and (for mail), 1311 W. Peachtree SL, Atlanta, Ga. McCarthy, John J. (A 1937), Chief Engr. (for mail). Providence Public School DepL, 20 Summer St., and 318 Academy Ave., Providence, R> I. McCAULEY. James H. (if 1921), Pres- (for mail), J. H. McCauley, Inc., 5558 West 65th St., Chicago, and 707 William SL, River Forest, 111. McCLAIN, Clifford H. (if 1937). Htg. Engr., Upper Darby Plumbing & Heating Co., Inc., 7127 Marshall Rd.. and (for mail). 1600 Darby Rd., W. Brookline, Upper Darby, Pa. McCLELLAN, James E. (if 1922), Branch Mgr. (for mail), American Blower Corp., 228 N. LaSalle St... Chicago, and 738 Marion Ave., Highland Park. 111. McCLINTOCK, Alexander. Jr. (if 1928: J 1920), Heating Contractor (for mail), A. McCIintock's Sons, 1937 Ridge Ave., and 121 Rochelle Ave., Philadelphia, Pa. . McCLINTOCK, William (if 1935), Supervising Engr., Design Unit, Administrative Staff, U. S. W. P. A., 70 Columbus Ave., and (for mail), 643 East 232nd St., New York, N. Y. McCLOUGHAN, Charles (A 1936; 5 1934), 14 Cottage St., E., Norwalk, Conn., and (for mail), 279 Ryerson SL, Brooklyn, N. Y. McCONACHIE, Lome L. (A 1928), Htg. and Plbg., 1003 Maryland Ave., and (for mail), 1379 Maryland Ave., Detroit, Mich. McCONNER. Charles R. (A 1925; J 1922). Gen. Sales Mgr- (for mail), Clarage Fan Co., and 1904 Waite Ave., Kalamazoo, Mich. McCORMACK. Denis (if 1933). Mgr., Air Cond. Instruments and Controls Dept, (for mail), Julien P. Friez & Sons. Inc., 4 N. Central Ave., Baltimore, and Ruxton Post Office, Baltimore County, Md. McCOY, C. E. (if 1936), Partner (for mail), Tumer-McCoy, 210 W. Second St., and 3922 S. Lookout Ave., Little Rock, Ark. McCOY, T. F. (if 1924), Mgr. (for mail). Powers Regulator Co., 125 St. Botolph St., Boston, and Glen Rd., Wellesley Farms, Mass. . 39 Heating Ventilating Air Conditioning Guide 1938 McCRAE, George W. (A 1936), Mech. and Htg. Engr., John McCrae Machine & Foundry Co., and (for mail), 51 Bond St., Lindsay, Ont., Canada. McCREA, Joseph B. (Af 1937), Owner, Heating & Ventilating, 3039 Coplin Ave., Detroit, Mich. McCREERY, Hugh J. (Af 1922), Owner (for mail), 335 Burrard St., and 1617-49th Ave., W., Vancouver. B. C. McCRIMMON, A. Murray (A 1935), Asst. Secy. and Controller (for mail), Hydro-Electric Power . Commission, 620 University Ave., Toronto- 2, Ont., and 83 Glen Rd., Toronto, Ont., Canada. . McCULLOUGH, Henry G. (Af 1936). Mgr., Commercial Dept., S. S. Fretz, Jr., Inc., 1902 . Chestnut St., Philadelphia, and (for mail),-328 Glen Echo Rd., Germantown, Philadelphia, Pa. McCUNE, Byron V. (M 1928), 2310 W. Yakima Ave., and (for mail), 101 W. Yakima Ave., Yakima, Wash. MCDONALD, Anthony K. (A 1936), Sales Engr., Standard Oil Co. of New Jersey, 261 Constitu tion Ave., N.W., and (for mail), 3035 Rodman St., N.W., Washington, D. C. McDonald, Thomas (A 1931), Mgr. (for mail). Minneapolis-Honeywell Regulator Co., Ltd., 117 Peter St., and 56 Kingsway, Toronto, Ont., Canada. McDONNELL. Everett N. (Af 1923). Pres, (for ' mail). McDonnell & Miller, Wrigley Bldg., and Drake Hotel, Chicago, III. McDONNELL, John E. (A 1936), Sales Engr. (for mail), McDonnell & Miller. 400 N. Michigan Ave., Chicago, and 2421 Central Park, Evanston, McDOWELL, Bert W. (7 1935). Scobell & Winston, 2027 State St., Erie, Pa. -. McELGIN, John W * (A 1937; 7 1931), Limekiln and Butler Pikes, Ambler, Pa. McELHANEY, Gerald W. (J 1936), Air Cond. Engr. (for mail), Ohio Edison Co., Akron, and 1724 Tenth St., Cuyahoga Falls, Ohio. McEWAN, Eugene E. (Af 1936), Sales Mgr., Air Cond. Div. (for mail), Frigidaire.Div., General Motors Sales Corp., 224 West 57th St., New York, and Seawane'Club, Hewlett Harbor, L. I., N. Y. ' McGAUG1IEY, Harold M. (Af 1937), Sales Mgr., . Nash Kelvinator Corp., Plymouth Rd., and (for mail), 300 Whitmore Rd., Detroit, Mich. - McGAUGHEY, John E., Jr. (7 1935), Air Cond. Engr. (for mail). Carrier Corp., 408 Chrysler Bldg., New York, N. Y., and Hotel Winfield . Scott, Elizabeth, N. J. McGEORGE, Richard H. (Af 1927), Mgr. Htg. and Air Cond. Dept., McCord Radiator & Mfg. Co.. 2587 E. Grand Blvd., and (for mail), 14565 Glastonbury Rd., Detroit, Mich. - McGONAGLE, Arthur (Af 1932), Consulting Engr. (for mail), 1013 Fulton Bldg., Pittsburgh, . and 6815 Prospect Ave., Ben Avon, Pa. McGRAIL, Thomas E. (Af 1926), Local. Repr. (for mail), Canadian Blower & Forge Co., P. O. Box 555 Sta. B., Ottawa, Ont., and 3465 . Belmore Ave., Montreal, P. Q., Canada. McGUlGAN, L. A. (A 1919). Salesman, National Radiator Corp., and (for mail), 724 Hastings St., Pittsburgh, Pa. MclLVAlNE, John H * (Af 1929), Vice-Pres. and Treas., Landwehr Heating Corp., Sixth and Cuyuga Sts., Philadelphia, Pa. McINTIRE, James F. (M 1915; A 1914), (2nd Vice-Pres., 1937; Counal, 1926-1928; 1932-1937), . Vice-Pres. (for mail), U. S. Radiator Corp., 1056-44 Cadillac Square, P. O. Box 686, and 3261 Sherbourne Rd., Detroit, Mich. McINTOSH, Fabian C. (Af 1921; 7 1917), (Council, 1929-1931; 1933-1935), Branch Mgr. - (for mail), Johnson Service Co., 1238 Brighton . . Rd., and 302 Marshall Ave., Pittsburgh, Pa. McKEEMAN, Clyde A.* (Af 1936). Asst. Prof, of Mech. Engrg. (for mail), Case-School of Applied Science, Cleveland, and 1359 Lynn Park Drive, Cleveland Heights. Ohio. McKlEVER, William H.* {Life Member; Af 1897; 7 1896), Pres, (for mail), William H. McKiever, Inc.. 247 West 13th St., New York, and 479 Eighth St., Brooklyn, N. Y. McKlNLEY, Carroll B. (7 1936; 5 1934), Sales Mgr. (for mail). General Refrigeration Corp., and 1309 Emerson, Beloit, Wis. McKINNEY, Carl A. (7 1937). Engr., United Gas Corp., 1018 Rusk Bldg., Houston, Texas. McKINNEY, William J. (A 1934), Mgr., Atlanta Dist., American Blower Corp., 716-101 Marietta St. Bldg., Atlanta, Ga. McKITRICK, Walter D. (Af 1936), Htg.-Vtg. Engr. (for mail), Mills, Rhines, Bellman & Nordhoff, Inc., 518 Jefferson Ave., and 3038 Gunckel Blvd., Toledo, Ohio. McKITTRICK, Percy A. (A 1934), Treas.-Gen. Mgr. (for mail), Parks-Cramer Co., 970 Main St., and 219 Blossom St.. Fitchburg, Mass. McLAREN, Fred S. (7 1935), Air Cond. Sales Engr., Frigidaire Div., General Motors Sales Corp., 4436 Toulouse St., and (for mail), 905 Fern St., New Orleans, La. McLARNEY, Harry W. (M 1933). Air Cond. Engr. (for mail). Union Electric Co. of Missouri, 315 North 12th Blvd., and 5038 Bancroft Ave.,, St. Louis, Mo. - McLAUGHLIN, Joseph D. (A 1930; J 1928), Owner (for mail), Braley & McLaughlin, 166 Aborn St., and 45 Roslyn Ave., Providence, R. I. McLEAN, Dermid (Af 1917), Member of Finn (for mail), Snyder & McLean, 2308 Penobscot Bldg., and 12651 Birwood Ave., Detroit, Mich. McLEAN, James E. (Af 1936), 520 Bigham Rd., Pittsburgh. Pa. McLElSH, William S. (A 1932; 7 1928), Dist. Engr. (for mail), Ric-wiL Co., 101 Park Ave., New York, and 4116--47th Ave., Long Island City, N. Y. McLENEGAN, David W. (Af 1933), Asst. Engr., Air Cond. Dept, (for mail). General Electric Co., 5 Lawrence St., Bloomfield, and 73 Arlington Ave., Caldwell, N. J. ' McLOUTH, Bruce F. (Af 1936; 7 1934), Chief Engr., Heater Div. (for mail), Dail Steel Products Co., E. Main St., Lansing, and 135 Gunson, ' East Lansing. Mich. ' McMAHON, Thomas W. (Af 1928). Dist. Mgr. (for mail), American Blower Corp., 1711 Railway Exchange Bldg., and 6173 Waterman Blvd., St. Louis, Mo. McMURRER, Louis J. (Af 1928; 7 1924), Pres., McMurrer Co.. 303 Congress St., Boston, and (for mail), 190 Harvard Circle, Newtonville, Mass. ,, McNAMARA, William (A 1930), Mgr. (for mail), Trane Co., 2694 University Ave., and 1355 Como ' Ave., W., St. Paul, Minn. - McNEVIN, Joseph E. (Af 1937), Vice-Pres. (for mail), George P. Braid, Inc., 950 Cherokee St., and 225 E. Dakota Ave., Denver, Colo. McPHERSON, William A. (Af 1929), Chief, Htg. and Vtg. Div., Dept, of School Bldgs.. 26 Norman , St., Boston, and (for mail), 86 Dwinnell St., West Roxbury, Mass. McQUAID, Daniel J. (Af 1934), Owner (for mail), D. J. McQuaid Engineering Service, 614 Cooper Bldg., and 1565 Milwaukee SU Denver, Colo. MEAD, Edward A. (Af 1926), Asst. Sales Mgr. (for mail), Nash Engineering Co., and 5 Thames Norwalk, Conn. - . MEAKIN, John B. (7 1935), Sales Engr., Foxboro Co., Foxboro, Mass. . MEARS, Leon A. (A 1938; J 1935), 721 Alice St., and (for mail), 906 Paramount Rd., Oakland, Calif. MEDOW, Jules (7 1937), Designing Engr. (for mail), Ilg Electric Ventilating Co., >2850 N. Crawford Ave., and 147 S, Springfield Ave., . Chicago, 111. ; i. MEHL, Oscar H. (7 1935), Engr. (for-mail). Carrier Corp.. 2022 Bryan St., and 5002 Colum bia Ave., Dallas, Texas. " . . MEHNE, Carl A. (Af 1929), P. O. Box A, Bedford Hills, N. Y. 40 Roll of Membership MEINHOLTZ, Herbert W. (Af 1936), Branch Mgr. (for mail), York Ice Machinery Corp., 603M W. Main St., and 1144Northwest 26th St., Oklahoma City, Okla. MEINKE, Howard G. (Af 1933). Div. Engr. (for mail). Consolidated Edison Co. of New York, MILES, Clarence N. (A 1937), Foreman, Kohlenberger Engineering Corp., 805 S. Spadra Rd., and (for mail), Rte. 1. Box 174A, Fullerton, Calif. MILLARD, Junius W. (Af 1929). Dist Mgr. (for mail). Carrier Corp., Statler Bldg., Boston, and 7 Tappan Rd., Wellesley, Mass. Inc., 4 Irving Place, New York, and 41 Harte St., Baldwin, L. I., N. Y. MELLON, James T. J. (Af 1911), Owner (for MILLER, Bruce R. (Af 1935; A 1930). Mech. Engr., 1533 Northwest 25th St., Oklahoma City, Okla. mail), Mellon Co., 4415-21 Ludlow St., and 431 North 63rd St., Philadelphia, Pa. MELONEY, Edward J. (Af 1937). Vice-Pres. and Secy, (for mail). Bowers Bros. Co., 2015 Sansom St., Philadelphia, and 100 E. Stewart Ave.. Lansdowne, Pa. MENDEN, Peter J. (Af 1935), Secy., Thomas Heating Co., Inc., 1046 Herrick Ave., and (for mail), 1509 Arthur Ave., Racine, Wis. MENSING, Frederick D. (Af 1920), (Treas., 2870 Marion Ave., New York, N. Y. MILLER, Charles W. (Af 1919; 7 1908), Pres, (for mail), Rado Co., 338 S. Second St., Milwaukee, and R-l, Box 42, Menomonee Falls, Wis. MILLER, Edgar R. (A 1935), Chief Engr. (for mail), Winnipeg Cold Storage, Cor. Jarvis and Salter and Ste. O, Bexley Court, Winnipeg, Man., Canada. ' 1931-1932), Consulting Engr., Mensing & Co., 2845 Frankford Ave., Philadelphia, Pa. MERCER, Charles F. (Af 1937), Prof. Physics - (for mail), University of South Carolina, Dept. of Physics, and 219 S. Waccamaw, Columbia, . S. C. MERLE, Andr& (Af 1934), Pres., Andre Merle Associates, Inc., Engrg., Cons., 3752-85th St., Jackson Heights, L. I., N. Y. - MERRILL, Carle J. (Af 1919), Treas. (for mail), MILLER, Floyd A. (Af 1911), Asst. Dist. Engr., U. S. Treasury Dept., Public Bldgs. Branch, and (for mail), 377 U. S. Court House. Chicago, 111. MILLER, George F. (Af 1936), Sales Engr. (for mail), 1625 K St.. N.W., Washington. D.C., and 209 Connecticut Ave., Kensington, Md. MILLER, Glen (A 1937), Htg. and Vtg. Engr. (for mail). Southern Counties Gas Co., 810 S. Flower St., Los Angeles, and 685 Luton Drive, Glendale, Calif. C. J. Merrill, Inc., 54 St. John St., and 15 Long fellow St., Portland, Maine. . MERRILL, Frank A. (Af 1934), Consulting Engr. (for mail). Office of Hollis French, 210 South St., MILLER, Jacob (Af 1936), Pres-* (for mail). Universal Heating Co.. Inc., 121 St. Marks Place, New York, and 435 East 92nd St., Brook lyn, N. Y. . Boston, and 19 Auburndale Rd., Marblehead, Mass. > MERTZ, W. A. (Af 1919), Secy, (for mail), Kehm Bros. Co., 51 E. Grand Ave.. and 3753 N. Keeler Ave., Chicago, 111. ` MERWIN, Glle E. (Af 1924; 7 1923), Secy.-Treas., MILLER, James E. (Af 1914; 7 1912), Hearing Contractor, 2210 Colfax St., Evanston, 111. MILLER, John F. G. (Af 1916), Vice-Pres. (for mail), B. F. Sturtevant Co., Damon St.. Hyde PMaarsks,. Boston, and 20 Chapel St., Brookline, Rockford Plumbing Supply Co., 700 S. Main St., and (for mail), 1536 Myott Ave., Rockford, III. MESSENGER, Theodore I. (A 1936), Power . Engr. (for mail), Buffalo Niagara & Eastern Power Corp., 1107 Electric Bldg., and 263 Highland Ave., Buffalo, N. Y. METCALFE, Curtis {A 1937), Engr., House Htg. Dept., Detroit City Gas Co., and (for mail), 8575 Dumbarton Rd., Detroit, Mich. METZGER,' H. J. (A 1937), Supt. (for mail), Wheeler-Blaney Co., and 706 Locust St., Kala- . -mazoo, Mich. MEYER, Charles L. (Af 1930), Mech. and Sales Engr., L. J, Wing Mfg. Co., 154 West 14th St., New York, and (for mail), 86-97 Palo Alto Ave., Hollis, L. I., N. Y. MEYER, Frank L. (Af 1932; 7 1928). Vice-Pres.. Meyer Furnace Co., and (for mail), 9 Cole Court, Peoria, 111. ` MEYER, Henry C., Jr.* ( LifeMember; Af 1898), (council, 1915-1916), Pres, (for mail), Meyer, Strong & Jones. Inc., 101 Park Ave., New York, N. Y., and 25 Highland Ave., Montclair, N. J. MEYER, Joseph, Jr. (7 1937), Engr., Atmos . pheric Control Co., 716 Marquette Bldg., and (for mail), 817 Atkinson SL, Detroit, Mich. MEYERS, John (Af 1937), Branch Mgr. (for mail), Johnson Service Co., Bond Bldg., 14th and New York Ave.. N.W., and 821 Maryland Ave., N.E., Washington, D. C. . MICH IE, D. Fraser {A 1930), Engrg. Sales Dept, (for mail). Crane, Ltd., .93 Lombard St., and MILLER, Leo B. (Af 1926), Mgr., Refrigeration and Air Cond. Div. (for mail), Minneapolis- Honeywell Regulator Co., 2753 Fourth Ave., S., and 2725 Park Ave., Minneapolis, Minn. MILLER, Lester L. (7 1937; 5 1935), 623-14th Ave., Minneapolis, and (for mail), 2127 Tenth Ave., Hibbing, Minn. MILLER, Prof. Lorin G.* (Af 1933). Head, Dept, of Mech. Engrg. (for mail), Michigan State College, R. E. Olds Hall, and 525. Albert St., East Lansing, Mich* MILLER, Merl W. (Af 1932; A 1932; 7 1926), Plant Engr., Trane Co., and (for mail), 333 ' North 23rd St., LaCrosse, Wis. MILLER, Robert A.* (Af 1931), Tech. Sales Engr. (for mail), Pittsburgh Plate Glass Co., 2200 Grant Bldg., Pittsburgh, and 1211 Carlisle St., Tarentum, Pa. MILLER, Robert E. (7 1935), Sales Engr. (for mail), American Radiator Co., 1344 Broadway; and 18264 Birchcrest Drive, Detroit, Mich. MILLER, Robert T. {A 1927), Chief Engr., Sales Dept, (for mail). Masonite Corp., Ill W. Washington St., Chicago, and Flossmoor, III. ' MILLER, Tolbert G. (A 1929; 7 1921), Supt. and Engr., Herre Bros., Seventh and Emeralds St., Harrisburg, and (for mail), 11 N. Second St., Wormleysburg, Pa. -. MILLHAM, Franklyn B. (Af 1937), Installation Mgr., S. S. Fretz, Jr., Inc., 1902 Chestnut St., and (for mail), 234 W. Walnut Lane, Phila- ' delphia. Pa. 492 Warlaw Ave., Winnipeg, Man., Canada. MIDDLETON, David K. (7 1936), Branch Mgr., Johnson Service Co., and (for mail), 1100 North west 38th St., Oklahoma City, Okla. MILLIKEN, J. H * (Af 1923), Dist. Repr. (for mail), American Air Filter Co., Inc., 20 N. Wacker Drive, Chicago, and 1021 Ridge Court, Evanston, 111. MIDDLETON, Howard A. (4 1935), Sales Engr. (for mail), Frigidaire Div., General Motors Sales Corp., 2619 McGee St., and 400 E. Armour Blvd., Kansas City, Mo. ' MILLIS, Linn W. {Life Member 1934; Af 1918), Secy., Security Stove & Mfg. Co., 1630 Oakland, and (for mail), 3534 Wabash Ave., Kansas City, Mo. ' MIDEKE, Joseph M. {A 1937), Sales, Mideke Supply Co., 100 E. Main, and (for mail), 2003 Northwest 13th St., Oklahoma City, Okla. MILENER, Eugene D. (Af 1930), Secy., Industrial Gas Section (for mail), American Gas Associa- ' tion, 420 Lexington Ave., Suite.550, New York, and 3719-83rd St., Jackson Heights, N. Y. MILLS, Clarence A.* (Af 1936), Prof, of Experi mental Medicine, University of Cincinnati (for . mail),. Cincinnati General Hospital, and 5046 Oberlin Blvd., Cincinnati, Ohio. -MILLS, Hartzell C. {A 1935),-'Salesman, Minne- apolis Gas Light.Co., 800 Hennepin Ave., and (for mail), 4137 Tenth Ave., S., Minneapolis, Minn. 41 y' Heating Ventilating Air Conditioning Guide 1938 MILWARD, Robert K. (A 1920). Mgr. (for mail). XJ. S. Radiator Corp.t 127 Campbell Ave., and 2441 Calvert Ave., Detroit, Mich. MITCHELL, Charles H. (Af 1924), Engr., The Pels Co., 42 Union St., Portland, and (for mail), 25 Everett Ave., S., Portland, Maine. MITCHELL, John G. (J 1937; S 1936), Sales Engr. (for mail), Fairbanks, Morse Sc Co., 220 E. Fifth SL, St. Paul, and 704 Delaware St., MOORE, H. Lee (Af 1919), (Council. 1927-1928), Repr. (for mail). Buffalo Forge Co., 431 Fulton Bldg.. Pittsburgh, and Flaccus Rd., Ben Avon, Pittsburgh, Pa. - MOORE, Henry W. (Af 1935), Mgr., Air Cond. Engrg. Dept., The Bimel Co., 306 Walnut SL, Cincinnati, Ohio, and (for mail), 816 Greenland Drive. Murfeesboro, Tenn. MOORE, Herbert S. (A 1923), DisL Repr., Iron Fireman Mfg. Co. of Canada, Ltd-. 602 King SL, S.E., Minneapolis. Minn. W., and (for mail), 107 Clendenan Ave., Toronto, MITTENDORFF, Edward M. (Af 1932), Asst. Ont., Canada. Engr., Sarco Co., Inc., 222 N. Bank Drive MOORE, R. Edwin (A 1928). Vice-Pres.. Bell & Chicago, and (for mail), 956 Greenwood Ave., . Gossett Co.. 3000 Wallace SL, Chicago,' and (for Winnetka. 111. mail), 425 Merrill Ave., Park Ridge, 111. MODIANO, Rene (Af 1925), Managing Dir., MOORE, Wesley . R. (Af 1937). Branch Mgr., Carrier Continentale, 4, Rue d'Aguesseau. Paris Minneapolis-HoneyweU Regulator Co., 4501 (Sr) and (for mail), 55 Boulevard Beausejour. Prospect Ave., Cleveland, Ohio. Paris, (I6r) France. MOREHOUSE, H. Preston (Af 1933). Gen. Air MOELLER, Robert (5 1935), 3256 East 119th St., Cond. Repr. (for mail). Public Service Electric Cleveland, Ohio. MOFFAT, Ormond G. (A 1937), Sales Engr. & Gas Co., 80 Park Place, Newark, and 85 Halsted St., East Orange, N. J. (Field Supervisor), Canadian Westinghouse Co., Ltd., Sanford Ave., N., and (for mail), 141 MORGAN, Glenn G. (Af 1911), Partner (for mail), Morgan-Gerrish Co., 307 Essex Bldg., 84 George St., Hamilton, OnL, Canada. S. Tenth St., and 4308 Fremont Ave., S- Minne MOFFITT, Lloyd C. (J 1937). Installation Engr. (for mail). Sidles Co., Airtemp Div., 19th and apolis, Minn. MORGAN, Robert C. (Af 1915), Pres.. Stewart Howard, and 1530 South 29th. Omaha. Nebr. A. Jellett Co., 1200 Locust St., and (for mail), MOHN, H. Leroy (M 1937), Research Engr. (for mail), Fitzgibbona Boiler Co., Inc., E. Tenth and 314 W. Seymour St., Philadelphia, Pa. MORIARTY, John M. (Af 1937), Owner ffor Mercer St., and 132H W. Fourth Si- Oswego, mail), Consolidated Heating Sc Ventilating Co., N. Y. 1709 W. Eighth St., and 2525 Burnside Ave., MOHRFELD, Herbert H. (J 1935), Air Cond. Los Angeles, Calif. Engr. (for mail), C. P. Mohrfeld, Inc., 24 Lees MORRIS, Arnold M. (J 1934). Sheet Metal Ave., Collingswood, and 131' Chestnut St., Haddonfield, N. J. Worker, Philadelphia Navy Yard, Sheet Metal Shop Bldg., No. 17. and (for mail), 3022 Baltz MOLER, William H. (Af 1927; J 1923), VicePres. (for mail), Kribs & Landauer, 200 House SL, Philadelphia. Pa. MORRIS, Fred H. (A 1929), 14704 Strathmore man Bldg., Dallas, and Box 69A R. F. D. No. 1, ' Ave., East Cleveland, Ohio. . Irving, Texas. MORRIS, John A. (J 1936), Htg. Dept., James MOLLENBERG, Harold J. (Af 1936). Vice-Pres., Robertson Co., Ltd., 946 William St., and (for Mollenberg-Betz Machinery Co., 22 Henry St., mail), 4134 Marlowe Ave., Montreal, Que., Buffalo, and (for mail), 172 Westgate Rd., Canada. Kenmore, N. Y. MORRISON, Chester B. (Af 1931), Mgr. (for MOLONEY. Roger R. (Af 1937), 26 Bonner Ave., mail), York Shipley, Inc., 81 Jinkee Rd., and 347 Manley, Sydney, Australia. . Route Cohen, Shanghai, China. MON1CK, Fred R, (A 1936), Mgr. (for mail). MORSE, Clark T, (Af 1913), Pres, (for mail), Cochran Sargent Co., and 1114 S. Sixth Ave., American Blower Corp., 6000 Russell St., and Sioux Falls, S. D. ` 8120 E. Jefferson Rd., Detroit, Mich. MONIER, Kurt A. J. (J 1937; S 1935), Secy.- MORSE, Floyd W. (A 1934), AssL Gen. Sales Treas., A. J. Monier- & Co., Inc. (for mail), Mgr. (for mail), Chamberlin Metal Weather 1446 N. Flores, and 515 W. Ridgewood Ct., Strip Co., 52 Vanderbilt Ave., New York, and San Antonio, Texas. ' -. 132 Villa SL. ML Vernon. N. Y. MONTGOMERY, John R. (A 1937), Mgr.. Standards and Research (for mail), Truscon Steel Co., Albert SL, and 296 Granada Ave., Youngstown, Ohio. MONTGOMERY, Ora C. (Af 1933), AssL Supt. of Power (for mail). New York Central Railroad, Grand Central Terminal, Room 1842, 70 East MORSE, Louis S., Jr. (A 1938; J 1936). Air . Cond. Sales Engr. (for mail), Westerlin & Camp . bell Co., 5924 Second Blvd., and 19480 Canter bury Rd., Detroit, Mich. MORSE, Robert D. (Af 1936). Branch Mgr. (for mail), American Blower Corp., 1534 First Ave., S., and 4316 East 43rd St., Seattle, Wash. 45th SL, and 255 West 84th St.f New York, N. Y. MORTON. Charles H. (A 1931). Sales Repr., MOODY, Lawrence E. (Af 1919), Member of Firm (for mail). Moody & Hutchison, 1701 Warren Webster & Co., 228 Ottawa Ave., N.W., and (for mail), 1106 Sherman St., S.E., Grand Architects Bldg.. 17th and Sansom Sts., Phila Rapids, Mich. delphia, Pa., and 237 Jefferson Ave., Haddon . MORTON, Harold S. (Af 1931), Sales Engr., field, N. J. MOON, Frank L. (A 1935), Utilization Engr.. Los Angeles Gas & Electric Corp., 810 S. Flower SL, . Los Angeles, and (for mail), 1264 Ruberta Ave., Glendale, Calif. MOON, L. Walter (Af 1915), Pres, (for mail), Bradley Heating Co., 3834 Olive SL, and 5006 ' N. Kingshighway, St. Louis, Mo. MOORE, Bill J., Jr. (J 1937). Pres., U. S. Air Conditioning Sales Corp., 1701 Grand Ave.. and (for mail), 1305 Valentine Rd., Kansas City, Mo. MOORE, Don R. (S 1936), 402 W. Penn St., Hoopeston, 111. MOORE, H. Carlton* (Af 1935), AssL Prof. ' Mecb. Engrg. (for mail), Massachusetts lnsti- ` tute of Technology, Mech. Engrg. DepL, Cam bridge, and 145 -B^umont Ave., Newtonvilie, Mass. ' Sutherland Air Conditioning Corp., 385 Min nesota St., St. Paul, and (for mail), 4330 Wood- dale Ave., Minneapolis, Minn. MOSES, Walter B., Jr. (S 1936), Student. Tulane University (for mail), 425 S. Peters St., and 1516 Dufossat St.. New Orleans. La. MOSHER, Clarence H. (A 1919). C. H. Mosher Co., 423 Ashland Ave., Buffalo, N. Y. MOSS, Edward (Af 1920), Htg. and Vtg. Engr. (for mail). New York Rapid Transit Corp., 385 Flatbush Ave. Extension, Brooklyn, and 9053 204th St., Hollis. L. I., N. Y. . MOTZ, O. Wayne (Af 1932), Consulting Engr., 234 Paramount Bldg., Cincinnati, and (for mail), 2524 Moundview Drive, Korvyuod, Ohio. MOULD, Delmar E. (Af 1936), Mgr. (for mail), J. W. Mould & Son. 10708 Jasper Ave., and 10548-128th SL, Edmonton, Alb., Canada. 42 Roll of Membership MOULDER, Albert W.* (Af 1917). Vice-Pres. (for mail), Grinnell Co., Inc., 260 W. Exchange St., Providence, and W. Barrington, Providence, R. I. MUELLER, Harold C. (M 1936; A 1930), Sales Engr. (for mail). Powers Regulator Co., 2720 Greenview Ave., Chicago, and 2720 Lawndale Ave., Evanston, 111. MUELLER, Harold P. (Af 1936), Pres, (for mall), L. J. Mueller Furnace Co., 2005 W. Oklahoma Ave., and 4721 N. Larkin St., Milwaukee, Wis. MUELLER, John E. (Af 1937). Mgr. of Com mercial Sales (for mail). West Penn Power Co., 14 Wood SL. and 3335 Portola St.. N.S., Pitts burgh. Pa. MUIRHEID, John G. (J 1937). Sales Engr.. Page-Williamson, Inc., 423 S. Church SL, and (for mail), 2311 Hopedale Ave., Charlotte, N. C. MULLEN, Thomas J., Jr. (J 1935), Sales Engr., B. F. Sturtevant Co., Hyde Park, Boston, Mass. MULLOY, Edward (A 1937), Engr. (for mail). The Travelers Indemnity Co.,-910 Chamber of Commerce Bldg., and 559 Parker Ave., India napolis, Ind. MUNIER, Leon L. (Af 1919; J 1915), Pres.-Treas. (for mail), Wolff & Munier, Inc., 222 East 41st SL, New York, and 63 Columbia Ave., Hartsdale, N. Y. . MUNN, E. Fitz (Af 1935), Designing (for mail); Over & Munn, 903 McArthur Bldg., and 65 Berrydale Ave., Winnipeg, Man., Canada. MUNRO, Edward A. (Charter Member; Life Member), Htg.-Vtg. Engr., 344 Northwest 37th St., Miami. Fla. MUNRO, George A. (Af 1937), Member of Firm and Gen. Mgr., Hugh F. Murno & Sons, 2404 N. Mascher St., and (for mail). 173 W. Godfrey - Ave.. Philadelphia, Pa. MUNSON, James L. (A 1935), Vice-Pres. in Charge Engrg., (for mail), Blulite Corp., 1000 . Clinton St., Hoboken. N. J., and 15 Parkwold Drive, W., Valley Stream, N. Y. MURDOCH, John P.. Jr. (Af 1937), Pres.. John P. Murdoch Co. (for mail), 30th and Oakford Sts., and 5423 Cedar Ave.', Philadelphia, Pa- MURNIN, Edward A., Jr. (A 1937), DepL . Head. Sarco Mfg. Co., and (for mail), 802 Broadway, Bethlehem, Pa. ' MURPHREE, Robert L. (J 1936). Mech. Engr. (for mail),' Farm Security Administration, Trussville, and 1509 North 21st Place, Birming ham, Ala. MURPHY, Charles G. (A 1936; 5 1934), Con struction Engr., Krich Radisco, Inc., 422 Eliza beth Ave., Newark, and (for mail), 286 Myrtle Ave., Irvington, N. J.' MURPHY, Edward T.* (Af 1915), Vice-Pres. (for mail). Carrier Corp., Merchandise Mart, and 230 E. Delaware Place, Chicago, 111. MURPHY, Howard C-* (Af 1923). Vice-Pres. (for mail), American Air Filter Co., Inc., 215 Central Ave., and 495 Lightfoot Rd., Louisville, Ky. Murphy, Joseph R. (Af 1934; A 1925), Vice- Pres. (for mail). Taco Heaters, Inc., 342 Madison Ave., New York, N. Y., and The Terrace, Riverside, Conn. MURPHY, William A. (M 1926), Gen. Sales Mgr., Watts Regulator Co., 417 W. Ohio SL, and (for mail), 6214 N. Richmond Ave., Chicago, HI. MURPHY, William W. (Af 1930), Treas. (for mail), W. W. Murphy Co.. 424 Worthington St., and 25 Mansfield SL< Springfield, Mass. MURRAY, Hayward G. S. (J 1936), Sales Engr. (for mail). Canadian Comstock Co., Ltd.. Refrigeration and Air Cond. Div., 1100 New Birks Bldg., and Apt. 6, 3727 De L'Oratoire, Montreal, Que., Canada. - MURRAY, John J. (A 1933), Salesman-Vice- Pres., Pierce Perry Co., 236,Congress St., Boston, and (for mail), 60 Commonwealth Park West, Newton Centre, Mass. ` MURRAY, Thomas F. (Af 1923), State Arch., and (for mail), 14 S. Lake Ave., Albany, N. Y. MUSGRAVE, Merrill N. (A 1935), Pres, (for . mail), Harrison Sales Co., 314 Ninth Ave., N., and 1005 E. Roy St., Seattle. Wash. MYERS, Frank L. (Af 1933), Sales Engr., Owens- Illinois Glass Co., Ohio Bldg., and (for mail), 22 Proctor Place. Toledo, Ohio. - MYERS, George W. F. (Af 1930; A 1928: J 1923), Pres., Myers Engineering Equipment Co., 3736 W. Pine Blvd., St. Louis, and (for mail), 476 Pasadena Ave., Webster Groves, Mo. MYLER, William M., Jr. (Af 1937), Mgr., Space Htg. Eng. DepL (for mail). Surface Com bustion Corp., 400 Dublin Ave., and 1120 Northwest Blvd., Columbus, Ohio. MYTINGER, Kenneth L. (M 1936), Mgr., Air Cond. Div. (Cor mail), Fitzgibbons Boiler Co., 101 Park Ave., New York, N. Y- and 119 E. Bergen Place, Red Bank, N. J. N NAROWETZ, Louis L,, Jr. (Af 1929; A 1912), Secy, (for mail), Narowetz Heating & Venti lating Co., 1711-17 Maypole Ave., Chicago, and 112 Park Ave.. Park Ridge, 111. NASS, Arthur F. (Af 1927), Vice-Pres. and Treas. (for mail), McGinness, Smith & McGinness Co., 527 First Ave.. Pittsburgh, and Elmhurst Rd., R. D. No. 8, Crafton P. O., Pittsburgh, Pa. NATKIN, Benjamin* (Af 1909; J 1907), Pres, (for mail), Natkin & Co., 1800 Baltimore Ave., and 5211 Rockhill Rd.. K>ns City, Mo. NEALE, Laurence I. (A 1927), 125 East 57th SL. New York, N. Y. - NEE, Raymond M. (Af 1936), Head of Engrg. and Utilization Div. (for mail). Boston Edison Co., 39 Boylston SL, Boston, and 10- Orkney Rd., Brookline, Mass. ' NEILER, Samuel G. (Life Member; M 1898), Senior Member (for mail), Neiler, Rich Sc Co.,. Consulting Engrs., 431 S. Dearborn SL, Chicago, and 737 N. Oak Park Ave., Oak Park, 111. NEIS, Willard A. (5 1935), 5538 Forbes SL, Pittsburgh, Pa. NELSON, Arnold W. (J 1936), Salesman, Ameri can Radiator Co., 1 Manor SL, and (for mail), 11 S. Lake Ave., Albany. N. Y. NELSON, Arthur W. (A 1936), Mgr.. Brockton Oil Heat, Inc., 27 Legion Parkway, Brockton, and (for mail), 12 Sylvan Rd- Sharon, Mass. NELSON, Chester L. (A 1937; J 1929). Air Cond. Engr., Sears 8c Piou, 814 S. Vandeventer, St. Louis, and (for mail), 1731 Princeton Place, Richmond Heights, St. Louis County, Mo. NELSON, D. W.* (Af 1928), Asst. Prof, of Steam and Gas Engrg. (for mail). University of Wis consin, Mech. Engrg. Bldg., and 3906 Council Crest, Madison, Wis. NELSON, Edwin L. (A 1936). Engrg. DepL (for mail), Union Ice Co., 1315 E. Seventh SL, and 4313 Victoria Ave.. Los Angeles, Calif. NELSON, George O. (M 1923), Engr., Carstens Bros:, Ackley, Iowa. NELSON. Harold M. (Af 1937), Pres, (for mail), H. M. Nelson & Co., Inc., 1223 Connecticut Ave., and Rear 2208 Que SL, N.W., Washington, D. C. . NELSON, Herman W. (Af 1909), Pres., Herman Nelson Corp., 1824 Third Ave.. and (for mail), 2500-lltb St., Moline. III. NELSON, Richard H. (A 1933; J 1928), Secy.Treas., Herman Nelson Corp., 1824 Third Ave- and (for mail), 13Q3-30th St., Moline, 111. NESBITT, Albert J* (Af 1921; / 1921), Secy.- . Treas. (for mail), John J. Nesbitt, Inc., State Rd. and Rhawn St., Philadelphia, and Rockfield Farm, Ambler, Pa. NESBITT, John J. (Af 1923), John J. Nesbitt, Inc., State Rd. and Rhawn SL, Philadelphia, Pa.' NESMITH. Oliver E. (A 1928), Htg. Engr.. Williams Oil-O-Matic Heating Corp., and (for mail), 107 Warner Ave., Bloomington, III. NESS, William H. C. (Af 1931). Gen. Mgr. (for mail). Master Fan Corp., 1323 Channing St., and 215 N. Kingsley Drive, Los Angeles, Calif. NESSELL, Clarence W. (Af 1937), Field Applica tion Engr.. Minneapolis-HoneyweU Regulator Co., 1024 Third National Bldg., Dayton, Ohio. 43 1938Heating Ventilating Air Conditioning Guide NESSI, Andr (Af 1930), Ingr. des Arts et MfrsExpert pres le Tribunal Civil de la Seine (for mail), 1 Ave. du president.Wilson, Paris, XVI, France. NEST, Richard E. (M 1936), Oil Burner Div., Anchor Post Fence Co.. Baltimore, Md., and (for mail), 725 Taylor St., N.W., Washington, D. C. NEU, Henri J. E. (M 1933), Pres- Etablissements . Neu, 47-49, Rue Fourier, Lille (Nord), France. NEWCOMB, Lionel B. (A 1936; J 1933), Junior Engr- Philadelphia Electric Co- and (for mail), . 6056 Walton Ave., Philadelphia, Pa. NEWPORT, Charles F * (M 1906), Sales Engr, Weil-McLain Co., Michigan City, Ind., and (for ` mail), 10001 Longwood Drive, Chicago, 111. NICELY, John E, (A 1925), Salesman, American Radiator Co., and (for mail), 1208 Marion St- Readinc, Pa. NlCHOlXs, Percy* (Af 1920), Supervising Engr Fuel Section, U. S. Bureau of Mines, Pittsburgh, Pa. NICKLE, Arthur J, (A 1936), Sales Engr. (for mail), Darling Brothers, Ltd- 140 Prince St- and 4356 Marcil Ave., Montreal, Que- Canada. NIESSE, Joe H. (Af 1937), Dist. Mgr. (for mail), ' llg Electric Ventilating Co- 836 Archts. and Bldrs. Bldg- and 5837 Winthrop Ave., Indian apolis, Ind. NIGHTINGALE, George F. (A 1931), Western Sales Mgr. (for mail), Tuttle & Bailey, Inc- 61 ' W. Kinzie St., Chicago, and 621 S. Maple Ave., Oak Park, 111. . NOBBS, Walter' W. (Af 1919), Consulting Engr- 26 Victoria St., London, S.W.l, and (for. mail), 50 Fairhazel Gardens, London, N.W.6, England. NOBIS, Harry M. (Af 1914), 1827 Stanwood Rd- East Cleveland. Ohio. NOBLE, James P. (A 1937), Dist. Repr- Refri- " geration Eauipment Co- 32 E. First St- and (for mail), 229 Delaware Ave., Dayton, Ohio. NOLL, William F. (Af 1924), Htg. and .Vtg. .. Contractor (for mail), 629 North 27th St., and 2850 North 47th St- Milwaukee. Wis. NORDLNE, Louis F. (Af 1914), Branch Mgr. (for r mail), Trane Co- 734 Jackson Place, N.W., Washington, D. C- and 812 Silver Springs Ave ' Silver Springs, Md. . NORMAN, Roy A, (Af 1937), Prof. Meeh. Engrg- . Iowa State College,, and (for mail), 715 Ridge wood Ave- Ames, Iowa. NORTHON, Louis (Af 1929), Consulting Engr- 132 Park Ave- Mt. Vernon, N. Y. . NOTTBERG, Gustav (A 1933), Secy.-Treaa. (for mail), U. S. Engineering Co- 914 Campbell St and 1835 East 68th St- Terrace, Kansas City, Mo. . NOTTBERG, Henry (if, 1919), Pres, (for mail), U. S. Engineering Co., 914 Campbell St., .and 150 West 54th St- Kansas City, Mo. - OAKS, Orion O. (Af 1917), Executive EngrAmerican Radiator Co- 40 West 40th St- New York, N. Y- and (for mail), 119 Oakridge Ave- Summit. N. J. OATES, Walter A. (Af 1931), Htg. and Industrial Engr- Lynn Gas & Electric Co- 90 Exchange St- Lynn, and (for mail), 265 Humphrey St., Swampscott, Mass. O'BANNON, Lester S.* (Af 1928), Prof, of Heat . Power Engrg., Head-Dept. of Mech. Engrg. (for mail), University of Kentucky, and 123 State Sfc- Lexington, Ky. OBERG, Harry C. (A 1933), Mgr. Engrg. Dept., Crane Co. of Minnesota, Fifth and Broadway, and (for mail), 1362 W. Minnehaha St- St. Paul, Minn. OBERT, Casin W.* (A/ 1916), Consulting Engr- Union Carbide & Carbon Research Lab- 30 East . 42nd St- New York, and (for mail), 122 N. Columbus Ave- Mt. Vernon. N. Y. O'BRIEN, Walter N. (A 1935), Secy.-Treas. (for mail), O'Brieni Equipment Co- 2726 Locust St., and 2221 Thurman Ave- St. Louis, Mo. O'CONNELL, Presly M. (Af 1916), 9726-49tb Ave- N.E.; Seattle, Wash. O'CONNOR, George P. (A 1937), Pac. Coast Div. Mgr. (for mail). The Ric-wiL Co- No. 417 Call Bldg., and 642 Mangels Ave- San Fran cisco, Calif. OFFEN, Ben (Af 1928), Owner (for mail), B. Offen & Co., 608 S. -Dearborn St- and 502 W. Briar ' Place, Chicago, 111. ' OFFNER, Alfred J.* (Af 1922), (National Treas- 1935-1937; Council, 1935-1937), Consulting Engr. (for mail), 139 East 53rd St- New York, . and 160-15-lith Ave- Beechhurst, L. 1- N. Y. O'FLAHERTY, John G. (Af 1937), Chief Engr., Unifin Tube Co- York St- and (for mail), 290 Central Ave., London, Out- Canada. ' OGARD. Norris L. (J 1937; S 1936), Sales Engr. Minneapolis-Honeywell Regulator Co- 2727-53 Fourth Ave- S- and (for mail), 701 Washington Ave., S.E., Minneapolis, Minn. O'GORMAN, John S., Jr. (A 1934), Mgr. (for mail), Johnson Service Co., 427 Brainard StDetroit, and 147 Abbey Rd- Birmingham, Mich. OKE, William C. (A 1938; J 1934), Air Cond. Engr. (for mail), Weathermakers (Canada), , Ltd- 593 Adelaide St., W- and 110 Oriole ' Parkway, Apt. 101, Toronto, Ont- Canada. OLD, William H. (Af 1937), Asst. Mgr. (for mail), Glanz & Killian Co- 1761 W. Forest Ave- and - 3472 Courville Ave- Detroit, Mich. . OLDES, Willard E. (J 1936), Piping and Incinera tor Designer, Standard Oil Co- Elizabeth, N. J. and (for mail), 610 West 204th St- New York, N. Y. OLSEN, Carlton F. (A 1925; J1920), Combustion Engr,, Kewanee Boiler Corp- 1858 S. Western Ave- and (for mail), 7314 Stewart Ave- Chicago, - NOTTBERG, Henry, Jr, (J 1937), Engr. (for 111. mail), 17. S. Engineering Co., 914 Campbell St OLSEN, Gustav E. (Af 1930), Vice-Pres- FiU- - and 150 West 54th St- Kansas City,,Mo. gibbons Boiler Co- Inc., 101 Park Ave- New- NOVOTNEY, Thomas A. (Af 1928), Gen. Mgr- York, and (for mail), 68-09 Amstel Blvd- Corivector Sales, National Radiator Corp- and Arverne, L. I- N. Y. - . ' (for mail), 403 Wayne St., Johnstown. Pa. . OLSON, Barney (A 1929), Mfre. Repr. (for mail), NOWITZKY, Herman S. (A 1931), Supt- 122 S. Michigan Ave., and 5724 N. Natoma Ave., Construction, Maintenance and Repairs, Wilmer . Chicago, III. & Vincent Corp. (Theatrical Chain), 1776 Broad OLSON, Gilbert E. (Af 1930), Partner (for mail). way, New York, N. Y- and (for mail), 151 General Air Conditioning Co., 1015 E. Douglas, Tenth St- Norfolk, Va. and 2235 S. Oliver, Wichita, Kan.' NUSBAUM, Lee* (if 1915), Owner (for mail), OLSON, Milton J. \J 1937), Vice-Pres- Olson Pennsylvania Engineering Co- 1119-21 N. Bros- 2612 Leavenworth St- and (for mail), Howard St., and 315 Carpenter Lane, German 5627 Williams St- Omaha, Nebr. town, Philadelphia, Pa. ' * OLSON, Robert G. (Af 1923), Eastern Mgr. (for -NYE, L. Bert; Jr. (J 1936), Htg. Engr- Washing mail). Hydraulic Coupling Div., American ton Gas Light Co- 411 Tenth St- N.W., Wash Blower Corp- 50 West 40th St- and 22 East 38th ington, D. C- and (for mail), 309 Piedmont St., St- New York, N. Y. Arlington, Va. OLVANY, William J. (Af 1912), Pres, (for mail). Wm. J. Olvany, Inc- 100 Charles'St- New York, o and 109-40-71st Rd- Forest Hills, N. Y. . OAKLEY, LeRoy W. (Af 1937), Htg. Engr. (for mail). Plumbing &. Heating Sales Co- 408 W. - Clinch Ave- and 175 Island Home Blvd- Knoxville. Tenn. O'NEILL, James W. (M 1929; A 1927; J 1925), Chief Engr., Trane Co. of Canada, Ltd- 4 Mowat Ave- and (for mail), 8 Springmount Ave., Toronto, Ont- Canada. ,44 Roll of Membership OONK, William J. (Af 1937), Dist. Mgr., B. F. Sturtevant Co., 915 Olive St- and (for mail), 4548 Redbud Ave- St. Louis, Mo. OPPERMAN, Everett F. (J 1935; 5 1933), Estimator, Frederick Opperman, Railroad Ave- and (for mail), 169 Milbank Ave., Greenwich, Conn. OREAR, Andrew G. (Af 1930). Sales Engr. and Pres, (for mail), Trade-Wind Motorfans, Inc- 1325 Maple Ave- and 1015 E. Raleigh St- Glendale, Calif. O'RJEAR, Lawrence R. (Af 1934), Pres, (for mail). Midwest Plumbing & Heating Co- 2450 Blake St., and 3033 West 37tb Ave- Denver, Colo. O'ROURKE, Hugh D., Jr. (J 1937; S 1936), Sales Engr., Trane Co., LaCrosse, Wis., and (for mail). 2306 E. Fayette St., Syracuse, N. Y. ORR. George M. (Af 1936), Pres, (for mail), G. M. Orr & Co- Consulting Engrs- 542 Baker Arcade Bldg- and 2223 Emerson Ave- N- Minneapolis. Minn. ORR, Leighton (Af 1937), Research Engr., Pittsburgh Plate Glass Co., Research Labora tory, Creighton, and (for mail), 1116 Cambridge St.. Tarentum, Pa. OSBERGER, Thomas L. (A 1937), Mgr. (for mail). Standard Sanitary Mfg. Co- 90 Market St., S.W., and 918 Orchard Drive, Grand Rapids, Mich. ' OSBORN, Wallace J. (A 1927), Vice-Pres., Keeney Publishing Co- Grand Central Term. Bldg- New York, N. Y- and (for mail), 599 Old Post Rd- Fairfield, Conn. OSBORNE, Gurdon H. (Af 1922), Gen. MgrVentilating & Blow Pipe Co., Ltd- 714 St. Maurice St- Montreal, and (for mail), 836 Pratt Ave., Outremont, Montreal, P. Q- Canada. OSBORNE. Maurice M. (Af 1925), 367 Beacon St- Boston, Mass. OSTROM. Eric W. (Af 1937), Engr., Svenska Flaktfabriken Kungsgatan 8, and (for mail). John Ericssonsgatan 18, Stockholm, Sweden. OTIS. Gerald E.* (Af 1922), Vice-Pres. (for mail), Herman Nelson Corp- and 1921-23rd Ave., Moline, III. OTT, Oran W. (Af 1925), (Council. 1934-1936). Consulting Mech. Engr. (for mail), 606 Wash ington Bldg., and 123 S. Virgil Ave., Los Angeles, Calif. OURUSOFF. L. S* (Af 1931), Engr. of Utilization - -(for mail), Washington Gas Light Co., 411 Tenth St- N.W., Washington, D. C. and 21 Cedar Parkway, Chevy Chase, Md. . OUWENEEL, William A. (Af 1937), Chief Engr., Standard Distributing Corp- 406 E. Wells St- Milwaukee, and (for mail), 801 Marshall Ave- South Milwaukee, Wis. . OVERTON, Sidney H. (Af 1929), Repr., N. V. Radiatoren, Amsterdam, Holland, and (for mail), P. O. Box 5985 Johannesburg, South Africa. OWEN, Jeff Davis (Af 1937), 4070 East Blvd- . Culver City, Calif. P PABST, Charles S. (Af 1934), Pres, and Mgr . Pabst Air Conditioning Corp- 55 West 42nd St- New York, and (for mail), 8727-98th St- Wood- ..haven. L. f-N. Y. PAETZ, Herbert E. (Af 1922), Div. Sales Mgr. (for mail), American Blower Corp- 632 Fisher Bldg . and The Wardell, Detroit, Mich. PAGE, Arvin (Af 1935), Asst. Chief Engr. (for mail), Bahnson Co., 1001 S. Marshall St- and 600 Arbor Rd- Winston-Salem, N. C- PAGE, Harry W. (Af 1923), Pres, (for mail), Wisconsin Equipment Co- 918 N. Fourth St . Milwaukee, and 7927 Warren Ave., Wauwatosa, Wis. - PAGE, Vernon C. (A 1936),- Director of Sales, .Automatic Heating & Cooling Systems, 2101 N. Charles St- and (for mail), 5610 Greenspring Ave., Baltimore, Md. PAINTER. David H. (Af 1924; A 1924), Mfrs- - Agent, Hoffman Specialty Co- and (for mail), 7331 Brooklyn St- Kansas City, Mo. ; PALMASON, John H. (7 1937). Engr. in Plant Engrg. Dept- McKinnon Industries, Ontario St- and (for mail, 163 Ontario St- St. Catharines, Ont., Canada. PALMER, Robert T. (A 1935), Patent Lawyer (for mail), 80 Federal St- Boston, and 15 N. Pleasant St- Sharon, Mass. PAOUET, Jean-Marie (J 1936), Engr- J. A. Y. Bouchard. Ltd- 9 Buade St- and (for mail), 62, De Salaberry, Quebec, Canada. PARK. Clifton D. (Af 1929), 67 Woodlawn Ave.,\ Needham. Mass. PARK, Harold E. (A 1938; J 1936). Salesman. Shaw-Perkins Mfg. Co- and (for mail), 31 Vilsack St- Etna, Pa. PARK, J. Frank (Af 1937; A 1936; J 1930), Sales Engr. (for mail). Western Air & Refrigeration, Inc- 1234 S. Grand, and 726 N. Occidental, Los Angeles. Calif. PARK, Nicholas W. (Af 1936), Htg. Engr- Philadelphia Saving Fund Society (Real Estate Dept.), 12 South 12th St- Room 309, Phila- ' delphia, and (for mail), 509 Jericho Rd- Abing- ton. Pa. PARKER, Philip (Af 1915), 8 Middle St- Woburn, Mass. PARKS. Charles E. (Af 1937). Dist. Mgr. (for mail), llg Electric Ventilating Co., 605 Profes sional Bldg- and 284 W. Steuben St- Crafton P. O- Pittsburgh, Pa. PARROTT, Lyle G. (Af 1922), Consulting Engr- (for mail), Snyder & McLean, 2308 Penobscot Bldg., and, 3788 Gladstone, Detroit, Mich. PARSONS. Leonard D., Jr. (J 1937; S 1936), 795 Park Blvd- Glen Ellyn, 111. PARSONS, Roger A. (J 1933), Htg. Engr- Board of Water and Electric Light Commissioners, 116 W. Ottawa St- and (for mail), 2609 Clifton St- Lansing, Mich. ' PARTLAN, James W. (Life Member; Af 1916). 14290 Goddard Ave- Detroit, Mich. PATERSON, Frederick C- Jr. (Af 1936; J 1928). Pres, (for mail), F. C. Paterson & Co- Inc., 76 Mechanic St- and 70'Stone Ave- Bradford, Pa. PATORNO, Sullivan A. S. (Af 1923), Consulting Engr. (for mail), 101 Park Ave- and 312 East . 163rd St- New York, N. Y. PATRICK, Horace M. (Af 1936; J 1929), Engr.. 411 Pembroke Rd- Bala-Cynwyd, Pa. PATTERSON, Frank H. (Af 1936). Sales- . Hoffman Specialty Co., and (for mail), 9201 Boleyn, Detroit, Mich. PATTON, Roy L. <M 1927), Pres, (for mail). , Roy L. Patton, Inc- 323 N.W. Tenth St- and ' 1111 Northwest 38th St- Oklahoma City, Okla. PAUL, Donald I. (Af 1936; J 1932), Chief Engr. (for mail), Gurney Foundry Co., Ltd- 4 Junction Rd- and 222 Fern Ave., Toronto, Out- Canada. PAUL, Lawrence O. (J 1935), Engr. (for mail). Carrier Corp- Merchandise Mart, and 2104 . Fargo Ave- Chicago, 111. PAULING, Robert E. (A 1936), Salesman and Repr., U. S. Radiator Corp., Detroit, Mich- and . (for mail), 211 S. Gary Ave., Tulsa, Okla. PAVEY, Charles A. (Af 1937), Dist. Mgr. (for mail). B. F- Sturtevant Co- 812 Michigan Bldg- and 17568 Roselawn Ave- Detroit,' Mich. PAYNE, Robert E. (Af 1935). Draftsman, E. I. DuPont de Nemours Co- Wilmington, Del- and (for mail), 244 Sedgewood Rd- Springfield, Pa. PEACOCK, James K. (Af 1921), Asst. Secy ' Hoffman Specialty Co., Inc- 500 Fifth Ave- New York, and (for mail), 440 Fowler Ave- Pelham ' Manor, N. Y. PEART, Allen M. (A 1937), Dist. Mgr. (for mail), Minneapolis-Honeywell Regulator Co- 637 Craig West, Room 812, and 4635 Melrose, Montreal, Que., Canada. PEEBLES. John K., Jr. (A 1925), Arch. Engr10 Oakhurst Circle, University Station, Chariot' ' tesville, Va. PEISER, Maurice B. (J 1937), Sales Engr. (for , mail), Natkin & Co- 1726 St. Mary's Ave and 5016 Casa St- Omaha. Nebr. 45 Heating Ventilating Air Conditioning Guide 1938 PELLER, Leonard (7 1934), Mech. Engr., PIETSCH, James A. (Af 1936), Consulting Engr. Internationa! Harvester Co., ISO N. Michigan (for mail), Jas. A. Pietsch, Inc., 155 Prospect Ave.,and (for mail), 1359 N.WellsSt., Chicago, 111. Ave., and 101 Cebia Ave., New Brighton, S. I., PELLMOUNTER, Thomas (A 1936), Dist. Sales N. Y. Mgr., Century Electric Co., 903 McGee St.. Room 512, and (for mail), 3308 Euclid Ave., Kansas City. Mo. ` PELOUZE, Henry L., 2nd (A 1934), Mgr. (for mail), Pelouze Sales Co., 110 N. Seventh St., and 4209 Grove Ave., Richmond. Va. PENNOCK. William B. (Af 1927). Sales Engr., PIHLMAN, Arthur A. (Af 1928), Service Engr. (for mail). Consolidated Gas Co. of New York, 4 Irving Place. New York, N. Y., and 98 Sherman ' Place, Jersey City, N. J. PIKE, Wallace H. (Af 1935), Engr. Designer (for mail), Newcomb David Co., 5779-81 Russell St., . and 4708 Buckingham Rd., Detroit, Mich. Pennock Engineering, 63 Sparks St., and (for PILLEN, Harry A. (A 1933), Owner (for mail), mail). 326 Waverly St., Ottawa. Out.. Canada. H. A. Pillen Co. (Mfg. Agent), 622 Broadway, PERINA, Arthur E. (7 1936; S 1933), Engr. (for and 2124 Crane Ave., Cincinnati, Ohio. * mail). Carrier Corp., 300 S. Geddes St., and 434 Cortland Ave., Syracuse, N. Y. PINES, Sidney (Af 1920), Vice-Pres. (for mail), Natkin & Co., 1800 Baltimore Ave., and 6625 PERKINS, Robert C. (A 1935), Sales Engr. (for Brookside Rd., Kansas City, Mo. mail), llg Electric Ventilating Co., 203 Natchez Bldg., and 1532 Foucher Ave., New Orleans, La. PINTO, Chester B, (A 1937), Div. Mgr., Plbg. and Htg. Dept, (for mail). Montgomery Ward & PERRAS, George E. (Af 1936), Htg. Expert. Co., 150*18 Jamaica Ave., Jamaica, and 11 Thomas Robertson & Co., Ltd., 262 Craig St., W., and (for mail), 6286 Chambord St., Montreal. Que., Canada. PERSSON. N. Bert (Af 1937), Design Engr., Frigidaire Div. of General Motors, University Buena Vista Ave.. Lawrence, N. Y. PISTLER, Willard C. (Af 1934), Mech. Engr. in charge of design, Carl J. Kiefer, Consulting Engr., 91S Schmidt Bldg., and (for mail). Orchard Lane and Crestview Ave., Pleasant Ridge, Ave., and (for mail), 1418 Simpson Ave., St. Paul, Minn. PESTERFIELD, Charles H. (A 1938; 7 1936; S 1932), Instructor, Michigan State College. Mech. Engrg. Dept., East Lansing, Mich. PETERSEN, Christian P. (A 1937), Owner (for mail), Petersen Sheet Metal Works, 4120 Cedar Ave., and 3914 Cedar Ave., Minneapolis, Minn. PETERSEN, Stanley E. (A 1937; 7 1935), Sales Cincinnati, Ohio. PITCHER, Lester J. (Af 1929; A 1928; 7 1924), Electrimatic Corp., 2100 Indiana Ave., and (for mail), 7921 S. LaSalle St., Chicago, ill. PIZIE, Stuart G. (A 1926), Mfg. Agent, Air Conditioning Equipment; 743 Ingraham Bldg., and (for mail), 50 Southwest 19tb Rd.. Miami. Fla. PLACE, Clyde R. (Af 1924), Consulting Engr. (for mail), 420 Lexington Ave., and 333 East 57th Engr. (for mail), W. A. Ramsay, Ltd., P. O. Box 1721, and 3608 Sierra Drive, Honolulu, Hawaii, PETERSON, Carl M. F.* (Af 1936). Instructor (Mech.. Engrg.), ((or mail), Massachusetts St., New York, N. Y. PLAYFAIR, George A. (A 1924), Mgr. (for mail), Johnson Temperature Regulating Co. of Canada, 113 Simcoe St., Toronto, and West Hill, Out., Institute of Technology. 69 Massachusetts Ave., Cambridge, and 40 Fletcher Rd., Woburn, Mass. PETERSON, Neil H. (Af 1937), Mgr. (for mail), The Trane Co., 1129 Folsom St., and 2744 Green Canada. PLEWES, Stanley E. (Af 1917), Branch Mgr. (for mail), Johnson Service Co., 2853 North 12th St., Station 8. Philadelphia, and 309 Evergreen Rd., St., San Francisco, Calif. - PETERSON, Sterling D. (A 1930), Branch Mgr. - (for mail), Johnson Service Co., 514 Colman Bldg., and 5051 Prince St., Seattle, Wash. Jenkintown, Pa. PLUM, Leroy H. (Af 1935; A 1934), Engr. (for mail), Warren Webster & Co., 17th and Federal Sts., Camden, and 207 Guilford Ave,, Collings- PETTIT, Ernest N., Jr. (Af 1937). Mech. Engr., Nate Downs, Cons. Engr., 317 Finance Bldg., Kansas City, Kan., and (for mail), 107 Ward wood, N. J. PLUMMER, Robert S- (7 1937), Asst, to SupL, . Franklin Heating Station, and (for mail). Quarry Pkwy., Kansas City, Mo. PEXTON, Frank S. (A 1936), Sales Engr. (for mail), Kansas City Gas Co., 824 Grand, and 43 Hill, Rochester, Minn. PLUNKETT, John H. (Af 1925), Chief of In spection, Retired, Commonwealth of Mass., 81 West 73rd Terrace, Kansas City, Mo. PFRIEM, Peter G. (A 1937), Sales Engr., The Knapp Supply Co., Ohio and Dudley Sts., and (for mail), 211 N. Hackley St., Munice, Ind. Woodrow Ave., Boston, Mass, POEHNER, Robert E. (Af 1928); Prop, (for mail), R. E. Poehner, Htg. Contractor, 849 Massa chusetts Ave., and 2308 Coyner Ave., India PFUHLER, John L. (A 1925; 7 1923), Plumbing and Heating, 600 Manor Rd., West New Brigh ton, Staten Island, N. Y. , PHILIP, William (Af 1937), Sales Engr.. Do napolis, Ind. POGALIES, Louis H. (Af 1931), Mech. Engr.. Wilbur Watson 8c Associates, 4614 Prospect Ave., and (for mail), 4102 Archwood Ave., minion Radiator & Boiler Co., Royce and Laos* downe Aves., and (for mail), 74 Bastedo Ave., . Toronto, OnL, Canada. Cleveland, Ohio. POHLE, Kenneth F. (A 1930), Vice-Pres., W. F. Hirschman Co., Inc., 202 East 44th St., New PHILLIPS, Frederic W. (Af 1921), Engr., House Htg. Dept., Queensborougb Gas & Electric Co., 1610 Far Rockaway Blvd., Far Rockaway, and . (for mail), 825 East 38th St.. Brooklyn, N. Y. York, N. Y. POLDERMAN, Lambert H. (M 1927). Western Dist. Mgr. (for mail). Carrier Corp., 748 E. Washington Blvd., and 3462 Lambeth SL, . PHILLIPS, Ralph E. (Af 1936), Consulting Engr. (for mail), 816 W. Fifth St., and 5153 Angeles Vista Blvd., Los Angeles, Calif. PHIPPS, Frederick G. (Af 1930), Vice-Pres., Preston Phipps, Inc., 955 St. James SL, W., and (for mail), 5431 Eamscliffe Ave,, Montreal, P. Q., Canada. Los Angeles, Calif. ` POLING, Dudley B. (Af 1936). Mgr. (for mail,) Metal Products Div.. 182 N. Yale Ave., and 797 E. Fulton St., Columbus, Ohio. POLLAK, Rudolf (Af 1937). Chief Engr. (for mail). Rockefeller Center, Inc., 30 Roockefelier Plaza, New York,. and 126 Aqueduct Drive, PICKETT, Clinton A. (Af 1937; A 1923), Mgr., Unit Ventilator Div. (for mail). The Herman Nelson Corp., 540 N. Michigan Ave., and 1118 East 46th St., Chicago, 111. PICOT, John W. (A 1937), Dir. and Mgr. (for mail), Unit Air Conditioners Pty., Ltd., 300 Pitt . St., and No. 11-32 Angelsea St., Waverly, Scaredale, N. Y. POLLARD, Alfred L. (A 1932), Gen. Supt. (for mail), Puget Sound Power & Light Co., 860 Stuart Bldg., and 3009-28th A., Seattle, Wash. POLLOCK, Carl A. (A 1937), Vice-Pres. and Gen. Mgr. (for mail). Dominion Electrohome In dustries. Ltd., 39 Edward St,, and 120 Sterling Sydney. Australia. PIERCE, Edgar D. (7 1933) Mgr.. Carrier Air Cond. Dept, (for mail). Electrical Products Con solidated. 585 S. Broadway, and 1365 Corona, Ave.. Kitchener, Ont., Canada. ' PONSELL, Francis I. (A 1935), Partner and - Sales Engr. (for mail), James P. Ponsell & Sons, 826 Orange St., and 2708 Madison SL, Wilming Denver, Colo. ton, Del. '. 46 Roll of Membership POPE, S. Austin (Af 1917), Pres, (for mail), William A. Pope Co., 26 N. Jefferson St.. Chicago, and 831 Ashland Ave., River Forest, 111- PORTER, Carl W. (7 1936), Engr. (for mail), Henry Bartlett, 417 W. Central Ave., P. O. Box 527, and 6 E. Lucerne Circle, Orlando, Fla. POSEY, James (Af 1919), Consulting Engr. (for mail), 1755 Baltimore Trust Bldg., and 4005 Liberty Heights Ave., Baltimore, Md. POUCHER, Richard C. (7 1937; 5 1935), Sales Engr. (for mail). Diamond Iron Works, 1728 N. Second St., and 1770 Emerson Ave., S-, Minne apolis, Minn. POUNDS, Carlos A., Jr. (7 1937), AssL Chief Engr. and Draftsman (for mail). Sunbeam Heating & Air Conditioning Co., 346 Peachtree St., N.E., and 927 Cypress St., N.W., Atlanta, Ga. POWERS, Edgar C. (A 1934 ; 7 1931), Retail Sales Mgr., Htg. and Cooling Dept, (for mail). Oil Burners Distributing Co., 1100 Cathedral St., and 5509 Wayne Ave., Baltimore, Md. POWERS. Fred W. (Life Member; M 1911), Pres, (for mail). Powers Regulator Co., 2720 Greenview Ave., and 900 Castlewood Terrace, Chicago, POWERS. Lowell G. (A 1937; 7 1930), Sales Engr. (for mail). Carrier Corp., 1501 Carew Tower, and 291 Southern Ave., Cincinnati, Ohio. PRATT, Foster J. (Af 1937), Marine Engr., Navy Yard Puget Sound, Bremerton, and (for mail). Port Ochard, Wash. PRATT, Joseph C. (A 1936), Air Cond.-Htg. Specialist, Canadian General Electric Co., Ltd.; and (for mail), 1 Rosemount Ave.. Westmount, P. Q., Canada. < PRAWL, Frank E. (7 1936), Branch Mgr-, Sidles Co., Airtemp Div., 425 Stuart Bldg., and (for mail), 2345 Euclid SL, Lincoln, Nebr. PREECE, Leo W: (A 1936), Owner and Engr., L. W. Preece Co., 1719 Sassafras SL, and (for mail), R. F. D. No. 7, Erie, Pa. . PRENTICE, Oliver J. (A 1927), Dir. of Publicity and Public Relations (for mail), C. A. Dunham Co., 450 E. Ohio St., and 850 Lake Shore Drive, Chicago, 111. PRESDEE, Cliff W. (A 1926), Mgr. S65 Div., S. R. Dresser Mfg. Co., Bradford, Pa. PRICE, Charles E. (A 1933), Treas. (for mail). Keeney Publishing Co., 6 N. Michigan Ave., Chicago, and 1151 Chatfield Rd., Winnetka, 111. PRICE, Charles F. (7 1937). Htg. Engr., The Knapp Supply Co., Ohio and Dudley, and (for mail), 1015 W. Washington St., Munice, IndPRICE, Douglas O. (Af 1934), Htg. and Air Cond. Engr.. General Steel Wares, Ltd., 199 River St., and (for mail), 131 St. Germaine Ave., Toronto, Ont.. Canada. PRICE, Ernest H. (A 1937; 7 1934; 5 1932), Htg. Engr. (for mail), International Heater Co., 101 Park Ave., and Y. M. C. A., Utica, N. Y. PRIESTER, Gayle B. (7 1935: 5 1934), Air Cond. Engr. (for mail). Carrier Corp., Merchandise Mart, and 4820 N. Winchester, Chicago, 111. PRINCE, Raymond F. (7 1936), Engr., R. B. Dunning & Co., and (for mail), 27 McKinley ' St., Bangor, Me. PRITCHARD, William J. (7 1937), Branch Mgr., Carrier Corp., 28 Terry Rd., East Hartford, Conn. PROIE, John (Af 1936), Pres, (for mail), Proie Borthers, 856 W. North Ave., and 101 Dilworth ' SL, Pittsburgh, Pa. PRUDDEN, Orrtn D. (7 1938; 5 1936), Engr., ' General Plastics, Inc., North Tonawanda, and (for mail), 37 Park Place, Lockport, N. Y. PRUDEN, Bradlee (Af 1936). Engr.. Barber- Colman Co.. 150 Loomis St., and (for mail), 1509 Grant Ave., Rockford, 111. PRYIBIL, Paul L. (A 1932), Partner, Hucker- Pryibil Co.. 1700 Walnut St., and (for mail), 328 E. Philellena SL, Philadelphia, Pa. PRYKE, John K. M. (A 1937), Htg. and Vtg. Engr., 7 Sunderland Terrace. London* W; 2, England. PRYOR. Frederick L. (Af 1913), 5 Colt St., Paterson. N. J. PULLEN, Royal R. (Af 1935; A 1935). Mech. Engr., 109 East Hill St., Lead, S. D. PURCELL, Frederick C. (Af 1926). Sales Engr. (for mail), Mianeapolis-Honeywell Regulator Co., 415 Brainard St., and 4711 Second Blvd., Detroit, Mich. PURDY. Randall B. (A 1927), Associate Editor, Power (for mail), McGraw-Hill Publishing Co., 330 West 42nd St., New York, and 224-05-139th Ave., Laureltoa, L. I., N. Y. PURINTON, Dexter J. (A 1923), Vice-Pres. (for mail), Mahoney-Troast Construction Co.,,511 Fifth Ave., and 104 East 40th St., New York, N. Y- PURSELL, H. E. (Af 1919), Special Repr., Kewanee Boiler Corp., Kewanee, 111. Q OUALL, Clarence O. (A 1937), Owner (for mail). Quail Plumbing & Heating, Ninth St., and 54 Pearl St., Clintonville, Wis. QUEER, Elmer R. (Af 1933), Instructor in Engrg. Research (for mail), Pennsylvania State College, Engrg. Experiment Station, and 338 Arbor Way, State College, Pa. . QUIRK, Clinton H. (Af 1916; 7 1915), Eastern Sales Repr. (for mail). Trane Co., 250 East 43rd SL, New York, and 465 Front St.,' Hempstead, N. Y. R RABER, Benedict F. (Af 1937). Prof, of Mech. Engrg. (for mail). University of California, Room 114, Engrg. Bldg., and 1124 Arch SL, Berkeley, Calif. RACHAL. John M. (A 1936; 7 1930), Air Cond. Section, Andersen, Meyer & Co., Ltd., P. O. Box 265, Shanghai, China. RAGATZ, Theodore E. (A 1937), Sales (for mail). Sidles Co., Airtemp Div., 14th St., Columbus, and Y. M. C. A.. Lincoln, Nebr. RAINE, John J. (3# 1912), Vice-Pres. (for mail), G. S. Blodgett Co., 190 Bank SL, Burlington, and. Essex Junction, Vt * RAINGER, Wallace. F. (A 1930; 7 1924),.441 Hawthorne Ave., Yonkers, N-. Y. ` RAISLER, Robert K- (A 1933; 7 1930), Treas. (for mail), Raisler Heating Co., 129 Amsterdam Ave., and 38 East 85th St., New York, N. Y. RAMSAY, James W. (A 1936), Sales Engr, (for mail). King & Shepherd, 50 Church St., New York, and 8415 Fourth Ave., Brooklyn, N. Y. RANDALL, Robert D. (A 1930), Partner (for mail). D. T. Randall & Co., 7310 Woodward Ave., No. 404, and 340 E. Grand Blvd., Detroit, Mich. - RANDALL, W. Clifton* (Af 1928), Chief Engr. (for mail), Detroit Steel Products Co., 2250 E. Grand Blvd., and 5540 Ridgewood Ave., Detroit, Mich. RANDOLPH, Charles H, (Af 1930; A 1928; ` 7 1926), Air Cond. Engr., Milwaukee Electric Railway & Light Co., 231 W. Michigan SL, and (for mail). 1614 E. Royall Place, Milwaukee, Wis, RANK, Arthur 1. (A 1936), Pres, (for mail), Universal Insulation Co., 2429 South SL, and 6308 Ross SL, Philadelphia, Pa. RANSOM, Clifford F. (7 1936; 5 1935), 313 E. Springfield, Champaign, 111. RASMUSSEN, Robert P. (Af 1931), Pres., Economy Equipment Co., 223 N. Wolcott Ave.,and (for mail), 1243 East 46th St., Chicago, 111. RATHBUN, Perry W. (Af 1933), 1809 Northwest 37th St., Oklahoma City, Okla. - RATHER. Max F. (Af 1919), Mgr. Eastern Territory, Johnson Service Co., 28 East 29th SL, New York. N. Y. RATHKE, Arthur C. (7 1937), 1025 Wayne SL, Sandusky, Ohio. 47 i i Heating Ventilating Air Conditioning Guide 1938 Roll of Membership ' RAY. Lewis B. (Af 1932), Mech. Engr. (for mail), REYNOLDS, Thurlow W. (Af 1922), Consulting Ray Engineering Co., Inc., 800 Broad St., Engr., 100 Pinecrest Drive, Hastings-on-Hudson, Newark, and 151 Augusta St., Irvington, N. J. N. Y. RAYMER, William F., Jr. (A 1936; J 1934), REYNOLDS, Walter V. (A 1928), Pres.. Walter Sales Engr. (for mail), American Blower Corp., Reynolds, Inc., 861 Third Ave., New York, N. Y. 249 High St., Newark, and 266 Fourth Ave., RHEA, Chester A. (A 1931). Steel Boilers. 722 East Orange, N. J. Carpenter Lane. Philadelphia. Pa. - RAYMOND, Fred 1.* (A 1929), Owner (for mail). RHOTON, Walter R. (Af 1936), Pres, (for mail), F. 1. Raymond Co., 629 W. Washington Blvd., W. R. Rhoton Co., 1305 East 107th St., Cleve Chicago, and 547 N. Keystone Ave., River land, and 1728 Lee Rd., Cleveland Heights, Ohio. Forest. 111. RAYNIS, Theodore (J 1934), Draftsman, HuU RICE, Clarence J. (A 1923), Pres, (for mail). Sterling Engineering Co., 3738 N. Holton St., and Drafting Room, Bldg. No. 5, Navy Yard, Brook Rte. 6, Box 374, Milwaukee, Wis. lyn, and (for mail), 8528-118th St., Richmond RICE, Robert B. (Af 1934), Assoc. Prof, of Mech. Hill. N. Y. Engrg. (for mail). School of Engineering, Uni REAMER, William S., Jr. (Af 1937), Vice-Pres. versity of North Carolina, and 708 Hillsboro St., and Treas. (for mail). Reamer Industries, Inc., Raleigh, N. C. Seaboard Park, and 2400 Blossom St., Columbia, RICHARD. Edwin J. (Af 1933). Sole Owner (for SC ' mail), Edwin J. Richard Equipment Co., 528-29 RECK, William E. (Af 1927}. Civil Engr. (for Chamber of Commerce Bldg., and 3147 Victoria mail). Reck Heating Co., Ltd., Copenhagen N., Ave., Cincinnati, Ohio. Esromgade 15, and Sundvej 16, Hellerup, RICHARDSON, Henry G. (Af 1934), Engr., Denmark. Williams-Richardson, 204 Dooly Bldg., and (for REDRUP, Will D. (Af 1936), Pres, (for mail),. mail), 1433 Harvard Ave., Salt Lake City, Utah. Majestic Co., and 310 Randolph St., Huntington, RICHFIELD, Nicholas H. (Af 1937), Field Engr., Ind. - REDSTONE, Arthur L. (Af 1931), Research Delco-Frigidaire Conditioning Division, General Motors, Dayton, Ohio, and (for mail), 173 N. Engr. (for mail), Proctor & Schwartz, Seventh Tyson Ave., Floral Park, L. I., N. Y. and Tabor Rd., and Park Towers, Kemble and RICHMOND, John (/ 1937; 5 1933), 5285 Forbes Ogontz Ave., Philadelphia, Pa. St., Pittsburgh, Pa., and (for mail), 951 Helms REED, Irving G. (A 1937; J 1934), Asst. Supt. dale Rd., Cleveland Heights, Ohio. ` and Chief Engr., Grant Building, Inc., 420 Grant RICHTMANN, William M.* (A 1932; J 1926), Bldg., and (for mail), 3227 Middletown Rd., Assoc. Prof, of Engrg. (for mail), Texas College Sheradan, Pittsburgh, Pa. ' of Arts and Industries, and 616 W. Santa Ger- REED, Van A., Jr. (Af 1930). Mech. Engr. (for trudis St., Kingsville, Texas. mail). Federal Engineering Co., 239 Fourth Ave.,. _ RICKNER, Charles A. (Af 1935), Sales Mgr. (for Pittsburgh, and 114 Water St., Elizabeth, Pa. mail). Gamp Electric Co., 2924 Locust St., REGER, Henry P. (Af 1934), Pres.-Treas. (for St. Louis, and 803 S. Berry Rd., Webster Groves, mail). H. P. Reger & Co., 1501 East 72nd Place, Mo. and 6939 Bennett Ave., Chicago, 111. RIES, Lester S. (Af 1929), Supt. of Bldgs, and REID, Henry P. (Af 1931; A 1927), Operating Grounds (for mail), Oberlin College,. 32 E. Engr. (for mail). Universal Atlas Cement Co., College St., and 68 Elmwood Place, Oberlin, 208 S. LaSalle St., Chicago, and 3507 Oak Park Ohio. Ave., Berwyn, 111. RIESMEYER, Edward H., Jr. (A 1936; J 1930), REID, Herbert F. (A 1932). Reid-Graff Plumbing Engr., Htg. and Air Cond., Schaffer Heating Co., Co., 1417 Peck St., Muskegon Heights, Mich. . 231-33 Water St., and (for mail), 4702 Stanton REIF, Allan F. (Af 1937), Pres, (for mail), Reif- Ave., Pittsburgh, Pa. Rexoil, Inc., 37-43 Carroll St., Buffalo, and 10 RIETZ, Elmer W.* (Af 1923), Gen. Sales Mgr. (for Livingston Pkwy., Snyder, N. Y. mail). Powers Regulator Co., 2720 Greenview REIF, Charles A. (Af 1937), Vice-Pres. (for mail), Ave., Chicago, and 2250 S. Sheridan Rd., Reif-Rexoil, Inc., 37-41 Carroll St., Buffalo, and Highland Park, 111. 77 Ruskin Rd., Eggertsville. N. Y. REIK, Robert C. (J 1935), Engr., L. E. Stevens . Co., 622 Broadway, Cincinnati, Ohio, and (for mail), 37 W. Southgate, Ft. Thomas, Ky. REILLY, Charles E. (A 1936; J 1928), 4920 City Line Ave., Philadelphia, Pa. REILLY, J, Harry (Af 1931; A 1931; J 1929), Sales Engr., American Radiator Co., 528 Ferry St., Newark, and (for mail), 14 Watson Ave., East Orange, N. J. REINKE, Alfred G. (J 1933), Secy., Reinke Machinery & Tool Co., 63 Dickerson St., RIGBY, Robert A. (A 1937), Sales Engr., Air Conditioning, and (for mail), 3325 North 48th Ave., Omaha, Nebr. RILEY, Robert C. (J 1936; 5 1934), Testing Engr.. Leviton Mfg. Co., 236 Green Point Ave., Brooklyn, and (for mail), 8S37-179th St., Jamaica. N. Y. . RIST, Lawrence M. (J 1937), Sales Engr. (for mail). Sidles Co., Airtemp Div., 502 South 19th St., and 3326 Harney, Omaha, Nebr. RITCHIE, A. Gordon (Af 1933); Pres, and Mgr. Newark, and (for mail), 321 Park Place, Irving (for mail), John Ritchie, Ltd., 102 Adelaide St., ton, N. J. E., and 41 Garfield Ave., Toronto, Canada. REINKE, Louis F. (A 1937), Owner (for mail). RITCHIE, Edmund J. (Af 1923), Vice-Pres., Reinke Sheet Metal Works, 534 S. Fifth St., and Sales, Sarco Co., Inc., 183 Madison Ave., New 1535 W. Walker St., Milwaukee, Wis. York, and (for mail), 2 Grace Court, Brooklyn, REINOLDI, Charles (J 1937), Cadet Gas Engr. N. Y. Washington Gas Light Co., 411 Tenth St., RITCHIE, William (Af 1909), 17 Van Rdpen Washington, D. C., and (for mail), 3965 Wilsby Ave., Jersey City, N. J. Ave., Baltimore, Md. RENOUF, E. Prince (Af 1933), Air Cond. Supv.. Westinghouse Electric & Mfg. Co., 1007 In surance Bldg., and 3431 Rankin, Dallas, Texas. RENTE, Harry W. (Af 1931), Owner, Oil Burner Engr. and Contractor, 114 Morris Ave., Buffalo, N. Y. . REPKO, Joseph J. (J 1936; 5 1934). 4924 Hamm Ave., Cleveland. Ohio. RESS, Otto J. (.J 1937), Gas Htg. Engr., Iowa- Nebraska Light & Power Co., 1401 "O" SL, and RITT, Chester F. (A 1936), Mgr., Air Cond. Div., Columbia Specialty Co., Inc., 1636 Connecticut . Ave., N.W., and (for mail), 2407-15th St., N.W., Washington, D. C. RITTER, Arthur (Af 1911), Dist. Mgr. (for mail), American Blower Corp., 50 West 40th St., New York, and 29 Edgemont Rd., Scarsdale, N. Y. RIVARD, Melvin M. (Af 1935), Mgr., Rivard Sales Co., 4550 Main St., and (for mail). 1805 West 49th Terrace, Kansas City, Mo. (for mail), 1909 South 17th, Lincoln, Nebr. ROBB, Joseph E. (A .1936), Sales Engr., Gas Div. RETTEW. Harvey F. (Af 1929), Chief Engr., (for mail), Minneapolis-Honeywell Regulator -Board of Education, 21st and Parkway, and (for . Co., 215 Pershing Rd., Kansas City, Mo., and mail), 6821 Martins Mill Rd., Philadelphia, Pa.' 6020 Maple Ave., Overland Park, Kans. ROBERTS. Henry L. (Af 1916), Htg. Engr. and Contractor (for mail), 228 North 16th St., Philadelphia, and 1014 Ailston Rd., Brookline, Del. Co.. Pa. ROBERTS, Henry P. (A 1936), Secy, (for mail). Roberts-Hamilton Co., 713 S. Third SL, and 1901 James Ave., S., Minneapolis, Minn. ROBERTS, James R. (A 1937; J 1934), Engrg. Mgr. (for mail), Sutherland Air Conditioning Corp., 15 N. Eighth SL, and 5705-llth Ave., S., Minneapolis, Minn. ROBERTSON, James A. M. (A 1936), VicePres. (for mail). James Robertson Co., Ltd., 946 William St., Montreal, and 109 Sunnyside Ave., Westmount, Que., Canada. ROBINSON, Arthur S. (Af 1936). E. I. duPont de Nemours Co., Wilmington, Del., and (for mail), 730 Ogden Ave., Swarthmore, Pa. ROBINSON, Donald M. (A 1936). Sales Engr. (for mail). Buffalo Forge Co.. 820 Woodward Bldg.. Washington, D. C,, and 16 Cedar SL. HyattsviUe, Md. ROBINSON. George L. (A 1935), Draftsman and Designer, E. I. duPont de Nemours (for mail), 210 West 28th St., Apt. 1, Wilmington, Del. ROBINSON, Jack A. (J 1936), Air Cond. Engr. (for mail). Australian Gas Light Co., Parker SL, Syndey, and 10 Manson Rd.. Strathfield. N.S.W., Australia. ROCHE, Ivor F. (A 1936), Mgr. (for mail), Fess Oil Burners of Canada. Ltd., 1405 Drummond SL, Montreal, Que., Canada. ROCK. George A. (Af 1937), Partner, Forbes & Co., 216 Southwest 12th Ave., and (for mail), 336 Southwest 13th Ave., Miami. Fla. ROCKWELL, Theodore F. (Af 1933; J 1932), Instructor in Htg. and Vtg. (for mail), Carnegie Institute of Technology, Pittsburgh, and 313 Sixth St.. Aspinwall, Pa. RODEE, E. John (Af 1936), Engr. (for mail), John B. Pierce Foundation, 290 Congress Ave., New Haven, and 130 Bellevue Ave., West Haven, Conn. RODENHEISER, George B. (Af 1933), Head Htg. and Air Cond. DepL (for mail), David Ranken, Jr., School of Mechanical Trades, 4431 . Finney Ave., and 3639a Dover Place, St. Louis, RODGERS, Frederick A. (A 1934), Branch Mgr., Minneapolis-Honeywell Regulator Co., 3817 Hastings St., El Paso, Texas. RODGERS, F. Edwin (J 1937), Installation Mgr. (for mail), Rodgers Plumbing & Electric Supply - Co., 651 Broadway,'McKees Rocks. Pa. RODGERS. Joseph S. (A 1937; J 1934), Engr. Draftsman, U. S. Government, Edgewood Arsenal, Edgewood, and (for mail), 1 Third Ave., Brooklyn Park, Md. RODGERS, William C. (/ 1936; 5 1935), 400 Morewood Ave., Pittsburgh, Pa. RODMAN, Robert W. (Af 1922), Supt. of Plant Operation (for mall), Board of Education, City of New York, 500 Park Ave., and 175 West 73rd St., New York. N. Y. ' ROEBUCK, William, Jr. (Af 1917), Mfrs. Agent (for mail), 220 Delaware Ave., and 154 Sanders Rd., Buffalo. N. Y. ROGERS, Robert C. (A 1937). House Htg. Engr., Community Natural Gas Co., and (for mail), 600 East 24th St., Bryan, Texas.'' ROHLIN, Karl W. (Af 1930). Engr. (for mail), Warren Webster & Co., 17th and Federal Sts., Camden, and `4453 Terrace Ave., Merchantvflle, . N. J. HOLLAND, S. L, (A 1934), Design Engr. (for mail), Oklahoma Gas & Electric Co., 321 N. Harvey Ave., and 2131 Northwest 20th St., . Oklahoma City, Okla. RONSICK, Edward H. (Af 1937), Industrial Gas Engr. (for mail). The St. Louis County Gas Co., 231W. Lockwood Ave., Webster Groves, and 7615 Marion Court, Maplewood, Mo. ROOS, Erik B. J. {J 1935), 405 N. Union Ave., Cranford, N. J. ROOT. Edwin B. (Af 1936), Mgr. Htg. and Air Cond. Dept., Nelson Co., 2604 Fourth Ave., Detroit, and (for mail), 964 Pierce St., Birming ham, Mich. ROSE, Arnold A. (A 1935), Sales Mgr. and Sect., (for mail). Suburban Air Conditioning Corp., 7 Depot Plaza and Briar View Manor ApL. White Plains, N. Y. * ROSE, Harold J. (Af 1937), Sr. Industrial Fellow (for maill. Anthracite Fellowship, Mellon Insti tute, 4400 Fifth Ave., and 219 Lytton Ave., Pittsburgh, Pa. ROSE. Howard J. (Af 1934). Sales Engr., Fltz- gibbons Boiler Co.; Inc., 32 Depot Plaza. White Plains, and (for mail), 100 Siebrecht Place, New Rochelle, N. Y. ROSE. Jerome C. (Af 1937). Air Cond. Engr., Buensod-Stacey Air Conditioning, Inc., 60 East 42nd St., New York, and ((or mail), 8831 FL Hamilton Parkway, Brooklyn, N. Y. ROSEBROUGH, J. Stoddard (A 1937). Sales Engr. (for mail), L. J. Mueller Furnace Co., 4246 Forest Park Blvd., and 5917 Washington Ave., SL Louis, Mo. ROSEBROUGH, Robert M. (Af 1920). Branch Mgr. (for mail), L. J. Mueller Furance Co.. 4246 Forest Park Blvd., St. Louis, and 204 S. Maple Ave., Webster Groves, Mo. - ROSELL. Axel F. (Af 1935), Mech. Engr., A. B. Svenska Flaktfabriken, Kingsgatan 8. Stockholm, and (for mail), Kv. Atlas 3, Lidingo I, Sweden. ROSENBACH, Rudolph F. (Af 1937), Chief Engr. (for mail). Sidles Co., Airtemp Div., 425 Stuart Bldg., Lincoln, Nebr. ROSENBERG, Philip (A 1928), Secy.-Treas.. Universal Fixture Corp.. 137 West 23rd St., and (for mail), 250 West 104th St.. New York, N. Y. ROSENBURG. William E. (J 1935). Plbg.-Htg., John C. Rosenburg. Birch Hill Rd., Locust Valley. L. L. N. Y. ROSENTHAL, Emanuel (5 1937), Student, New York University (for mail), 1893 Vyse Ave.. New York, N. Y. ROSS, John D. (A 1937), Sales (for mail). Railway and Engineering Specialties. Ltd., 637 Craig SL, W., and 4376 Earnscliff Ave., Montreal. P. Q., Canada. ROSS, John O.* (Af 1920), Pres., Ross Industries Corp., 350 Madison Ave., New York, N. Y. ROSS, Roderick (Af 1937), Consulting Engr. (for mail), Nicholas Bldg., 37 Swanston St., Mel bourne. C. 1., P. O. Box 1381 M., and 5 Burns SL, Elwood. Melbourne, S. 3, Australia. ROTH, Charles F. (A 1930), Pres.. International Exposition Co., Grand Central Palace, and (for mail), 141 East 36th St., New York, N Y. ROTH, Harold R. (M 1935), Mgr., Toronto Office (for mail), Canadian Sirocco Co., Ltd., 57 Bloor St., W.t and 18 Tichester Rd., Toronto, Ont., Canada. ROTHMANN, S. C, (Af 1936), Industrial Hygiene Engr. (for mail),' West Virginia Workmen's Compensation Commission, State Capitol -Bldg., and 1586 Lee St.. Charleston. W Va. ROTTMAYER, Samuel I. (A 1933; J 1928), Mech. Engr. (for mail), Samuel R. Lewis, 407 S. Dearborn St., Chicago, and 625 Duane St.. Glen Ellyn, 111. ROWE, Irving E. (A 1936), Engr. and Estimator, Etie Sheet Metal Works, 1416 Summer St., and (for maill, 512 Bishop St., Houston, Texas. ROWE, William A.* (Af 1921). (Council. 1929 1931), Mech. Engr. (tor mail). The Trane Co., LaCrosse. Wis., and 718 Longfellow Ave., Detroit, Mich. ROWE, William M. (/ 1936), Sales Engr. (for mail), American Blower Corp., 1302 Swetland ' Bldg.. Cleveland, and Bentleyville Rd., Chagrin Falls. Ohio. ROWLEY, Frank B* (Af 1918), (Presidential Member), (Pres., 1932; 1st Vice-Pres., 1931; 2nd Vice-Pres.. 1930; Council, 1927-1933). Prof, of Mech. Engrg. and Director of Experimental Engrg; Lab., University of Minnesota, and (for mail), 4801 E. Lake Harriet Blvd., Minneapolis, Minn. 48 49 Heating Ventilating Air Conditioning Guide 1938 ROY, Arthur C. (A 1937), Metropolitan Sales Mgr. (for mail), Hoffman Specialty Co., Inc., 600 Fifth Ave., New York. N. Y., and Box 607, Columbia Rd., Morristown, N. J. ROY, Leo (A 1937), Power Sales Engr. (for mail), Quebec Power Co., Quebec Power Bldg., and 41 Laurentide Ave., Quebec, Que., Canada. ROYER, Earl B. (Af 1928), Designing Engr., Fosdick & Hilmer, Consulting Engrs., 1703 Union Trust Bidg., and (for mail). 6635 Iris Ave., . Cincinnati, Ohio. RUDD, Dann J. (Af 1937), Mech. Designer, New YoTk World's Fair 1939, Inc., Administration SAITO, Shozo (Af 1923), Saito Shozo Shoten, Ltd. (for mail), Marunouchi Bldg.. Tokyo. Japan. SALINGER, Robert J. (7 1937), 909 Bankers Mortgage Bldg., Houston, Texas. ' SALTER, Ernest M. (Af 1936). Engr. (for mail). Electrical Testing Laboratories, 80th St. and East End Ave., New York, and 182 Cleveland Ave., Great Kills, S. L, N. Y. SALZER, Alfred R., Jr." (S 1936), Box 7255, Oakland Station, Pittsburgh, Pa., and (for mail), 2322 N. Villere St., New Orleans, La. SALLANDER, H. A. (A 1937), Branch Mgr., Sidles Co., Airtemp Div., and (for mail), 4514 Bldg., Flushing, and (for mail), 367 Deer Park Ave., Babylon, L. I., N. Y. ' RUDIO, H. M. (M 1921), Regional Engr., Air- temp Sales Corp., 631 Investment Bldg., VVash- - ington, D. C., and (for mail). 2704 N. Lexington St., Arlington, Va. RUFF, Adolph G. (Af 1935), Supt. of Power, U. S. Playing Card Co., Park Ave., Norwood, and (for mail). 3824 Woodford Rd., Cincinnati, Ohio. RUFF, DeWitt C. (Af 1922), Healy-Ruff Co.. 765 Hampden Ave.. St, Paul. Minn. RUGART, Karl (A 1924), DisL Repr. (for mail). Warren Webster & Co., 26 South 20th St., Philadelphia, and 612 Bryn Mawr Ave., Penn Valley, Narberth Post Office, Pa. RUGGLES, Robert F. (Af 1936; A 1927; 7 1926), Dist. Mgr., Autovent Fan & Blower Co., 2 Rector St., New York, and (for mail), 15 Gregg ' Fontenelle Blvd., Omaha, Nebr. SAMUELS, Sidney (A 1928; J 1925), Pres, (for mail), Sidney Samuels, Inc., 146 West 99th St., and 825 West End Ave., New York, N. Y. SANBERN, E. Nute* (Af 1923). Engr., Hoffman . Specialty Co., 500 Fifth Ave., New York, and ' (for mail), 317 Windsor'Ave., Rockville Centre, L. I,, N. y: .. - SANDS, Clive C. (Af 1929). G. P. O. Box 601 F. F., Sydney, N.S.W., Australia. - SANFORD, Arthur L. (Af 1915), Mech. Engr., C. H. Johnston, Archt.,360 Robert St., and (for mail), 1671 Marshall Ave., St. Paul, Minn. ' . SANFORD, Sterling S.* (Af 1930), Sales Engr. (for mail), Detroit Edison Co., 2000 Second Ave., and 1503 Seybum Ave., Detroit, Mich. SAPP, Charles L. (A 1936), Sales Mgr., Farquhar Furnace. Co., and (for mail), 620 N. Walnut St., Place, Randall Manor, S. I., N. Y. RUMMEL, Adolph J. (Af 1937), Air Cond. Engr. Wilmington, Ohio. SAUNDERS, Laurence P. (Af 1933), Chief-Engr., (for mail). San Antonio Public Service Co., 201 N. St. Marys St., and 319 Thorman Place, San Antonio, Texas.' RUNKEL, Charles (Af 1935), Pres, (for mail). Acme Heating & Ventilating' Co., Inc., 4224 S. Lowe Ave., and 7921 S. Hermitage Ave., Chicago, 111. RUPLE, Paul E. (A 1936), Chief Engr.. Man hattan Mfg. Co... 210 S. Lexington Ave., and (for mall), 170 Grand St., White Plains, N. Y. RUSSELL, Edward A. (Af 1936), Chief Engr.. Vapor Car Heating Co., Inc., 1600 S. Kilboum Ave., and (for mail), 8103 Dorchester Ave., Harrison Radiator Corp., Lockport, N. Y. SAWDON, Will M.* (Af 1920). Prof., Experi mental Engrg. (for mail), Cornell University, Col * lege of Engrg., and 1018 E. State St., Ithaca, N. Y. SAWHILL, R. V. (A 1929), Exec. Vice-Pres, (for mail). Domestic Engineering Co., 110 East 42nd St., New York, and 115 Townsend Ave., Pelham Manor, N. Y. SAWYER, J. Neal (7 1933), Engr., Gustin-Bacon Mfg. Co., 1412 West 12th St., Kansas City, Mo. SCANLON, Edward S. (A 1934). Utilization- Engr.. Equitable Gas Co., 427 Liberty Ave., and (for mail), 35 W. Francis Ave.,' Brentwood, Chicago, 111. . RUSSELL, J. Nelson (Life Member; Af 1899), Managing Dir. (for mail), Rosser & Russell, Pittsburgh, Pa. SCARLETT, William J. (Af 1936). Dist. Repr, (for mail). Carrier Corp., 6017 Walnut St-, Ltd., Romney House, Marsham St., Westminster, and Fernacres Fulmer near Slough, Buckingham shire, England. RUSSELL, Wayne B. (A 1936). Engr., Russell Furnace Co., 601 N. Monroe, and (for mail), 1203 S. Cedar, Spokane, Wash. RUSSELL, William A. (Af 1921), (Council, 1934 1937), Capitolaire Div. (for mail), U. S. Radiator Corp.. 1056 Natl. Bank Bldg., Detroit, Mich., and 628 West 57th Terrace, Kansas City, Mo. RYAN, Harry J. (Af 1922), Branch Mgr. (for ` mail), Trane Co., 47 Harris Ave., Albany, N. Y. RYAN, James D. (Af 1935), Supt. and Engr., Whitney National Bank, St. Charles and Gravier St., and (for mail), 215 N. Rendon St., New Orleans, La. . RYAN, William F. (7 1933). Engr., 310 W. Kansas City, Mo. SCHAD, Clifford A. (A 1938; J 1937), Engr., United States Air Conditioning Corp., 2101 N.E. Kennedy St., and (for mail), 914 Fulton St., S.E.i Minneapolis. Minn.: .` ' SCHAFER, Harry C. (Af 1937), Sales Mgr. (for . mail), Iroquois Gas Corp., 45 Church St., Buffalo, and 197 Union St., Hamburg, N. Y. ' SCHECHTER, Jack E. (J 1937). Sales Engr.\ York Ice Machinery Co., and (for mail), 1720* N. Orange Grove Ave., Los Angeles, Calif. SCHECHTER, John P, (J 1935), Engr., House . Htg. Dept., Detroit City Gas Co., 415 Clifford, . and (for mail),T812 Bums Ave., Detroit, Mich. SCHEIDECKER, Daniel B. (A 1919). Secy, (for mail), Hunter-Clark Ventilating System Co., 2800 Cottage Grove Ave., and 4626 N. Kilbourn Republic, Salina, Kan. '. RYDELL, Carl A, (Af 1931; J 1928), Owner, ,C. A. Rydell Associates (for mail), 14 Chambria St., Boston, and 286 Quinobequin Rd., Waban, Mass. ' RYERSON, Herbert E. (Af 1937), Mgr., Air Cond. Sales (for mail), Bryant Air Conditioning Con>., 122 S. Michigan Ave., Chicago, and 813 Ave., Chicago, 111. * SCHERMER, Richard (J 1938; 5 1936), Sales Engr., American Radiator Co., 40 West 40th St., New York, and (for mail), 40-67 Hampton St., Elmhurst, L. I., N. Y, SCHERNBECK, Fred H. (A 1930). Salesman (for . mail). William Bros. Boiler & Mfg.'Co., Nicollet Island, and 5045 Portland Ave., Minneapolis, S. Clinton, Oak Park, 111. ' Minn. SCHERRER, Kenneth C. (J 1936), Engr. Natkin & Co., 114 E. Third, and (for mail); 12 East 12th SL, Tulsa, Okla. . * SABIN, Edward R. (Af.1919), Pres., Edward R. Sabin Co., 4710-12 Market St., Philadelphia,' Pa. SADLER, C. Boone (Af 1928), Associate Civil - Engr. (for mail). Public Works Office. 11th Naval ,, District,, and 2223 Soto St., San Diego, Calif. SAHLMANN, Frank L. (A 1937), Transportation Dept, (for mail),General Electric, East Lake Rd., and 3926 Beech Ave., Erie, Pa. SCHERRER, Leon B: (J 1936), Dist. Engr.. Reynolds Corp., 19 Rector St., New York, N. Y., and (for mail), 6112 Simpsbn Terrace, St. Louis, Mo. SCHICK. Karl W. (A 1934), Dist. Mgr., Minae- apolis-Honeywell Regulator Co., B. M. A. Bldg., and (for mall), 209 East 72nd Terrace, Kansas City, Mo.. '. ' 50 Roll of Membership SCHLEMMER, Byron G. (J 1938; 5 1937), Engr. (for mail), Johnson Service Co., 300 Bond Bldg., Washington, D. C., and 162 Manchester Ave., Wabash, Ind. SCHLICHTING, Walter G. (M 1932), Mgr., Mr Cond- Dept., Clarage Fan Co., North and Porter Sts., and (for mail). 1417 W. Lovell St., Kala mazoo, Mich. SCHMIDT, Harry (Af 1937). Air Cond- Engr., Fedders Manufacturing Co., 57 Tonawanda St., and (for mail), 233 Norwalk Ave., Buffalo. N. Y. SCHMIDT, Horace I. (J 1937). Branch Mgr. (for mail), Fedders Manufacturing Co., Inc., 209 S. Pearl St., and 2615 Laclede St., Dallas, Texas. SCHMIDT, Karl, Jr. (J 1937), House Htg. Engr., Detroit City Gas Co., 415 Clifford, and (for mail), 18055 Schoenherr Rd., Detroit, Mich. SCHMUTZ, Jean (Af 1933), Administrateur- Delegue. Societe P. R. S. M.. 8, Passage de I*Atlas, and (for mail), 18, rue Dufrenoy, Paris 16$, France. SCHNEIDER, Charles H. (7 1937). Sales Engr. (for mail), Ilg Electric Ventilating Co.. 1031 Commercial Trust Bldg., Philadelphia, Pa., and 222 Second Ave., Haddon Heights, N. J. SCHOENIJAHN, Robert P. (Af 1919). Consulting . Engr. (for mail), 304-5 Industrial Trust Bldg., and 719 Nottingham Rd., Wilmington. Del. SCHOEPFLIN, Paul H. (Af 1920), Pres, (for mail), Niagara Blower Co., 6 East 45th St., New York, and 91 Valley Rd.,' Larchmont, N. Y. SCHOLL, Howard O. (J 1938; 5 1937). Asst. Engr. for Residence Htg., American Foundry & Furnace Co., Washington and McClun St., and ' (for mail), 505 E. Washington St., Bloomington, 1U. ' - SCHREIBER, Herbert W. (A 1937), Sales (for mail),' Johnson Service Co., 507 E. Michigan St., and 3136 N. Eighth St,, Milwaukee, Wis. SCHUCANY, Oscar W. (J 1936; $ 1935), 4927 Columbia Ave., Dallas, Texas. SCHUETZ, Clyde C. (A 1936), Research Engr., U. S. Gypsum Co., 1253 Diversey Parkway, and (for mail), 3425 N. Avers Ave., Chicago, 111. SCHULEIN, Ernst H. (7 1937), Consulting Engr., Birch & Krogboe, Vester farimagsgde 31, Copenhagen K. Denmark, and (for mail), 245 Puritan Ave., Forest Hills, L. I.. N. Y. SCHULER, William B. (A 1937), Sales, Taco Heaters, Inc., 342 Madison Ave., New York, ' N111.. Y.,and (for mail), 1536 East 69th St., Chicago, SCHULTZ, Albert W. (Af 1936), Engr. (for mail), Grinnell Co., Inc., 240 Seventh Ave., S., and 5204 France Ave., S:, Minneapolis, Minn. SCHULZ, Edward L. (J 1937), Engr., Carrier Corp., S. Geddes St., and (lor mail), 600 James St., Syracuse, N. Y. SCHULZ, Howard I. (A 1915), Crane Co., 1223 W. Broad-St., Richmond, Va. . SCHULZE, Benedict H: (Af 1921), Eastern Sales .Mgr. (for mail), Kewanee Boiler Corp., 37 West 39th St., and 67 Park Ave., New York, N. Y. SCHURMAN, John A., Jr. (Af 1936; J 1935), Regional Air Cond. Div. Mgr. (for mail), York Ice Machinery Corp., 2700 Washington Ave., N.W., Cleveland, and 14503 Delaware Ave., Lakewood, Ohio. - SCHWANTES, Arno R. (7 1935), Factory Sales and Service Engr. (for mail). Waterman-Waterbury Co., 1121 Jackson, N.E., Minneapolis, and 1416 Arona, St. Paul, Minn. SCHWARTZ,'Harold (S 1936), 3450 Ainslie St.. Chicago. 111. SCHWARTZ, Jacob (A 1936; J 1929), Contractor (for mail), Samuel Schwartz & Son, Inc., 30 West 27th St., Bayonne, and 12 Van Houten Ave., Jersey City, N. J. SCHWEIM, Henry J. (Af 1928), Secy, and Chief . Engr. (for mail). Gypsum Association. 211 W. Wacker Drive, and 1637 Estes Ave., Chicago, III. SCOFIELD, Paul C. (A 1937; J 1933), Erigr. (for mail). Carrier Corp., 748 E. Washington Blvd., and 3879 Edenhurst Ave., Los Angeles, Calif. SCOTT, Allison F. H. (Af 1937), Asst, to Pres, (for mail), Anthracite Industries, Inc., Chrysler Bldg., and Hotel Tudor, 304 East 42nd SL, New York. N. Y. SCOTT, George M. (Af 1915), Pres, (for mail). Child & Scott-Donohue. Inc., 153 East 38th St., New York, and 654 King St., Port Chester, N.Y. SCRIBNER, Eugene D. (A 1933; 7 1929), Service Mgr., Quinn Engineering Corp., 151 East 50th St., New York, N. Y., and (for mail), 261 Clark St., Westfield. N. J. SCUDDER, Barrett (A 1935), Vice-Pres., James P. Marsh Co., 2073 Southport Ave., Chicago, and (for mail). Washington Rd., Lake Forest, 111. SEARLE, William J., Jr. (Af 1937). Air Cond. Engr., The Ballinger Co., 1Q5 South 12th St., Philadelphia, and (for mail), 207 Maple Ave., Narberth, Pa. ' SEEBER, Rex R.* (Af 1934). Head-Mecb. Engrg. Dept., Michigan College of Mining and Tech nology. Houghton, Mich. SEELBACH, Herman (Af 1931), Pres, (for mail). Equipment Sales, Inc., 800 Erie County Bank Bldg., Buffalo, and 31 Central Ave., Hamburg, N. Y. SEELBACH, Herman, Jr. (A 1937). Sales Engr. (for mail), Minneapolis-Honeywell Regulator Co., 45 Allen SL. and 280 Crescent Ave., Buffalo, N. Y. SEELERT, Edward H. (A 1935), Secy.-Treaa. (for mail), McQuay, Inc., 1600 Broadway, N.E., and 2927 Ulysses SL, N.E., Minneapolis,' Minn. SEELEY. Lauren E* (Af 1930), Asst. Prof. Mech. Engrg. (for mail). Mason Laboratory, Yale University, and 130 Event SL, New Haven, Conn. ' .-' SEEL1G, Alfred E. (Af 1926), Pres, and Gen. Mgr.. L. J. Wing Mfg. Co., 154 West 14th SL. and (for mail), 310 Convent Ave., New York, N. Y. SEELIG, Lester (Af 1925), Chief. Engrg. Dept.. Museum of Science and Industry, Jackson Park, and (for mail), 725 Irving Park Blvd:, Chicago, III. SEELY, Irving R. (7 1936; S 1935), General Electric Co., and (for mail). 1059 Wendell Ave.( Schenectady, N. Y. SEIDEL, Glenn E. (7 1937; S 1936), Tulane' University, and (for mail). 1437 Audubon SL,' New Orleans, La. . SEITER, J. Earl* (Af 1928), Asst. Mgr., New Business Dept., Consolidated Gas Electric Light & Power Co., and (for mail), 7117 Bristol Rd., Baltimore, Md. SEKIDO, Kunisuke (Af 1903), Consulting Engr., 685 Marunouchi Bldg., and' (for mail), 19 Momo^ono, Nakano,-Tokyo, Japan. SELIG, Ernest T., Jr. (Af 1936). Industrial Fellow (for mail). Mellon Institute of Industrial Research, 4400 Fifth Ave., and' 6622 North umberland SL, Pittsburgh, Pa. SELLMAN, Nils T. (Af 1922), AssL Vice-Pres. (for mail), Consolidated Edison Co. of New York, 4 Irving Place, New York, and 56 Wal worth Ave., Scarsdale, N. Y. SENIOR, Richard L. (Af 1925), Pres, (for mail). R. L. Senior. Inc., 103 Park Ave., New York, and 10 Cherry Ave., New Rochelle, N. Y. SENNET, Lowell E. (7 1936; S 1934). Sales Engr., Crane Co., 6215 Carnegie Ave., Cleveland, and (for mail), 1684 East 133rd SL, E. Cleveland. - Ohio. SETTELMEYER, James T- (7 1937), Air Cond. Engr., Blocker Air Conditioning Corp., 825 Frelinghuysen Ave., Newark, and (for .mail), 293 N. Oraton Pkwy., East Orange, N. J. SEVERNS, William H.* (Af 1933), Prof. Mech. Engrg. (for mail). University of Illinois, and 609 Indiana Ave., Urbana, 111. - SEYMOUR. James E. (A 1937), Partner and Mgr., Lee & Seymour, 346 Russell SL, and (for mail), 1438 Rutledge St., Madison, Wis. SHAER, I. Ernest (A 1934), Treas., Sales Engr., : Capitol Engineering Co., Potter and Binney Sts., Cambridge, and (for mail), 35 Fessenden SL, Dorchester, Mass. ' 51 Heating Ventilating Air Conditioning Guide 1938 SHAFFER, Chester E. (Af 1937). Research Engr.. Koppers Co., Kearny, N. J., and (for mail), 11 Waverly Place, New York, N. Y. SHANKLIN, Arthur P. (Af.1929), Sales Engr. (for mail). Carrier Corp., 12 South 12th St., Phila delphia. and 40 Amherst Ave., Swarthmore, Pa. SHANKLIN, John A. (Af 1928), Secy.-Treas. (for mail). West Virginia Heating & Plumbing Co., 233 Hale St., and 1507 Quarrier St., Charleston, W. Va. SHAPIRO, Maurice M. (7 1937), Branch Engr., Sidles Co., Airtemp Div., 425 Stuart Bldg., and (for mail), 2145 "N" St., Lincoln, Nebr. SHARP, Henry C. (Af 1935), In Charge of Application Engineering, Automatic Heat and Air Cond. Div. (for mail), Herman Nelson Corp., and 1204-24th Ave., Moline, 111. SHARP, John R. (A 1937), Supervisor, Htg. and Air-Cond. Reprs., Public Service Electric & Gas Co., 235 Main St., Hackensack, and (for mail). Maple St., Haworth, N. J. SHAVER, Herbert H. (A 1929), Asst. Gen. Sales Agt. (for mail), Hudson Coal Co., 424 Wyoming Ave., and 1208 Vine St., Scranton, Pa. SHAW, Burton E.* (A 1936; 7 1934), Research Chief (for mat}), Penn Electric Switch Co., Goshen, and The Maples, Bristol. Ind. SHAW, Charles G. (A 1936). Engr. and Prop.. Shaw Engineering Co., Port Arthur, Texas. SHAW, Norman J. H. (Af 1927; 7 1925), Barnes 8c Jones, Inc., 128 Brookside Ave.. Jamaica . Plain, and (for mail), 37 Benjamin Rd., Arling ton. Mass. SHAWLIN, Walter C. (A 1931), Mgr., Industrial Air Cond. (for mail), Northwestern Ventilation Co., 2540 W. Wells St., Milwaukee, Wis. SHEA, Michael B. (Af 1921), Sales Dept, (for mail). American Radiator Co., 8019 Jos Campau, and 4366 Tyler Ave., Detroit, Mich. SHEARS, Matthew W. (Af 1922), Engr. (for mail), C. A. Dunham Co., Ltd., 1523 Davenport Rd., and 39 Sylvan Ave., Toronto, Canada. SHEFFIELD, Raymond A. (Af 1937). Prop, (for mail). Air Conditioning Engineering Co., 61 N Rogers St., Cambridge, and 84 Governor Win- throp Ave., Somerville, Mass. SHEFFLER, Morris (Af 1921), Pres, (for mail), Sheffier-Gross Co., 1000 Drexel Bldg., Phila delphia, and 419 Chapel Rd., Melrose Park, . Montgomery Co., Pa. - SHELDON, Nelson E. (Af 1927), DisL Sales Mgr. (for mail), Carrier Corp,, S. Geddes St., Syracuse, and 41 Lanark Crescent, Rochester, N. Y. SHELDON, William D,, Jr. (A 1936; 7 1934), Chief Engr., Sheldon's, Ltd., and (for mail). Cedar St.. Galt, Ont., Canada. SHELEY, Earl D. (Af 1937), Pres, (for mail). Plumbing, Heating, Ventilating Contractors, 1761 W. Forest Ave., Detroit, and R. R. No. 1, Birmingham, Mich. SHELNEY, Thomas (Af 1931), Pres, (for mail). Pierce Blower Corp., 100 Rhode Island St., Buffalo, and Grand Island, N. Y. SHENK, Donald H. (Af 1934). Assoc. Prof. Mech. Engrg. (for mail), Clemson Agricultural College, and 106 Calhoun Circle, Clemson, S. C. SHEPARD, John deB. (Af 1937; 7 1929). Air Cond. Repr. (for mail). Consolidated Gas Electric Light & Power Co., 406 Lexington Bldg., and Tudor Arms Apts., W. University Parkway, Baltimore, Md. SHEPHERD, Clark B. (Af 1937). Chemical Engr. (for mail), E. 1. duPont de Nemours & Co., SHERET, Andrew (Af 1929; A 1925), Pres, (for mail), Andrew Sheret, Ltd., 1114 Bianshard St., and 1030 SL Charles St., Victoria, B. C., Canada. SHERMAN, Ralph A.* (Af 1933). Supervisor, Fuels Div. (for mail), BatteDe Memorial Insti tute, 505 King Ave., and 1893 Coventry Rd., Columbus. Ohio. SHERMAN, Victor L. (Af 1935), Acting Head, ' Dept. Mech. Engrg., Lewis Institute, 1951 W. Madison St., Chicago, and (for mail),' 643 Hillside Ave., Glen Ellyn, 111. SHERMAN, W. P. (if 1937), Commercial Div. Engr., York Ice Machinery Corp., Southeastern Div., 412 Houston St., N.E., Atlanta, and (for mail), 208 Michigan Ave., Decatur, Ga. SHERWOOD, Laurence T. (Af 1937), Glass Technologist (for mail), Penna. Wire Glass Co., Dunbar, and 11 Angle St., Connellsville, Pa. SHIELDS. Carl D. (7 1937; 5 1936), 213 Crescent Drive, Akron, Ohio. SHILLING, Howard C. (A 1936), Salesman (for mail), Barber-Colman Co.. 221 N. LaSalle St., and 7068 N. Paulina St., Chicago, 111. SHIRLEY, William B. (Af 1937), Dist. Mgr., Lennox Furnace Co., Inc., Syracuse, N. Y., and (for mail), Mayfair Hotel, Charlotte, N. C. SHIVERS, Paul F. (Af 1930), Chief Engr., Research Div. (for mail), Minneapolis-Honeywell Regulator Co., and 75 W. Maple SL, Wabash, Ind. SHODRON, John G. (Af 1921). Prof., Marquette. Univ. Engrg. School, and (for mail), 1810 W. Wisconsin Ave., Milwaukee, Wis. SHOEMAKER, Forrest F. (A 1936}. Pres, and Mgr. (for mail). Air Conditioning Co., Inc., 222 Central Bank Bldg., and 2412 East 22nd St., Tulsa, Okla. SHORB, Will A. (Af 1909), Treas. (for mail). Field & Shorb Co., 705 N. Pine St., Decatur, III. SHOTWELL, Roger W. (Af 1935), Chief Engr, Air Conditioning Appliance Co., and (for mail), 97 Franklin St., Verona, N. J. SHROCK, John H. (Af 1924), Vice-Pres. (for mail). New York Blower Co., 171 Factory St., and 1002 Indiana Ave., LaPorte, Ind. SHULTZ, Earl (A 1919), Vice-Pres. (for mail), Illinois Maintenance Co., 1136-72 W. Adams St., and Edgewater Beach Apts., Chicago, 111. SICKERT, Gene D. (J 1936), Mgr. Htg. Div., Perfex Radiator Co., 415 W. Oklahoma Ave., and (for mail), 4315 W. Lisbon Ave., Milwaukee, Wis. S1DELL, Philip A. (7 1938; 5 1937). Mech. Engr. (for mail), Fngidaire Div., General Motors Sales Corp., and 927 N. Broadway, Dayton, Ohio. S1DWELL, E. W. (A 1937), Sales Mgr., Arm strong Furnace Co., and (for mail), 306 King Ave., Columbus, Ohio. SIEBS, Claude T. (A 1927). Service Systems Engr. (for mail). Western Electric Co., Ind., 195 Broadway, New York, N. Y., and 185 Kent Place Blvd., Summit, N. J. SIEGEL, William A. (Af 1937), Field SupL, York Ice Machinery Corp., 117 South 11th SL, SL Louis, and (for mail), 3333 Cambridge, Maplewood, Mo. SIGMUND, Ralph W. (Af 1932), DisL Mgr. (for mail), B. F. Sturtevant Co., 913 Provident Bank Bldg., and 304 Oak St., Cincinnati, Ohio. SILBERSTEIN, Bernard G. (Af 1937), DisL Sales Mgr. (for mail), Ilg Electric Ventilating Co., 622 Broadway, and 814 E, Mitchell Ave., Cincin nati, Ohio. SIMISON, Allen L. (Af 1937), Research Engr., Technical Div., duPont Experimental Station, Owens-Illinois Glass Co., Owens-Illinois Lab., and 1211 Delaware Ave., Wilmington, Del. and (for mail), 166 North 21st St., Newark, Ohio. SHEPPARD, Frank A. (Af 1913), Salesman (for SIMKIN, Milton (7 1936; 5 1933), Assoc. Engr., mail), Johnson Service Co., 1031 Wyandotte St., Charles Simkin, 103 Brighton Ave., Perth and 27 East 70th St., Kansas City, Mo. SHEPPARD, William G. F. (Af 1922). Partner, ' Sheppard & Abbott, 119 Harbord SL, and (for mail), 1 Clarendon St.. Toronto, Ont.. Canada. SHERBROOKE, Walter A. (Af 1937), Mgr.. Tech. Div. (for mail), Utica Radiator Corp., 101 Park Ave., Room 518, and Hotel Shelton, Lexington Ave. at 49th St., New York, N. Y. Amboy, N. J. SIMON, Andrew (7 1937), Engr., Minneapolis- Honeywell Regulator Co., and (for mail), 2798 East 228th, Cleveland. Ohio. SIMONSON, George M. (Af 1937), Consulting Engr. (for mail), G. M. Simonson, 74 New . Montgomery SL, San Francisco, and 20 Loreta. * Ave., Piedmont, Calif. 52 Roll or Membership SIMPSON, Arthur M.* (A 1935), Chief Engr. and Sales Mgr. (for mail). Van Kannel Revolving Door Co.. 101 Park Ave., New York, and 37-34 85th St., Jackson Heights, N. Y. SIMPSON, William K. (Af 1919). Vice-Pres. (for mail), Hoffman Specialty Co., 193 Grand St., and 9 Sands St., Waterbury, Conn. SINGLETON, John H. (A 1937), Gen. Mgr. (for mail), Annas Heat & Cold, Inc., 13 N. Perry, and 66 Franklin Blvd., Pontiac, Mich. SKAGERBERG, Rutcher (Af 1924; 7 1921), Market Development Engr. (for mail). Brown Instrument Co., Wayne and Roberts St., and 211 Rockglen Rd., Penn Wynne, Philadelphia, Pa. SKIDMORE, John G. (A 1937; 7 1930), Sales Engr., Carrier Corp., 1931 Holland Ave., Utica, N. Y. SKINNER, Henry W. (Af 1920), Consulting Engr. (for mail), 4816 Dexter St., Fort Worth, Texas. SKLAREVSKI, Rimma (7 1936), Instrument Engr., Russian Div., Brown Instrument Co., Wa'yne and Roberts Aves., Philadelphia, Pa., and (for mail), 226 E. University Parkway, Baltimore, Md. SKLENARIK, Louis (A 1937; 7 1928), 305 East 72nd St., New York. N. Y. SLAYTER, Games (Af 1931), Director. In dustrial and Structural Prod. Lab., Owens- Illinois Glass Co., and (for mail), 1181 Evansdale SL, Newark, Ohio. SLEMMONS, John D. (Af 1937), Branch Mgr., American Blower Corp., Columbus, and (for mail), Rte. 2, Wilson R. D., Worthington, Ohio. SLUSS, Alfred H. (Af 1935), Prof. Mech. and Industrial Engrg., University of Kansas, and (for mail), 827 Mississippi Ave., Lawrence, Kans. SMAK, Julius R. (A 1934), Supt. of Service Depts., Crane Co., South Ave., and (for mail), 3135 Park Ave., Bridgeport, Conn. SMALL, Bartlett R. (A 1937; 7 1932), Secy., Sam E. Beck, Inc., and Mgr., Guilford Engrg. Co. (for mail), 625 Security Bank Bldg., Greens . boro, N. C. ' SMITH, D. Kennard (A 1938; 7 1937), Engr. and Estimator, H. F. Wampler, 6312 Callowhill St., and (for mail), 525 S. Conestoga St., Phila delphia. Pa. SMITH, Elmer G.* (Af 1929), Asst. Prof, of ' Physics (for mail). Agricultural and Mechanical College of Texas, College Station, Texas. , SMITH, Frank J, (A 1937; 7 1930), Engr., 1 Fernwood Place, Upper Montclair, N. J. SMITH. Gard W. (Af 1927), Sales Engr., Premier Furnace Co., Dowagiac, Mich., and (for mail), 1131 Guilford St., Huntington, Ind. SMITH, Jared A. (A 1933), Distributor (for mail), Bryant Heater Co., 626 Broadway, Cincinnati, and 3817 Indian View Ave., Mariemont, Ohio. SMITH, J. Darrell (Af 1933), Mech. Engrg. Dept., Philadelphia & Reading Coal & Iron Co., and (for mail), 317 North 19th SL, Pottsville, Pa. SMITH, Milton S. (Af 1919), Treas. (for mail), Buensod Stacey Air Conditioning, Inc., 60 East 42nd St.. New York, N. Y., and 13 N. Terrace, - Maplewood, N. J. SMITH, Reginald J. (Af 1936). Mgr.. Smith & Elston, 71 Third Ave., and (for mail), 112 S. Maple SL, Timmins, Ont.. Canada. SMITH, Robert H. (A 1937; 7 1934; 5 1933), Asst. Buyer, Sears Roebuck & Co., Chicago, and (for mail), 611 Washington Blvd., Oak Park, 111. SMITH, Stuart (A 1936). Branch Mgr. (for mail), American Radiator Co., 807 Times Star Bldg., > and 1188 Herschel Ave., Cincinnati, Ohio. SMITH, Wilbur F. (Af 1920), Consulting Engr., W. M. Anderson Co., 600 Schuylkill Ave., and (for mail). Garden Court Plaza, 47th and Pine St., Philadelphia, Pa. SMITH, William D, (Af 1937; A 1935), Pres, (for mail), Bryant-Smith, Inc., 2153 Prospect Ave.,' Cleveland, and 3265 Enderby Rd., Shaker Heights, Ohio. * SMITH, William O. (A 1937), Pres, (for mail). Smith Automatic Heat Service Co., 19250 .John R. St., Detroit, and 343 E. Maplehurst, Ferndale, Mich. SMOOT, Theo H. (Af 1935), Chief Engr., Fluid Heat Div., Anchor Post Fence Co.. Eastern Ave. and Kane St., and (for mail), 2512 Talbot Rd., Baltimore, Md. ' SMYERS, Edward C. (A 1933), Sales Engr., Barber Colman Controls, 1013 Penn Ave., Wilkinsburg. and (for mail), 148 Jamaica Ave., West View, Pittsburgh, Pa. ' SNAVELY, A. Bowman (if 1937), Chief Engr., Hershey Chocolate Corp., Hershey, Pa. SNAVELY, Earl R. (Af 1937), Gen. Mgr.. Air Cond. Dept., Nash Refrigeration Co.. Summit and New Sts.. Newark, and (for mail), 222 Victory St.. Roselle, N. J. SNELL, Ernest (Af 1920), 3914 LeMay Ave.. Detroit. Mich. SNYDER, Allen K. (A 1937; 7 1930). Application Engr., Airtemp, Inc., 1119 Leo St., and (for mail). 2122 Shroyer Rd., Dayton, Ohio. SNYDER, Jay W. (Af 1917), Member of Firm (for mail). Snyder & McLean, 2308 Penobscot Bldg., and 8987 Martindale Ave., Detroit, Mich. SNYDER, Joseph S. (A 1925), Sales Repr., Detroit Lubricator Co., 1807 Elmwood Ave., Buffalo, and (for mail), 9 Knowlton Ave., Kenmore (Buffalo), N. Y. SODEMANN, Paul (Af 1926; 7 1920). Sales Engr., ' Sodemann Heat & Power Co., 2300 Delmar Blvd-, and (for mail), 4136 Farlin Ave.. St. Louis, Mo. SODEMANN, William C. B. (Af 1919), Pres, (for mail). Sodemann Heat & Power Co., 2306 Detmar Blvd., St. Louis, and 7542 Teasdale . Ave., University City, Mo. SOETERS, Matthew (Af 1937), Consulting Engr., 5392 Seebaldt, Detroit, Mich. " SOGG, Allen (A 1937), Sales Engr., Strong, Carlisle & Hammond Co., 1392 W. Third St., Cleveland, and (for mail). 3084 E. Derbyshire Rd.. Cleveland Heights. Ohio. SOLSTAD, Lester L. (7 1936), Development Engr. (for mail), American Radiator Co., Filter Div., 1330 W. Congress, and 5132 Blackstone, Chicago, IU. SOLZMAN, Isel I. (A 1937), Owner (for mail). Paso! Engineering Co., 606H World Herald Bldg., and 4410 William SL. Omaha, Nebr. SOMMERFIELD, Sumner S. (7 1936), In structor, Refrigeration & Air Conditioning Inst.. 2150 Lawrence Ave., and (for mail), 5705 School St., Chicago, IU. SOMMERS. William. J. (Af 1937), Mfrs. Agent. 505 Delaware Ave., Buffalo, and (for mail), 150 Stillwell Ave., Kenmore. N. Y. SONNEBORN, Charles (Af 1930), R. D. No. 3, New Castle, Pa. SONNEY, Kermlt J. (7 1936; 5 1934), L. B. 136, Wilcox. Pa., and (for mail), 316 W. Symmes St., Norman, Okla. SOPER, Horace A. (Af 1916), Vice-Pres. (for mail), American Foundry & Furnace Co., and 1122 . Monroe St., Bloomington. 111. SOULE, Lawrence C.f (Af- 1908), Secy, and Consulting Engr., Aerofin Corp., 410 S. Geddes. St., Syracuse, N. Y., and (for mail). Cor. Stewart and Gordon Rds., Essex Fells, N. .J. SOUTHMAYD, Richard T. (7 1936), Salesman, American Blower Corp. (for mail), 11433 May ' held Rd., Cleveland, Ohio. SPARKS, James D. (A 1937), Northwest Repr., Ilg Electric Ventilating Co., 7331 W. Green Lake Way, Seattle', Wash. SPECKMAN, Charles H. (Af 1918), Prof. Engr., 375 Bourse Bldg., Philadelphia, Pa. SPELLER, Frank N.* (Af 1908), Director, Dept, of Metallurgy and Research (for mail). National Tube Co., Frick Bldg., and 6411 Darlington Rd., Pittsburgh. Pa. . y" Heating Ventilating Air Conditioning Guide 1938 SPENCE, Morton R. (7 1934), Asst. Purch. Agt., Runelle & Spence Mfg. Co., 445 N. Fourth St., and (for mail), 709 E. Lexington Blvd., Mil waukee, Wis. SPENCE, Robert A. (7 1937). Engr., Boston Edison Co., 39 Boylston St., Boston, and (for mail). 37 Davis Rd., Belmont, Mass. SPENCE, Robert T. (A 1935). 1556 South 60th St.. West Allis, Wis. SPENCER, Dean (A 1937), Commercial Mgr. (for mail), Brown Electric Division, Brown Supply STARK. W. Elliott* (if 1926), (Council, 1932 1937), Dist Sales Mgr., Bryant Heater Co., 17825 SL Clair Ave., Cleveland, and (for mail), 1875 Rosemont Rd., East Cleveland, Ohio. STEELE, John B. (if 1932), Chief Operating EngT., Winnipeg School Board, Ellen and William Ave., and (for mail), 184 Waterloo St., Riverheights, Winnipeg, Man., Canada.- STEELE, Maurice G. (M 1929), Tech. Advisor (for mail. Revere Copper & Brass, Inc., 1301- Wicomico St., and 4109 Roland Ave., Baltimore, Co., 120 E. Grand, and 3110. Northwest 23rd. Oklahoma City. OklaSPENCER. J. Boyd (if 1935), Owner (for mail). Spencer Cooling & Air Conditioning Co., 413 S. Md. STEENECK, Kenneth C. (J'1935), Sales Engr.. Warren Webster & Co., 95 Madison Ave., New York, and (for mail), 9410-211th SL, Beliaire, Sixth, and 2215 Newton Ave., S.`, Minneapolis, Minn. SPIELMANN, Gordon P. (A 1931: 7 1923), Vice-Pres. (for mail), Harrison-Spielmann* Co., 408 Milwaukee Ave.,' ` Chicago, and 730 N. Prospect Ave., Park Ridge. 111. SPIELMANN, Harold J. (M 1933), Air Cond. Engr., Vilter Mfg. Co., 53 W. Jackson Blvd., Chicago, and (for mail); 507 Elmore Ave., Park Ridge. Ill SP1TZLEY, Ray L. (Af 1020), 1200 W. Fort St., Detroit, Mich. SPOELSTRA, William J. (if 1935). Pres., W. J, Spoelstra Co., Inc., 154 Parker Ave., Hawthorne, N. J. SPOERR, Frank F. (7 1937). Carrier Engr., W. L. .Thompson, Inc., ,700 Commonwealth Ave., and . (for mhil), 137 Peterboro St., Boston Mass. SPOFFORTH, Walter (if 1930), Chief Mech. ' Services, U. S. Penitentiary, McNeil Island, and (for mail). 615 N. Ainsworth. Tacoma, Wash. SPROULL' Howard E. (if 1920), Div. Sales Mgr. (for mail), American ' Blower Corp., 1005-6 ' American Bldg., and 3588 Raymar Drive, Cincinnati, Ohio. `' SPURGEON, Joseph'H. (if 1924), Salesman. L. I., N. Y. STEFFNER, Edward F. (A 1937; 7 1934), Htg. and Air Cond. Engr:, Henry Furnace & Foundry Co., 3471 East 49th SL, Cleveland, and (for mail). 1427 East 133rd St., East Cleveland, Ohio. STEGGALL, Howard B. (A 1934), Branch Mgr. (for mail), U. S. Radiator Corp., 941 Behan St., N.S.. and 1166 Murray Hill Ave., Pittsburgh, Pa. STEHL, Howard V. (A 1936), Sales Engr. (for mail), Campbell Metal Window Corp-. Bush and Hamburg Sts.. Baltimore, and 5 Beacon Hill-Rd., Woodlawn, Baltimore Co., Md. STEINHORST. Theodore F, (if 1919), Pres., Emil Steinhorst & Sons, Inc., 612-16 South SL, and (for mail), 1664 Brinckerhoff Ave., Utica, N. Y. STEINKE, Bernard J. (S 1937), Htg- and Vtg. .Engr., Bernard H. Steinke & Son. 1104 East 180th St., New York, N. Y., and (for mail), 17 Westervelt Place, West Englewood, N. J. STEINKELLNER, Edward J. (J 1936; 5 1935), 2162 South 32nd St., Milwaukee, Ws. STEINMETZ, C. W. Arthur (if 1934), Branch Mgr. (for mail), American Blower Corp., 249 High St., Newark, and 50. Oakwood Ave., Bogota, N. J. STELLWAGEN, Frank G. (A 1937), Sales, Spurgeon Co. (for mail), 5-203 General Motors Bldg., and 17215 Pennington Drive. Detroit. Fitzgibbons Boiler Co., Inc., 101' Park Ave., New York, and (for mail), 8637-77th St., Wood- Mich. '' ' haven, N. Y. - . STACEY, Alfred ., Jr.* (if 1914), BuensodStacey Air Conditioning, Inc., 60 East 42nd St.,' New York, N. and (for mail), Wootton Rd., STENGEL, Frank J. (A 1935), Secy, (for mail), R. F. Stengel & Son, 76 RosehiU Place, Irvington, and 23 Russell Place, Summit, N. J. Essex Fells, N.' J. STACK, Arthur E, (A 1935), Lab. Stipv., Wash ington Gas Light Co., 411 Tenth' Si., N.W., . Washington, D. C., and (for mail), 911 Gist Ave., : Silver Spring, Md. - ' " STACY, L. David (A 1936), Sales Engr., Ilg Electric Ventilating Co., 182 N. LaSalle St., and . (for mail), 2247 Greenleaf Ave., Chicago, 111. STACY, Stanley C- (Af 1931). Mech. Engr. (for , mail). Board of Education, 13 S. Fitzhugh St., ' and'531 Wellington Ave., Rochester, N. Y. STAFFORD, Thomas D. (A 1937), Secy, and Mgr., Alexander-Stafford Corp., 313-319 Allen St.; N.W., and (for mail), 954 Ogden Ave., S.E.,' Grand Rapids, Mich. - STALE. Joseph'C. (A 1934), Mgr. Air Cond. Div.; Reynolds Corp., 19 Rector St;, New York, and (for mail), 149 Columbia Heights, Brooklyn, STEPHENSON, Lewis A. (M 1917), Mgr. (for mail), Powers Regulator Co., 409 East 13th St., and 801 West 57th St. Terrace, Kansas City, Mo. STERLING, James G., Jr. (S 1936), 1841 Wilton Rd., Cleveland Heights, Ohio. ' STERMER, Clarence J. (Af 1936), Engr., Crane - Co., 836 S. Michigan Ave., and (for mail), 7839 Clyde Ave., Chicago, 111. STERNBERG, Edwin (A 1932; J 1931), Air Cond. Engr., Armo Cooling & ventilating Co'., 30 West 15th St.', and (for mail), 315 East 68tb SL, New York, N. Y. STERNE, Cecil M: (A 1934), Chief Engr. (for mail). Metropolitan Refining Co., Inc., 23-28 50th Ave., Long Island City. N. Y. - STERNER, Douglas S. (A 1936), Sales Engr. (for ' mail), Minneapoli9-Honeywell Regulator- Co., 415 Brainard SL, and 1313 Seward Ave., Detroit, N. Y. STAMMER, Edward L. (if 1919), SupL Htg. and Vtg., Board of Education, Ninth and Locust Sts., and (for mail), 4430 Tennessee Ave., St. Louis,' Mo. . -- - STANGER, Ralph B. (if 1920), Owner (for mail), Robinson & Stanger, Empire Bldg:, Pittsburgh, and Middle Rd., Glenshaw, Pa. STANGLAND, B. F. (Charier Member),(2nd Vice- Pres-, 1908; Board of Governors. 1905-1906 1909; Board of Mgrs., 1895-1899; Coundl, 1896- 1897), Retired. Kendall, N. Y. STANNARD, James M.* (Life Member: M 1906), Pres, and Treas. '(for mail), Stannard Power Equipment Co.. 53-W. Jackson Blvd., Chicago, and 1402 Elinor Place. Evanston, 111. - STANTON, Harold W. (if 1937), Commercial Sales Dir. (for mail), Iowa-Nebraska Light & Power Co., and 2807 Washington. Lincoln, Nebr. Micb. - STETSON, Lawrence R. (Af 1913), Engr. (for mail), McMurrer Co., 303 Congress SL, and 35 Bradfield Ave., Roslindale, Boston, Mass. - STEVENS, Harry L. (M 1934; A 1927; J 1924), Secy.-Treas. (for mail), M. M. Stevens Co., 108 W. Sherman SL, and 7 West 22nd St., Hutchin son, Kans. - - * STEVENS, Kenneth M. (/1936). Sales Engr. (for mail). Powers Regulator Co., 409 East 13th SL, and 900 E. Armour, Kansas City, Mo. STEVENS, William R. (A 1934). Partner, L. E. Stevens Co., 626 Broadway, Cincinnati, Ohio, and (for mail), 159 Tremont Ave., Ft. Thomas, . Ky. ', ' . STEVENSON, Melvin J. (If 1935), Mgr., Air- temp Div., Sidles Co., 425 Stuart Bldg., and (for mail), 1643 South 20th SL, Lincoln, Nebr. 54 Roll of Membership STEVENSON, Wilbur W. (M 1928), Steam Htg- Engr. (for mail), Allegheny County Steam Heating Co., 435 Sixth Ave., and 1125 l^ncaster Ave., Pittsburgh, Pa. STEWART, Charles W. (M 1919; A 1918), Asst. Secy, (for mail). Hoffman Specialty Co.. Waterbury National Bank Bldg., and 21 Yates Ave., Waterbury, Conn. STEWART, Duncan J * (M 1936; A 1930), Mgr., Electrical Div. (f-or mail), Barber-Colman Co., P. O. Drawer 99, and R. R. No. 4, Rockford, 111. STEWART, James P. (J 1937), Engr. (for mail), 12 South 12th St., and 4709 Conshohocken Ave., Philadelphia. Pa. STIEGLER, Alvin J. (A 1937). Owner (for mail), Valley Sheet Metal Works, 315 Main SL, and 319 Monroe.St., Neenah, Wis. STILES, Gordon S. (7 1936), Sales Engr., (for mail), Airtemp Div., Sidles. Co.,-118 Tenth St., and 206 11th St.. Des Moines. Iowa. STILL, Fred R.* (Af 1904), (Presideniial Member), (Pres.. 1918; 2nd Vice-Pres., 1917; Council, 1916*1919), Vice-Pres. (for mail), American Blower Corp., 50 West 40th St., New York, and 3457-82nd St., Jackson Heights, N. Y. STILLER, Frederick W.(7 1933). Estimator (for mail). F. C. Stiller & Co., 129 S. Tenth St., and 138 West 49th St., Minneapolis, Minn. STINARD, Rurberford L. (7 1934), Engr., American Radiator Co., 40 West 40th SL, New York, N. Y., and (for mail), 1377 Boulevard East, West New York. N..J. ` . STITES, Richard, Jr. (J 1937), Sales Engr. (for mail), Coon DeVisser Co., & Buffalo Forge Co., 2051 W. LaFayette- Blvd., and 35 Edison, Detroit, Mich. ' STITT, Arthur B. (J 1935; S 1933). Mech. Engr., F. H. McGraw & Co., 51 East 42nd SL, New York. N. Y,, and (for mail), 22 -Bundy Apts., Middletown, Ohio. ' STOCK, Charles S. (Af 1936), DisLRepr., Herman Nelson Corp., Room 404, 1108-16th St., N.W., Washington, D. C., and (for mail), 6752 Fairfax Rd., Bethesda, Md. STOCKWELL, William R.. (Af 1903; J 1901). Gen. Mgr., Mfg. Div., Weil-McLain Co., Michigan City, Ind. . STROCK, Clifford (Af 1937; A 1929), Associate Editor (for mail). Heating & Ventilating, 148 Lafayette St., New York, and 82-15 Britton Ave.. Elmhurst, L. I., N. Y. .. STROUSE. Sidney B. (Af 1921), Consulting Engr. (for mail), S. B. & B. H. Strouse. 5P0-29 Guarantee Trust Bldg., and 22 S. Illinois Ave., Atlantic City, N. J. - 1 ' - STRUNIN, Jay (J 1933). Engr., and Contractor (for mail). Strunin Plumbing & -Heating Co., Inc., 408 Second Ave., and 54 West 89th St.,' New York. N. Y. STUART, Milton C* (M 1935), Prof, of Mech. Engrg. (for mail). Lehigh University, Mech. Engrg. Dept., and 505 Norway Place, Bethlehem, Pa. . STUBBS, William C. (Af 1934), Associate Naval Archt., (J. S. Government (for mail), . Hull Drawing Room, Norfolk Navy Yard,'and 36 Channing Ave., Portsmouth, Va. - . -. . STURM, William .(J 1937; S 1936), Engr.,' Spencer Cooling & Air Conditioning Co., 413 S. Sixth St., and (for mail), 315-16th Aye., S.E., Minneapolis, Minn. - -- SUDDERTH. Leo, Jr. (7 1936), Atlanta Branch Mgr., Johnson Service Co., 813 Bona-Allen Bldg., and (for mail), 310 Sixth' SL; ApL. 4, Atlanta. Ga. : =' SUMMERS. Ernest T: (A 1930), Pres. (for. mail), Summers-Darling & Co.. 121 Smith St., and Ste. 22 Newcastle Apts., Winnipeg, Man., Canada. . _ SUNDELL, Samuel S. (7 1935; S 1933), Engr;, Larx Co., Inc., 607 S. Fifth Ave-. and (for mail), 3040 Longfellow Ave., Minneapolis.. Minn. - SUPPLE, Graeme B. (Af 1934), Sales Engr. (for mail), American Blower Corp., 625 Architects and Builders Bldg., and 6224 Park Ave., India napolis. Ind. * ' SUTCLIFFE, Arthur G. (Af 1922; A 1918), Chief Engr., Ilg Electric Ventilating -Co., 2850 N. Crawford Ave.. and (for mail), 4146 N. SL Louis Ave., Chicago, 111. SUTFIN, George V. (A 1937), Sales Engr. (for mail), American Blower Corp., 1005-6 American Bldg., Cincinnati, and 2951 Montana Ave., Westwood. Cincinnati, Ohio. . STOKES, Alvin D. (Af 1936), Erection Engr. (for SUTHERLAND, David L. (A 1934). Pres, and mail). York Ice Machinery Corp., 123S North Treas. (for mail), Sutherland Air Conditioning 44tb St.; Philadelphia, and 331Cheswold Rd., Drexel Hill, Pa. . Corp., 15 N. Eighth St., and 1815 Colfax-Ave-, S., Minneapolis. Minn. - - STOKES, Arledge (J 1936). Air Cond. Engr. (for . SUTTER, Edgar E. (A 1936), Sales Engr., Mueller mail). Mehring & Hanson Co., 162 N. Clinton \ Brass Co., Port Huron, Mich., and (for mail), ` St., and 901 Argyle St., Chicago, 111. . 6705 Sixth St., N.W.;Washington, D. C. ' STONE, Eugene R. (Af 1913), Treas. (for mall), Stone-Underhill Co., 78 Woodbine St., and 86 Sea Ave., Quincy, Mass. '. . STORMS, Robert M. (Af 1936), Consulting Engr., Storms & Gibbs, 604 Architects Bldg., Los Angeles, and (for. mail), 354 W. Wilson Ave., Glendale, Calif. STOTT, F. W. (Af 1937), Sales Engr. (for mail), C. A. Dunham Co-, Ltd., 1139 Bay St., Toronto, and Palmer Ave., Oakville, OnL, Canada. STRAKOSH. Walter C. (J 1937; S 1935), 911 S. Fourth St., Champaign, 111. ' SWANEY, Carroll R. (Af 1929 ; 7 1921). Sales Engr. (for mail), G. H. Gleason & Co., 28 St. Botolph St., Boston, and 43 Clyde St., Newton- ville, Mass. SWANSON, Earl C. (A 1935), Plant Mgr. (for mail), Andersen Corp., BayporL Mian. SWANSON, Nils W. (A 1936). Sales Engr. (for ' mail), McDonnell & Miller, 400 N. Michigan Ave., Room 1316, and 7438 N. Artesian. Ave.-, Chicago, 111. . -- SWANSTROM, Alfred E. (7 1935; S 1932). Construction Foreman, U. S. Dept, of Interior, and (for mail), 1444 Van Buren SL, SL Paul, STRAUCH, Paul C. ' (A 1934), Sales Engr., Minn. Henry Furnace & Foundry Co., 18th and Merrir man Sts., and (for mail), Sherwood Hall, Cam . bridge Court Apts., Edgewood Boro, Pittsburgh, Pa. ' STRAVITSCH, Joseph J. (7 1936). Estimator and Salesman, Standard Air, Inc.. 40 West 40th St., New York, and (for mail), 9508 Linden Blvd., Ozone Park, L. I., N. Y. STREVELL, Roger P. (Af 1934), Secy.-Treas. (for mail), William R. Hogg Co., Inc., 900 Fourth. Ave., Asbury Park, and. State Highway and Victor Place, Neptune. N. J. ;, STRICKLAND, Albert W. (A 1929), Htg. and Vtg. Engr., Big Timber, MonL STRINGFELLOW, Jack C. (7 1936; S 1935), A. M. Lockett & Co., 305 Magnolia Bldg., Dallas, Texas. SWEATT, Charles H. (7 1936; S 1935), 274 Lexington Ave., Buffalo, N. Y. ' SWENSON, John E. (A 1930), Industrial Engr. (for mail), Minneapolis Gas Light Co.,-800 Hennepin Ave., ana 4853 South 14th Ave., Minneapolis, Minn. ' SWIFT, Paul F. (A 1935), Secy., Carl F. Scheffer Co., 838 S. Main St., and (for'mail),. 1115 Old .Orchard Ave., Dayton, Ohio. , . , . SWISHER, Stephen G., Jr. (Af 1936; A 1934), Branch Mgr. (for mail), Trane Co.. 1835 N. Third SL, and 1711 E. Dean Rd., Fox Point, -Milwaukee, Wis. ... - . '. - SYDOW, Louis J. (Af 1936), Owner (for mail). Colonial Heating & Sheet Metal Co., 1423 - Hodiamont Ave., and 3841 Maffit Ave., .SL Louis, Mo. ' - -- 55 Heating Ventilating A^r Conditioning Guide 1938 SYSKA, Adolph G. (Af 1933), Consulting Engr.. Syska & Hennessy, 420 Lexington Ave., New York. N. Y. . SZEKELY, Ernest (Af 1920), Vice-Pres. and Gen. Mgr. (for mail), Bayley Blower Co., 1817 South 66th St., and 3104 W. Kilboum Ave., Mil waukee, Wis. SZOMBATHY, Louis R. (A 1930), Pres., Fergu son Sheet Metal Works, 34 N. Florissant Blvd., Ferguson, Mo. TENNEY, Dwight (if 1932), Pres, and Chief Engr. (for mail), Tenney Engineering. Inc., Bloomfield Ave. at Grove St., Bloomfield, and 33 Summit Rd., Verona, N. J. TERHLTNE, Ralph D. (A 1936), Repr., American Gas Products Corp., Fourth and Channing Sts., N.E., Washington, D. C., and (for mail), 4516 Highland Ave., Bethesda. Md. TERRY, Matson C. (if 1936), Chief Engr. (for mail). Standard Air Conditioning, Inc., Second and Beechwood Sts., and 138 Calhoun Ave., T New Rochelle, N. Y. THEOBALD, Art (A 1937), Research Engr. (for TAGGART, Ralph C.* (Af 1912), 14 Lyon Ave., Menands, Albany, N. Y. ' TALIAFERRO, Robert R * (Af 1919), Service Engr., Carrier Corp,, 330 S. Geddes St., and (for mail). 1409 Euclid Ave., Syracuse, N. Y. TALLMADGE, Webster (Af 1924), Pres, (for . mail). Webster Tallmadge & Co., Inc., 256 * North 18th St., East Orange, and 7 Claremont Place, Montclair, N. J. TANGER, O. C. F. (A 1937), Director N. V. Technische Handels Maatschappij, " Renova," and (for mail), Rembrandtlaan 34, Arnhem. Netherlands. TANKER, George E, (J 1937; 5 1936). Mech. Engr., Weatherhead Co.,. 620 Frankfort Ave., Cleveland, and (for mail), 1303 Virginia Ave., Lakewood, Ohio. TAPLEY, Mark S. (M 1937), Htg., Vtg. and Air Cond. Engr., 3280 Holdrege St., Lincoln, Nebr. TARR, Harold M. (Af 1931), Htg. and Vtg. Engr., 21 Montague St., Arlington Heights, Mass. TASKER, C* (Af 1935), Research Fellow (for mail), Ontario Research Foundation, 43 Queens Park, and 737 Avenue Rd., Toronto, Ont., Canada. TAVERNA, Frederick F. (Af 1928; A 1927; J 1924), Engr., Raisler Heating Co., 129 Amster dam Ave., New York, N. Y., and (for mail), 406-12th St., Union City, N. J. TAYLOR, Edward M. (A 1934), Tech. Mgr. (for mail). Taylors, Ltd., 32-A Lichfield St., and Cr. Kabu Rd., Totara St.. Christchurch, New Zealand. TAYLOR, Harold J. (Af 1937), Htg.-Vtg. Con tractor, 17514 Greenlawn Ave., Detroit, Mich. TAYLOR, R. F. (Af 1915). Consulting Engr. (for mail). 911 Bankers Mortgage Bldg., and 1734 W. Alabama, Houston, Texas. TAYLOR, Thomas E. (J 1937), Engr., Control Equipment Co., 304 Selling Bldg., and (for mail), 8424 Southeast 13th Ave., Portland, Ore. TAZE, Donovan L. (Af 1931), Mgr. (for mail), mail), Payne Furnace & Supply Co., Inc., 336 N. Foothill Rd., Beverly Hills, and 116J$ S. Kings Rd., Los Angeles, Calif. THEORELL, Hugo G. T.* (Life Member;M 1902), Consulting Engr.. Hugo Theorells Ingeniorsbyra, Skoldungagatan 4. Stockholm, Sweden. THETFORD, James E. (J 1936; 5 1935), 411 E. Healey St., Champaign. III. TIIINN. Christian A* (M 1921), Chief Engr., C. A. Dunham Co., 450 E). Ohio St., Chicago, 111. THOM, George B. (M 1937), Asst. Prof. Mech. Engrg., Swarthmore College, Swarthmore, Pa. THOMAS, Gleggc (M 1923). Branch Mgr. (for mail), Clarage Fan Co.. 816 District National Bank Bldg., Washington, D. C., and 7 Leland St.. Chevy Chase, Md. THOMAS. L. G. Lee (Af 1934), Vice-Pres., Economy Pumps, Inc.. Hamilton, Ohio. THOMAS, Melvem F. (Af 1909), Consulting Engr., (for mail), Thomas & Wardell, 24 Bloor St., W., and 74 Rivercrest Rd., Toronto, Ont., Canada. THOMAS, Norman A. (Af 1928), Pres., Thomas . Heating Co., 142 South 14th St., LaCrosse, Wis. THOMAS. Richard H. (Life Member; M 1920), Pres., Ecohomy Pumping Machinery Co., 3431 West 48th Place. Chicago, HI. THOMMEN, Adolph A. (A 1929), Metal Worker,: John W. Thomson, 1437 West 103rd St., and (for mail), 3400 West 61st Place. Chicago, 111. THOMPSON, Frank (Af 1935), Chief Engr., Vulcan Iron Works, Ltd., Sutherland Ave., and (for mail), 543 Newman St., Winnipeg, Man., Canada- ' THOMPSON, Nelson S.* (Jf 1917; J 1897), 1615 Hobart St., N.W., Washington, D. C. THOMSON, Thomas N.* (Life Member; M 1899), Consulting Engr., Plbg. and Htg., 37 Irwin Place, Huntington, L. t., N. Y. THORNBURG. Harold A. (Af 1932; J 1929), c/o N. V. Industrieeie Mi j Gebr. Van Swaay, Societeitstraat 16, Soerabaia, Java, Dutch East American Blower Corp., 1302 Swetland Bldg., Cleveland, and 19412 Winslow Rd., Shaker Heights, Ohio. TAZE, Edwin H. (if 1937), Sales Engr. (for mail), Indies. THORNTON, Thaddeus L. (Af 1937), Main tenance Engr., Prudential Insurance, 96 Barclay St.. Newark, and (for mail), 37 Perry St., Belle American Blower Corp., 50 West 40th St., and 542 East 89th St., New York, N. Y. TEAL. Edwin T. (J 1936; 5 1935), Graduate Asst., Dept, of Mech. Engrg. (for mail), Agricultural * and Mechanical College of Texas, College Station, and 6416 Velasco. Dallas, Texas. TEASDALE, Lawrence A. (if 1926), Partner (for mail). Office of Hollis French, 20 Ashmun St., and 262 W. Rock Ave., New Haven, Conn. . TECKMYER. Fred C., Jr. (S 1936), 1515 Wood ville. N. J. THORNTON, William B.* (Af 1931), Sales Engr., Norge Nestor, Inc., 1024 w. Adams St.; and (for mail), 3329 Randall St., Jacksonville, Fla. THRUSH, Homer A. (Af 1918), Pres., H. A. Thrush & Co., 21-23 Riverside Drive, Peru, Ind. THUNEY, Francis M. (J 1936), Application Engr. (for mail), William E. Kingswell, Inc. (Minneapolis-Honeywell Regulator Co.), 3707 Georgia Ave., N.W., and 4474 Conduit Rd., ward Ave., Lakewood, Ohio. TEELING, George A. (if 1930). Consulting Engr., (for mail), 1 Columbia Place, Albany, N.W., Washington, D. C. TIBBETS, John C. (Af 1920), Engrg. Dept., B. & O. R. R. Co., and (for mail), P. O. Box 106, and Box 81, Clarkesville, N. Y. TEMPLE, Walter J. (if 1931), Engr., J. A. .Temple Co., 120 Red Arrow Parkway, and (for ' mail), 1215 Reed St., Kalamazoo. Mich. TEMPLIN, Charles L. (if 1921). Pres, (for mail). Carrier Atlanta Corp., 348 Peachtree St., and 781 Sherwood Rd., N.E., Atlanta, Ga. TENKONOHY, Rudolph J. (if 1923), Vice-Pres.1 EUicott City, Md. TILLER, Louln (A 1935; S 1933), Air Cond. Engr., Oklahoma Gas & Electric Co., 321 N. Harvey, and (for mail), 2712 Northwest 15th St., Oklahoma City, Okla. TILTZ, Bernard E. (Jf 1930). Pres, (for mail), Tiltz Air Conditioning Corp., 230 Park Ave., New York, and 24 Barnum Rd., Larchmont, Airtberm Mfg. Co., 1474 S. Vandeventer Ave., and (for mail), 3650 Shaw Blvd., St. Louis, Mo. TENNANT, Raymond J. J. (A 1929), Engr. (for mail), Pittsburgh Business Properties, Inc., Oliver Bldg., Room 2237, and 1215 Mississippi Ave., Pittsburgh, Pa. N. Y. TIMMINS, W. W. (Af 1937), Dist. Mgr. (for mail), Viking Pump Co. of Canada, Ltd., and Canadian Powers Regulator Co., Ltd., 344 University Tower Bldg., Montreal, and 351 Brock Ave., N.. Montreal West, Que., Canada. 56 Roll or Membership T1MM1S, Pierce (Af 1920), Service Equip. Dept, (for mail). United Engineers & Constructors, Inc., 1401 Arch St., Philadelphia, and 202 Midland Ave., Wayne, Pa. TIMMIS, W. Walter (Af 1933; A 1925). Mgr-, Systems and Control Div. (for mail), American Radiator Co., 40 West 40th St., New York, and 32 Oak Lane. Glen Cove. L. 1.. N. Y. TJERSLAND, Alf (Af 1916; J 1906), E. Sunde & Co., Ltd., Oslo, Norway. TOBIN, George J. (Life Member; M 1905), Owner and Prop, (for mail). Geo. J. Tobin, 187 191 North Ave., and 510 Grant Ave., Plainfield, N. J. TOBIN, John F. (A 1934), Salesman (for mail), American Blower Corp., 228 N. LaSalle St., and 11256 S. Artesian Ave., Chicago, III. TODD, Meryl L. (J 1936), Mech. Engr. (for mail), 901 Waterloo Bldg., and 1119 Vine St., Waterloo, Iowa. TODD, Stanton W., Jr. (J 1935), Sales Repr., American Radiator Co., 8019 Joseph Campau. Detroit, and (for mail), 309 Paris, S.E., Grand Rapids, Mich. TOLHURST. George C. (Af 1936), Htg. Designer, Gurney Massey Co., Ltd., Principal St., and (for mail), 142 Blvd. St. Germain, St. Laurent, near Montreal, Canada. TONRY, Robert C. (Af 1936), Mgr. (for mail). Wiedebusch Plumbing & Heating Co., 511 First St., and 217 Fairmont Ave., Fairmont, W. Va. TOONDER, Clarence L. (Af 1933), Air Cond. Sales Engr., Norge Div., Borg Warner Corp., 670 E. Woodbridge, and (for mail), 13391 Marlow, Detroit, Mich. . TORNQUIST, Earl L. (A 1934), Utilization Supv. (for mail). Public Service Co. of Northern Illinois, 72 W. Adams St., Chicago, and 465 Parkside Ave., Elmhurst. III. TOROK, Elmer (Af 1936), Supt. of Power (for mail). North American Rayon Corp., Elizabeth- ton, and 203 West "G'* St., Elizabethton, Tenn. TORR, Thomas W. (Af 1933), Chief Engr., Rudy Furnace Co., and (for mail). P. O. Box 73. Dowagiac. Mich. . TORRANCE, Henry (Af 1933), Chairman. Carbondale New York Co., 175 Christopher St., and (for mail), 112 East 17th St., New York, N. Y. TOUTON, R. D. (Af 1933), Tech. Director (for mail). Bayuk Cigars, Inc., Ninth and Columbia Ave., Philadelphia, and 19 Lodges Lane, Cynwyd, Pa. TOWER, Elwood S. (Af 1930). Engr. (for mail). 213 Investment Bldg., and 5644 Forbes St., Pittsburgh, Pa. ' TRACY, William E. (J 1937), Dist. Mgr., (for . mail), B. F. Sturtevant Co., 237 Grain Exchange Bldg., and 5016 Cass St., Omaha, Nebr. TRAMBAUER, Charles W. (J 1936), Sales Engr.. . Hoffman Specialty Co., 500 Fifth Ave., New York, N. Y., and (for mail), 78 Argyle Place, N. Arlington, N. J. . TRANE, Reuben N> (M 1915), Pres, (for mail), Trane Co., and 126 South 15th St., LaCrosse, Wis. TRAUGOTT, Mortimer (A 1930), East Sales Mgr. (for mail), Bryant Heater Co., 830 N. Broad St., Philadelphia, and 721 Meeting House Rd.. Elkins Park, Pa. - TRAWICK, Jack G. (Af 1937). Dist. Repr. (for . mail), Minneapolis-Honeywell Regulator Co., 1316 Comer Bldg., and 315 Altamont Apts., Birmingham, Ala. TRAYNOR, Harry S. (/ 1937), Export Dept., . Remington Air Conditioning Co., 44 Beaver St.r New York, N. Y., and (for mail), 443 Morris Ave., Elizabeth, N. J. . TREADWAY, John Q. (A 1936; J 1932), Dist. , Sales Mgr. (for mail), Clarage Fan Co., 410 Reynolds Arcade, and 826 Winona Blvd., Rochester, N. Y. TROSTEL, Otto A. (Af 1935), Engr.. (for mail), . Kern Engineering Co., Inc., 5083 Plankinton . ..Bldg., and 3155 N. Seventh St*, Milwaukee, Wis. TRUITT, G. Scott (J 1937; 5 1936). Production Dept, (for mail), Bastian-Morley Co., Inc., and 907 Indiana Ave., LaPorte, Ind. TRUMBO, Silas M. (A 1926). Sales (for mail). Buffalo Forge Co., 20 N. Wacker Drive, Chicago, and 921 Franklin St., Downers Grove, III. TRUMP, Charles C. (Af 1934), Pres, (for mail), James Spear Stove & Heating Co., 1823 Market St., Philadelphia, and 503 Baird Rd., Merion Station, Pa. TUCKER, Frank N. (Af 1926), Field Engr., Ilg Electric Ventilating Co., Room 1108. 13 Park Row, New York, and (for mail), 239 Whaley St., Freeport. L. I., N. Y. TUCKER, Leonard A. (Af 1935). Dist. Engs.. J. J. Pocock, Inc., 1920 Chestnut St., Phila delphia, and (for mail), 518 Monroe Ave., Ardsley, Pa. TUCKER, Thomas T. (A 1936). Chief Engr., - Armor Insulating Co., 200 Peachtree St., and (for mail). 3619 Ivey Rd., N.E., Atlanta, Ga. TUCKERMAN, George E. (Af 1932), Mgr. (for mail), Anderson York Co., 600 Schuylkill Ave., Philadelphia, and 502 Rodman Ave., Jenkintown. Pa. TURLAND, Charles H. (Af 1934; A 1930), Sales Engr. (for mail), R. E. Johnston Co., Ltd., 1070 Homer St., and 4579 W. First Ave., Vancouver, B. C., Canada. TURNER, George G. (A 1934), Western Repr. (for mail). Industrial Press, 228 N. LaSalle St., Chicago, and 744 Hinman Ave., Evanston, 111. TURNER, Harry S., Jr. (/ 1937; S 1936), Dallas Power & Light Co., 1001 Dallas Power & Light Bldg., and (for mail), 4950 Gaston, Dallas. Texas. TURNER, John- (Af 1930), Engr. (for mail). Capitol Engineering Co., Potter and Binney Sts., Cambridge, Mass., and Contoocook. New Hampshire. TURNER, Prescott K. (A 1937; J 1935), Head Engr., Airco Heating Equipment Co., 29 Barbour St., and (for mail), 22 Maplewood Ave., Brad ford, Pa. TURNO, Walter G. W. (Af 1917; A 1912), Secy., H. W. Porter 8c Co., Newark, and (for mail), 71 Lafayette Ave.,-East Orange, N. J. TUSCH, Walter (Af 1917), Htg. and Vtg. Engr., Tdnney 8c Ohmes, Inc., 101 Park Ave., New York, and (for mail). 881 Sterling Place, Brook lyn, N. Y. TUTTLE, George H. (Af 1937; A 1936; J 1934). Htg. Engr. (for mail), Detroit Edison Co., 2000 Second Ave., and 16714 Kentfield, Detroit, Mich. TUTTLE, J. Frank (Af 1913), Sales Agt. (for mail), Warren Webster & Co., 127 Federal St., Boston, and 9 Lewis Rd., Winchester, Mass. TUVE, George L.* (Af 1932). Prof, of HeatPower Engrg. (for mail). Case School of Applied Science, and 1294 Cleveland Heights Blvd., Cleveland, Ohio. TUXHORN, David B. (Af 1936), Htg. Engr.. L. P. Steuart & Bro., Inc, 138-12th St.. N.E., and (for mail). 4853 Sedgwick St.. N.W., Wash ington, D. C. TWIST, Charles F. (Af 1921), Pres, (for mail), Ashwell-Twist Co., 967 Thomas St., and 2310 . Tenth Ave., N., Seattle, Wash. TWIZELL, Edwin W. (Af 1937), Partner (for mail), Connolly 8c Twizell Reg'd., 1405 Bishop St., and 4944 Eamscliffe Ave., Montreal, Que., Canada. . TYLER, Roy D. (Af 1928). Mgr. (for mail), Modine Mfg. Co., 101 Park Ave., New York, and 15 Highbrook Ave.. Pelham, N. Y. TYSON. William H. (Af 1928), Mgr. of Engrg. (for mail), Goodyear Tyre & Rubber Co., Ltd., and "Kipewa" Codsall Rd., Nr. Wolverhamp ton, England. u UHL, Edwin J. (A/ 1925), Partner (for mail), Uhl Co.. 132 S. Tenth St., and 4830 Pleasant Ave., S., Minneapolis, Minn. . * t ` ' ^ 57 Heating Ventilating Air Conditioning Guide 1938 UHL, Willard F. (Af 1918), Partner (for mail), -Uhi Co., 132 S. Tenth Si., and 4716 Lyndale Ave., S. Minneapolis, Minn. UHLHORN, W. J. (Af 1920), 733 S. Highland Ave.. Oak Park, 111. . ULLMAN, Herbert G. (A 1928), American Radiator Co., 40 West 40th St., New York, and (for mail). 107 White Rd., Scarsdale. N. Y. ULLRICH, Anton B., Jr. (7 1937), Sales Engr., . Gilbert Engineering Co.. 1314 Liberty Bank '-Bldg.-, and (for mail), 1330 Hollywood, Dallas, Texas. . URDAHL, Thomas H. (Af 1930), Consulting Engr. (for mail), 726 Jackson Place, N.W., and 1505-44th SL, N.W., Washington, D. C. VOGEL, Andrew (Af 1926), Engr., General . Electric Co., 1 River Rd., and (for mail), 1821 Lenox Rd;, Schenectady, N. Y. - VOGELBACH, Oscar (Af 1923), Consulting Engr., Chamber of Commerce Bldg., Newark, N. J., and (for mail), R. F. D. 3, Montgomery, N. Y. . VOIGT, Robert N. (5 1937), Student, Purdue University, West Lafayette, and (for mail), 601 New York St. Lafayette, ind. VOISINET, Walter E. (Af 1930), Sales Repr. (for mail), John J. Nesbitt, Inc., 250 Delaware Ave., Buffalo, and 151 Warren Ave., Kenmore, N. Y. VOLBERDING, Leroy A. (A 1936), Air Cond. Engr. (for mail), Norge Div. of Borg-Warner, 670 E. Woodbridge, Detroit, and 471 Oakland V Ave., Birmingham, Mich. VOLK, Joseph H. (Af 1923), Pres, and Treas. (for VALE, Henry A. L. (Af 1929), Managing Director (for mail). Vale'& Co., Ltd., 141-43 Armagh St., and 241 Ilam Rd., Fendalton, Christchurch, New Zealand. VAN ALEN, Walter T. (Af 1924). Htg. Engr. and ' Sales Agt., 1300 Darlington Rd., Beaver Falls, Pa. - VAN ALSBURG, Jerold H.* (Af 1931), Engr. of Application, Hart & Cooley Mfg. Co., 61 W. Kinzie St., Chicago, 111. VANCE, Louis G. (Af 1919), Partner. Vance- McCrea Sales Co., 2700 Sisson St., and (for mail), 4402 Maine Ave., Baltimore. Md. VANDERHOOF, Austin L. (A 1933); DisC Repr. (for mail), Warren Webster & Co., 2341 Carnegie Ave., Cleveland, and 2762 -Landon Rd., Shaker Heights, Ohio. mail), Thos. E. Hoye Heating Co., 1906 W. St Paul Ave., and 2965 South 43rd St, Milwaukee, Wis. - vonCHRISTIERSON, Carl A. (7 1937), Esti mating Engr. (for mail). Carrier Engineering (S. A.). Ltd., P. O. Box 3249, and 63 Claim Str., Johannesburg. South Africa. VOORHEES, Guy A. (Af 1922), Consulting Engr., 633 S. Delaware St, and (for mail), 3451 Broad way. Indianapolis. Ind. VOYE, Vernon J. (A:1936), Salesman. Richardson & Boynton Co., 17 Farnsworth St, Boston, and (for mail), 20 Richview St, Dorchester, Mass. VROOME, Albert E. (Af 1932), Air Cond. Engr., . Phoenix Engineering Corp., 2 Rector St, New . York, N. Y., and (for mail), 6218 Amboy Rd., Prince Bay, Staten Island. N. -Y. . VANDERLIP, P. J. (A 1935), Consulting Engr. (for mail), Howland Engineering Co., 206 S. .- W 0 Grand Ave., and 911 W- Ottawa St., Lansing, Mich. VAN NOUHUYS, Herbert C. (7 1937), Engr.. Air Cond. Div., Nasb-Kelvinator Corp., 14250 Plymouth Rd., and (for mail), 2007 Seward Ave., Detroit, Mich. - VAN NUYS, Jay C. (7 1938; 5 1936), Junior Partner, P. C. Van Nuys, Archt, 1 W. Main St., and (for mail), 56 W. Cliff St., Somerville, N. J. VARNER, John L. (A 1935). Air Cond. and Commercial Engr., Jacksonville Refrigeration, Inc., 35 W. Monroe ... and (for mail), Seminole Hotel, Jacksonville, Fla. VAUGHAN, John G., Jr. (7 1935), American Heating Engineering Co., Inc., 1005 New York Ave., N.W., Washington, D. C., and (for mail), 4415 Maple Ave., Bethesda, Md. VAUGHN, Frank R. (Af 1937; A 1936), Vice- Pres, (for mail). Green Foundry & Furnace Works, and'532 Polk Blvd., Des Moines, Iowa. VERNON. J. Rexford (Af 1928; A 1926), (for mail), Johnson Service Co., 1355 Washington Blvd., Chicago, and 733 Brummel St, Evanston, 111. . VERVOORT, Edward L. (7 1937; 5 1936), House Htg. Engr., Brooklyn Union Gas Co., 180 WACHS, Louis J. (A 1936; 7 1930), Salesman, Carrier Corp., Chrysler Bldg., New York, and (for mail), 354 East 21st St., Brooklyn, N. Y. WADE, Richard H. (Af 1937), Engr., Spencer Heater Co., 101 Park Ave., New York, and (for mail). 130-73-230th St., Laurelton, L. I., N. Y. WADSWORTH, Raymond H. (7 1937), Sales Engr. (for mail), Clarage Fan Co., 500 Fifth Ave., New York. N. Y., and 24 Carlton St, East Orange, N. J. . WAECHTER, Herman P. (A 1930; 7 1927), Air Cond, Engr., W. T. Grant Co., 1441 Broadway, New York, and (for mail), 89 Sherman Ave., Staten Island, N. Y. WAGGONER, Jack H. (Af 1937), General Factories Chemist (for mail). Industrial and Structural Products Div., Owens-Illinois Glass Co., and Rte. 5, Munice, Ind. WAGNER, A, M. (A 1921), Branch Mgr. (for mail), American Radiator Co., 1741 W. St Paul' Ave., and 1857 N. Prospect Ave., Milwaukee, . Wis. WAGNER, Edward A. (Af 1937; A 1936), Pres., Wagner Engineering Corp., 22 Dunham St, and (for mail),''28 Waverly St., Pittsfield, Mass. Remsen St, Brooklyn, and (for mail), 31 Yale WAGNER, Frederick H., Jr. (Af 1934), Vice- Place. Rockville Centre, L. I., N. Y. Pres. (for mail), Niagara Blower Co., 6 East 45th VETLESEN, G. Unger (Af 1930). 1 Beekman St., New York, and 1126 Post Rd.t Scarsdale, Place, New York, N. Y. . VIDALE, Richard (Af 1935), Air Cond. Engr. (for ' mail), Flesch & Schmidt Inc., 60 Brown St, and 572 Flower City Park, Rochester, N. Y. N. Y. WAGNER, John G. (A 1937), 1st Lt F. A. Res. (for mail). Civilian Conservation Corps. H. Q. Trenton Dist CCC, Trenton, N. J,, and 1486 VIESSMAN, -Warren (if 1930), Mech. Engr., Public Buildings Branch. Procurement Div., ' U. S. Treasury Dept, Washington, D. C., and (for mail), 2205 Lake Ave., Baltimore,.Md. ' VINCENT, Paul J. (Af 1931), Engr. (for mail), P. J. Vincent Co., 2208 Maryland Ave., Balti more, Md. VINSON, Neal L. (7 1936; 5 1932), Engr. and Estimator, L. W. Vinson & Son, Bisbee and Douglas, and (for mail). Box 3007, Lowell, Arlz. VISSAC, Gustave A. (Af 1937), Consulting Engr., T325 Frontenac Ave., Calgary,. Alta., Canada. ' VIVARTTAS. E. Arnold (if 1910), Engr., 247 Potter Ave., West New Brighton, S. I.; N. Y. Bedford Ave., Brooklyn, N. Y. WAHRENBROCK, Grin K. (7 1936), Engr., Automatic Appliance Corp., 36 Richmond Hill Ave., Stamford, and (for mail), 366 West Ave. (Box 117), Glenbrook, Conn. WAID, Glen H. (A 1930), . Dist Sales Engr., Scott Valve Mfg. Co., 3963 McKinley Ave., and (for mail), 2928 Northwestern Ave., Detroit, Mich. . WAITE, Harry (A 1929), Secy.-Treaa. (for mail). Gray Plumbing Co., 1214 Ogden Ave., and 1409 17th St, Superior, Wis. - WALDON, Charles D. (A 1932), Consulting ; Engr.', Spencer Foundry Co., Penetang, and (for mail), 32 Femdale Ave., Toronto, Out, Canada. 58 Roll or Membership WALKER, Edmund R. (M 1934). Sales Mgr. (for mail), Fedders Mfg. Co., Inc., 57 Tonawanda St, Buffalo, and 365 McKinley Ave., Kenmore, N. Y. . WALKER, James E. (7 1937; 5 1936), 214 Rock- wood Ave.. Dayton, and (for mail), 2139 Abing- ton Rd., Cleveland, Ohio. WALKER, J. Herbert* (M 1916). (Council, 1925); Engr., Asst, to Gen. Mgr. (for mail), Detroit Edison Co., 2000 Second Ave., Detroit, and 432 Arlington Rd., Birmingham, Mich. WALKER, William K. (If 1935), Sales Engr., American Radiator Co., 40 West 40th St, New York, N. Y. WALLACE, David R. (A 1937), Engr. (for mail). Young & Bortic, 9 Franklin Ave., Ridgewood, and 94 Harding Rd., Glen Rock, N. J. WALLACE, George J. (Af 1923), Principal Engr. and Contractor, 96-19-35th Ave., Corona, and (for mail), 27-36 Ericsson St., East Elmhurst, N. Y. WALLACE, George N. (Af 1937), (for mail), George N. Wallace Co., 271 Madison Ave., New York, and 77 Valley Rd., New Rochelle, N. Y. WALLACE, Harry P., Jr. (A 1936), Mgr., Sales Promotion (for mail). Crane Co., 400 Third Ave., N., and 4909-34th Ave., S., Minneapolis, Minn. ` WALLACE, Kenneth S. (Af 1931), Dist Engr. (for mail), Waterola Southwest Sales Corp., 316-18 S. San Pedro St, and 1438 West 83rd St. Los Angeles, Calif. - WALLACE, William M., II (Af 1929), Partner. Temperature Sales Co., 139 North Mill St., and 185 Kentucky Ave., Lexington. Ky. WALSH, Edward R-, Jr. (Af 1936; A 1935), Head of Automatic Htg. Div., York Ice Machinery Corp., and (for mail), 32-34 Elm Terrace Apts., York. Pa. ` WALSH, James A. (A 1932; 7 1929), Vice-Pres.- ' Gen. Mgr., Air Conditioning Co., 4304 Main St., and 803 Hawthorne St., Houston, Texas. WALSH, Malcolm (Af 1924), Vice-Pres. (for mail), Walsh & `Wertheim, 504 W. Broadway, New York, and 91 Penbroke Ave., S. L. N. Y. WALTERS, Arthur L. (Af 1926; A 1925; 7 1924), Chief Engr. (for .mail). Green Foundry & Furnace Works, Third and Elm Sts., and 900-2^lh St, Des Moines, Iowa. WALTERS, William T. (Af 1917), Engr.. Illinois Engineering Co., Cor. 21st St. and Racine Ave., and (for mail), 7965 Phillips Ave., Chicago, 111. WALTERTHUM, John J. (A 1922), Htg. and . Vtg. Contractor, 212 East 58th St., New York, N. Y., and (for mail), 42-a Van Reipen Ave., Jersey City, N. J. WALTON, Charles W.. Jr. (Af 1934), Mech. Engr. (for mail). Rockefeller Center, Inc., 30 Rockefeller Plaza, New York, N. Y., and 120 Monte Vista Ave., Ridgewood, N. J. WALZ, George R. (7 1937), Sales Engr., Minne- apolis-Honeywell Regulator Co., 1101 'Vermont Ave., N.W., and (for mail), 1365 Geranium St, N.W., Washington, D. C. WARD, Edward B. (Af 1937), Owner (for mail). Edward B. Ward & Co., 270 Fremont St, and 235 Lansdale, San Francisco, Calif. WARD, Frank J. (Af 1935), Owner, Frank J. Ward Co., Cold Spring, Ky. ' WARD, Harry H. (A 1937). Dist. Engr. (for mail), Delco-Frigidaire Cond. Div.', 230 Northeast 19th St, and 724 Northwest 12th St., Miami, Fla. WARD, Jerry J. (A 1921), Pres, (for mail). . Wenzler & Ward. Inc., 1703 Textile Tower, and 1107-31st Ave.. Seattle, Wash- ' WARD, Oscar G. (Af 1919), Dist Mgr. (for mail). Johnson Service Co., 1230 California St, and 675 Bellaire St., Denver, Colo. WARDELL, Arthur (Af 1935), Partner, (for mail), Thomas & Wardell. 24 Bloor St., W., and 124 Melrose Ave., Toronto. Ont., Canada. WARE, John H,, 3rd (Af 1937). Vice-Pres. (for mail), Oxford Co. & Citizen Gas & Fuel Co;, 45 S. Third St, and "The Woods." Oxford, Pa. WARING, James M. S. (Af 1932), Consulting Engr., 277 Park Ave., New York, N. Y. WARREN, Charles W. (7 1936; S 1935), Mech. Engr., A. J. Warren (for mail), 2313 Ave. E, and 3317-R-H* Galveston, Texas. WARREN, Francis C. (Af 1934), Branch Mgr. (for mail), American Blower Corp., 200 Division Ave., N-. and 329 Gladstone-Ave., S.E., Grand Rapids, Mich. WARREN, Harry L. (Af 1930), Sales Research Engr., Southern California Gas Co.,' 950 S. Broadway, Los Angeles, and (for mail), 1303 Huntington Drive, South Pasadena,- Calif. WARREN, John S,, Jr. (7 1937), Sales Engr. (for mail), York Ice Machinery Corp., 115-121 South ilth St., and 2017 Maury Ave., St Louis, Mo. - WASHBURN, Marcus J. (A 1934), Insulation Engr. (for mail), Eagle-Picher Lead Co.; Temple Bar Bldg., and 2211 Park Ave., Cincinnati. Ohio. WASHINGTON, George (Af 1934), Engr., Hoffman Specialty Co., Waterbury, Conn., and (Tfiol r - mail), 4327 Johnson Ave., Western Springs, WASHINGTON, Laurence W. (Af 1929), Modutrol Div. Mgr. (for mail), Minneapolis-Honeywell Regulator Co., 433 E: Erie St, Chicago, and 778 Laurel Ave., Des Plaines, 111. WATERMAN, John H. (Af 1931), Engr. (for mail), Charles T. Main, Inc., 201 Devonshire St., Boston, and 7 Centre St., Cambridge, Mass. WATERS, Frank A. (A 1936). Htg. and Vtg. Engr., Westinghouse Electric Supply Co., 150 Varick St., New York, and (for mail), Bedford Hills, N. Y. WATERS, George G- (Af 1931; A 1926); Dist. Mgr. (for mail), American Blower Corp., 1433 Oliver Bldg., and 110 Longuevue Drive, Pitts-burgh (16), Pa. ` WATKINS, George B. (A 1936), Director of Research (for mail), Libby-Owens-Ford Glass Co., Research Dept., Oakdale and E. Broadway, and 3004 Berdan Ave., Toledo, Ohio. WATSON, H. Dalton (A 1935). Branch Mgr. (for mail), Linde Canadian Refrigeration Co., 124 King St, and 830 Mulvey Ave., Winnipeg, Man., Canada. - WATSON, M. Barry (Af 1928), Consulting Engr., 184 College St., and (for mail), 121 Welland Ave., Toronto 5, Canada. v-unbuiuug oecunues mag., ; mail), 1306 Madison St., Seattle, Wash. WATTS, Albert E. (A 1937). Mgr., A. E. Watts, 637 Craig St., W., and (for mail), 2347 Beaconsfield Ave., N. D. G., Montreal, Que., Canada. WAUNG, Tsing-fi (Af 1935; 7 1933), Htg. Engr. (for mzril), Andersen Meyer & Co., Ltd., Yuen Ming Yuen Rd., Shanghai, China. WAYLAND, Clarke E. (A 1937), Vice-Pres. (for mail), Western Asbestos Co., 675 Townsend St., and 42 Allston Way, San Francisco, Calif. WEATHERBY, Edward P., Jr. (7 1936; 5 1935), Product Engr., Air Cond- Dept, General Electric Co., 4966 Woodland Ave., and (for mail), 11125 Lake Ave., Apt. No. 2, Cleveland, Ohio. WEBB, Ernest C. (Af 1935), Engrg. Service Mgr. (for mail). Iron Fireman Mfg. Co., 3170 West 106th St., Cleveland, and 1202 Woodside Drive, Rocky River, Ohio. ' WEBB, John S. (Af 1920), Sales Engr., W. D. Cashin Co., 69 A St., Boston, and (for mail), 345 Brookline St., Needham. Mass. WEBB, John W. (Af 1926). Managing Director (for mail). Webb Dust Removing & Drying Co., Ltd., Vinery Works. Town Lane, Denton Nr. Manchester, and "Ebor." Brinnington, Stock port, England. WEBER, Erwin (Af 1921), Consulting Engr., 534 Medical Arts Bldg., Seattle, Wash. - WEBER, Eugene F., Jr. (7 1937), Sales Engr. (for mail), York Ice Machinery Corp., 117 South . 11th, and 4515 Maryland Ave., St Louis, Mo. Heating Ventilating Air Conditioning Guide 1938 WEBSTER, E. Kessler (M 1915), Warren Webster & Co., 17th and Federal Sts., Camden, N. J. WEBSTER, Warren (Life Member; M 1906; A 1899), Pres., WarTen Webster & Co., 17th and Federal Sts., Camden, N. J., and Pass-a-Grille, Fla. ,r. WEBSTER, Warren, Jr. (M 1932; 7 1927), Vice- Pres. and Treas. (for mail). Warren Webster & Co., 1625 Federal St.. Camden, and 200 Colonial Ridge Drive, Haddonfield, N. J. WEBSTER, William H., Jr. 04 1935), Vice-Pres. (for mail). Hurst Heating Engineers, Inc., 400 York St., and 200 N. Shore Rd., (Academy Terrace), Norfolk, Va. WECHSBERG, Otto (Af 1932), Pres, and Gen. Mgr., Coppus Engineering Corp., 344 Park Ave., and (for mail), 1006 Main St., Apt. 4, Worcester Mass. WEDDELL, George O. (Af 1936), Branch Mgr., York Ice Machinery Corp., 2400 Carson St., Pittsburgh, and (for mail), 3114 Wainbell Ave., Dormont, Pittsburgh, Pa. WEEKS, Paul (A 1937), Mgr., Engine Sales Div. (for mail). Caterpillar Tractor Co., and 124 Barker Ave., Peoria, 111. WEGMANN, Albert (M 1918), 6206 North 17th St., Philadelphia, Pa. WEIDELE, Erwin J. (A 1937), Htg. and Vtg. Inspector, City of Los Angeles. Room M8, City Hall, and (for mail). 8519 Colecrest Drive, Los Angeles, Calif. WEIL, Martin (A 1925), Vice-Pres- (for mail), Weil-McLain Co., 641 W. Lake St., and 4259 Hazel Ave., Chicago, 111. WERNER, John G. (Af 1937). Branch Mgr. (for mail), L. J. Mueller Furnace Co., Delaware Ave. and Morris St., 'Philadelphia, and 215 N. Easton Rd., Glenside, Pa. WERNER, Richard K. (Af 1936), Consulting Engr. (for mail), 316 W. T. Waggoner Bldg., and 3671 Monticello Drive, Fort Worth, Texas. WESLEY. Ray O. (A 1937), Sales Engr. (for mail), U. S. Radiator Corp., 334 Boren Ave., N., Seattle, and Yarrow Point, Bellevue, Wash. WEST, Perry* (Af 1911), (Council. 1920-1925; Treas., 1924-1925), Prof, of Steam and Power Engrg., Head of Dept, of Mech. Engrg. (for mail). University of Kentucky, College of Engrg., and 185 E. Maxwell St., Lexington, Ky. WESTOVER, Wendell (Af 1936), Pres, (for mail), Westover-Wolfe, Inc., 170 Washington Ave., and 221 S. Main Ave., Albany, N. Y. WESTPHAL, Norman E. (S 1937), Student. Purdue University, West Lafayette, and (for mail). Long Beach, Michigan City, Ind. WETHERED, Woodworth (Af 1937), Consulting Engineer, Hotel Sir Frands Drake, San Fran cisco, Calif. ._ ,, WETZELL, Horace E. (Af 1934), Chief Engr. (for mail), Smith & Oby Co., 6107 Carnegie Ave.. and 8796 Elsmere Drive, Cleveland, Ohio. WHEELER, Joe, Jr. (Af 1937), Sales Repr. (for mall), Johnson Service Co., 28 East 29th St., New York, N. Y., and 30 Dunnell Rd., Maple wood, N. J. . WHELAN, William J. (Af 1923), Purchasing and Estimating (for mail), Harrigan & Reid Co., 1365 Bagley. and 3790 Seminole Ave.. Detroit, ' Mich. _ __ WEIL, Maurice I. (A 1928), Pres, (for mail), WHELLER, Harry S. (Af 1916), Vice-Pres., L. J. Chicago Pump Co., 2336 Wolfram St., and 1409 Wing Mfg. Co., 154 West 14th St.. New York, W. Elmdale Ave., Chicago, 111. N. Y., and (for mail), 725 Union Ave., Elizabeth, WEIMER, Fred G. (A 1919), Mgr., Milwaukee N. J. Office. Kewanee Boiler Corp., 312 E. Wisconsin WHITE, Elmer D. (J 1937), Engr. (for mail), Ave., Room 412, and (for mail), 3958 N. Stowell Ranco, Inc.. 601 W. Fifth Ave., and 2086 Neil `Ave., Milwaukee, Wis. Ave., Columbus, Ohio. WEINERT, Fred C. (A 1937), Asst. Sales Mgr. WHITE, Eugene B. (Af 1934), Arch, and Engr. (for mail), Chamberlin Metal Weather Strip Co., (for mail), Y. M. C. A., 19 S. LaSalle St., Chicago, Inc., 1254 Labrosse St., Detroit, and 9909 York and 309 N. Taylor Ave., Oak Park, 111. Ave., R. No. 2, Plymouth, Mich. WHITE, Everett A. (Af 1921), Engrg. Dept., WEINFELD, Charles (7 1936), Sales Engr., Ilg Crane Co., 30 South 16th St., and (for mail), Electric Ventilating Co., 182 N. LaSalle St., 5244 Nottingham St., St. Louis, Mo. and (for mail), 5100 Cornell Ave., Chicago, 111. WHITE, Elwood S. (Af 1921), Pres, (for mail). WEINSHANK, Theodore*(Life Member;M 1906), U. S. Radiator Corp., 1056 National Bank Bldg., (Board of Governors, 1913), Consulting Engr., Detroit, Mich., and Meadowbank Rd., Old 3307 Belderi Ave., Chicago, 111. Greenwich, Conn. WEISS, Arthur P. (Af 1928), Burnham Boiler Corp., Irvington, and (for mail), 134 Farrington Ave., North Tariytown, N. Y. . 1 WHITE, Harry S. (A 1936). Mgr., Sheet Metal Dept, (for mail). Sellers & Marquis Roofing Co., 2201 Broadway, and 20 W. Dartmouth Rd., WEISS, Carl A. (Af 1936; A 1924), Gen. Mgr. (for mail), Kornbrodt Komice Co., 1811-15 Troost Ave., and 29 East 68th St., Kansas City, Mo. WEITZEL, Cameron B. (M 1936). Owner and Operator, 122 E. High St., Manheim, Pa. WEITZEL, Paul H. (7 1936; S 1934), Junior Engr., Cameron B. Weitzel, 122 E. High St., Manheim, Pa. WELCH, Louis A., Jr. (A 1929), 443 Second St., Schenectady, N. Y. WELDY, Lloyd O. (M 1930), Dist. Mgr. (for mail). Powers Regulator Co., 2341 Carnegie Ave., Cleveland, and 19623 Laurel Ave., Rocky River, Ohio. WELSH, Harvey A. (A 1936), Engr., A. P. Woodson Co., 1313 H St., N.W., Washington, D. C.t and (for mail), 4118 Lee Highway, Arlington, Va. WELTER, M. A. (A 1925), Engrg. and Htg. Contractor (for,mail). Welter Furnace Mfg. Co., 2023 S. Lyndale St., and 4200 S. Aldrich Ave., Minneapolis, Minn. WENDT, Edgar F. (M 1918), Pres, (for mail). Buffalo Forge Co., 490 Broadway, and 120 Lincoln Parkway, Buffalo, N. Y. WENDT, Edwin H. (J 1936), Estimator and Draftsman (for mail), Wendt & Crone Co., 2124 Southport Ave., and 3809 N. Troy St., Chicago, III. Kansas City, Mo. WHITE, John C. (Af 1932), State Power Plant Engr., Wisconsin Bureau of Engineering, Power Plant Div. (for mail), 624 E. Main St., and 622 E. Main St., Madison, Wis. WHITE, Taylor G., Jr. (A 1937), Sales Engr., U. S. Radiator Corp., and (for mail), 615 State St., Louisville, Ky. WHITE, Thomas J. (7 1937), Sales Engr., American Blower Corp., and (for mail), 1472 Filbert, San Francisco, Calif. WHITE, William R. (A 1936), Air Cond. Engr. ' (for mail), Nebraska Power Co., 17th and Harney St., and 4339 Larimore Ave., Omaha. Nebr. WHITELAW, H. Leigh (Af 1916), Vice-Pres. (for mail), American Gas Products Corp., 40 West 40th St., New York, N. Y., and Ring9 End Rd., Noroton, Conn. WHITELEY, Stockett M. (Af 1933), Consulting Engr. (for mail), 908 Baltimore Life Bldg., and 3931 Canterbury Rd., Baltimore. Md. WH1TMER, Robert P. (Af 1935), Secy, (for mail), American Foundry & Furnace Co., McClun and Washington Sts., and 1402 E. Washington St.. Bloomington, 111. '- WHITNEY, C. W. (Af 1935), Pres., ABC Oil Burner & Engineering Co., 2012-14 Chestnut St., Philadelphia, and (for mail). Apt. F-l, Sevilla Court, Bala-Cynwyd. Pa. 60 Roll of Membership WHITT, Sidney A. (A 1938; 7 1937). Air Cond. and Refg. Engr. (for mail), Kelvinator Corp., 14250 Plymouth Rd., and 11950 Ohio Ave., Detroit, Mich. WHITTAKER, Wayne K. (A 1935), Bldg. Maintenance Mechanic, Irving Trust Co. Bldg., 1 Wall St., New York, and (for mail), 221-14 114th Ave.. St. Albans, L. L, N. Y. WHITTALL, Ernest T. (A 1933), Vice-Pres., May Oil Burner of Canada, Ltd., 17 Elm St., and (for mail), 11 Cottingham Rd., Toronto, Ont., Canada. WHITTEN, Horace E. (Af 1924), Pres, and Treas., . H. E. Whitten Co., 9 Federal Court, Boston, and (for mail), 56 Highland Rd., Somerville, Mass. WHITTINGTON. James A. (Af 1936), Utilization Testing Engr. (for mail). Peoples Gas Light & Coke Co., 3921 S. Wabash Ave., Chicago, and 622 Sheridan Square, Evanston, 111. WIDDOWFIELD, Arthur S. (7 1937), Sales Engr. (for mail). The Mercoid Corp., 4201 Belmont Ave., and 6610 N. Maplewood Ave., Chicago, III. WIEGNER, Henry B. (Af 1919), Branch Mgr., Johnson Service Co., 20 Winchester St., Boston, and (for mail), 143 Standish Rd., Watertown, Mass. WIERIMAN, William J. (A 1937; 7 1936), Draftsman (for mail), Kearney & Trecker Corp., and 1462 South 70th St.. West Allis, Wis. WIGGS. G. Lome (Af 1936; A 1932; 7 1924), Consulting Engr. (for mail). University Tower, and 4797 Grosvenor Ave., Montreal, Que., Canada. WIGLE, Bruce M. (A 1926), Pres, (for mail), Bruce Wigle Plumbing & Heating Co., 9117 Hamilton Ave., and 18114 Oak Drive, Detroit, Mich. WILDER, Edward L. (Af 1915), Mgr., Gas Sales (for mail). Utility Management Corp., 150 Broadway, New York, and 12 Mereland Rd., New Rochelle, N. Y. WILEY, Donald C. (7 1936), Engr., (for mail), John J. Nesbitt, Inc., State Road & Rhawn St., and 3338 St. Vincent St., Philadelphia, Pa. WILHELM, Joseph E. (7 1936; S 1934), Office Engr. and Purch. Agent, Avery Engineering Co., 2341 Carnegie Ave., and (for mail), 1804 East 100th St., Cleveland, Ohio. WILKES, Gordon B* (Af 1937). Prof, of Heat Engrg. (for mail). Massachusetts Institute of Technology, Cambridge, Mass., and 51 Everett St.. Newton Centre, Mass. WILKINSON, Arthur (A 1936), Mgr. (for mail). Wilkinson Engineering Agencies, 1253 McGill College Ave., Montreal, and 469 Argyle Ave., Westmount, Que., Canada. - WILKINSON, Farley J. (Af 1933). Mgr., Cent. Engrg. Service, Montgomery Ward & Co., and (for mail), 18257 Martin Ave., Homewood,'III. WILLARD, Arthur C* (Af 1914), (Presidential Member). (Pres., 1928; 1st Vice-Pres.. 1927; 2nd Vice-Pres., 1926; Council, 1925-1929), (for mail). President. University of Illinois, and 711 Florida - Ave., IJrbana, 111. W1LLEK. Murray D. (7 1937; S 1936), Air Cond. Engr., F. W. Chambers & Co., Ltd., 96 Bloor St., W., and (for mail), 1243 St. Clair Ave., W., Toronto, Ont., Canada. WILLEY. Earl C. (Af 1934). Asst. Prof, of Mech. Engrg.. Oregon State College, and (for mail), 1652 "A" St., Corvallis, Oregon. , WILLIAMS, Allen' W. (A 1915), Managing Director (for mail). National Warm Air Heating & Air Conditioning Association, 50 W. Broad St., Columbus, and 51 Meadow. Park, Bexley, Ohio. WILLIAMS, Donald D. (7 1937), Gas Htg. Engr. (for mail), Iowa Nebraska Light and Power Co., 1401 "0" St., and 2236 A St., Lincoln, Nebr. WILLIAMS. Frank H. (7 1934). Engr., DelcoFrigidaire Cond. Div. of General Motors, and (for mail), 603 Rockford Ave., Dayton, Ohio. WILLIAMS, Gordon S. (7 1937; 5 1936), 207 Orange St., New Haven, Conn. WILLIAMS, J. Walter (Af 1915), Pres, (for mail). Forest City Plumbing Co., 332 E. State St., and 923 E. State St., Ithaca, N. Y. WILLIS, Leonard L. (7 1936; S 1935), Engr., Conrad Refrigeration Co., 17 E. Hennepin Ave., and (for mail), 5036 Lyndale S., Minneapolis, Minn. WILLNER, Ira (Af 1937), Pres, (for mail), Willner Heating Co., Inc., 210 East 38th St., and 3875 Waldo Ave., New York, N. Y. WILMOT, Charles S. (Af 1919), (for mail). Building Insulation Co.. Lancaster Ave. at Jefferson St., Philadelphia, and 406 Essex Ave., Narberth, Pa. WILSON, Alexander (Af 1936), Consulting Engr. (for mail), 315 New Birks Bldg., and 3750 Cote des Neiges Rd., Montreal, Canada. WILSON, Andrew (Af 1935), Survey and Esti mating Engr., Paragon Oil Burner Corp., 75 Bridgewater St., and (for mail), 5523 Seventh Ave., Brooklyn, N. Y. WILSON, Eric D. (Af 1936), Special Agent for India. Carrier Corp., c/o Volkart Bros., Ballard Estate, Bombay, India. WILSON, George T. (Af 1925), Sales Engr.. Gurney Foundry Co.. Ltd., 4 Junction Rd., - Toronto, and (for mail). Tyre Ave., Islington, Ont., Canada. . WILSON, Harry B. (7 1937). Sales Engr., Brook lyn Union Gas Co., 180 Remsen St., and (for mail), 801 Ocean Ave., Brooklyn, N. Y. WILSON, James W. (7 1936; S 1935). Route 1, Box 132 A, Irving, Texas. WILSON, Raymond W. ;(Af 1934), Member of Firm (for mail), Wilson-Brinker Co., 412 Pythian Bldg., and 429 Creston Ave., Kalamazoo, Mich. WILSON, Robert A. (Af 1936), Sales Engr., Minneapolis-Honeywell Regulator Co., 4501 Prospect Ave., Cleveland, and (for mail), 1520 Grace Ave., Lakewood, Ohio. WILSON, W. H. (A 1932), Steamfitter Foreman, Pullman-Standard Car Mfg. Co., 11001 Cottage . Grove Ave., and (for mail), 22 West 110th Place. Chicago, 111. WILTBERGER, Constant F. (Af 1935), Partner, S. Howard Pennell & Co., Land Title Bldg., and (for mail), 2650 N. Ninth St., Philadelphia. Pa. WINANS, Glen D. (Af 1929), Engr. of Steam Distribution (for mail), Detroit Edison Co., 2000 Second Ave., and 16183 Wisconsin Ave., Detroit, Mich. WINKLER, Ralph A. (7 1937), Sales Engr. (for mail), Alfred C. Goethel Co., 2337 North 31st St., and 2766A North 41st St., Milwaukee. Wis. WINSLOW, C.-E. A.* (Af 1932), Prof, of Public Health (for mail), Yale University, 310 Cedar St., and 314 Prospect St., New Haven, Conn. ' WINTERBOTTOM, Ralph F. (Af 1923). Engr., Winterbottom Supply Co., and (for mail), 400 Campbell Ave., Waterloo, Iowa. WINTERER, Frank C. (Af 1920), Sales Mgr. (for mail). Cochran Sargent Co., Broadway and Kellogg Blvd., and 836 Juno St., St. Paul, Minn. WINTHER, Anker (Af 1937; A 1936; 7 1932), Air Cond. Engr. (for mail), York Ice Machinery Corp., 659 E. Sixth St., and 3620 Stettinius Ave., Cincinnati. Ohio. WISSING, Clement B. (A 1936), Secy, and Sales Mgr. (for mail). Ebner Ice & Cold Storage Co., Locust and Chestnut Sts., and 702 N. Sixth St., ' Vincennes, Ind. WITHERIDGE, David E. (7 1936), Engr., W. A. Witheridge Co., 746 S. Fourth Ave., Saginaw, Mich. WITMER, Charles N. (A 1937; 7 1930), Dist. Dealer Supv. (for mail). Carrier Corp., 2022 Bryan St., and 4154 Prescott St., Dallas, Texas. WITMER, Howard S. (A 1937). Sales Engr. (for mail), Dail Steel Products Co., Hosmer and Main, and 204J6 E. Kalamazoo, Lansing, Mich. WOESE, Carl F. (Af 1934). Consulting Engr. (for mail), Robson & Woese, Inc., 1001 Burnet Ave., and 256 Robineau Rd., Syracuse, N. Y. WOLF, John C. (Af 1923), Htg. and Vtg. Engr. (for mail), B. F. SturteVant Co., and 76 Beacon St., Hyde Park, Mass. 61 Heating Ventilating Air Conditioning Guide 1938 WOLF, Philip (Af 1935), Proprietor. City Con tracting Co., 304 East 62nd St., New York. N. Y. WOLFF. Peter P. (Af 1935), Engr., Bell & Gossett Co., 3000 Wallace St., and (for mail). 7609 S. Coles Ave., Chicago, III. ' WOLIN, Milton W. (7 1938; S 1937), Engr., (for mail), 1393 Lexington Ave., New York, N. Y., and R. F. D. No. 2, Box 73-D, New Brunswick, N. J. WOOD, Charles F. (Af 1937). Director, New Product Demands. DelcoFrigidaire Division, 1420 Wisconsin Blvd., and (for mail), 359 Aber deen Ave., Dayton, Ohio. WOOD, Roderick A. (7 1937), Editorial Asst., Fowler-Becker Publishing Co., 420 Madison Ave., New York, and (for mail), 482 Bard Ave., West New Brighton, Staten Island, N. Y. WOODMAN, Lawrence E. (Af 1934), Pres, (for mail). Woodman Appliance & Engineering Corp., 203 E. Capitol, and Prince Edward Apt., Jeffer son City, Mo. WOODS, Baldwin M. (Af 1937), Prof. Mech. Engrg. (for mail), University of California, and 249 The Uplands, Berkeley, Calif. WOOLLARD, Mason S. (Af 1934), Draftsman, H. H. Angus, Consulting Engr., 1221 Bay St., and (for mail), 31 Hillcrest Park Ave., Toronto 5. Ont., Canada. WOOLLEY, J. Herbert (A 1936), Vice-Pres. (for mail), Woolley Coal Co., Inc., 12 Burnett Ave., Maplewood, and 75 Oakview Terrace, Short Hills, N. J. WOOLSTON. A. H. (Af 1919), Woolston-Woods Co., 2132 Cherry St., Philadelphia, Pa. WOOTAN, Charles (A 1937), Sales Engr. (for mail), Crane Co., 6215 Carnegie Ave., and 11118 "Clifton Blvd., Cleveland, Ohio. WORLD, Harry P. (Af 1936). Engr. (for mail), Col. Mackenzie Waters, Archt., 96 Bloor St.,- W., and 30 Roswell Ave., Toronto, Ont., Canada. WORSHAM, Herman (Af 1925; 7 1918), National Business (for mail), Delco-Frigidaire Condition ing Division, 1420 Wisconsin Blvd., and 519 W. Norman Ave., Dayton, Ohio. WORTHING. Stanley L. (Af 1936), Consulting Engr. (for mail), 433 Kelsey Bldg., Grand Rapids, and Spring Lake, Mich. WORTHINGTON, Thomas H.'(Af 1937), Local Mgr. (for mail). Dominion Radiator & Boiler Co., Ltd., 405 Beaubien St., W., and 5145 Cote St. Luc Rd., Montreal, Que., Canada. WORTON, William (Af 1937), Mgr., Branch Office (for mail), C. A. Dunham Co., Ltd., 504 Scott Bldg., and 292 Lansdowne, Winnipeg, Man., Canada. . WRIGHT, Clarence E. (7 1935; 5 1933). Sales Engr., Fairmont Wall Plaster Co., Tenth-St., and (for mail), 908 Gaston Ave., Fairmont, W. Va. WRIGHT, Harris H. (Af 1917), Mfrs. Repr. (for mail), 320 E. Tenth St.,' and 808 Greenway Terrace, Kansas City, Mo. WRIGHT, Kenneth A. (Af 1921), Branch Mgr. (for mail). Johnson Service Co., 1113 Race St., Cincinnati, Ohio, and 113 Orchard Rd., Ft. Mitchell, Covington, Ky. . WRIGHT, M. Bimey (A 1932; 7 1929), Mech. Engr. (for mail), E. I. duPont deNemours & Co., P. O. Box 1537, and Cedar Ave., S. Hills, Charles ton, W. Va. ' WRIGHT, William J. (7 1936; S 1935), 1114 W. Illinois St., Urbana, 111. .- WRIGHTSON, Wilbur T. (Af 1937), Eastern Mgr. (for mail). Garden City Fan Co., 55 West 42nd St., and 324 East 41st St., New York, N; Y. WUNDERLICH, Milton S.* (Af 1925). Chairman Research and Test Committee, Insulite Co., 1100 Builders Exchange, Minneapolis, and (for mail), 545 Mt. Curve Blvd., St. Paul, Minn. WYATT, DeWltt H. (Af 1936), Pres, and Gen. Mgr., Cooling & Heating, Inc., 364 N. High St., and (for mail), 226 Northridge Rd., Columbus, Ohio. WYLD, Reginald G. (Af 1937), Executive Engr. (for mail), Airtemp, Inc., 1119 Leo St., and 431 Brookside Drive, Dayton, Ohio. - WYLIE, Howard M. (Af 1925; 7 1917), Vice- Pres. in charge of Sales (for mail), Nash Engi neering Co., and 51 Elmwood Ave., South Norwalk, Conn. Y YAGER, Johri J. (Af 1921), 425 Woodbridge Ave.. Buffalo, N. Y. YAGLOU, Constantin P * (Af 1923), Asst. Prof, of Industrial Hygiene (for mail). Harvard School of Public Health, 55 Shattuck St, Boston,' and 10 Vernon Rd., Belmont, Mass. YATES, George L. (7 1936; 5 1934), Instructor, Dept. Oil and Gas Prod., University of Pitts burgh, Pittsburgh, Pa., and (for mail), 1220 Johnstone, Bartlesville, Okla. .' YATES, James E. (Af 1934), Mgr. (for mail), Yates-Neale & Co., 231 Tenth St., andj431-16th St., Brandon, Man., Canada. YATES, James E., Jr. (7 1936), Iron Fireman Dealer, and (for mail), Yates, Neale & Co., 231 Tenth St., and 431-16th St., Brandon, Man., Canada. . YATES, Walter {Life Member; M 1902), Govern ing Director (for mail), Matthews & Yates, Ltd., Cyclone Works, and Parksend, Swinton, Man., England. YERKES, William L. {A 1937), Engr. (for mail). Carrier Corp., 12 South 12th St., Philadelphia, and 295 W. Essex Ave., Lansdowne, Pa. YOUNG, Emil O. (A 1935), Pres, (for mail). Young Regulator Co., 4500 Euclid Ave., and 2040 East 83rd St., Cleveland, Ohio. YOUNG, Forest H., Jr. (A 1936), Secy.-Treas., Young Heat Engineering Co., 116 North 26th .St.. Billings, Mont. YOUNG, Harold J. (Af 1937), Sales Engr., Young Radiator'Co., Occidental Hotel Bldg., and (for mail), 1364 Lakeshore Drive, Muskegon, Mich. YOUNG, J. T., Jr. (A 1936), Sales Engr. (for mail). Crane Co., Box 1410 (307 W. Second So.), and 237 D St., Salt Lake City,' Utah. Z .` ZACK, Hans J. (Af 1928), Pres., Zack Co., 2311 Van BureD St., Chicago, 111. . ZANGRILLI, Albert J. (7 1937; 5 1935), Junior Engr., Electric Products Corp., 5624 Penn Ave., and (for mail), 537 Turrett St., Pittsburgh, Pa. ZIBOLD, Carl E. (Af 1929), Mech. Engr., Htg. and Vtg., 13 Chadwick Rd., Westminster Ridge, White Plains, N. Y. . - ZIEBER, William E. (Af 1935), Asst. Chief Engr. - (for mail), York Ice Machinery Corp., Roosevelt Ave., and 112 S. Penn St., York, Pa. ZIESSE, Karl L. (A 1931), Secy.-Treas. (for mail), Phoenix Sprinkler & Heating Co.. 115 Campau Ave., N.W., and 315 Hampton Ave., S.E., Grand Rapids, Mich. .' - ZIMMERMAN, Alexander H. (A 1930), Venti-. lation Engr., Chicago Board of Health, Randolph and LaSalle St., and (for mail), 5449 N. St. Louis Ave., Chicago, IU. . ZINK, David D. (Af 1931). Consulting Engr. (for mail), 320 West 47th St., Kansas City, and Hickman Mills, Mo. ZOKELT, Carl G. (Af 1921), Consulting Engr., 3810-24th Ave., S.. Seattle, Wash. ZUHLKE, William R. (Af 1928), Exec. Engr., American Radiator Co., 40 West 40th St., New York, and (for mail), 54 Midland Ave., Yonkers, N. Y. - ZUROW, William (7 1937), Sales Engr. (for mail), St. Joseph Railway, Light, Heat and Power Co., Sixth and Francis St., and 1018 Messanie St., St. Joseph, Mo. ZWALLY, August L. (A 1937), Air Cond. Engr.. Interstate Electric Co., 300 Spring St., and (for mail), 908 Elmwood, Shreveport, La. 62 ALABAMA Birmingham-- Cone, W. E. Fried, H. V. Gause, H. C. Hardy, F. L. Lichty, C. P. . Murphree. R. L. Trawick, j. G. Mobile-- Kistler. M. L. ARIZONA Lowell-- 'Vinson, Neal-L. Phoenix-- Hummel, G. W. ARKANSAS Little Rock-- McCoy,- C. E. Pine Bluff-- Greer, W. R. Siloam Springs-- Jones, C. R. . CALIFORNIA Albany-- . ICaup, E. O. Bakersfield-- Baker, H. S. Berkeley--. Bentley, C. E. Cherry, V. H. Foote, A. G. Raber, B. F. Woods, B. M. Beverly Hills--Theobald, A. Culver City-- Owen, J. D.. Fullerton-- Miles, C. N. Glendale-- Moon, F. L. Orear, A. G. Storms, R. M. LIST OF MEMBERS Geographically Arranged UNITED STATES and ISLAND TERRITORIES Los Angeles-- San Francisco-- Anderson, C. S. Ames, C. S. Baender, F. G. Anaya, M. Berglund, N. W. Bouey, A. J.. Blumenthal, M. I. Cochran, L. H. Bullock, H. H. Coclrins, W. W. . Cawby, E. L. ' Conrad, R. Cline, E. A. Cooley, E. C. Cooper, A. W. Corrao, J. Cranston, W. E., Jr. Feyge, H. . Dickinson, T. Haley, H. S. Douglas, H. H. Higdon, H. S. Downes, A. H. s Hill. J. A. . Ellingwood, E. L. Holland, R. B. English, H. - Hook, F. W. Hajek, W. J. Hudson, R. A. Hendrickson, H. M. Kindorf, H. L. Hess, A. J. Kooistra, J. F. Hill. F. M. Krueger, J. I. Hogue, W. M. Leland, W. E. Hungerford, L. Marshall, T. A. Kendall, E. H. . O'Connor, G. P. Kennedy, M. Peterson, N. H. Kilpatrick, W. S. - Simonson. G. M. Lauer, H. B. Ward, E. B. Leilich, R. K. Wayland, C. E. Miller, G. Wethered, W. Moriarty, J. M. White, T. J. Nelson. E. L. Ness, W. H. C. Santa Monica-- Ott, o. w. Park, J. F. Phillips R. E. Coghlan, S. F. Sausalito-- Polderman, L. H. Schechter. J. E. . Scofield, P. C. Wallace. K. S. Howe, W. W. South Pasadena--' Warren, H. L. Weidele, E. J. West Los Angeles-- Oakland-- . Cummings,'G. J. Mears, L. A. Fabling, W. D. Lehmann, M. COLORADO OrInda-- Harrison; G. G. Colorado Springs-- Jardine, D. C. Pacific Palisades-- Finney, B. Palo Alto-- Johnson, O. W. Pasadena-- ' Gifford, R. L. - Piedmont-- Gayner, J. . . Denver-- Davis. A. F. McNevin, J. E. McQuaid, D. J. O'Rear, L. R. Pierce, E. D. Ward, O. G. . . . Fort Collins-- ' Curtice, J. M. CONNECTICUT Sacramento--. '. Freeman, J. C.. ' ' Bridgeport-- Earle. F. E. * Smak, J. R. San Diego1--' Sadler, C. B. East Hartford-- Pritchard. W. J. Fairfield-- Osborn, W. J. . Glenbrook-- Wahrenbrock, O. K. Greenwich-- Jones. A. L. Opperman, E. F. Hartford-- Krintzman.H. Middlebifty-- Lincoln, R. L. New Britain-- Leupold, H; W. New Haven-- Blakeley, H. J. Rodee, E: J. Seeley, L. E. Teasdale, L. A. Williams, G. S. Winslow, C.-E. A.' New London-- Chapin, C. G. Forsberg, W. Hopson, W. T. South Norwalk-- Adams, H. E. Harvey, A. D. iennings, I. C. -yons, C. J. Mead, E. A.' ' Wylie, H; M. ' Stamford-- Hoyt. L. W. Jehle, F. Jessup, B. H. ' Torrington-- Doster, A. Wallingford-- Bums, J. R. Waterbury-- Simpson, W. K. Stewart, C. W. ' DELAWARE Wilmington-- Belt, N. O. Gawthrop, F. H. Hayman, A. E.,` Jr. Kershaw, M. G. Lownsbery, B. F. ,, Ponsell,' F. I. Robinson, G. L. , Schoenijahn. R. P. Shepherd, C. B. . Heating Ventilating Air Conditioning Guide 1938 DISTRICT OF COLUMBIA Washington-- Bennett, C. A. Bensinger, M. Cover, R. R. Cullen, A. G. Day, I. M. Devore, A. B. De Witt, E. S. Downes, H. H. Eagleton, S. P. Erisman, P. H., Jr. Febrey, E. J. FeltweU, R H. Fife, G. D. Fineran, E. V. Fisher, J. T. France, C. N. Frankel, G. Frederick, W. L. Gardner, S. F. Goddard, W. F. Gregg, S. L. . Grimes, F. M. Hanlein, J. H. Hartline, W. R. Holmes, P. B. Iverson, H. R Keplinger, W. L. Kiczales, M. D. Kingswell/W. E. Leser, F. A. Liebrecht, W. J. Littleford, W. H. Lloyd, E. H. . Lockhart, W. R Loughran, P. H., Ji Loving, W. H. Mayette, C. E. McDonald, A. K. Meyers, J. Miller. G. F. Nelson, H. M. Nest. R. E. Nordine, L. F. Nye, L. B., Jr. Ourusoff, L. Reinoldl, C. Ritt, C. F. Robinson. D. M. Schlemmer, B. G. Sutter, E. E. Thomas, ,G. Thompson, N. S. Thuney, F. M. Tuxhom, D. B. Urdahl. T. H. Walz, G. R FLORIDA Jacksonville-- Allen. W. W. Thornton, W. B. Varner, J. L. Miami-- Lingo, C. K. Munro, E. A. Pizie, S. G. Rock, G. A. Ward, H. H. Miami Beach-- Friedman, D. H., Jr. Orlando-- , Lyle, E. T. Porter, C. W. West Palm Beach-- Hodeaux, W. L. GEORGIA Atlanta-- Baker, C. T. Barnes, L. L. Beechler, J. S. Boyd. S. W. Brockinton, C. E. Clare, F. W. Cole. C. B. Driscoll, M. G. Foss. E. R Gouedy, K. E. Gunnell, G. T. Hahn, R. F. Kagey, I. B., Jr. Kelley, R. D. Kent, L. F. Klein, E. W. Krayenhof, H. G. McCain, H. K. McKinney, W. J. Pounds, C. A. Sudderth, L.. Jr. Templin, C. L. Tucker, T. T. Augusta-- Akerman, J. R Arndt, H. W. Decatur-- Sherman, W. P. Savannah-- Hamlin, J. B., Jr. HAWAII Honolulu-- Manning, C. E. Petersen, S. E. ILLINOIS Alton-- Carlock, M. F. Bloomington-- . MaGirl, W. J. Nesmith, O. E. Scholl, H. O. Soper, H. A. Whitmer, R P. Champaign-- Hintz, H. P. Ransom, C. F. Strakosh, W. C. Thetford, J. E. Chicago-- Adams, B. P. Aeberly, J. J. Aikman, J. M. Ammerman, A. S., Jr. Arenberg, M. K. Baker, W. H.. Jr. Bamond, M. J. Baumgardner, C. M. Baur, J. W. ' Becker, W. A. Beery, C. E. Benson, B. C. Bemstrom, B. Bishop, M. W. Black, F. C. Boehmer, A. P. Bolte, E. E. ' Boiling, J. R. Bowles, E. N. Boyle. J. R. Bracken, J. H. Braun, L. T. Brigham, C. Mv Brightly, F. C., Jr. Brocha, J. F. Brooke, I. E. Broom, B. A. Brown, A. P. Brown, T. Buraam, C. M., Jr. Casey, B. L. Chapin, H. G. Christman, W. F. Christopherson, A. E. Clegg. R. R Cochran, C. C. Crone, C. E., Jr. Crump, A. L. Cunningham, T. M. Cutler, J. A. Dasing, E. Dauber, O. W. DeLand, C. W. Dolson, C. N. Dunham, C. A. Emmert, L. D. Ericsson, E. B. Eskin, S. G. Fatz, J. L. Finan, J. J., Sr. Fleming, J. P. Fleming, T. F. Frank, J. M. Gardner, W., Jr. Gaylord, F. H. Getschow, R M. Gibbs, F. C. Goelz, A. H. Gossett, E. J. .Gothard, W. W. Gotschall, H. C. Graham, E. W. Graves, W. B. Haas, S. L. Haines, J. J. Hale. J. F. * Hanley, T. F., Jr. Hart, H. M. Hattis, R E. Hayden, C. F. , Hayes, J. J. Hebley, H. F. J. Heckel, E. P. Herlihy, J. J. Hess, D. K. Hill, E. V. Hinckley, H. B. Hines. J. C. Horner, S. D. Howard, F. L. . Howatt, J. Howell, L. Hubbard, G. W. Hustoel, A. M. Isett, W. M. Jenson, J-. S. Johns, H. B. Johnson, C. W. Keating, A. J. Keeney. F. P. Kehm, H. S. King. A. C. Knudsen, W. R. Krez, L. Kyle, W. J. Lagodzinski, H. J. La Roi, G. H., II Larson, C. P. Lauterbach, H., Jr; Leuthesser. F. W., Jr. Lewis. S. R. Lindsay, G. W., Jr. Linn, H. R. Lockhart, H. A. Luders, R. H. Mabley, L. C. Machen, J. T. Malone, D. G. Malvin, R C. - 64 Manny. J. H. Marschall, P. J. Martin, A. B. Matchett, J. C. Mathis, E. Mathis, H. Mathis, J. W. .May, E. M. May, M. F. McCauley, J. H. McClellan, J. E. , McDonnell, E. N. McDonnell, J. E. Medow, J. Mertz, W. A. Miller, F. A. Miller, R T. Milliken, J. H. Mueller, H. C. Murphy, E. T. Murphy, W. A. Narowetz, L. L., Jr. Neiler, S. G. Newport, C. F. Nightingale, G. F. Offen, B. Olsen, C. F. Olson, B. Paul, L. O. Peller, L. Pickett, C. A. - " Pitcher, L. J. Pope, S. A. Powers, F. W. Prentice, O. J. Price, C. E. Priester, G. B. Rasmussen, R P. Raymond, F. I. xveiu, n. r. Rietz, E. W. Rottmayer, S. 1. Runkel, C. . Russell, E. A. Ryerson, H. E. Scheidecker, D. B. Schuetz, C. C. Schuler, W. B. Schwartz, H. J. Schweim, H. J. Seelig, L. - Shilling, H. C. Shultz, E. Solstad, L.'L. Sommerfield, S. S. Spielman, G. P. Stacy, L. D. Stannard, J. M. Stermer, C. J. . Stokes, A. Sutcliffe, A. G. Swanson, N. W. Thinn, C. A. Thomas, R H. Thommen, A. A. Tobin, J. F. Tornquist, E. L. Trumbo, S. M. Turner, G. G. Van Alsburg, J. H. Vernon, J. R. Walters, W. T. Washington, L. W. Weil. M. Weil. M. I. Weinfeld, C. Weinshank, T. Wendt, E, H. White, E. B. . Whittington, J. A. Widdowfield, A. S. Wilson, W. H. Wolff, P. P. Zack, H. J. Zimmerman, A.TL Roll of Membership Chicago Heights-- Boyar, S. L. Cicero-- Brown, N. A. Decatur-- Shorb, W. A. East St. Louis-- Cover, E. B. Edwardsville-- Blackmore, J. J. Elmhurst-- Jones, D. J. Evanston-- Horton, H. F. Maccubbin, H. A. . Miller, J. E. Glencoe-- ` Hornung, J. C. Glen Ellyn-- Parsons, L. D,, Jr. Sherman, V. L. Homewood-- Wilkinson, F. J. Hoopeston-- Moore, D. R. _ Kewanee-- Bronson, C. E. Dickson, R. B. Hartman, J. M. PurseU, H. E. LaGrange-- Eaton, B. K. . Lake Forest-- Scudder, B. Moline-- Belihg, E. H. * Johnson, W. G. Nelson, H. W. Nelson, R H. Otis, G. E. Sharp, H. C. __ _ Mt. Vernon-- Benoist, L. L. Benoist, R E. Oak Park-- Blanding, G. H. Fitzgerald, M. J. Smith, R H. Uhlhorn, W. J. Park Ridge-- Bevington, C. H. Kuechenberg, W. A. Moore, R E. Spielmarin, H. J. Peoria-- . Baird, S. A. . Farnsworth, J. G. Fox, E. L. Hauer, F. Logan, T. M. Meyer, F. L. . . Weeks, P. Peru-- Gallagher, P. Rockford-- Braatz, C. J." Dewey, R P. Drake, G. F. Merwin, G. E. Pruden, B. Stewart, D. J. Urbana-- Bowditch, R. P. Broderick, E. L. Compton, W. E. Fahnestock, M. K. Konzo, S. Kratz, A. P. Sevems, W. H. Willard, A. C. Wright, W. J. VJlla Park-- Armspach, O. W. Waukegan-- Killian, T. J. Western Springs-- Washington, G. Winnetka-- Close, P. D. Killian. V. J. Mittendorff, E. M. Zion-- Baughman, L. R INDIANA St-Mary-of-theWooda-- Bisch, B. J. Vincennes-- Wissing, C. B. Wabash-- Shivers, P. F. West Lafayette-- Hoffman, J. D. IOWA Ackley-- Nelson, G. O. Ames-- Norman, R A. Cedar Rapids-- Friedline, J. M. Des Moines-- Daubert, L. L. Elbert, B. F. Stiles, G. S. Vaughn, F. R Walters, A. L. Sioux City-- Hagan, W. V. Waterloo-- Todd, M. L. . Winterbottom, R F. Evansville-- Bulleit, C. R Grossman, F. A. Goshen-- Shaw, B. E. Huntington--. Redrup, W. D. Smith. G. W. Indianapolis-- Ammerman, C. R. Fenstermaker, S. E. Fillo, F. B. . Hagedon, C. H. Hamerski, F. D. Hayes. J. G. Hildreth. E. S. Mulloy, E. Niesse, J. H. Poehner, R. E. Supple, G. B. Voorhees, G. A. Lafayette-- Voigt, R N. LaPorte-- Shrock, J. H. Truitt, G. S. Lawrenceburg-- Bechtol, J. J. Michigan City-- Stockweil, W. R ` Westphal, N. E. Muncle-- Pfriem, P. G. Price, C. F. Waggoner, J. H. Peru-- Thrush, H. A. KANSAS Fort Leavenworth-- Foley, D. F. Gamble, C. L. Hutchinson--' Mann, A. R Stevens, H. L. Lawrence-- Machin, D. W. Sluss, A. H. Neodesha-- Berzelius, C. Ei Russell-- Danielson, E. B. Salina-- . Ryan. W. F. Wichita-- Leverance, H. J. Olson, G. E. KENTUCKY Anchorage-- Brooks, H. B. Cold Spring--' Ward. F. J. Fort Thomas-- Leupold, G. L. Reik. R. C. Stevens, W. R Lexington-- Bozeman, R. W. Cabot, M. A. May, J. W. O'Bannon, L. S. Wallace, W, M,, II West, P. 65 Louisville-- . Danielson, W. A. Fitch. H, M.' Grabensteder, L. Graham, J. M. Groot. H. W. Hellstrom, J. Murphy, H. C. White, T. G., Jr. LOUISIANA New Orleans-- Blum, H., Jr. ' Gamble, C. B. Gammill, O. E., Jr. Herman, N. B. Kaufman, C. W. May. G. E. McLaren, F. S. Moses, W. B., Jr. Perkins, R C. Ryan, J. D. Salzer, A. R, Jr. Seidel, G. E. Shreveport-- . Fitzgerald, W. E. Zwally, A. L. MAINE Bangor-- Prince, R F. Lewiston-- Fowles, H. H. Portland-- Fels, A. B. Merrill, C. J. Mitchell, C. H. MARYLAND Annapolis-- Gale, H. A. Baltimore-- Collier, W. I. Crosby, E. L. Dorsey, F. C. Dull, E. J. Hunt, M. Tex. J., Jr. Leilich, R L. McCormack, D. Page, V. C. Posey, J. Powers, E. C. Seiter, J. E. Shepard, J. deB. Sklarevski, R Smoot, T. H. Steele. M. G. Stehl, H. V. Vance, L, G. Viessman, W. Vincent, P. J. Whiteley, S. M. Bethesda-- Goodwin, E. W. Stock, C. S. Terhune, R D. . Vaughan, J. G., Jr. Brooklyn Park-- Rodgers, J. S. College Park-- Gifford, W. R Heating Ventilating Air Conditioning Guide 1938 Ellicott City-- . Tibbets, J. C. Rockville-- Brunett, A. L. Silver Spring-- Black. F. M. Stack, A. E. ' MASSACHUSETTS Arlington-- Shaw, N. J. H. Arlington Heights-- Tarr, H. M. . Auburndale-- Frederick, H. W. Belmont-- Spence, R A. - Boston-- Archer, D. M. Barron, J. T. Berchtold, E. W. Boyden, D. S. Brinton, J. W. Brissette, L. A. ` Bryant, A. G. . Bullock, T. A. Cummings, C. H. Dickson, G..P. Donohoe, J. B. Drinker, P. Edwards, D. J. Foulds, P. A. L. Franklin. R S. * Gleason. G.H. Hashagen, J. B. Jenning9, R A. Jennings, W. G. Keefe. E. T. Kelley, J. J. Kellogg. A. Keyes, R E. Kimball, C. W. Little, D. H. . Macrow, L. . McCoy, T. F. Merrill. F. A. Millard. J. W. Miller, J. F. G. Mullen, T. J., Jr. Nee. R M. Osborne, M. M. Palmer, R T. Plunkett, J. H. Rydell, C. A. Spoerr, F. F. Stetson, L. R Swaney, C. R Tuttle, J. F. Waterman, J. H. Whitten. H. E. Yaglou, C. P. Bridgewater-- Beaulieu, A. A. Cambridge-- Daitsh, A. Flint, C. T. Gerrish, G. B. Haddock. I. T. Holt, J. Hoyt, C. W. Longwell, J. S. MacDonald, E. A. Moore, H. C. Peterson. C. M. F. Sheffield, R A. Turner, J. Wilkes, G. B. . Cochituate-- Ahearn, W. J. Dalton-- Dakin, H. W. Dorchester-- . Brayman, A. I. . Goodrich, C. F. Hosterman, C. O. Shaer, I. E. Voye, V. J. East Milton-- Austin. W. H. Fall River-- Fenner, E. M. Fitchburg-- Earley, T. J. Iffig. W. R Karlson, A. F. McKittrick, P. A. Foxboro-- Meakin, J. B. Harwich Port-- Maxwell, G. W. Holyoke-- Colby, C. W. Hyde Park-- Bartlett, A. C. Ellis. F. R Wolf, J. C. Lawrence-- Bride, W. T. Leominster-- Kern, R T. Lynn-- Farrow, H. L. Feehan, J. B. Mattapan-- Ahlberg, H. B. Milton-- Corey, G. R Needham-- Park, C. D. Webb. J. S. Newton Centre-- Murray, J. J. Newtonville-- Emerson, R. R Jones, W. T. McMurrer, L. J. Pittsfield-- Wagner, E. A. ' Quincy-- Stone, E. R Reading-- ' Ingalls, F. D. B. Rosllndale-- Larson, C. W. Roxbury-- t Madden, J. J. Sharon-- Nelson, A. W. South Hamilton-- Mandell, T. P. * South Boston--. Hilliard, C. E. Springfield-- Blair, H. A. Cross, R. E. Holmes, R. E. Leland, W. B. Murphy, W. W. Swampscott-- Knowles, M. G. Oates. W. A. Watertown-- Wiegner, H. B. Wellesley Hills-- Barnes, W. E. West Roxbury--. Christie, A. Y. McCafierty, J. E. McPherson, W. A. Woburn-- Parker, P. Wollaston-- - Hodgdon, H. A. Worcester-- Wechsberg, O. MICHIGAN Ann Arbor-- - Backus, T. H. L. Bichowsky, F. R Emswiler, J. E. Marin, A. Battle Creek-- Christenson, H. Birmingham--* . Hadjisky, J. N. Hyde, E. F. ' Root, E. B. Dearborn-- King, H. K. Detroit-- . Akers, G. W. Annas, H. C. Araoldy,\W. F. Baker, R H. Baldwin, W. H. Barth, H. E. Barton,-J. Bishop, F. R Blackxnore, F. H. Boales, W. G. * Brown, R E. G. Brown. W. Burks, R H. Clark, E. H. Connell, R. F. Coon, T. E. Cummins, G. H. Darlington, A. P. Dauch, E. O. . ' Deppmann, R L. Dickenson, F. R ` Dubry, E. Eckert, E. K. Estep. L. G. Falk, D. S. Feely, F. J. Feinberg, E. ' . Flink, C. H. * Ford, E. F. Giguere, G. H. Halleck, L. P. Hamaker, A. C. Harrigan, E. M. Hesselschwerdt, A L., Jr. Heydon, C. G. ` Hogan, E. L. Hubbard. N. D. Hughson, H. H. Hutzel, H. F. Kaufman, H. J. Keyser, H. M. Kilner. J. S. Kincaide, M. C. Kirkpatrick, A. H. Knapp, A. E. Knibb, A. E. Lee, J. A; Lewis, G. M. Linsenmeyer, F. J. Long, D. J. Luty, D. J. Maier, G. M. Martel. C. L. Marzelf, F. X. McConachie, L. L. McCrea, J. B. McGaughey, H. M. McGeorge, R. H. Mclntire, J. F. McLean, D. Metcalfe; C. ` Meyer, J., Jr. Miller, R E. Milward, R. K. , Morse, C. T. Morse, L. S., Jr. . O'Gorman, J. S. . Old. W. H. Parrott, L. G. . Partlan, J. W. Patterson, F. H. Pavey, C. A. ' Pike. W. Purcell, F. C. Randall, R D. Randall, W. C. Russell, W. A. - Sanford, S. S. Schechter, J. P. . Schmidt, K., Jr. Shea. M: B. Sheley, E. D. Smith, W. O. Snell, E. . Snyder, J. W. Soeters, M. Spitzley, R. L. Spurgeon, J. H. Sterner, D. S. . Stites. R. Jr. ; Taylor. H. J. Toonder, C.-L. TutUe, G. H. Van Nouhuys, H. C. Volberding, L. A. Waid, G. H. . Walker. J. H. Weinert, F. C. Whelan. W. JJ - White, E. S. Whitt, S. A. Wigte, B. M. . Winans, G. D. Dowaglac-- Cunningham, J. S. Torr, T. W. East Lansing-- Miller, L. G. Pesterfield, C. H. 66 Roll of Membership Grand Rapids-- . Bradfield, W. W. Bratt, H. D. . ' Epple, A. B. Graff. W. F. Marshall, O. D. Morton, C. H. Osberger,.T. L. Stafford, T. D. Todd, S. W. Warren, F. C. Worthing. S. L. Ziesse, K. L. Highland Park-- Harrower, W. C. Houghton-- Seeber, R. R Iron Mountain-- Eisele, L. G. Jackson-- Gerhard, D. H. Kalamazoo-- Brinker, H. A.. . Downs, S. H. McConner, C. R' Metzger, H. J. - Schlichting, W. G. Temple, W. J. `' . Wilson. R. W. ' `Lansing-- Chrouch, R B. ' Haas, R B. McLouth. B. F. / Parsons, R. A. Vanderlip, P. J. Witmfer, H. S. Mt. Clemens-- ' Bailey, E. P., Jr. Muskegon-- Young, H. J. Muskegon Heights-- ' Reid, H. F. Pontiac-- . Singleton, J. H. .Port Huron--. : Blessed, W. A^..: Royal Oak-- Burch, L. A. . Helmrich, G. B. . Saginaw-- Witheridge, D. E. MINNESOTA Bayport-- Swanson, E. C. Duluth-- Foster, C. Hibbing-- Miller, L. L. Minneapolis-- Albrecht. H. P. Algren, A. B. Anderson, S. H. Armstrong, R W. Bell, E. F. Bensen. C. L. Betts, H. M. . Bjerken, M. H. Bredesen, B. P. Bums. E. J. ' Burritt, C. G. Campbell. R. L. Carlson, C. O. Comb, F. R, Jr. Cooper, T. E. Copperud, E. R Cumming, F. J. Dablstrom, G. A. Davidson, J. C. Dovolis, N. J. Doxey, H. E. Edelman, B. P. Fergestad, M. L. Forfar, D. M. Francis, P. E. . Gausewitz, W. H. Gerrish, H. E. r Gordon, E. B.t Jr. Gross, L. C. Hall. J. R. Hanson, L. P. Harris, J. B. - Hawkinson, C. F. Helstrom, H. G. Hitchcock, P. C. Huch, A. J. Johnson, L. H. . King, R L. Kingsland, G. D. Knapp, D. S. Knowles, E. L. Kuehn, W. C. . * Lange, F. F. Legler, F. W. . . ` Lilja, O. L. ' Lund, C. E. - Miller, L. B. Mills. H. C. ` . Morgan, G. C. Morton. H. S. Ogard, N. L. Orr, G. M. Petersen, C. P. Poucher, R C. . ' Roberts, H. P. Roberts, J. R. . . Rowley, F. B. Schad, C. A. Schernbeck, F. H. Schultz, A. W. Schwantes, A. R ' Seelert, E. H. Spencer, J. B. Stiller. F. W. Sturm, W. Sundell, S. S. Sutherland; D. L. . Swenson, J. E. Uhl, E. J. . Uhl, W. F. . Wallace, H. P.. Jr. Welter, M. A. Willis. L. L. * . Owatonna-- Anderson, G. A. M. . Rochester-- Adams, N..D. Maynard; H. R. ` Plummer, R S. . St. Paul-- Anderson, D. B. Ayers, E. H. ' Backstrom, R E. Barnum, C. R Bauer, A. E. ' Bean, G. S. Cook. G. E. Cuthbertson, M. W. Diamond, D. D. -- . Estes, E, C. Fitts. C. D. Gausman, C. E. Hickey. D. W. Hyde, L. L. Jones, E. F. McNamara, W. Mitchell. J: G. Oberg. H. C. Persson, N. B. Ruff, D. C. Sanford, A. L. Swanstrom, A. E. Winterer, F. C. Wunderlich, M. S. Wayzata-- r Heberiing, C. W. MISSOURI Clayton-- DuBois, L. J. Ferguson-- Szombathy, L. R. Independence-- Cook, B. F,. ' Jefferson City-- Woodman, L. E. Kansas City-- ' Adams, C. W. Allen, D. M. Angus, F. M. Arthur, J. M., Jr. ' Ball, W. Barnes, A. R . Barnes. H..P. Betz, H. D. Bliss, G. L. Caleb. D. Cameron, W. R. Campbell, E. K. Campbell, E. K., Jr. Carlson, C. V. Case. D. V. Cassell, W. L. Chase, L. R /->i__ r> uawson, i. l*. Dean, F. J., Jr. Dean, M. H. DeVilbiss, P. T. Disney, M. A. Dodds. F. F. ' Downes, N. W. Farber, L. M. Fehlig, J. B. Flarsheim, C. A. Forslund, O. A. . Garnett, R. E. Gillham, W. E. . Gould. H. E. Haas. E., Jr. Hallar, E. VHarbordt, O. E. Kitchen, J. H. Lang. J. C. Maillard, A. L; Marston, A. D. Matthews, J.*E. Middleton, H. A, Millis, L. W. . Moore, B. J., Jr. Natkin, B. . Nottberg, G. Nottberg, H. Nottberg, H., Jr. Painter, D. H. Pellmounter, T. Pettit. E. N., Jr.. 67 Pexton, F. S. Pines, S. - Rivard, M. M. Robb. J. E. . Sawyer, J. N. Scarlett. W. J. Schick. K. W. Sheppard, F. A. Stephenson, L. A. Stevens, K. M. Weiss, C. A. White. H. S. Wright, H. H. Zink. D. D. Kirkwood-- Hartwein, C. E. Maplewood-- Droppers, C. J. Siegel, W. A. Mexico-- Badaracco, J. A. Normandy-- Dulle, W. L. . Richmond Heights-- Nelson, C. L. Springfield-- James, R. E. Karchmer, J. H. St. Joseph-- Flynn, F. J. Harton, A. J, Zurow, W. St. Louis-- . Allen, C. V. Barry, J. G., Jr. Bayse, H. V. . Boester, C. F.. Jr. Bradley, E; P. , Carlson,- E. E. Carter, J. H. Cooper, J. W. Corrigan, J. A. Davis, C. R. Driemeyer, R C. Edwards, D. F. Evans, B. L. Fagin, D. J. Foster, J. M. Gilmore, L. A. Grossmann, H. A. Haller, A. L. Haxnig, L. L. Hamilton, J. E. Hester. T. J. Hugoniot, V. E. Irwin, R. R . Kent. J. K. . Kimmel, W. G. Kuntz, E. C. Langenberg, E. B. Laufketter, F. C. Lautz, F. A. Malone, J. S. - Matousek, A. G. McLarney, H. W. McMahon, T. W. Moon, L. W. O'Brien, W. N. Oonk, W. J. . Rickner, C. A. Rodenheiser, G. B. Rosebrough, J. S. Rosebrough, R M. Scherrer, L. B. Sodemann, P. ` Sodemann, W. C. B. Stammer, E. L. Sydow, L. J. Heating Ventilating Air Conditioning Guide 1938 Tenkonohy, R. J. Warren, J. S., Jr. Weber, E. F. White, E. A. University City-- Falvey, J. D. Webster Groves-- Harbaugh, J. W. Myers, G. W. F. Ronsick, E. H. MONTANA Big Timber-- Strickland, A. W. Billings-- Cohagen, C. C. Young, F. H., Jr. Great Falls-- Ginn, T. M. NEBRASKA Clarks-- Manning, W. M. Columbus-- Ragatz, T. E. Lincoln-- Darling, J. K. Dexter, E. R. Hellmers, C. C., Jr. Hennessy, W. J. King, L. D. Leach, L. S. , Lehman. M. G. Matthews. W. M. Prawl, F. E. Ress, O. J. Rosenba<, R. F. Shapiro, M. M.- Stanton, H. W. Stevenson, M. J. . Tapley, M. S. Williams, D. D. Omaha-- Anderson, J. W. Banner, F. L. D. Goll, W. A. Kleinkauf, H. Larkin, P. Lindberg, A. F. Lycan, L. K. Malcolm, B. L. Moffitt, L. C. Olson, M. J. Peiser, M. B. Rigby, R. A. Rist, L. M. Sallander, H. A. Solzman, I. I. Tracy, W. E. . White, W. R. * Scottsbluff-- Davis, O. E. NEW HAMPSHIRE Elkins-- Baker, R. H. NEW JERSEY Arlington-- Adler, A. A. Bock. B. A. Atlantic City-- Labov, M. Strouse, S. B. Asbury Park-- Strevell, R. P. Bayonne-- Schwartz, J. Belleville-- Thornton, T. L. Bloomfield-- Clericuzio, G. P. Faust, F. H. Harrington, E. McLenegan, D. W. Tenney, D. Bogota-- Griess, P. G. Camden-- Brown, W. M. Coward, C.W. Kappel, G. W. A. Lanning, E. K. Plum. L. H. Webster, E. K. Webster, W. Webster, W., Jr. Clifton-- Hilder, F. L. Cliffslde ParkButler, P. D.. Colllngswood-- Bolsinger, R. C. ' Mohrfeld. H. H. Cranford-- Roos, E. B. J. Dover-- Hedden, W. M. East Orange-- . Atkins, T. J. Ferguson, R. R. Gombers, H. B. Maddux, O. L. Reilly, J. H. Settdmeyer, J. T. Tallmadge, W. Tumo, W. G. W. Wadsworth, R. H. Elizabeth-- Cornwall, G. I. Faulkner, G. Lyman, S. E. Traynor, H. S. Wheller, H. S. Essex Fells-- Soule, L. C. Stacey, A. E., Jr. Freehold-- Buck, D. T. ' Hasbrouck Heights-- Goodwin, S. L. Haworth-- Sharp, J. R. Hawthorne-- Spoelstra, W. J. Hoboken-- Munson, J. L. Irvington-- Reinke, A.G. Stengel, F.J. Jersey City-- Jones, H. L. Ritchie. W. Walterthum, J. J. Lyndhurst-- Ehrlich, M. W. Maplewood-- Kepler, D. A. Kylberg, V. C. Woolley, J. H. Merchantville-- ' Binder, C. G. Rohlin, K. W. Montclair-- Bentz, H. Newark-- Bryant, P. J. Carey, P. C. Holbrook, F. M. Leinroth, J. P. Morehouse, H. P. Ray, L. B. Raymer, W. F., Jr. . Steinmetz, C. W. A. North Arlington-- Bermel, A. H. Trambauer, C. W. North Bergen-- Constance, J. D. Orange-- Crawford, J.H., Jr. Paterson-- Bannon, L. E. Cox, H. F. Pryor, F. L. Perth Amboy-- Simkin, M. Plainfield-- Tobin, G. J. Ridgefield Park-- Davis, A. C. Ridgewood-- Fitts. J. C. Wallace, D. R. Rochelle Park-- Emery, &. W. Roselle-- Snavely, E. R. Roselle Park-- Kampish, N. S. Somerville-- Van Nuys, J. C. South Orange-- Browne. A.. L. Feldermann, W. ' Summit-- Oaks, O. O. Teaneck-- Heebner, W. M. Trenton-- Wagner, J. G. 68 Union City-rTaverna, F. F. Upper Montclair-- Smith, F. J. Verona-- Boxall, F. Shotwell, R. W. West Englewood-- Gumaer, P. W. Steinke, B. J. Westfield-- Scribner, E. D. West Orange-- Adlam, T. N. West New York-- Stinard, R. L. NEW YORK Albany-- Bond, H. A. Dick, A. V. Johnson, H. S.' Lewis, H. F. Murray, T. F. Nelson, A. W. Ryan, H. J. Taggart, R. C. Teeling, G. A. Westover, W. Bedford Hills-- Mehne, C, A. Waters, F. A. Bronxville-- Bishop, C. R. Domheim, G. A. Buffalo-- Beman, M. C. Booth, C. A. Bulkeley, C. A. Cherry, L. A. Cheyney, C. C. Currier, C. H. Curtis, W. A. Davis, J. . Day. H. C. Drake, G. M. Eisele. W. S. Farnham, R. Farrar, C. W. Gifford, C. A. Grieves, T. R. Harding, L. A. Hart, F. D. Hawk, J. K. Heath, W. R. Hedley, P. S. . Hexamer, H. D. Hirschman. W. F. Jackson, M. S. Kaiser, F. Kamman, A. R. Landers, J. J. Lenihan, W. O. Lighthart, C. H. Love, C. H. Madison, R. D. Mahoney, D. J. Messenger, T. I. Mosher, C. H. Reif. A. F. Reif. C. A. Rente, H. W. Roebuck, W., Jr. Schafer, H. f. Roll of Membership Schmidt, H. Seelbach, H. Seelbach, H., Jr. Shelney, T. Snyder, J. S. Sweatt, C. H. Voisinet, W. E. Walker. E. R. Wendt, E. F. Yager, J. J. Corning-- . Bates, H. C. Croton-- , Elliott, I. Derby-- Ensign, W. A. Elmira-- Davis, B. C. Glens Falls-- Hollister, E. W. Hamburg-- Graham, C. H. Hartsdale-- - Hedlund, R. A. Hastings-on - Hudson Reynolds, T. W. Hyde Park-- Burr, G. C. ~ Irvington-- Bastedo, A. E. Murphy, C. G. . Ithaca-- Barns, A. A. Elwood, W. H. Fairbanks, F. L. Sawdon, W. M. Williams, J. W. Kendall-- Stangland, B. F. Kenmore-- Candee, B. C.' ' Criqui, A. A. Mollenberg. H. J. Sommers, W. J.-- Larchmont-- Downe, E. R. Gayior, W. S. Lockport-- Prudden, O. D.. Saunders, L. P. Montgomery-- Vogelbach, O. Mt.* Vernon-- Cribari, H. E. Finnerty, J. A. Freitag, F. G. Northon, L. Obert, C. W. New Rochelle-- Abrams, A. Farley, W. F. Giannini, M. C. Lambert, R. D. Rose. H. J. Terry, M. C. Wallace, G. N. New York City-- Addams, H. Adler, J. C. (Forest Hills, L. I.) Alt. H. L. (St. Albans) Apt. S. R. (Flushing) Ashley. E. E., Jr. Baker, H. L., Jr. Ballman, W. H. Balsam, C. P. (Brooklyn) Barbieri, P. J. Barnum, M. C. Bastedo, G. R. (Richmond Hill). Baum, A. L. Bearman, A. A. Beebe, F. E. W. Belsky, G. A. Bennett, E. A. Berman, L. K. Bernhard. G. (Brooklyn) Bianculli, V. A. Blackburn, E. C., Jr. (Garden City, L. I.) Blackman, A. O. ` Blackmore, J. J. Blackshaw, J. L. (Brooklyn) Blakeslee, D. (Patchogue) Bloom, L. (Brooklyn) Bodinger, J. H. Bolton, R. P. Bonthron, R. C. Borak. E. 1 Bowles, P. Brabbee, C. W. Broome, J. H. (Brooklyn) Brown, D. Buensod, A. C. Burr, K. Buttaravoli, F. (Brooklyn) Callahan, P. J. (Great Kills, S. I.) Campbell, F. B. Campbell, R. E. (Brooklyn) Carbone, J. H. (Baldwin, L. I.) Carpenter, R. H. Charles, T. J. (Brooklyn) Charlet, L. W. Chase, C. L. Connell, H. (Staten Island) Cross, F. G. ' Cucci, V. J. Dailey, J. A. . (Astoria, L. 1.) Daly. R. E. Darts, J. A. Davison, R. L. Deely, J. J. (Brooklyn) Denny, H. R. De Somma, A. E. - (Brooklyn) Deterling, W. C. Dodge. H. A. Donnelly, R. Downs, C. R. Duff, K. Duncan, J. R. Dwyer, T. F. (Brooklyn) Eadie, J. G. Elliott, L. Engle, A. Erickson, E. V. Etlinger, M. J. Everetts, J., Jr. Faile, E. H. Fay, D. P. (Richmond Hill) Fay. F. C. Feldman, A. M. Fenner, N. P. ' Fidelius, W. R. (Brooklyn) Fiedler. H. W. Fischer, L. (Sayville,`L. I.) Fitz, J. C. Fleisher, W. L. Frank, O. E. Friedman, M. Frimet, M. (Stapleton, S. I.) Fritz, C. V. (Freeport) Galloway, J. F. (Kew Gardens, L. I.) Gates, R. A. (Brooklyn) Gitterman, H. Glore, E. F. Goldberg,'M. ' (Brooklyn) Goldschmidt. O. E. Gordon, P. B. Gornston. M. H. (Brooklyn) Goulding, w. (Brooklyn) Graber, E. (Astoria, L. I.) ' Greben, D. Green, A. W. (Jackson Heights, L. I.) Greenberg, I. Greenburg, L. Groves, S. A. - . Hament, L. ` Hamje, M. C. (Brooklyn) Harsch, R. J. (Brooklyn) Hateau, W. M. Hechler, S. . Heibel, W. Henry, A. S., Jr. Hering, A. Herkimer, H. Herske, A. R. Herty, F. B. (Brooklyn) Hiers, C. R. ' (Great Neck) Hildreth, L. W. Hinkle, E. C. (Hempstead) Hinrichsen, A. F. Hobbie, E. H. Hoehl, E. R. Hoffman, C. S. Hollister, N. A. (Brooldyn) Honerkamp, F. Hosking. H. L. Hotchkiss, C. H. B. Hyman, W. M. d'lssertelle, H. G. ' Jacobus, D. S. Jalonack, I. G. (Patchogue, L. I.) James, J. W. . Janet, H. L. (Brooklyn) Jarcho, M. D. Johnson, E. B. c W. New Brighton, S. I.) Johnson, W. A. Johnston, W. H. Jordan, W. D. Josephson, S. (Brooklyn) Kaczenski, C. (Bridgehampton, L. I.) Kastner, G. C. Kelly. C. J. Kenney, T. W. Kern, J. F., Jr. (Elmhurst) Kessler, J. Kimball, D. D. Knopf, C. (Brooklyn) Koehler, C. S. Kuhlmann, R. Kurth, F. J. Landewit, C. J. (St. Albans, L. I.) Lane, D. D. . (Elmhurst) Leventhal, B. (Brooklyn) Lewis, C. A. (Astoria, L. I.) Lewis, T. Lucke, C. E. Lyons. M. A. Maher, T. F., Jr. (St. Albans, L. I.) Markush, E. U. Martens, E. D. Martin, G. W. Matzen, H. B. (Rockville Centre, L. I.) McClintock, W. McCloughan, C. (Brooklyn) McEwan, E. E. McGaughey. J. E. Jr. McKiever, W. H. McLeish, W. S. Meinke, H. G. Merle, A. (Jackson Heights. L. I.) Meyer, C. L. (Hollis, L. I.) Meyer, H. C., Jr. Milener, E. D. Miller, C. A. Miller, J. Montgomery, O. C. Morse, F. W. Moss, E. (Brooklyn) Munier, L. L. Murphy, J. R. Mytlnger, K. L. Neale, L. I. Offner, A. J. Oldes, W. E. Olsen, G. E. (Arveroe, L. I.) Olson, R. G. Olvany, W. J. Pabst, C. S. (Woodhaven, L. I.) Patomo, S. A. S. Pfuhler, J. L. (W. New Brighton. S. I.) Phillips, F. W., Jr. (Brooklyn) ' Pietsch, J. A. (New Brighton, ' S. I.) Pihlman, A. A. Pinto, C. B. (Lawrence, L. 1.) Place, C. R. Pohle, K. Heating Ventilating Air Conditioning Guide 1938 Poliak, R. Purdy, R. B, Purinton, D. J. Quirk, C. H. . Raisler. R. K. Ramsay, J. W. Rather, M. F. Raynis, T. (Richmond Hill) Reynolds, W. V. Richfield. N. H. (Floral Park, L. I.) Riley, R. C. (Jamaica)' Ritchie, E.J. (Brooklyn) Ritter, A. Rodman, R. W. Rose! J. C. (Brooklyn) Rosenberg, P. Rosenburg, W. E. (Locust Valley, L. I.) Rosenthal, E. Ross, J. O. Roth, C. F. Roy, A. C. ' Rudd, D. J. (Babylon) Ruggles, R. F. (Randall Manor, . S. I.) Salter, E. H. Samuels, S. - Sanbem, E. N. (Rockville Centre, L. I.) Sawhill, R. V. Schermer, R. * ' (Elmhurst, L. I.) Schoepflin, P. H. Schulein, E. H. . (Forest Hills,-L. I.) Schulze, B. H/ Scott, A. F. H. Scott,- G. M. Seelig, A. E. Sellman. N. T. Senior, R. L. Shaffer, C. E. Sherbrooke, W. A. Siebs, C. T. . Simpson, A. M. Sklenarik, L. Smith. M'. S. ' Stalb, J. G. - (Brooklyn) . Steeneck, K. C. (Bellaire, L. I.) Stellwagen, F. G. (Woodhaven) Sternberg, E. - (Long Island City) Still, F. R. Stravitsch, J. J. (Ozone Park, L. I.) Strock, C. . Strunin, J. Syska, A. G. Taze, E. H. Thomson, T. N. (Huntington, L. I.) Tiltz, B. E. Timmis, W. W, Torrance. H. Tucker. F. N. (Freeport, L. I.) Tusch, W. (Brooklyn) Tyler. R. D. Vervoort, E.- L. - (Rockville Centre, * L. I.) . Vetlesen, G..U, . Vivarttas,' E. A. (W. New Brighton, S. I.) Vroome, A. E. (Prince Bay, S. L) Wachs, L. J. (Brooklyn) Wade, R. H. ' (Laurelton, L. I.) Waechter, H. P. (Staten Island) Wagner, F. H., Jr. Walker, W. K. Wallace, G. J. (East Elmhurst) Walsh, M. ' Walton. C. W., Jr. Waring, J. M. S. Wheeler, J., Jr. Whitelaw, H. L. Whittaker, W. K. (St. Albans, L. I.) Wilder, E. L. Wiilner, I. Wilson, A. (Brooklyn) _ Wilson, H. B. (Brooklyn) Wolf, P. Wolin, M. W. Wood, R. A. (West New Brigh ton, S.I.) Wrightson, W.-T. Niagara Falls-- Kessler, M. E. North Pelham-- . Dome, A. G. North Tarrytowri-- Weiss, A. P. North Tonawanda-- Conaty, B. M. Oswego-- Mohn, H. L. ' Pelham-- Crone, T. E., Pelham Manor-- Peacock, J. K. ; Rochester-- . Andresen, G. C. Betlem. H. T. Cook, R. P. Eschenbach, S. P. Hakes, L. M. Hewett, J. B. Hutchins, W. H. Lee, R. T. Leonhard, L. W. Stacy, S. C. Treadway, J. Q. Vidale, R. Rome-- Lynch, W. L. Scarsdale-- Cumming, R. W. Ullman, H. G. Schenectady-- ' Danielson, L. C. Hunziker, Cl E. Seely, I. R. ' Vogel, A. . Welch, L. A,, Jr. Schodack Landing-- ' Freas, R. B. Snyder-- John, V. P. Syracuse-- Acheson, A. R. Ashley. C. M. Cady. E. F. Carrier, W. H. Cherne, R. E. Day. V. S. Dee. L. H. Des Reis. J. F. Driscoll, W. H. Evans, E. C. . French, D. Graham, W. D. Grant, W. A. Hockensmith; F. E. Ingeis, M. M. Jackes, H. D. . Lewis, L. L. - Lyle. J. I. ' O'Rourke, H. D., Jr. Perina, A. E. Schulz, E. L. Sheldon, N. E. . Taliaferro. R. R. Woese, C. F. Tonawanda-- Karlsteen, G. H. Utica-- Knapp, J. H. Price. E. H. Skidmore, J. G. Steinhorst, T. F. White Plains-- Bennitt, G. E.' Durkee, M. E. Rose, A. A. Ruple, P. E. Zibold, C. E. ' Yonkers-- - Dean, D. . Goerg, B. ` Harmonay, W. L. Hayter, B. ' Hopp, H. K. Kelly, J. G. Rainger, W. F. Zuhlke, W. R. NORTH CAROLINA Charlotte-- Arden, I. L. Brandt, E. H., Jr. Campbell,.A. Q., Jr. Hill, H. H.' Hodge, W. B. * Muirheid, J. G. Shirley. W. B. Durham-- Cooke, T. C. Greensboro-- Harding, E. R. . Small, B. R. High PointGray. W. E. Raleigh-- Rice, R. B. Winston-Salem-- Bahnson, F. F. . Brown, M. D. Cornwall, C. C. Page, A. 70 OHIO Akron-- McElhaney, G* W. Shields, C. D. ' Cincinnati-- Bird, C. - ' Boyd, T. D.- . Coombe, J. Doneison, W. N. Doyle, W. J. Edwards, A. W. Fenker, C. M. Green, W. C. : Helburn, I. B. Houlis, L. D. ' Houliston, G. B.' Hudepohl, L. F. Hust. C. E. " Junker, W. H. Kiefer, C. J. Kinney, A'. M. Kramig, R. E., Jr. Little. K. B. Mason, G.'C. ` Mathewson, M.- E. Mayer, R. W. Mayne, W. L. Mills, C. A. - Pillen, H. A. Pistler,-W. C;- . ` Powers, L. G.'. . . Richard, E. J. Royer, E. B, - - . Ruff, A. G.- . Sigmund, R. W. Silberstein, B. G.- Smith, J. A. . Smith, S. " . Sproull, H. E. Sutfin, G. V. . . - Washburn, M. J. ' Winther, A. Wright, K. A.' Cleveland-- . Avery, L. T.' ' ' Beach, W. R. 4 Borkat, P. ' Brezina, E.A. Cary, E. B. Cheeseman, E. W. Cohen, H. . Cohen; P. Conner, R. M. Curtis, H. F. Eveleth, C. F. Friedman, A. Geissbuhler, J. O. Gottwald, C. Gray, E. W. Greenleaf, R. P. Harris, J. G. * Harvey, L. C. . Heisterkamp, H. W. Jones, J. P. Kaercher, C. M. H. Kain, E. M. Kalinsky, A. G* Kitchen, F. A. Klie, W. Kofoed, V. B. - Levy, M. I. Marotta, J. A. . Martinka, P. D. ` Maurer, F. J. McKeeman, C; A. Moeller, R. ' Moore, W. R. Pogalies, L. H. Repko, J. J. Rhoton, W. R. Rowe, W. M. Schurman, J. A. Roll of Membership r Simon, A. Smith. W. D. Southmayd, R. T. Taze,' D. L. - Tuve, G. L. Vanderhoof, A. L. Walker, J. E. Weatherby. E. P., Jr. Webb, E. C. Weldy, L. O. Wetzell, H. E. Wilhelm, J. E. Wootan, C- C. ` Young, E. O; Cleveland Heights-- Davis, R. G. Richmond, J. Sogg, A. Sterling, J. G., Jr. Columbus-- . Ailonier, H. R. _ Breneman, R. B. ' Brown. A. I. - " . ' Cooper, W. B. '; Cross, R. C. Denise, J. R. Kimmell, P. M. Myler, W. M., Jr. Poling, D. B. Sherman, R. A. Sidwell, E. W. White, E. D. Williams, A. W. Wyatt, D. H. Cuyahoga Falls-- Humphrey, D. E.. Jennings, H. K. Dayton-- Baker, I. C. Brown, J. S., Jr. Buenger, A. Chapman, W. A., Jr. Clarke, J. G. Gibbons, M. J., Jr. Gonzalez, R. A. Hansler, y. E. . . Hull, H. B. Hutchings, R. L. Kuempel, L. L. .. La Salvia, J; J. Lewis, C. E. Livar, A. P. MacMillan. A. R. Nessell, C. W. Noble. J. P. Sidell, P. A. Snyder, A. K. Swift. P. F. Williams, F. H. Wood. C. F. Worsham. H. . Wyld, R. G. East Cleveland-- Geltz, R. W. Morris, F. H. Nobis. H. M. Sennet, L. E. Stark, W. E. Steffner, E. F. Elyria-- . Maynard, J. E. t* Hamilton-- Thomas. L. G. L. Hudson-- . Follett; T. L. : Lakewood-- Kubasta, R. W. Longcoy, G. B. Tanker, G. E. Teckmyer, F. C., Jr. Wilson, R. A. Middletown-- Byrd, T. Maier, A. H. . Stitt, A. B. . Newark-- Simison, A. L. Slayter, G. . Norwood-- Braun, J. J. Motz, O. W. Oberlfn-- . Ries. L. S. Palnesville-- Hobbs, J. C. ' Parma-- Kajuk, A. E. Piqua-- Lange, R. T. ' Sandusky-- . . Rathke, A. C. Shaker Heights-- ' Harvey, R. A. South Park-- Barney, W. E. Springfield-- , Hauck,--E. L. ` Toledo-- Baker, H. C. Bergan, J. R. Damm, D. A. ' Jones, S. . Mayes, C. McKitrick. W. D. Myers, F. L. Watkins! G. B. Waveriy-- Armbruster, F. T. W. Wilmington-- ` Marconett, V. G'.' Sapp, C. L.. Worthington-- Slemmons, J. D. Youngstown-- Boucherle, H. N. ' Montgomery, J. R. OKLAHOMA AlvaHusky. S. T. Bartlesville-- Yates, G. L. Norman;-- . Adams, B. C., Jr. Dawson, E. F. GUes, J. C. Sonney, K. J. Oklahoma City-- Carnahan. J. H. Dolan. R. G. Dugger, E. R. Earl, W. Gray, E. W. Holyfield, E. F. ' Hoppe, A. A. Howlett-, I. G. Loeffler, F. X. Loeffier, L., Jr. . Meinholtz, H. W. Middleton, D. K. Mideke, J. M. Miller, B. R. Patton, R. L. - Rathbun, P. W. Rolland, S. L. Spencer; D. . Tiller, L. Tulsa-- . Dean, C. H. . Holmes, A. D. Jones, E. Jordan, R. C. Pauling, R. E. Scherrer,. K. C. . Shoemaker, F. F. . OREGON Corvallis-- Willey, E. C. Portland-- Kroeker, J. D. Taylor. T. E. . PENNSYLVANIA Abington--....... . Park, N. W' Allentown-- Hersh, F. C. Kom, C. B. Ambler-- McElgin. J. W. Ardmore-- Haynes, C. V. Ardsley-- Tucker, L. A. . Bala-Cynwyd-- Patrick, H. M. Whitney. C, W. Beaver Falla-- Van Alen, W. T. Bethlehem-- Bomstein, W. Murnin, E. A., Jr. Stuart, M. C. . ; .. Bradford-- '' ` Cleveland. C. C. . Paterson, F. C., Jr. Presdee, C. W. Turner, P. K. Brookline-- . . Donnelly, M. A. ) 71 Clearfield-- . Gault. G.W.- ' . Dunbar-- Sherwood, L. T. ' Elizabeth town-- Dibble, S. E. Erie-- Joyce, H. B. McDowell, B. W. Preece, L. W. Sahimann, F. L. Etna-- Park, H. E. Glenside-- Werner, J. G. . Greensburg-- . Burkhart, E. M. Harrisburg-- Eicher. H. C. , Geiger, I. H. " . Haverford-rBlack, E. N.. Ill' ' Hershey-- Snavely, A. B. ' Johnstown-- Huettner, H. F. Hunter, L. N. Knowles, F. R. Novotney, T. A. * . Kingston-- . ; Macdonald, D( BJ Lancaster:-- ' Chenoweth, D. M. Jones, A. ' Lloyd, E. C. Lansdowne-- Hicks, H. K. James, H. R. Lauer, R. F. Mawby, P. Lemont-- - Henszey, W. P. ; Manheim-- ' .. Weitzel, C. B: Weitzel, P. H. \ McKeesport-- . . Dugan, T. M. - McKees Rocks-- Rodgers, F. E. - Middletown-- " Locke, R. A. ; Midland-- ; Crichton. H. C. Narberth-1- .. Dever, H. F. . Searte, W. J., Jr. .v Heating Ventilating Air Conditioning Guide 1938 New Castle-- Andrews. G. H. Sonneborn, C. New Kensington-- Edwards, J. D. Norristown-- Hucker, J. H. Oxford-- Ware, J. H., Ill Philadelphia-- Adams, B. ' Ahlff, A. A; Arnold, R. S. Bachman. F. Barnard, M. E. Bartlett. C. E. Black! H. G. Blankin.M. F. Bogaty, H. S. Bornemann, W. A. Burke. J. Caldwell, A. C. Call, J. Cassell, J. D.' Clodfelter, J. L. Cody. H. C. Culbert, W. P. Dambly, A. E. Davidson, L. C. Dietz, C. F. Donovan, W. J. Elliot, E. Erickson, H. H. Evleth, E. S. . Faltenbacher, H. J. Familetti, A. R. Galligan, A. B. Gant, H. P. Gillett. M. C. Gilman, F. W. Guler, G. D. ' Hackett, H. B. Hance. W. W. Hedges. H. B. Hibbs, F. C. Hunger, R. F. Hynes; L. P. ' Ickeringill, J.. Jopson, J. M. Kelble, F. R. Kriebel, A. E. Landau, M. Leopold, C. S. Lyon, P. S. . MacDade, A. H. Mack, L. ' Martocello, J. A. Mather, H. H. McClintock, A., Jr; McCullough, H. G. Mcllvaine, J. H. Mellon, J. T. J. Meloney, E. J. Mensing, F. D. Millham, F. B. Moody, L.` E. Morgan, R. C. Morris, A. M. Munro, G. A. Murdoch, J. P., Jr. Nesbitt, A. J. Nesbitt, J. J. Newcomb, L. B. Nusbaum, L; Plewes, S. E. Pryibil, P. L. Rank, A. I. Redstone, A. L. Reilly, C. E. Rettew, H. F. Rhea, C. A. Roberts, H. L. Rugart. K. Sabin, E. R. Schneider, C. H. Shanklin, A. P. Sheffler. M. Skagerberg, R. Smith, D. K. Smith, W. F. Speckman, C. H. Stewart, J. P. Stokes, A. D. Timmis, P. Touton, R. D. Traugott, M. Trump, C. C. Tuckerman, G. E. Wegmann, A. Wiley, D. C. Wilmot, C. S. Wiltberger, C. F. Woolston, A. H. Yerkes. W. L. Pittsburgh-- Beighel, H. A. Btber, H. A. Blackmore, G. C. Brauer, R. Bushnell, C. D. Carr, M. L. Collins, J. F. S., Jr. Comstock, G. M. Dorian, M. I. Edwards, P. A. Eils, L. C. Ellis, G. P. Frisse, J. L. Giles. A. F. Goodman, D. J. Greiner, G. E., Jr. Griest, K. Hecht,' F. H. Heilman, R. H. Houghten, F. C. Humphreys, C. M. Hyde, E. H. Kennedy, O. A. Kennedy, P. V. Landes, B. D. Loucks, D. W. Maehling, L. S. Maginn, P. F. Mahon, F. B. Marshall, A. W. McGonagle, A. McGuigan, L. A McIntosh, F. C. McLean, J. E. ' Miller, R. A. Moore, H. L. Mueller. J. E. Nass, A. F. Neis. W. A. Nicholls, P. , Parks, C. E. Proie, J. Reed. I. G. Reed, V. A.. Jr. Riesmeyer. E. H,, Jr. Rockwell, T. F. Rodgers, W. C. Rose, H. J. Scanlon, E. S. Selig, E. T., Jr. Smyer8. E. C.- Speller, F. N. Stanger, R. B. Steggall, H. B. Stevenson, W. W. Strauch, P. C. Tennant, R. J. J. Tower, E. S. Waters, G. G. Weddell, G. O. Zangrilli, A. J. Pottsvllle-- Marty, E. O. Smith, J. D. Prim03-- Hall. M. S. Johnson, A. J. Radnor-- Davidson, P. L. Reading-- Luck, A. W. Nicely, J. E. Rutledge-- Jones, N. R. Scranton-- Mahon, B. B. . Shaver, H. H. Springfield-- Grossman, H. E. Payne, R. E. State College-- Queer, E. R. Stroudsburg-- Kiefer. E. J., Jr. Swarthmore-- Hobbs, W. S. Robinson, A. S. Thom, G. B. Tarentum-- Orr, L. Uniontown-- Marks, A. A.. Upper Darby-- Aughenbaugh, H. Beitzell, A. E. Blackmore, J. S. . Currie, F. J. Eastman, C. B. Kipe, J. M. McClain. C. H. Villanova-- Barr. G. W. Carey, J. A. Washington-- Frazier, J. E. Wilklnsburg-- Campbell, T. F. Williamsport-- Axeman, J. E.' ' Wormleysburg-- Miller. T. G. Wyncote-- Buck, L. , 72 York-- Barnum, W. E., Jr. Clippinger, J. V. Hertzler, J. R. Kartorie, V. T. Walsh. E. R.. Jr. Zieber, W. E. PHILLIPINE ISLANDS Manila-- Hausman, L. M. Macrae, R. B. RHODE ISLAND Providence-- Coleman, J. B. Gibbs, E. W. Hartwell, J. C. McCarthy, J. J. McLaughlin, J. D. Moulder, A. W. SOUTH CAROLINA Clemson College-- Shenk, D. H. Columbia-- Hartin, W. R., Jr. Kerr, W. E. Mercer, C. F. Reamer, W. S,, Jr. SOUTH DAKOTA Lead-- Pullen, R. R. Sioux Falls-- Monick, F. R. - TENNESSEE Chattanooga-- Campbell, G. S. EUzabethton-- Torok, E. Knoxville-- Oakley, L. W. Memphis-- Flinn, G. S. HoshaU, R. H. Murfreesboro-- Armistead, W. C. Moore, H. W. Nashville-- Brown, F. TEXAS Amarillo-- Burnett, E.'S. Houska, A. D. . r Bryan-- Griesser, C. E. Rogers, R. C. College Station-- Badgett, W. H. Giesecke, F. E. Hines, G. M. Long. W. E. Smith. E. G. Teal, E. T. Dallas-- Anspacher, T. H. Bock. 1. I. Boruch, E. R. Constant, E. S. Durning, E. H. Gardner, C. R. . Gilbert, L. S. ' Jelinek, F. R. . Kribs, C. L,, Jr. Landauer, L. L. Martyn, H. J. Mehl, O. H. Moler, W. H. Renouf, E. P. Schmidt. H. I. Schucany, O. W. Stringfellow, J. C. Turner, H. S., Jr. Ullrich, A. B. Witmer, C. N. El Paso-- Rodgers, F. A. Fort Worth-- Skinner, H. W. Werner, R. K. Galveston-- Huff, J. M. Warren, C. W. Hereford-- ` Jones, A. P. Houston-- Cheatwood, W. H. Cochran, W. B. Cooper, D. S. Kiesling, J. A. Kurtz, R. W. McKinney. C. A. Rowe, I. E. Salinger, R. J. . Taylor, R. F. Walsh. J. A. Irving-- Wilson, J. W. Kingsville-- Richtmann, W. M. Port Arthur-- Shaw, C. G. San Antonio-- Billingsley, O. F. Cotter, R. P. Div6r, M. L, Ebert, ^V. A. Kotzebue, R. W. Monier, K. A._J. Rummel, A. J. Roll of Membership Somerville-- Barton, D. H. UTAH Salt Lake City-- Richardson, H. G. Young, J. T. Jr. VERMONT . Burlington-- Lanou, J. E. Raine, J. J. . North Ferrisburg-- . Breckenridge, L. P. VIRGINIA Arlington-- Ferrarini, J. Marshall, W. D. Rudio, H. M. Welsh, H. A. Blacksburg-- Johnston, R. M. Charlottesville--. Peebles, J. K.. Jr. Lynchburg-- Doering, F. L. Norfolk-- Capps, E. L. Nowitzky, H. S. Webster. W. H.. Jr. Portsmouth-- Stubbs. W. C. Richmond-- Belding, H. H. Carle, W. E. Johnston, J. A. Pelouze, H. L,, II Schulz. H. I. WASHINGTON Kent-- Boyker, R. O. Port Orchard-- Pratt, F. J. Seattle-- Beggs, W. E. ' , Bouillon, L. - Case. R. H. Cox, W. W. Daly, C. P. Eastwood, E. O. Granston, R. O. Hauan, M. J. MacLeod, K. F. -. Mallis, W. May. C. W. Morse, R. D. Musgrave, M. N. . O'Connell, P. M. Peterson, S. D. Pollard, A. L. Sparks, J. D. Twist, C. F. Ward, J. J. Watt. R. D. Weber, E. L. Wesley, R. O.. Zokelt, C. G. Spokane-- Russell, W. B. Tacoma-- Foote, E. E. Spofforth, W. . Yakima-- Leichnitz, R. W. McCune, B. V. WEST VIRGINIA Charleston-- Rothmann, S. C. Shanklin, J. A. Wright, M. B. Fairmont-- Tonry, R. C. Wright. C. E. Huntington-- Johnson, L. O. Largent-- Donnelly, J. A. Wheeling-- Hitt, J. C. WISCONSIN Beloit-- McKinley, C. B. Clintonvilie-- Quail, C. O. Cuba City-- Kellner. D. C. Green Bay-- Haus, I. J. Kohler-- Hvoslef, F. W. Kohler. W. J.. Jr. La Crosse-- Anderegg. R. H. Bledsoe. R. P. Miller, M, W. Rowe, W. A. Thomas, N. A. Trane, R. N. Madison-- Dean, C. L. Feirn, W. H. Hall, G. Larson, G. L. Nelson, D. W. Seymour, J. E. White, J. C. Milwaukee-- Allan. W. Banks, J. B. Berghoefer, V. A; Bernert, L. A. Bowers, A. F. Brown, W. H. Cook, H. R. Davis, K. T. Elliott, N. B. Ellis. H. W. Errath, E. O. Frentzel, H. C. Goldsmith, F. W. Gregg, S. H. Hanley, E. V. Hays, C. A. Heasier, L. W. Hughey, T. M. Jackson, C. H. Jepertinger, R. C. Jones, E. A. Jung, J. S. Ketter, J. W. Knab, E. A. Koch, R. G. Krenz, A. S. Lofte, J. A. Miller, C. W. Mueller. H. P. Noll, W. F. Page, H. W. Randolph, C. H. Reinke, L. F. Rice, C. J. Schreiber, H. W. Shawiin, W. C. Shodron, J. G. Sickert, G. D. Spence, M. R. Steinkellner, E. J. Swisher, S. G., Jr. Szekely, E. Trostel, O. A. Volk, J. H. Wagner, A. M. Weimer, F. G. Winkler, R. A. Neenah-- Angermeyer, A. H. . Eiss, R. M. Stiegler, A. J. Racine-- Dixon, A. G. Menden, P. J. South Milwaukee-- Ouweneel, W. A. Superior-- Waite, H. West Allis-- . Erickson, M. E. Spence, R. T. . Wieriman, W. J. 73 i Heating Ventilating Air Conditioning Guide 1938 CANADA Brandon, Man.-- * Yates. J. E. Yates. J. E., Jr. Calgary, Alberta-- Vissac, G. A. Edmonton, Alberta-- Mould, D. E. Flln Flon, Man.-- Foster, P. H. Fort Garry, Man.-- Davis, G. C. Freeman, Ont.-- Goodram, W. E. Galt, Ont.-- Sheldon, W. D.. Jr. Hamilton, Ont.-- . Barnes, H. ' Best. M. W. Charters. W. A. Dickenson, M. E. Moffat, O. G. Islington, Ont.-- Wilson. G. T. Kirkland Lake, Ont.-- Calver, R. W. . Kitchener, Ont.--' Beavers, G. R. Pollock, C. A. Lindsay, Ont.-- 4 McCrae, G. W. . London, Ont.-- Dobie. T. K. O'Flaherty, J. G. Montreal, P. 0*-- Allaire, L. Ballantyne, G. L. Barnsley, F. R. Darling. A. B. Dewar, W. G. Dixon, M. F. Dufault, F. H. . Dupuis, J. R. . Dykes, J. B. Forrester, N. J. Freeman. E. M. Friedman, F. J. Garaeau, L. . ' Gendron, H. ' Gittleson, H. - . ' Hamlet, A. Hughes, W. U. Johnson. C. W. Laffoley, L. H. Lamontagne.vA. F. Linton, J. P. ' Madely. F. J. . - Marshall, A. G. Martin, L. Martin, R- Morris, J. A. Murray, H. G. S. Niclde, A. J. Osborne, G. H. Peart, A. M. Perras, G. E. ' Phipps, F. G. Robertson. J. A. M. Roche, I. F. Ross, J. D. Timmins, W. W. Tolhurst, G. C. TwizeU. E. W. Watts, A. E. ' Wiggs, G. L. Wilkinson, A. Wilson, A. . - Worthington,-T. H. Ottawa, Ont.-- Allen, A. W. Colclough, O. T. Gray, G. A. ` McGrail, T. E. Pennock, W. B. , Preston, Ont.-- Everest, R. H. Quebec, Que.-- ' La Rocque, P. E. Paquet, J. M. Roy, L. ' Rigaud, Que.-- Fogarty, O. A. St. Catherines, Ont.-- i Palmason, J. H. St. Lambert, Que.-- Lefebvre, E. J., Three Rivers, Que.-- . Germain, O. . Timmins, Ont.-- Smith, R. J. Toronto, Ont.-- Alexander, S. W. Allcut, E. A. Allsop, R. P. Angus. H. H. Anthes, L. Arrowsmith, J. O. Baker, G. R. Baker, L. P. Blackball, L. C. ' Blackball, W. R. : Boddington, W. P; Bowerman, E. L. Cairns, J. H. Carter, A. W. Chambers, F. W. ' Church, H. J. Cole, G. E. Cornish, D. F. Davenport, R. F. Dickey, A. J. Dion, A. M. Dowler, E. A. Duncan, W. A. Eaton. W. G. M. Ellis. F. E. ' Ewens, F. G. ' Fitzsimons, J. P. Forrester, C. M. - Fox, E. Fox, J. H. Gauley, E. R. Givin, A. W. . Gordon, W. D. Gurney, E. H. . Gurney, E. R. " Harrington, C. -Heard, R. G. Henion, H. D. Hills, A. H. . Hopper, G. H. Hughes, L. K- . Jeffrey, T. G.- Jenney, H. B. ' Jennings, S. A. Jones, A. T. Kelly, W. C. Lawlor, J. J. Ledgett, F. D. Leitch, A. S. ' Libby, R. S. . Lower, ;H. C. MacDonald, D. J. Marriner, J. M. S. Maxwell, R. S. McCrimmon, A. M. McDonald, T. Moore, H. S. Oke. W. C. O'Neill. J. W. . Paul. D. I. . Philip, W. Playfair, G. A. Price, D. O. Ritchie, A. G. Roth. H. R. . Shears, M. W. : Sheppard, W. G. F. Stott. F. W. Tasker. C. '' Thomas, M. F. . Waldon, C. D. Warden. A. Watson, M. B. Whittall, E. T. Wilier, M. D. Woollard, M. S. World, H. P. ; Vancouver, B. C.-H Dawson, G. S. - Hale, F. J. Johnston, R. E. . Leek, W. : McCreery. H. J. ` Turland, C. H. . Victoria, B. C.-- ' Sheret, A. Wellington, Ont.-- Johnston, H. D. Westmount, Que.-- Colford, J. . : Pratt, J. C. . Windsor, Ont.-- Aitken, J. . ' Hare, W. A. Winnipeg, Man.-- ' Argue, E. J.- Cunliffe, J. A. Eade, H. R. . Glass, W. Jones* B. G. Kent, R. L. ' Kipp, T. Michie, D. F. ' Miller, E. R. . Munn, E.` F. Steele, J. B. . - Summers, E. T. . Thompson;;F. ! Watson, H. D. . Worton, W.. . ' Woodstock, Ont.-- Karges, A. AUSTRALIA Melbourne-- Atherton, A. E. Ross, R. Sydney-- Davey, G. I. Hunt. N. P. Moloney, R. R. Picot, J. W. Robinson, J. A. Sands, C. C: BELGIUM Brussels-- Mautsch, R. BRAZIL Rio de Janeiro-- Botelho, N. J. Darby, M. H. CHINA Nanking-- Loo. P. Y. Shanghai-- Bradford, G. G. Chen, S. T. Doughty, C. J. Gange, F. B. Hart-Baker, H. W. Kwan, 1. K. Boh. N. S. Morrison, C. B. Rachal, J. M. Waung, T. F. . CUBA Havana-- .'... Edwards, H. B. ' 74 CZECHOSLOVAKIA Praha-- Brust, O. .. DENMARK Copenhagen-- Reck, W. E. DUTCH : EAST INDIES ; JAVA ' Soerabala-- . t Thornburg, H. A. Roll of Membership ENGLAND Birmingham-- Bird, G. L. H. Caterham-- Carter, D. Cheshire-- Adsheqd, B. Dartford-- Figgis, T. G. Denton-- Webb, J. W. Leeds-- Jennins, H. H. London-- . . Bailey. W. M. Benham, C. S. K. Butt. R. E. W. Chester, T. Faber, O. Fraser, J. J. Greenland, S. F. Haden, G. N. . Herring, E. Kraminsky, V. Linebaugb, J. E. Nobbs, W. W. Pryke, J. K. M. Russell, J. N. Middlesex-- Case, W. G. ' Gill, E. F. Sutton-- Casperd, H. W. H. Swinton-- Yates, W. . Trowbridge-- Haden, W. N. Wolverhampton-- Tyson, W. H.. . FRANCE Dijon-- Bur, J. R. C. Lille-- Neu, H. J. E. Lyon-- Goenaga, R. Paris-- Beaurrienne, A. Bodmer, E. Downe, H. S. Ghilardi, F. Modiano, R. Nessi, A. ' Schmutz, J. GERMANY Hamburg-- . Brandi, O. H. Stuttgart-- Klein, A. R. INDIA Bombay-- . Wilson, E. D. New Delhi-- Heard; J. A. E. IRELAND- . Cork-- Barry, P. I. Dublin-- Leonard, L. C. G. ITALY Milan-- Gini, A. Hauss, C. F. Torino-- Baldi, G. . JAPAN Osaka-- Fukui, K. Tokyo-- Kitaura, S. Kozu, T. . Saito, S. Sekido, K. MANGHOUKUO Hslking-- Kawase, S. MEXICO Mexico, D. F. . Gilfrin, G, F. Martinez; J. j; NETHERLANDS Arnhem-- ' Tanger, O. C. F. NEW ZEALAND Christchurch-- Taylor, E. M. Vale, H. A. L.. Dunedin-- Davies, G. W. NORWAY Oslo-- . Alfsen, N. Tjersland, A. . SCOTLAND Angus-- Knox, J. R. SOUTH AFRICA Durban-- Kothe, F. H. Johannesburg--. Carrier, E. G. Ehlers, J. Overton. S. H. vonChristierson, C. A, SPAIN Madrid-- Alfageme, B. , Jimenez, J. G. STRAITS SETTLEMENTS Singapore-- Faxon, H. C. Hill, C. F. SWEDEN Lidingo-- Rosell, A. F. Stockholm-- Gille, H. Ostrom, E. W. Theorell, H. G. T. TRINIDAD Port of Spain-- Cox, T. M., Jr. TURKEY Istanbul-- . Karakash, T. J. U.S.S.R. Moscow-- Dunne, R. V. VENEZUELA Caracas-- Bias. R. J. Alabama............... 8 Arizona.................. 2 Arkansas............... 3 California............. 91 Colorado............... . 8 Connecticut........ 32 Delaware............... 9 Dis.of .Columbia 56 Florida............... 12 Georgia................. 27 Hawaii.....;.;.. 2 Illinois.........?____ 271 UNITED STATES AND ISLAND TERRITORIES Indiana.................. 31 Iowa........................ 10 Kansas................... 11 Kentucky............. 19 Louisiana............. 14 Maine...................'. ~ 5 Maryland....... 32 Massachusetts;. 115 Michigan.............. 154 Minnesota........... 105 Missouri................ 132 Montana............... 4 Nebraska............... 36 New Hampshire. 1 New Jersey:......... 98 New York............. 442 North Carolina.. 16 Ohio........................ 179 Oklahoma............ 32 Oregon............... 3 Pennsylvania...; 251 Phillipine Is......... 2 Rhode' Island___ 6 South Carolina.. 5 South Dakota.. . 2 ' Tennessee........... 8 Texas..................... 57 Utah.....................,. 2 Vermont............... 3 Virginia........;.. 16 Washington.... 30 West Virginia.. . 8 Wisconsin........ 77 .. ` 2427 . DOMINION OF CANADA . .. 182 Australia........ 8 Belgium................ 1 Brazil...................... 2 China..................... II Cuba....................... 1 Czechoslovakia.. 1 Denmark.............. * 1 England..............; 26 FOREIGN COUNTRIES France................... Germany............... India............ Ireland.............. Italy........................ Japan.................... Java. . . ............... Manchouko......... 10 2 2 2 3 5 1 1 Mexico................... Netherlands*.... New Zealand____ Norway.................. Scotland............... South Africa____ . Spain................. Str't. Segments. 2 Sweden................. ' 4 1 Trinidad............... 1 3 Turkey.................. 1 2 U. S. S. R............. 1 1 ' Venezuela........... I 5-- 2 ... 103 2 -----^ Total Membership .. 2712 75 PAST OFFICERS ' American Society of Heating and Ventilating Engineers 1894 1897 PresidentEdward P. Bates President.......................................................... ..........................Wm. M. Mackay 1st Vice-President.Wm. M. Mackay, 1st Vice-PresidentH. D. Crane 2nd Vice-President:______________Wiltsie F. Wolfe 2nd Vice-President-------------------------..Henry Adams Srd Vice-PresidentChas. S. Onderdonk Srd Vice-President.------------------------- :---------------- ^A. E. Kenrick TreasurerHudson A. Goodrich TreasurerJudson A. Goodrich Secretary__________________________ __ L. H. Hart Secretary________________________H. M. Swetland Board of Managers Chairman, Fred P. Smith Henry Adams . A. A. Cary . Hugh J. Barron James A. Harding Edward P. Bates, Pres. L. H. Hart, Secy. Council Chairman. R. C. Carpenter Albert A. Cryer Chas. W. Newton F. W. Foster Ulysses G. Scollay, Secy. ' Board of Managers Chairman, R. C. Carpenter. Edward P. Bates Stewart A * Jellett W. S. Hadaway, Jr. Wiltsie F. Wolfe . ' Wm. M. Mackay. Pres. H. M. Swetland. Secy. Council Chairman, Albert A. Cryer John A. "Fish James Mackay Wm. McMannis ' B. F. Stangland 1895 President.Stewart A. Jellett 1st Vice-PresidentsWm. M. Mackay 2nd Vice-PresidentChas. S. Onderdonk Srd .Vice-President_____ _.D. M. Quay Treasurer____________ ________Judson A. Goodrich SecretaryL. H. Hart / Board of Managers Chairman, James A. Harding Geo. B. Cobb Ulysses G. Scollay Wm. McMannis B. F. Stangland Stewart A. Jellett, Pres. L. H. Hart, Secy. . Council Chairman, R. C. Carpenter Henry Adams. ' T. J. Waters . Edward P. Bates . Albert A. Cryer, Secy. 1898 President__Wiltsie F. Wolfe 1st Vice-PresidentJ. H. Kinealy 2nd-Vice-President__________ ______A. E. Kenrick Srd Vice-President______ ____________ John A. Fish TreasurerJudson A. Goodrich Secretary.--__________________ _.Stewart A. Jellett Board of Managers Chairman, Wm. M. Mackay ' Thomas Barwtck A. C. Mott John A. Connolly Francis A. Williams wiltsie F. Wolfe, Pres. Stewart A. Jellett, Secy. Council Chairman, R. C. Carpenter. Henry Adams W. S. Hadaway,-Jr, Albert A. Cryer Wm. McMannis Wiltsie F. Wolfe, Pres. Stewart A. Jellett, Secy. 1896 President____ ___________________ R. C. Carpenter 1st Vice-President.J). M. Quay 2nd Vice-President,_____________ Edward P. Bates Srd Vice-President.F. W. Foster Treasurer_____ _____________Judson A. Goodrich SecretaryL. H. Hart Board of Managers Chairman, Win. M. Mackay Hugh J. Barron Stewart A. Jellett W. S. Hadaway, Jr. Wiltsie F. Wolfe R. C. Carpenter, Pres. L. H. Hart, Secy. Council Chairman, A. A. Cary Albert A. Cryer B. F. Stangland Wm. McMannis J. J. Blackmore, Secy. 1899 President________ __________________Henry Adams 1st Vice-President.D. M. Quay 2nd Vice-President.-.,,,,A. E. Kenrick Srd Vice-PresidentFrancis A. Williams TreasurerJudson A. Goodrich Secretary_____ _JVm. M., Mackay Board of Managers Chairman, Stewart A. Jellett B. H. Carpenter Wm. Kent A. A. Cary Wiltsie F. Wolfe Henry Adams. Pres. Wm. M. Mackay, Secy. Council Chairman, R. C. Carpenter John Gormly Wm. McMannis- W. S. Hadaway. Jr. B. F. Stangland Henry Adams, Pres. Wm. M. Mackay, Secy. 76 Roll of Membership 1900 1905 President------ ------------------------------------D. M. Quay President________ ____ _______________ .Wm. Kent 1st Vice-President-------- ;A. E. Kenrick 1st Vice-PresidentR. P. Bolton 2nd Vice-President-----------------Francis A. Williams 2nd Vice-PresidentC. B. J. Snyder Treasurer------------------------------ Judson A. Goodrich TreasurerJUlysses G. Scollay Secretary----------------------------------- Wm. M. Mackay Secretary_______________ ______ Wm. M. Mackay Board of Governors Chairman, D. M. Quay . Wm. Kent, Vice-Chm. D. M. Nesbit . R. C. Carpenter C. B. J. Snyder John Gormly Wm. M. Mackay, Secy. Board of Governors . Chairman, Wm. Kent R. P. Bolton James Mackay C. B. J. Snyder B. F. Stangland B. H. Carpenter J. C. F. Trachsel A. B. Franklin Wm. M. Mackay, Secy. 1901 . President ,,j. H. Kinealy 1st Vice-President....... _______ ______ A. E. Kenrick 2nd Vice-President____Andrew Harvey TreasurerJudson A. Goodrich SecretaryWm. M. Mackay Board of Governors Chairman, J. H. Kinealy Wm. Kent, Vice-Chm. John Gormly R. C. Carpenter C. B. J. Snyder R. P. Bolton Wm. M. Mackay, Secy. 1906 President__________________________ John Gormly 1st Vice-President,,C. B. J. Snyder 2nd Vice-President............ .... ... ......... _T. J. Waters Treasurer_________________ ,,,,..UlyssesG. Scollay Secretary_____ Wm. M. Mackay Board of Governors Chairman, John Gormly C. B. J. Snyder, Vice-Chm. James Mackay . R. C. Carpenter B. F. Stangland Frank K. Chew T. J. Waters A. B. Franklin Wm. M. Mackay, Secy. . 1902 President-_________________________A. E. Kenrick 1st Vice-President_______________ Andrew Harvey 2nd Vice-President_Robert C. Clarkson Treasurer----------------- -----...___ Judson A. Goodrich SecretaryWm. M. Mackay Board of Governors . Chairman, A. E. Kenrick John Gormly, Vice-Chm. J. H. Kinealy ` R. C. Carpenter C. B. J. Snyder Wm. Kent Wm. M. Mackay, Secy. 1907 PresidentC. B. J. Snyder 1st Vice-President________________ James Mackay 2nd Vice-President____ ________ ___ .Wm. G. Snow TreasurerUlysses G. Scollay Secretary_____ __ .______ ___ Wm M. Mackay Board of Governors Chairman, C. B. J. Snyder James Mackay, Vice-Chm. Frank K. Chew R. E. Atkinson A. B. Franklin . R. C. Carpenter Wm. G. Snow Edmund F. Capron Wm. M. Mackay, Secy. 1903 President<H. D. Crane 1st Vice-President...___________ Wm Kent 2nd Vice-President___ _R. P. Bolton Treasurer------------------------------ Judson A. Goodrich Secretary-----------------------------------.Wm. M. Mackay Board of Governors . ' Chairman, H. D. Crane C. B. J. Snyder, Vice-Chm. A. E. Kenrick R. C. Carpenter ' Geo. Mehring John Gormly Wm. M. Mackay, Secy. 1908 President________ __ ____ ________James Mackay 1st Vice-President........................... Jas. D. Hoffman 2nd Vice-Presidents__ ___________B. F. Stangland TreasurerUlysses G. Scollay Secretary..*__________Wm. M. Mackay Board of Governors .' Chairman. James Mackay Jas.D. Hoffman. Vice-Chm. John F. Hale B. F. Stangland August Kehm R. C. Carpenter . C. B. J. Snyder Frank K. Chew Wm. M. Mackay, Secy. 1904 President-----------.------------------------- Andrew Harvey 1st Vice-President.:._______ John Gormly 2nd Vice-President__________^.Robert C. Clarkson Treasurer.._________ _ ______ Ulysses G. Scollay Secretary_____ _____ ..____ . .___ Wm. M. Mackay 1909 _ President.Wm. G. Snow 1st Vice-PresidentAugust Kehm 2nd Vice-President____... -..... ........... B. S. Harrison TreasurerUlysses G. Scollay SecretaryJ.Wm..M. Mackay Board of Governors Chairman, Andrew Harvey John CJonnly H. D. Crane . Robert C. Clarkson A. E. Kenrick J. J. Blackmore C. B. J. Snyder R. C. Carpenter Wm'. M: Mackay, Secy. Board of Governors Chairman, Wm. G. Snow August Kehm, Vicq-Chm. Samuel R. Lewis John R. Alien James Mackay R. C. Carpenter ' B. F. Stangland B. S. Harrison Wm. M. Mackay, Secy. 77 Heating Ventilating Air Conditioning Guide 1938 President................ . 1st Vice-President__ 2nd Vice-Presidents. Treasurer___:__ __ Secretary__________ _.Jas. D. Hoffman ____ R. P. Bolton ..Samuel R. Lewis ,,Ulysses G. Scollay __Wm. M. Mackay Board of Governors Chairman, Jas. D. Hoffman R. P. Bolton, Vice-Chm. John F. Hale Geo. W. Barr Samuel R. Lewis . R. C. Carpenter James Mackay Judson A. Goodrich Wm. M. Mackay. Secy. 1st Vice-President__ 2nd Vice-President-- Treasurer_________ Secretary__i___ _ ..Dwight D. Kimball __________ Harry M. Hart ______ Frank T. Chapman __________ Homer Addams __________ J. J. Blackmore Council - Chairman, Dwight D.-Kimball Harry M. Hart, Vice-Chm. Samuel R. Lewis Homer Addams Frank G. McCann Frank T. Chapman J. T. J. Mellon Frank I. Cooper . Henry C. Meyer, Jr. E. Vernon Hill Arthur K. Ohmes Wm. M. Kingsbury J. J. Blackmore, Secy. President__ ...______ 1st Vice-President__ 2nd Vice-President._ Treasurer... ....... ..... . Secretary_______ __ .JoRh-npR- . Allen ..A. B. Franklin _.Ulysses G. Scollay __ Wm. W. Macon Board of Governors . Chairman, R. P. Bolton John R. Allen, Vice-Chm. A. B. Franklin . John T. Bradley Jas. D. Hoffman R. C.. Carpenter August Kehm ' James H. Davis Wm. W. Macon, Secy. President.. 1st Vice-President____ 2nd Vice-President___ Treasurer_______ ____ Secretary ____ Harry M. Hart ..Frank T. Chapman . _JYrthur K. Ohmes ____ Homer Addams ____ Casin W. Obert Council Chairman, Harry M. Hart F. T. Chapman, Vice-Chm. Dwight D. Kimball Homer Addams Henry C. Meyer, Jr. Charles R. Bishop Arthur K. Ohmes. Frank I. Cooper Fred R. Still ' Milton W: Franklin Walter S. Timmis E. Vernon Hill Casin W. Obert, Secy. President.............. ....... _ 1st Vice-President____ '2nd Vice-President___ Treasurer........ ...... ...... Starclary____ _________ __ John R. Allen .John F. Hale ..Edmund F. Capron _James A. Donnelly ____ Wm. W. Macon Board of Governors Chairman, John R. Allen John F. Hale. Vice-Chm. Dwight D. Kimball Edmund F. Capron Samuel R. Lewis R. P. Bolton ' Wm. M. Mackay Jas. D. Hoffman Wm. W. Macon, Secy. President__ _______ 1st Vice-President_ 2nd Vice-PresidentTreasurer--_______ ; Secretary__________ ____ J. Irvine Lyle ..Arthur K. Ohmes ._,_,,.,,Fred R. Still __..Homer Addams __ Casin W. Obert Council - Chairman, J. Irvine Lyle A. K. Ohmes, Vice-Chm. Harry M. Hart Homer Addams E. Vernon Hill Davis S. Boyden James M. Stannard - Bert C. Davis . Fred R. Still - ` Milton W. Franklin Walter S. Timmis Charles A. Fuller Casin W. Obert, Secy. 1st Vice-Presidents-- 2nd Vice-President__ Treasurer__________ Secretary___________ __ John F. Hale .A. B. Franklin ..Edmund F. Capron ..James A. Donnelly. _____Edwin A,. Scott Board of Governors * Chairman, John F. Hale A. B. Franklin, Vice-Chm. James A. Donnelly John R. Allen Dwight D. Kimball Edmund F. Capron Wm. W. Macon R. P. Bolton - James M. Stannard Frank T. Chapman Theodore Weinshank Ralph Collamore ` Edwin A. Scott, Secy. 1918 President-- ..Fred R. Still 1st. Vice-PresidentWalter S.- Timmis 2nd Vice-President...:..E, Vernon Hill Treasurer _______Homer Addams Secretary Casin W. Obert Council . Chairman, Fred R. Still W. S. Timmis, Vice-Chm. - J. Irvine Lyle Homer Addams E. Vernon Hill William H.` Driscoll ` Frank G. Phegley" ` Howard H. Fielding .. Fred. W. Powers H. P. Gant Champlain L. Riley C. W. Kimball Casin W. Obert, Secy. President.. 1st Vice-President________ 2nd Vice-President_______ Treasurer__:_____________ Secretary-__ J------------------- ..Samuel R. Lewis _Edmund F. Capron _Dwight D. Kimball ..James A. Donnelly. _____ J. J. Blackmore . . - Council . Chairman, Samuel R. Lewis E. F. Capron, Vice-Chm. John F. Hale Dwight D. Kimball . ` Harry M. Hart John R. Allen Frank G. McCann * Frank T. Chapman. Wm. W. Macon Frank IrCooper ' James M. Stannard - James A. Donnelly J. J. Blackmore, Secy. 1919 President.__ ___________________Walter S. Timmis 1st Vice-President___ _____________ E. Vernon Hill 2nd Vice-President__ ________ Milton W. Franklin TreasurerHomer Addams Secretary_______--Casin.W. Obert Council Chairman, Walter S. Timmis E. Vernon Hill, Vice-Chm. Frank G. Phegley Homer Addams ' Fred. W. Powers ` Howard H. Fielding Robt. W. Pryor. Jr. Milton W. Franklin Champlain L. Riley - Harry E. Gerrish Fred R. Still George B/Nichols Casin W. Obert, Secy. 78 Roll of Membership 1920 1925 c President_________ 1st Vice-President-- 2nd Vice-President. Treasurer________ Secretary_________ ____________ E. Vernon Hill _______ Champlain L. Riley ______ __ ___ Jay R- McColl _________ 1_Homer Addams ___________ Casin W. Obert President______ ____ _____ 1st Vice-President__________ 2nd Vice-President_________ Treasurer_____________ ..... Secretary--__ _____________ _____S. E. Dibble ..Wm. H. Driscoll .F, Paul Anderson ___ :__ Perry West __F. C. Houghten Council Chairman, E. Vernon Hill C. L. Riley, Vice-Chm. Jay R. McColl Homer Addams ' ` George B. Nichols Jos. A. Cutler Robt. W. Pryor, Jr. . Wm. H. Driscoll W. S. Timmis . A. C. Edgar Perry West Alfred Kellogg Casin W. Obert, Secy. ' Council . Chairman, S. E. Dibble Wm. H. Driscoll, Vice-Chm. W. T. Jones Homer Addams . Thornton Lewis F. Paul Anderson ` J. H. Walker W. H. Carrier Perry West J. A. Cutler A. C. Willard : W. E. Gillham F. C. Houghten. Secy. President.--_____ 1st Vice-President_ 2nd Vice-President. Treasurer________ Secretary_________ 1921 . _______ Champlain L. Riley _____ _______Jay R. McColl ________________H. P. Gant ____ __ ____ Homer Addams ______ ,,..,,.Casin W. Obert Council . Chairman, Champlain L. Riley Jay R. McColl, Vice-Chm. E. S. Hallett Homer Addams E. Vernon Hill . Jos. A. Cutler Alfred Kellogg Samuel E. Dibble E. E. McNair Wm. H. Driscoll Perry West H. P. Gant ' . Casin W. Obert, Secy. 1922 President__________________ 1st Vice-President____ ____ 2nd Vice-President Treasurer.__ ____________..... Secretary_*_____ ___ _____ __ Jay R. McColl ______ H. P. Gant .Samuel E. Dibble ....Homer Addams __Casin W. Obert Council Chairman, Jay R. McColl H. P. Gant, Vice-Chm. . L. A. Harding Homer Addams . E. E. McNair Jos. A. Cutler H. J. Meyer Samuel E. Dibble C. L. Riley . Wm. H. Driscoll Perry West E. S. Hallett Casin W. Obert, Secy. 1923 PresidentH. P. Gant 1st Vice-President___ _Homer Addams 2nd Vice-President__..._E. E. McNair Treasurer------------ ^____ l.______Wm. H. Driscoll Secretary--C. W. Obert 3 Council Chairman, H. P. Gant Homer Addams, Vice-Chm. E. S. Hallett W. H. Carrier Alfred Kellogg J. A. Cutler Thornton Lewis S. E. Dibble E. E. McNair Wm. H. Driscoll - Perry West Casin W. Obert, Sccy. * 1924 - President---______ ___;___ Homer Addams 1st Vice-President____________________S. E. Dibble 2nd Vice-President...__________.William H. Driscoll Treasurer________ ________ _Perry West Secretary------------------------:F. C. Houghten . Council . Chairman, Homer Addams S. E. Dibble, Vice-Chm. W. E. Gillham F. Paul Anderson L. A. Harding W. H. Carrier Alfred Kellogg ,; J. A. Cutler Thornton Lewis ` William H. Driscoll Perry West ., H. P. Gant .. F. C. Houghten, Secy. 1926 President_____________ :____ 1st Vice-President ............. 2nd Vice-President_________ Treasurer Secretary ___W. H. Driscoll .F. Paul Anderson ____A. C. Willard ___W. E. Gillham .A. V. Hutchinson Council - Chairman, W. H. Driscoll F. Paul Anderson, Vice-Chm. C. V. Haynes W. H. Carrier W. T. Jones . J. A. Cutler E. B. Langenberg S. E. Dibble . Thornton Lewis W. E. Gillham. J. F. Mclntire ; A. C. Willard 1927 President___________:______ 1st Vice-President_____ ____ 2nd Vice-President _______ Treasurer Secretary_______ ....... ........... ,F. Paul Anderson ___ .A. C. Willard _Thornton Lewis ___W, E. Gillham .A, V. Hutchinson Council . Chairman-, F. Paul Anderson A. C. Willard, Vice-Chm. , John Howatt . H. H. Angus W. T. Jones W. H. Carrier J. J. Kissick W. H. Driscoll E. B. Langenberg Roswell Faraharm Thornton Lewis H. H. Fielding J. F. Mclntire W. E. Gillham H. Lee Moore C. V. Haynes F. B. Rowley . . President_________ 1st Vice-President- 2rtd Vice-President. Treasurer_________ Secretaryi. 1928 ___ Jl. C. Willard _Thornton Lewis ___ L. A. Harding ___W. E, Gillham _A. V. Hutchinson - Council Chairman, A. C. Willard ` - Thornton Lewis, Vice^hm. C. V.'Haynes F. Paul Anderson John Howatt H. H. Angus ' W. T. Jones W. H. Carrier. J. J. Kissick N. W. Downes E. B. Langenberg Roswell Farnham J. F. Mclntire W. E. Gillham H. Lee Moore F. B. Rowley President.________ 1929 1st Vice-President______ 2nd Vice-President_____ Treasurer._____________ Secretary.- Technical Secretary.. .Thornton Lewis -..L. A. Harding ,,.W, H. Carrier ,,W. E. Gillham A. V. Hutchinson _____ P. D. Close Council, Chairman, Thornton Lewis L. A. Harding, Vice-Chm. John Howatt # H. H. Angus W. T. Jones - Ws. H. Carrier . E. B. Langenberg N. W. Downes . G. L. Larson J Roswell Farnham '' F. C. McIntosh W. E. Gillham . W. A. Rowe ' C. V. Haynes F. B. Rowley.' ` . A. C. Willard . ; 79 v Heating Ventilating Air Conditioning Guide 1938 1930 1934 President.L. A. Harding President____________________________________________________ C. V. Haynes W H Carrier P W Farrar Secretary. ....................... ..... .A. V. Hutchinson Technical Secretary................ . P. D. Close . Counci] Chairman, L. A. Harding W. H. Carrier, Vice-Chm. John Howatt H. H. Angus W. T. Jones D. S. Boyden E. B. Langenberg R. H. Carpenter G. L. Larson J. D. Cassell Thornton Lewis N. W. Downes F. C. McIntosh Roswell Famham W. A. Rowe C. W. Farrar F. B. Rowley Secretary.____ ___ __________ __ A. V. Hutchinson Council Chairman, C. V. Haynes John Howatt. Vice-Chm. W. T. Jones M. C. Beman G. L. Larson D. S. Boyden J. F. Mclntire Albert Buenger F. C. McIntosh L. Walter Moon 0. W. Ott W. A. Russell E. H. Gurney W. E. Stark 1931 President.W. H. Carrier 1st Vice-PresidentF. B. Rowley Snd Vice-President_______ ____ ,_W. T. Jones Treasurer__________ ______________ F. D. Mensing Secretary_______________________A. V. Hutchinson Technical Secretary__________________ P. D. Close Council Chairman, W. H. Carrier F. B. Rowley, Vice-Chm. L. A. Harding ' D. S. Boyden John Howatt E. K. Campbell W. T. Jones R. H. Carpenter E. B. Larigenberi J. D. Cassell . G. L. Larson E. O. Eastwood F. C. McIntosh Roswell Famham F. D. Mensing E. H. Gurney . ' W. A. Rowe 1935 President......................:______ ............. John Howatt 1st Vice-President____.._____ _____ ___G. L. Larson Snd Vice-President_______ __________D. S. Boyden Treasurer_____ _____________________A. J. Offner Secretary__________________ A. V. Hutchinson Council Chairman, John Howatt G. L. Larson. Vice-Chm. C. V. Haynes M. C. Beman J. F. Mclntire D. S. Boyden F. C. McIntosh Albert Buenger L. Walter Moon R. H. Carpenter A. J. Offner J. D. Cassell O. W. Ott F. E. Giesecke W. A. Russell E. H. Gurney W. E. Stark 1933 President................ ------------- ..._____F. B. Rowley 1st Vir.*-President , ..........--____ W. T. Jones Snd Vice-President_____________ ___C. V. Haynes Treasurer.F. D. Mensing SecretaryA. V. Hutchinson Technical SecretaryP. D. Close Council Chairman, F. B. Rowley W. T. Jones, Vice-Chm. F. E. Giesecke D. S. Boyden E, H. Gurney E. K. Campbell C. V. Haynes R. H. Carpenter John Howatt W. H. Carrier G. L. Larson John D. Cassell J. F. Mclntire E. O. Eastwood F. D. Mensing Roswell Famham W. E. Stark President.......... . 1st Vice-President,, Snd Vice-President Treasurer__ _____ Secretary.________ 1936 .. ..... G. L. Larson .. .... D. S. Bolden ___ E. H. Gurney _____ A. J. Offner _A. V. Hutchinson Council Chairman, G. L. Larson D. S. Boyden, Vice-Chm. John Howatt M. C. Beman C. -M-. --Humph reys R. C. Bolsinger L. Walter Moon Albert Buenger J. F. Mclntire S. H. Downs A. J. Offner W. L. Fleisher O. W. Ott F^E. Giesecke W. A. Russell E. H. Gurney W. E. Stark President--------------- 1st Vice-President Snd Vice-President.. Treasurer_________ Secretary._________ _____ .W. T. Jones ____C. V. Haynes _____ John Howatt _____D. S. Boyden ,,A. V. Hutchinson Council Chairman, W. T. Jones C. V. Haynes, Vice-Chm. E. H. Gurney D. *S. Boyden John Howatt E. K. Campbell G. L. Larson R. H. Carpenter J. F. Mclntire J. D. Cassell F. C. McIntosh E. .O. Eastwood L. W, Moon R. Farnhatn F. B. Rowley F. E. Giesecke W. E. Stark President............... .. 1st Vice-President.... Snd Vice-President.. Treasurer__________ Secretary__________ 1937 ____ D. S. Boyden .... E. Holt Gurney ......Jf.'F. Mclntire .......... A. J. Offner .A. V. Hutchinson Council Chairman, D. S. Boyden ' E. H. Gurney, Vicc-Chm. E. O. Eastwood J. J. Aeberly W. L. Fleisher M. C. Beman F. E. Giesecke R. C. Bolsinger C. M. Humphreys Albert Buenger G. L. Larson S. H. Downs W. A. Russell W. E. Stark 80 s